another 5 minutes wasted life time

* ask for confirmation when group method is changed in account settings activity
* reset address books/force reload when contact group method has changed since last sync

.gitlab-ci.yml

@@ -3,13 +3,12 @@ image: registry.gitlab.com/bitfireat/davdroid:latest
 before_script:
   - git submodule update --init --recursive
   - export GRADLE_USER_HOME=`pwd`/.gradle; chmod +x gradlew
-  - emulator64-arm -avd test -no-audio -no-window & wait-for-emulator.sh
-  - wget -q https://f-droid.org/repo/org.dmfs.tasks_103.apk && adb install org.dmfs.tasks_103.apk
+  - (cd /sdk/emulator; ./emulator @test -no-audio -no-window & wait-for-emulator.sh)
+  - wget -q https://f-droid.org/repo/org.dmfs.tasks_481.apk && adb install org.dmfs.tasks_481.apk
 
 cache:
   paths:
-     - .gradle/wrapper
-     - .gradle/caches
+     - .gradle/
 
 test:
   script:

README.md

@@ -5,14 +5,17 @@
 DAVdroid
 ========
 
-Please see the [DAVdroid Web site](https://davdroid.bitfire.at) for
+Please see the [DAVdroid Web site](https://www.davdroid.com) for
 comprehensive information about DAVdroid.
 
 DAVdroid is licensed under the [GPLv3 License](LICENSE).
 
-News and updates: [@davdroidapp](https://twitter.com/davdroidapp)
+News and updates: [@davdroidapp](https://twitter.com/davdroidapp) on Twitter
 
-Help and discussion: [DAVdroid forums](https://davdroid.bitfire.at/forums)
+Help and discussion: [DAVdroid forums](https://www.davdroid.com/forums/)
+
+**If you want to support DAVdroid, please consider [donating to DAVdroid](https://davdroid.bitfire.at/donate/)
+or [purchasing it](https://davdroid.bitfire.at/download/).**
 
 Parts of DAVdroid have been outsourced into these libraries:
 
@@ -21,16 +24,15 @@ Parts of DAVdroid have been outsourced into these libraries:
 * [ical4android](https://gitlab.com/bitfireAT/ical4android) – iCalendar processing and Calendar Provider access
 * [vcard4android](https://gitlab.com/bitfireAT/vcard4android) – VCard processing and Contacts Provider access
 
-[![Flattr this!](https://api.flattr.com/button/flattr-badge-large.png)](https://flattr.com/submit/auto?user_id=bitfire&url=https://davdroid.bitfire.at&title=DAVdroid&category=software)
-
 
 USED THIRD-PARTY LIBRARIES
 ==========================
 
 Those libraries are used by DAVdroid (alphabetically):
 
+* [Ambilwarna](https://github.com/yukuku/ambilwarna) – [Apache License, Version 2.0](https://github.com/yukuku/ambilwarna/blob/master/LICENSE)
 * [dnsjava](http://www.xbill.org/dnsjava/) – [BSD License](http://www.xbill.org/dnsjava/dnsjava-current/LICENSE)
-* [ez-vcard](https://code.google.com/p/ez-vcard/) – [New BSD License](http://opensource.org/licenses/BSD-3-Clause)
-* [iCal4j](http://ical4j.sourceforge.net/) – [New BSD License](http://sourceforge.net/p/ical4j/ical4j/ci/default/tree/LICENSE)
-* [okhttp](https://square.github.io/okhttp/) – [Apache License, Version 2.0](https://square.github.io/okhttp/#license)
+* [ez-vcard](https://github.com/mangstadt/ez-vcard) – [New BSD License](http://opensource.org/licenses/BSD-3-Clause)
+* [iCal4j](https://github.com/ical4j/ical4j) – [New BSD License](http://sourceforge.net/p/ical4j/ical4j/ci/default/tree/LICENSE)
+* [okhttp](https://square.github.io/okhttp) – [Apache License, Version 2.0](https://square.github.io/okhttp/#license)
 * [Project Lombok](http://projectlombok.org/) – [MIT License](http://opensource.org/licenses/mit-license.php)

app/build.gradle

@@ -7,26 +7,31 @@
  */
 
 apply plugin: 'com.android.application'
+apply plugin: 'kotlin-android'
+apply plugin: 'kotlin-android-extensions'
 
 android {
-    compileSdkVersion 25
-    buildToolsVersion '25.0.2'
+    compileSdkVersion 26
+    buildToolsVersion '26.0.2'
 
     defaultConfig {
         applicationId "at.bitfire.davdroid"
 
-        minSdkVersion 15
-        targetSdkVersion 25
-
-        versionCode 138
-
+        versionCode 184
         buildConfigField "long", "buildTime", System.currentTimeMillis() + "L"
         buildConfigField "boolean", "customCerts", "true"
+
+        minSdkVersion 16
+        targetSdkVersion 25
+
+        vectorDrawables.useSupportLibrary = true
     }
 
+    flavorDimensions "type"
+
     productFlavors {
         standard {
-            versionName "1.4.0.3-ose"
+            versionName "1.9.1-ose"
         }
     }
 
@@ -42,23 +47,17 @@ android {
 
     lintOptions {
         disable 'GoogleAppIndexingWarning'      // we don't need Google indexing, thanks
-        disable 'GradleDependency'
-        disable 'GradleDynamicVersion'
-        disable 'IconColors'
-        disable 'IconLauncherShape'
-        disable 'IconMissingDensityFolder'
-        disable 'ImpliedQuantity', 'MissingQuantity'
+        disable 'ImpliedQuantity', 'MissingQuantity'		// quantities from Transifex may vary
         disable 'MissingTranslation', 'ExtraTranslation'	// translations from Transifex are not always up to date
+        disable "OnClick"     // doesn't recognize Kotlin onClick methods
         disable 'Recycle'           // doesn't understand Lombok's @Cleanup
         disable 'RtlEnabled'
         disable 'RtlHardcoded'
         disable 'Typos'
-        disable "RestrictedApi"		// https://code.google.com/p/android/issues/detail?id=230387
     }
     packagingOptions {
-        exclude 'LICENSE'
-        exclude 'META-INF/LICENSE.txt'
-        exclude 'META-INF/NOTICE.txt'
+        exclude 'META-INF/DEPENDENCIES'
+        exclude 'META-INF/LICENSE'
     }
 
     defaultConfig {
@@ -72,30 +71,33 @@ dependencies {
     compile project(':ical4android')
     compile project(':vcard4android')
 
-    compile 'com.android.support:appcompat-v7:25.+'
-    compile 'com.android.support:cardview-v7:25.+'
-    compile 'com.android.support:design:25.+'
-    compile 'com.android.support:preference-v14:25.+'
+    compile "org.jetbrains.kotlin:kotlin-stdlib-jre7:$kotlin_version"
+
+    compile 'com.android.support:appcompat-v7:26.1.0'
+    compile 'com.android.support:cardview-v7:26.1.0'
+    compile 'com.android.support:design:26.1.0'
+    compile 'com.android.support:preference-v14:26.1.0'
 
     compile 'com.github.yukuku:ambilwarna:2.0.1'
 
-    compile 'com.squareup.okhttp3:logging-interceptor:3.6.0'
+    compile 'com.squareup.okhttp3:logging-interceptor:3.9.0'
     compile 'commons-io:commons-io:2.5'
-    compile 'dnsjava:dnsjava:2.1.7'
-    compile 'org.apache.commons:commons-lang3:3.4'
+    compile 'dnsjava:dnsjava:2.1.8'
+    compile 'org.apache.commons:commons-lang3:3.6'
     compile 'org.apache.commons:commons-collections4:4.1'
-    provided 'org.projectlombok:lombok:1.16.14'
 
     // for tests
+    //noinspection GradleDynamicVersion
     androidTestCompile('com.android.support.test:runner:+') {
         exclude group: 'com.android.support', module: 'support-annotations'
     }
+    //noinspection GradleDynamicVersion
     androidTestCompile('com.android.support.test:rules:+') {
         exclude group: 'com.android.support', module: 'support-annotations'
     }
     androidTestCompile 'junit:junit:4.12'
-    androidTestCompile 'com.squareup.okhttp3:mockwebserver:3.6.0'
+    androidTestCompile 'com.squareup.okhttp3:mockwebserver:3.9.0'
 
     testCompile 'junit:junit:4.12'
-    testCompile 'com.squareup.okhttp3:mockwebserver:3.6.0'
+    testCompile 'com.squareup.okhttp3:mockwebserver:3.9.0'
 }

app/proguard-rules.txt

@@ -12,23 +12,28 @@
 -allowaccessmodification
 -dontpreverify
 
+# Kotlin
+-dontwarn kotlin.**
+
 # ez-vcard
 -dontwarn ezvcard.io.json.**            # JSON serializer (for jCards) not used
 -dontwarn freemarker.**                 # freemarker templating library (for creating hCards) not used
 -dontwarn org.jsoup.**                  # jsoup library (for hCard parsing) not used
--dontwarn sun.misc.Perf
 -keep class ezvcard.property.** { *; }  # keep all VCard properties (created at runtime)
 
 # ical4j: ignore unused dynamic libraries
 -dontwarn aQute.**
 -dontwarn groovy.**                       # Groovy-based ContentBuilder not used
+-dontwarn net.fortuna.ical4j.model.**
 -dontwarn org.codehaus.groovy.**
--dontwarn net.fortuna.ical4j.model.**     # ignore warnings from Groovy dependency
+-dontwarn org.apache.log4j.**             # ignore warnings from log4j dependency
 -keep class net.fortuna.ical4j.** { *; }  # keep all model classes (properties/factories, created at runtime)
+-keep class org.threeten.bp.** { *; }     # keep ThreeTen (for time zone processing)
 
 # okhttp
--dontwarn java.nio.file.**   # not available on Android
--dontwarn org.codehaus.mojo.animal_sniffer.IgnoreJRERequirement
+-dontwarn okio.**
+-dontwarn javax.annotation.Nullable
+-dontwarn javax.annotation.ParametersAreNonnullByDefault
 
 # dnsjava
 -dontwarn sun.net.spi.nameservice.**   # not available on Android

app/src/androidTest/java/at/bitfire/davdroid/SSLSocketFactoryCompatTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
+ * Copyright © Ricki Hirner (bitfire web engineering).
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the GNU Public License v3.0
  * which accompanies this distribution, and is available at
@@ -8,40 +8,43 @@
 
 package at.bitfire.davdroid;
 
-import android.os.Build;
-import android.support.test.runner.AndroidJUnit4;
-
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
-import org.junit.runner.RunWith;
 
 import java.io.IOException;
 import java.net.Socket;
 
 import javax.net.ssl.SSLSocket;
+import javax.net.ssl.TrustManagerFactory;
+import javax.net.ssl.X509TrustManager;
 
 import at.bitfire.cert4android.CustomCertManager;
 import okhttp3.mockwebserver.MockWebServer;
 
+import static android.support.test.InstrumentationRegistry.getInstrumentation;
 import static android.support.test.InstrumentationRegistry.getTargetContext;
 import static junit.framework.TestCase.assertFalse;
+import static org.apache.commons.lang3.ArrayUtils.contains;
 import static org.junit.Assert.assertTrue;
 
 public class SSLSocketFactoryCompatTest {
 
+    CustomCertManager certMgr;
     SSLSocketFactoryCompat factory;
     MockWebServer server = new MockWebServer();
 
     @Before
     public void startServer() throws Exception {
-        factory = new SSLSocketFactoryCompat(new CustomCertManager(getTargetContext().getApplicationContext(), true));
+        certMgr = new CustomCertManager(getInstrumentation().getContext(), true, null);
+        factory = new SSLSocketFactoryCompat(certMgr);
         server.start();
     }
 
     @After
     public void stopServer() throws Exception {
         server.shutdown();
+        certMgr.close();
     }
 
 
@@ -51,13 +54,10 @@ public class SSLSocketFactoryCompatTest {
         assertTrue(s instanceof SSLSocket);
 
         SSLSocket ssl = (SSLSocket)s;
-        assertFalse(org.apache.commons.lang3.ArrayUtils.contains(ssl.getEnabledProtocols(), "SSLv3"));
-        assertTrue(org.apache.commons.lang3.ArrayUtils.contains(ssl.getEnabledProtocols(), "TLSv1"));
-
-        if (Build.VERSION.SDK_INT >= 16) {
-            assertTrue(org.apache.commons.lang3.ArrayUtils.contains(ssl.getEnabledProtocols(), "TLSv1.1"));
-            assertTrue(org.apache.commons.lang3.ArrayUtils.contains(ssl.getEnabledProtocols(), "TLSv1.2"));
-        }
+        assertFalse(contains(ssl.getEnabledProtocols(), "SSLv3"));
+        assertTrue(contains(ssl.getEnabledProtocols(), "TLSv1"));
+        assertTrue(contains(ssl.getEnabledProtocols(), "TLSv1.1"));
+        assertTrue(contains(ssl.getEnabledProtocols(), "TLSv1.2"));
     }
 
 }

app/src/androidTest/java/at/bitfire/davdroid/model/CollectionInfoTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
+ * Copyright © Ricki Hirner (bitfire web engineering).
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the GNU Public License v3.0
  * which accompanies this distribution, and is available at
@@ -9,10 +9,10 @@
 package at.bitfire.davdroid.model;
 
 import android.content.ContentValues;
-import android.support.test.runner.AndroidJUnit4;
 
+import org.junit.After;
+import org.junit.Before;
 import org.junit.Test;
-import org.junit.runner.RunWith;
 
 import java.io.IOException;
 
@@ -32,8 +32,20 @@ import static org.junit.Assert.assertTrue;
 
 public class CollectionInfoTest {
 
+    HttpClient httpClient;
     MockWebServer server = new MockWebServer();
 
+    @Before
+    public void setUp() {
+        httpClient = new HttpClient.Builder().build();
+    }
+
+    @After
+    public void shutDown() {
+        httpClient.close();
+    }
+
+
     @Test
     public void testFromDavResource() throws IOException, HttpException, DavException {
         // r/w address book
@@ -50,13 +62,13 @@ public class CollectionInfoTest {
                         "</response>" +
                         "</multistatus>"));
 
-        DavResource dav = new DavResource(HttpClient.create(null), server.url("/"));
+        DavResource dav = new DavResource(httpClient.getOkHttpClient(), server.url("/"));
         dav.propfind(0, ResourceType.NAME);
-        CollectionInfo info = CollectionInfo.fromDavResource(dav);
-        assertEquals(CollectionInfo.Type.ADDRESS_BOOK, info.type);
-        assertFalse(info.readOnly);
-        assertEquals("My Contacts", info.displayName);
-        assertEquals("My Contacts Description", info.description);
+        CollectionInfo info = new CollectionInfo(dav);
+        assertEquals(CollectionInfo.Type.ADDRESS_BOOK, info.getType());
+        assertFalse(info.getReadOnly());
+        assertEquals("My Contacts", info.getDisplayName());
+        assertEquals("My Contacts Description", info.getDescription());
 
         // read-only calendar, no display name
         server.enqueue(new MockResponse()
@@ -74,17 +86,17 @@ public class CollectionInfoTest {
                         "</response>" +
                         "</multistatus>"));
 
-        dav = new DavResource(HttpClient.create(null), server.url("/"));
+        dav = new DavResource(httpClient.getOkHttpClient(), server.url("/"));
         dav.propfind(0, ResourceType.NAME);
-        info = CollectionInfo.fromDavResource(dav);
-        assertEquals(CollectionInfo.Type.CALENDAR, info.type);
-        assertTrue(info.readOnly);
-        assertNull(info.displayName);
-        assertEquals("My Calendar", info.description);
-        assertEquals(0xFFFF0000, (int)info.color);
-        assertEquals("tzdata", info.timeZone);
-        assertTrue(info.supportsVEVENT);
-        assertTrue(info.supportsVTODO);
+        info = new CollectionInfo(dav);
+        assertEquals(CollectionInfo.Type.CALENDAR, info.getType());
+        assertTrue(info.getReadOnly());
+        assertNull(info.getDisplayName());
+        assertEquals("My Calendar", info.getDescription());
+        assertEquals(0xFFFF0000, (int)info.getColor());
+        assertEquals("tzdata", info.getTimeZone());
+        assertTrue(info.getSupportsVEVENT());
+        assertTrue(info.getSupportsVTODO());
     }
 
     @Test
@@ -92,6 +104,7 @@ public class CollectionInfoTest {
         ContentValues values = new ContentValues();
         values.put(Collections.ID, 1);
         values.put(Collections.SERVICE_ID, 1);
+        values.put(Collections.TYPE, CollectionInfo.Type.CALENDAR.name());
         values.put(Collections.URL, "http://example.com");
         values.put(Collections.READ_ONLY, 1);
         values.put(Collections.DISPLAY_NAME, "display name");
@@ -102,18 +115,19 @@ public class CollectionInfoTest {
         values.put(Collections.SUPPORTS_VTODO, 1);
         values.put(Collections.SYNC, 1);
 
-        CollectionInfo info = CollectionInfo.fromDB(values);
-        assertEquals(1, info.id);
-        assertEquals(1, (long)info.serviceID);
-        assertEquals("http://example.com", info.url);
-        assertTrue(info.readOnly);
-        assertEquals("display name", info.displayName);
-        assertEquals("description", info.description);
-        assertEquals(0xFFFF0000, (int)info.color);
-        assertEquals("tzdata", info.timeZone);
-        assertTrue(info.supportsVEVENT);
-        assertTrue(info.supportsVTODO);
-        assertTrue(info.selected);
+        CollectionInfo info = new CollectionInfo(values);
+        assertEquals(CollectionInfo.Type.CALENDAR, info.getType());
+        assertEquals(1, (long)info.getId());
+        assertEquals(1, (long)info.getServiceID());
+        assertEquals("http://example.com", info.getUrl());
+        assertTrue(info.getReadOnly());
+        assertEquals("display name", info.getDisplayName());
+        assertEquals("description", info.getDescription());
+        assertEquals(0xFFFF0000, (int)info.getColor());
+        assertEquals("tzdata", info.getTimeZone());
+        assertTrue(info.getSupportsVEVENT());
+        assertTrue(info.getSupportsVTODO());
+        assertTrue(info.getSelected());
     }
 
 }

app/src/androidTest/java/at/bitfire/davdroid/settings/DefaultsProviderTest.kt

@@ -0,0 +1,39 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.settings
+
+import at.bitfire.davdroid.App
+import junit.framework.Assert.assertEquals
+import junit.framework.Assert.assertFalse
+import org.junit.Test
+
+class DefaultsProviderTest {
+
+    private val provider: Provider = DefaultsProvider()
+
+    @Test
+    fun testHas() {
+        assertEquals(Pair(false, true), provider.has("notExisting"))
+        assertEquals(Pair(true, true), provider.has(App.OVERRIDE_PROXY))
+    }
+
+    @Test
+    fun testGet() {
+        assertEquals(Pair("localhost", true), provider.getString(App.OVERRIDE_PROXY_HOST))
+        assertEquals(Pair(8118, true), provider.getInt(App.OVERRIDE_PROXY_PORT))
+    }
+
+    @Test
+    fun testPutRemove() {
+        assertEquals(Pair(false, true), provider.isWritable(App.OVERRIDE_PROXY))
+        assertFalse(provider.putBoolean(App.OVERRIDE_PROXY, true))
+        assertFalse(provider.remove(App.OVERRIDE_PROXY))
+    }
+
+}

app/src/androidTest/java/at/bitfire/davdroid/settings/SettingsTest.kt

@@ -0,0 +1,44 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.settings
+
+import android.content.ServiceConnection
+import android.support.test.InstrumentationRegistry
+import android.support.test.InstrumentationRegistry.getTargetContext
+import at.bitfire.davdroid.App
+import junit.framework.Assert.*
+import org.junit.After
+import org.junit.Before
+import org.junit.Test
+
+class SettingsTest {
+
+    lateinit var settings: Settings.Stub
+
+    @Before
+    fun init() {
+        InstrumentationRegistry.getContext().isRestricted
+        settings = Settings.getInstance(getTargetContext())!!
+    }
+
+    @After
+    fun shutdown() {
+        settings.close()
+    }
+
+
+    @Test
+    fun testHas() {
+        assertFalse(settings.has("notExisting"))
+
+        // provided by DefaultsProvider
+        assertTrue(settings.has(App.OVERRIDE_PROXY))
+    }
+
+}

app/src/androidTest/java/at/bitfire/davdroid/ui/setup/DavResourceFinderTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
+ * Copyright © Ricki Hirner (bitfire web engineering).
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the GNU Public License v3.0
  * which accompanies this distribution, and is available at
@@ -8,13 +8,9 @@
 
 package at.bitfire.davdroid.ui.setup;
 
-import android.support.test.runner.AndroidJUnit4;
-import android.test.InstrumentationTestCase;
-
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
-import org.junit.runner.RunWith;
 
 import java.io.IOException;
 import java.net.URI;
@@ -24,12 +20,9 @@ import at.bitfire.dav4android.exception.DavException;
 import at.bitfire.dav4android.exception.HttpException;
 import at.bitfire.dav4android.property.AddressbookHomeSet;
 import at.bitfire.dav4android.property.ResourceType;
-import at.bitfire.davdroid.App;
 import at.bitfire.davdroid.HttpClient;
-import at.bitfire.davdroid.ui.setup.DavResourceFinder;
+import at.bitfire.davdroid.log.Logger;
 import at.bitfire.davdroid.ui.setup.DavResourceFinder.Configuration.ServiceInfo;
-import at.bitfire.davdroid.ui.setup.LoginCredentials;
-import okhttp3.OkHttpClient;
 import okhttp3.mockwebserver.Dispatcher;
 import okhttp3.mockwebserver.MockResponse;
 import okhttp3.mockwebserver.MockWebServer;
@@ -46,7 +39,7 @@ public class DavResourceFinderTest {
     MockWebServer server = new MockWebServer();
 
     DavResourceFinder finder;
-    OkHttpClient client;
+    HttpClient client;
     LoginCredentials credentials;
 
     private static final String
@@ -68,8 +61,9 @@ public class DavResourceFinderTest {
         credentials = new LoginCredentials(URI.create("/"), "mock", "12345");
         finder = new DavResourceFinder(getTargetContext(), credentials);
 
-        client = HttpClient.create(null);
-        client = HttpClient.addAuthentication(client, credentials.userName, credentials.password);
+        client = new HttpClient.Builder()
+                .addAuthentication(null, credentials.getUserName(), credentials.getPassword())
+                .build();
     }
 
     @After
@@ -82,25 +76,25 @@ public class DavResourceFinderTest {
         ServiceInfo info;
 
         // before dav.propfind(), no info is available
-        DavResource dav = new DavResource(client, server.url(PATH_CARDDAV + SUBPATH_PRINCIPAL));
+        DavResource dav = new DavResource(client.getOkHttpClient(), server.url(PATH_CARDDAV + SUBPATH_PRINCIPAL));
         finder.rememberIfAddressBookOrHomeset(dav, info = new ServiceInfo());
-        assertEquals(0, info.collections.size());
-        assertEquals(0, info.homeSets.size());
+        assertEquals(0, info.getCollections().size());
+        assertEquals(0, info.getHomeSets().size());
 
         // recognize home set
         dav.propfind(0, AddressbookHomeSet.NAME);
         finder.rememberIfAddressBookOrHomeset(dav, info = new ServiceInfo());
-        assertEquals(0, info.collections.size());
-        assertEquals(1, info.homeSets.size());
-        assertEquals(server.url(PATH_CARDDAV + SUBPATH_ADDRESSBOOK_HOMESET + "/").uri(), info.homeSets.iterator().next());
+        assertEquals(0, info.getCollections().size());
+        assertEquals(1, info.getHomeSets().size());
+        assertEquals(server.url(PATH_CARDDAV + SUBPATH_ADDRESSBOOK_HOMESET + "/").uri(), info.getHomeSets().iterator().next());
 
         // recognize address book
-        dav = new DavResource(client, server.url(PATH_CARDDAV + SUBPATH_ADDRESSBOOK));
+        dav = new DavResource(client.getOkHttpClient(), server.url(PATH_CARDDAV + SUBPATH_ADDRESSBOOK));
         dav.propfind(0, ResourceType.NAME);
         finder.rememberIfAddressBookOrHomeset(dav, info = new ServiceInfo());
-        assertEquals(1, info.collections.size());
-        assertEquals(server.url(PATH_CARDDAV + SUBPATH_ADDRESSBOOK + "/").uri(), info.collections.keySet().iterator().next());
-        assertEquals(0, info.homeSets.size());
+        assertEquals(1, info.getCollections().size());
+        assertEquals(server.url(PATH_CARDDAV + SUBPATH_ADDRESSBOOK + "/").uri(), info.getCollections().keySet().iterator().next());
+        assertEquals(0, info.getHomeSets().size());
     }
 
     @Test
@@ -184,7 +178,7 @@ public class DavResourceFinderTest {
                                 "</resourcetype>";
                         break;
                 }
-                App.log.info("Sending props: " + props);
+                Logger.log.info("Sending props: " + props);
                 return new MockResponse()
                         .setResponseCode(207)
                         .setBody("<multistatus xmlns='DAV:' xmlns:CARD='urn:ietf:params:xml:ns:carddav'>" +

app/src/main/AndroidManifest.xml

@@ -52,81 +52,8 @@
         android:theme="@style/AppTheme"
         tools:ignore="UnusedAttribute">
 
-        <receiver
-            android:name=".App$ReinitLoggingReceiver"
-            android:exported="false"
-            android:process=":sync">
-            <intent-filter>
-                <action android:name="at.bitfire.davdroid.REINIT_LOGGER"/>
-            </intent-filter>
-        </receiver>
-        <receiver
-            android:name=".AccountSettings$AppUpdatedReceiver"
-            android:exported="true">
-            <intent-filter>
-                <action android:name="android.intent.action.PACKAGE_REPLACED" />
-                <data android:scheme="package" android:path="at.bitfire.davdroid" />
-            </intent-filter>
-        </receiver>
-
-        <service
-            android:name=".syncadapter.AccountAuthenticatorService"
-            android:exported="false">
-            <intent-filter>
-                <action android:name="android.accounts.AccountAuthenticator"/>
-            </intent-filter>
-
-            <meta-data
-                android:name="android.accounts.AccountAuthenticator"
-                android:resource="@xml/account_authenticator"/>
-        </service>
-        <service
-            android:name=".syncadapter.ContactsSyncAdapterService"
-            android:exported="true"
-            android:process=":sync"
-            tools:ignore="ExportedService">
-            <intent-filter>
-                <action android:name="android.content.SyncAdapter"/>
-            </intent-filter>
-
-            <meta-data
-                android:name="android.content.SyncAdapter"
-                android:resource="@xml/sync_contacts"/>
-            <meta-data
-                android:name="android.provider.CONTACTS_STRUCTURE"
-                android:resource="@xml/contacts"/>
-        </service>
-        <service
-            android:name=".syncadapter.CalendarsSyncAdapterService"
-            android:exported="true"
-            android:process=":sync"
-            tools:ignore="ExportedService">
-            <intent-filter>
-                <action android:name="android.content.SyncAdapter"/>
-            </intent-filter>
-
-            <meta-data
-                android:name="android.content.SyncAdapter"
-                android:resource="@xml/sync_calendars"/>
-        </service>
-        <service
-            android:name=".syncadapter.TasksSyncAdapterService"
-            android:exported="true"
-            android:process=":sync"
-            tools:ignore="ExportedService">
-            <intent-filter>
-                <action android:name="android.content.SyncAdapter"/>
-            </intent-filter>
-
-            <meta-data
-                android:name="android.content.SyncAdapter"
-                android:resource="@xml/sync_tasks"/>
-        </service>
-
-        <service
-            android:name=".DavService"
-            android:enabled="true">
-        </service>
+        <service android:name=".DavService"/>
+        <service android:name=".settings.Settings"/>
 
         <receiver android:name=".AccountsChangedReceiver">
             <intent-filter>
@@ -188,6 +115,7 @@
 
         <activity
             android:name=".ui.DebugInfoActivity"
+            android:parentActivityName=".ui.AppSettingsActivity"
             android:exported="true"
             android:label="@string/debug_info_title">
         </activity>
@@ -201,6 +129,92 @@
                 android:resource="@xml/log_paths" />
         </provider>
 
+        <!-- account type "DAVdroid" -->
+        <service
+            android:name=".syncadapter.AccountAuthenticatorService"
+            android:exported="false">
+            <intent-filter>
+                <action android:name="android.accounts.AccountAuthenticator"/>
+            </intent-filter>
+
+            <meta-data
+                android:name="android.accounts.AccountAuthenticator"
+                android:resource="@xml/account_authenticator"/>
+        </service>
+        <service
+            android:name=".syncadapter.CalendarsSyncAdapterService"
+            android:exported="true"
+            android:process=":sync"
+            tools:ignore="ExportedService">
+            <intent-filter>
+                <action android:name="android.content.SyncAdapter"/>
+            </intent-filter>
+
+            <meta-data
+                android:name="android.content.SyncAdapter"
+                android:resource="@xml/sync_calendars"/>
+        </service>
+        <service
+            android:name=".syncadapter.TasksSyncAdapterService"
+            android:exported="true"
+            android:process=":sync"
+            tools:ignore="ExportedService">
+            <intent-filter>
+                <action android:name="android.content.SyncAdapter"/>
+            </intent-filter>
+
+            <meta-data
+                android:name="android.content.SyncAdapter"
+                android:resource="@xml/sync_tasks"/>
+        </service>
+
+        <!-- account type "DAVdroid Address book" -->
+        <service
+            android:name=".syncadapter.NullAuthenticatorService"
+            android:exported="false">
+            <intent-filter>
+                <action android:name="android.accounts.AccountAuthenticator"/>
+            </intent-filter>
+
+            <meta-data
+                android:name="android.accounts.AccountAuthenticator"
+                android:resource="@xml/account_authenticator_address_book"/>
+        </service>
+        <provider
+            android:authorities="@string/address_books_authority"
+            android:exported="false"
+            android:label="@string/address_books_authority_title"
+            android:name=".syncadapter.AddressBookProvider"
+            android:multiprocess="false"/>
+        <service
+            android:name=".syncadapter.AddressBooksSyncAdapterService"
+            android:exported="true"
+            android:process=":sync"
+            tools:ignore="ExportedService">
+            <intent-filter>
+                <action android:name="android.content.SyncAdapter"/>
+            </intent-filter>
+
+            <meta-data
+                android:name="android.content.SyncAdapter"
+                android:resource="@xml/sync_address_books"/>
+        </service>
+        <service
+            android:name=".syncadapter.ContactsSyncAdapterService"
+            android:exported="true"
+            android:process=":sync"
+            tools:ignore="ExportedService">
+            <intent-filter>
+                <action android:name="android.content.SyncAdapter"/>
+            </intent-filter>
+
+            <meta-data
+                android:name="android.content.SyncAdapter"
+                android:resource="@xml/sync_contacts"/>
+            <meta-data
+                android:name="android.provider.CONTACTS_STRUCTURE"
+                android:resource="@xml/contacts"/>
+        </service>
 
     </application>
 

app/src/main/aidl/at/bitfire/davdroid/settings/ISettings.aidl

@@ -0,0 +1,28 @@
+package at.bitfire.davdroid.settings;
+
+import at.bitfire.davdroid.settings.ISettingsObserver;
+
+interface ISettings {
+
+    void forceReload();
+
+    boolean has(String key);
+
+    boolean getBoolean(String key, boolean defaultValue);
+    int getInt(String key, int defaultValue);
+    long getLong(String key, long defaultValue);
+    String getString(String key, String defaultValue);
+
+    boolean isWritable(String key);
+
+    boolean putBoolean(String key, boolean value);
+    boolean putInt(String key, int value);
+    boolean putLong(String key, long value);
+    boolean putString(String key, String value);
+
+    boolean remove(String key);
+
+    void registerObserver(ISettingsObserver observer);
+    void unregisterObserver(ISettingsObserver observer);
+
+}

app/src/main/aidl/at/bitfire/davdroid/settings/ISettingsObserver.aidl

@@ -0,0 +1,7 @@
+package at.bitfire.davdroid.settings;
+
+interface ISettingsObserver {
+
+    void onSettingsChanged();
+
+}

app/src/main/java/at/bitfire/davdroid/AccountSettings.java

@@ -1,416 +0,0 @@
-/*
- * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-package at.bitfire.davdroid;
-
-import android.accounts.Account;
-import android.accounts.AccountManager;
-import android.annotation.SuppressLint;
-import android.annotation.TargetApi;
-import android.content.BroadcastReceiver;
-import android.content.ContentProviderClient;
-import android.content.ContentResolver;
-import android.content.ContentValues;
-import android.content.Context;
-import android.content.Intent;
-import android.content.PeriodicSync;
-import android.database.sqlite.SQLiteDatabase;
-import android.os.Build;
-import android.os.Bundle;
-import android.provider.CalendarContract;
-import android.provider.ContactsContract;
-import android.support.annotation.NonNull;
-import android.support.annotation.Nullable;
-import android.text.TextUtils;
-
-import java.lang.reflect.Method;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Set;
-import java.util.logging.Level;
-
-import at.bitfire.davdroid.model.ServiceDB;
-import at.bitfire.davdroid.model.ServiceDB.Collections;
-import at.bitfire.davdroid.model.ServiceDB.HomeSets;
-import at.bitfire.davdroid.model.ServiceDB.Services;
-import at.bitfire.davdroid.resource.LocalAddressBook;
-import at.bitfire.davdroid.resource.LocalCalendar;
-import at.bitfire.davdroid.resource.LocalTaskList;
-import at.bitfire.ical4android.CalendarStorageException;
-import at.bitfire.ical4android.TaskProvider;
-import at.bitfire.vcard4android.ContactsStorageException;
-import at.bitfire.vcard4android.GroupMethod;
-import lombok.Cleanup;
-import okhttp3.HttpUrl;
-
-public class AccountSettings {
-    private final static int CURRENT_VERSION = 5;
-    private final static String
-            KEY_SETTINGS_VERSION = "version",
-
-            KEY_USERNAME = "user_name",
-
-            KEY_WIFI_ONLY = "wifi_only",            // sync on WiFi only (default: false)
-            KEY_WIFI_ONLY_SSID = "wifi_only_ssid";  // restrict sync to specific WiFi SSID
-
-    /** Time range limitation to the past [in days]
-        value = null            default value (DEFAULT_TIME_RANGE_PAST_DAYS)
-              < 0 (-1)          no limit
-              >= 0              entries more than n days in the past won't be synchronized
-     */
-    private final static String KEY_TIME_RANGE_PAST_DAYS = "time_range_past_days";
-    private final static int DEFAULT_TIME_RANGE_PAST_DAYS = 90;
-
-    /* Whether DAVdroid sets the local calendar color to the value from service DB at every sync
-       value = null (not existing)     true (default)
-               "0"                     false */
-    private final static String KEY_MANAGE_CALENDAR_COLORS = "manage_calendar_colors";
-
-    /** Contact group method:
-        value = null (not existing)     groups as separate VCards (default)
-                "CATEGORIES"            groups are per-contact CATEGORIES
-    */
-    private final static String KEY_CONTACT_GROUP_METHOD = "contact_group_method";
-
-    public final static long SYNC_INTERVAL_MANUALLY = -1;
-
-    final Context context;
-    final AccountManager accountManager;
-    final Account account;
-
-
-    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
-    public AccountSettings(@NonNull Context context, @NonNull Account account) throws InvalidAccountException {
-        this.context = context;
-        this.account = account;
-
-        accountManager = AccountManager.get(context);
-
-        synchronized(AccountSettings.class) {
-            String versionStr = accountManager.getUserData(account, KEY_SETTINGS_VERSION);
-            if (versionStr == null)
-                throw new InvalidAccountException(account);
-
-            int version = 0;
-            try {
-                version = Integer.parseInt(versionStr);
-            } catch (NumberFormatException ignored) {
-            }
-            App.log.fine("Account " + account.name + " has version " + version + ", current version: " + CURRENT_VERSION);
-
-            if (version < CURRENT_VERSION)
-                update(version);
-        }
-    }
-
-    public static Bundle initialUserData(String userName) {
-        Bundle bundle = new Bundle();
-        bundle.putString(KEY_SETTINGS_VERSION, String.valueOf(CURRENT_VERSION));
-        bundle.putString(KEY_USERNAME, userName);
-        return bundle;
-    }
-
-
-    // authentication settings
-
-    public String username() { return accountManager.getUserData(account, KEY_USERNAME); }
-    public void username(@NonNull String userName) { accountManager.setUserData(account, KEY_USERNAME, userName); }
-
-    public String password() { return accountManager.getPassword(account); }
-    public void password(@NonNull String password) { accountManager.setPassword(account, password); }
-
-
-    // sync. settings
-
-    public Long getSyncInterval(@NonNull String authority) {
-        if (ContentResolver.getIsSyncable(account, authority) <= 0)
-            return null;
-
-        if (ContentResolver.getSyncAutomatically(account, authority)) {
-            List<PeriodicSync> syncs = ContentResolver.getPeriodicSyncs(account, authority);
-            if (syncs.isEmpty())
-                return SYNC_INTERVAL_MANUALLY;
-            else
-                return syncs.get(0).period;
-        } else
-            return SYNC_INTERVAL_MANUALLY;
-    }
-
-    public void setSyncInterval(@NonNull String authority, long seconds) {
-        if (seconds == SYNC_INTERVAL_MANUALLY) {
-            ContentResolver.setSyncAutomatically(account, authority, false);
-        } else {
-            ContentResolver.setSyncAutomatically(account, authority, true);
-            ContentResolver.addPeriodicSync(account, authority, new Bundle(), seconds);
-        }
-    }
-
-    public boolean getSyncWifiOnly() {
-        return accountManager.getUserData(account, KEY_WIFI_ONLY) != null;
-    }
-
-    public void setSyncWiFiOnly(boolean wiFiOnly) {
-        accountManager.setUserData(account, KEY_WIFI_ONLY, wiFiOnly ? "1" : null);
-    }
-
-    @Nullable
-    public String getSyncWifiOnlySSID() {
-        return accountManager.getUserData(account, KEY_WIFI_ONLY_SSID);
-    }
-
-    public void setSyncWifiOnlySSID(String ssid) {
-        accountManager.setUserData(account, KEY_WIFI_ONLY_SSID, ssid);
-    }
-
-
-    // CalDAV settings
-
-    @Nullable
-    public Integer getTimeRangePastDays() {
-        String strDays = accountManager.getUserData(account, KEY_TIME_RANGE_PAST_DAYS);
-        if (strDays != null) {
-            int days = Integer.valueOf(strDays);
-            return days < 0 ? null : days;
-        } else
-            return DEFAULT_TIME_RANGE_PAST_DAYS;
-    }
-
-    public void setTimeRangePastDays(@Nullable Integer days) {
-        accountManager.setUserData(account, KEY_TIME_RANGE_PAST_DAYS, String.valueOf(days == null ? -1 : days));
-    }
-
-    public boolean getManageCalendarColors() {
-        return accountManager.getUserData(account, KEY_MANAGE_CALENDAR_COLORS) == null;
-    }
-
-    public void setManageCalendarColors(boolean manage) {
-        accountManager.setUserData(account, KEY_MANAGE_CALENDAR_COLORS, manage ? null : "0");
-    }
-
-
-    // CardDAV settings
-
-    @NonNull
-    public GroupMethod getGroupMethod() {
-        final String name = accountManager.getUserData(account, KEY_CONTACT_GROUP_METHOD);
-        return name != null ?
-                GroupMethod.valueOf(name) :
-                GroupMethod.GROUP_VCARDS;
-    }
-
-    public void setGroupMethod(@NonNull GroupMethod method) {
-        final String name = method == GroupMethod.GROUP_VCARDS ? null : method.name();
-        accountManager.setUserData(account, KEY_CONTACT_GROUP_METHOD, name);
-    }
-
-
-    // update from previous account settings
-
-    private void update(int fromVersion) {
-        for (int toVersion = fromVersion + 1; toVersion <= CURRENT_VERSION; toVersion++) {
-            App.log.info("Updating account " + account.name + " from version " + fromVersion + " to " + toVersion);
-            try {
-                Method updateProc = getClass().getDeclaredMethod("update_" + fromVersion + "_" + toVersion);
-                updateProc.invoke(this);
-                accountManager.setUserData(account, KEY_SETTINGS_VERSION, String.valueOf(toVersion));
-            } catch (Exception e) {
-                App.log.log(Level.SEVERE, "Couldn't update account settings", e);
-            }
-            fromVersion = toVersion;
-        }
-    }
-
-    @SuppressWarnings({ "Recycle", "unused" })
-    private void update_1_2() throws ContactsStorageException {
-        /* - KEY_ADDRESSBOOK_URL ("addressbook_url"),
-           - KEY_ADDRESSBOOK_CTAG ("addressbook_ctag"),
-           - KEY_ADDRESSBOOK_VCARD_VERSION ("addressbook_vcard_version") are not used anymore (now stored in ContactsContract.SyncState)
-           - KEY_LAST_ANDROID_VERSION ("last_android_version") has been added
-        */
-
-        // move previous address book info to ContactsContract.SyncState
-        @Cleanup("release") ContentProviderClient provider = context.getContentResolver().acquireContentProviderClient(ContactsContract.AUTHORITY);
-        if (provider == null)
-            throw new ContactsStorageException("Couldn't access Contacts provider");
-
-        LocalAddressBook addr = new LocalAddressBook(account, provider);
-
-        // until now, ContactsContract.Settings.UNGROUPED_VISIBLE was not set explicitly
-        ContentValues values = new ContentValues();
-        values.put(ContactsContract.Settings.UNGROUPED_VISIBLE, 1);
-        addr.updateSettings(values);
-
-        String url = accountManager.getUserData(account, "addressbook_url");
-        if (!TextUtils.isEmpty(url))
-            addr.setURL(url);
-        accountManager.setUserData(account, "addressbook_url", null);
-
-        String cTag = accountManager.getUserData(account, "addressbook_ctag");
-        if (!TextUtils.isEmpty(cTag))
-            addr.setCTag(cTag);
-        accountManager.setUserData(account, "addressbook_ctag", null);
-    }
-
-    @SuppressWarnings({ "Recycle", "unused" })
-    private void update_2_3() {
-        // Don't show a warning for Android updates anymore
-        accountManager.setUserData(account, "last_android_version", null);
-
-        Long serviceCardDAV = null, serviceCalDAV = null;
-
-        ServiceDB.OpenHelper dbHelper = new ServiceDB.OpenHelper(context);
-        try {
-            SQLiteDatabase db = dbHelper.getWritableDatabase();
-            // we have to create the WebDAV Service database only from the old address book, calendar and task list URLs
-
-            // CardDAV: migrate address books
-            ContentProviderClient client = context.getContentResolver().acquireContentProviderClient(ContactsContract.AUTHORITY);
-            if (client != null)
-                try {
-                    LocalAddressBook addrBook = new LocalAddressBook(account, client);
-                    String url = addrBook.getURL();
-                    if (url != null) {
-                        App.log.fine("Migrating address book " + url);
-
-                        // insert CardDAV service
-                        ContentValues values = new ContentValues();
-                        values.put(Services.ACCOUNT_NAME, account.name);
-                        values.put(Services.SERVICE, Services.SERVICE_CARDDAV);
-                        serviceCardDAV = db.insert(Services._TABLE, null, values);
-
-                        // insert address book
-                        values.clear();
-                        values.put(Collections.SERVICE_ID, serviceCardDAV);
-                        values.put(Collections.URL, url);
-                        values.put(Collections.SYNC, 1);
-                        db.insert(Collections._TABLE, null, values);
-
-                        // insert home set
-                        HttpUrl homeSet = HttpUrl.parse(url).resolve("../");
-                        values.clear();
-                        values.put(HomeSets.SERVICE_ID, serviceCardDAV);
-                        values.put(HomeSets.URL, homeSet.toString());
-                        db.insert(HomeSets._TABLE, null, values);
-                    }
-
-                } catch (ContactsStorageException e) {
-                    App.log.log(Level.SEVERE, "Couldn't migrate address book", e);
-                } finally {
-                    client.release();
-                }
-
-            // CalDAV: migrate calendars + task lists
-            Set<String> collections = new HashSet<>();
-            Set<HttpUrl> homeSets = new HashSet<>();
-
-            client = context.getContentResolver().acquireContentProviderClient(CalendarContract.AUTHORITY);
-            if (client != null)
-                try {
-                    LocalCalendar calendars[] = (LocalCalendar[])LocalCalendar.find(account, client, LocalCalendar.Factory.INSTANCE, null, null);
-                    for (LocalCalendar calendar : calendars) {
-                        String url = calendar.getName();
-                        App.log.fine("Migrating calendar " + url);
-                        collections.add(url);
-                        homeSets.add(HttpUrl.parse(url).resolve("../"));
-                    }
-                } catch (CalendarStorageException e) {
-                    App.log.log(Level.SEVERE, "Couldn't migrate calendars", e);
-                } finally {
-                    client.release();
-                }
-
-            TaskProvider provider = LocalTaskList.acquireTaskProvider(context.getContentResolver());
-            if (provider != null)
-                try {
-                    LocalTaskList[] taskLists = (LocalTaskList[])LocalTaskList.find(account, provider, LocalTaskList.Factory.INSTANCE, null, null);
-                    for (LocalTaskList taskList : taskLists) {
-                        String url = taskList.getSyncId();
-                        App.log.fine("Migrating task list " + url);
-                        collections.add(url);
-                        homeSets.add(HttpUrl.parse(url).resolve("../"));
-                    }
-                } catch (CalendarStorageException e) {
-                    App.log.log(Level.SEVERE, "Couldn't migrate task lists", e);
-                } finally {
-                    provider.close();
-                }
-
-            if (!collections.isEmpty()) {
-                // insert CalDAV service
-                ContentValues values = new ContentValues();
-                values.put(Services.ACCOUNT_NAME, account.name);
-                values.put(Services.SERVICE, Services.SERVICE_CALDAV);
-                serviceCalDAV = db.insert(Services._TABLE, null, values);
-
-                // insert collections
-                for (String url : collections) {
-                    values.clear();
-                    values.put(Collections.SERVICE_ID, serviceCalDAV);
-                    values.put(Collections.URL, url);
-                    values.put(Collections.SYNC, 1);
-                    db.insert(Collections._TABLE, null, values);
-                }
-
-                // insert home sets
-                for (HttpUrl homeSet : homeSets) {
-                    values.clear();
-                    values.put(HomeSets.SERVICE_ID, serviceCalDAV);
-                    values.put(HomeSets.URL, homeSet.toString());
-                    db.insert(HomeSets._TABLE, null, values);
-                }
-            }
-        } finally {
-            dbHelper.close();
-        }
-
-        // initiate service detection (refresh) to get display names, colors etc.
-        Intent refresh = new Intent(context, DavService.class);
-        refresh.setAction(DavService.ACTION_REFRESH_COLLECTIONS);
-        if (serviceCardDAV != null) {
-            refresh.putExtra(DavService.EXTRA_DAV_SERVICE_ID, serviceCardDAV);
-            context.startService(refresh);
-        }
-        if (serviceCalDAV != null) {
-            refresh.putExtra(DavService.EXTRA_DAV_SERVICE_ID, serviceCalDAV);
-            context.startService(refresh);
-        }
-    }
-
-    @SuppressWarnings({ "Recycle", "unused" })
-    private void update_3_4() {
-        setGroupMethod(GroupMethod.CATEGORIES);
-    }
-
-    /* Android 7.1.1 OpenTasks fix */
-    @SuppressWarnings({ "Recycle", "unused" })
-    private void update_4_5() {
-        // call PackageChangedReceiver which then enables/disables OpenTasks sync when it's (not) available
-        PackageChangedReceiver.updateTaskSync(context);
-    }
-
-
-    public static class AppUpdatedReceiver extends BroadcastReceiver {
-
-        @Override
-        @SuppressLint("UnsafeProtectedBroadcastReceiver,MissingPermission")
-        public void onReceive(Context context, Intent intent) {
-            App.log.info("DAVdroid was updated, checking for AccountSettings version");
-
-            // peek into AccountSettings to initiate a possible migration
-            AccountManager accountManager = AccountManager.get(context);
-            for (Account account : accountManager.getAccountsByType(Constants.ACCOUNT_TYPE))
-                try {
-                    App.log.info("Checking account " + account.name);
-                    new AccountSettings(context, account);
-                } catch (InvalidAccountException e) {
-                    App.log.log(Level.SEVERE, "Couldn't check for updated account settings", e);
-                }
-        }
-
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/AccountSettings.kt

@@ -0,0 +1,485 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+package at.bitfire.davdroid
+
+import android.accounts.Account
+import android.accounts.AccountManager
+import android.content.ContentResolver
+import android.content.ContentValues
+import android.content.Context
+import android.content.Intent
+import android.os.Build
+import android.os.Bundle
+import android.os.Parcel
+import android.os.RemoteException
+import android.provider.CalendarContract
+import android.provider.ContactsContract
+import at.bitfire.davdroid.log.Logger
+import at.bitfire.davdroid.model.CollectionInfo
+import at.bitfire.davdroid.model.ServiceDB
+import at.bitfire.davdroid.model.ServiceDB.*
+import at.bitfire.davdroid.model.ServiceDB.Collections
+import at.bitfire.davdroid.resource.LocalAddressBook
+import at.bitfire.davdroid.resource.LocalCalendar
+import at.bitfire.davdroid.resource.LocalTaskList
+import at.bitfire.davdroid.settings.ISettings
+import at.bitfire.ical4android.AndroidCalendar
+import at.bitfire.ical4android.AndroidTaskList
+import at.bitfire.ical4android.CalendarStorageException
+import at.bitfire.vcard4android.ContactsStorageException
+import at.bitfire.vcard4android.GroupMethod
+import okhttp3.HttpUrl
+import org.apache.commons.lang3.StringUtils
+import java.util.*
+import java.util.logging.Level
+
+class AccountSettings @Throws(InvalidAccountException::class) constructor(
+        val context: Context,
+        val settings: ISettings,
+        val account: Account
+) {
+
+    companion object {
+
+        val CURRENT_VERSION = 7
+        val KEY_SETTINGS_VERSION = "version"
+
+        val KEY_USERNAME = "user_name"
+
+        val KEY_WIFI_ONLY = "wifi_only"               // sync on WiFi only (default: false)
+        val KEY_WIFI_ONLY_SSIDS = "wifi_only_ssids"   // restrict sync to specific WiFi SSIDs
+
+        /** Time range limitation to the past [in days]
+        value = null            default value (DEFAULT_TIME_RANGE_PAST_DAYS)
+        < 0 (-1)          no limit
+        >= 0              entries more than n days in the past won't be synchronized
+         */
+        val KEY_TIME_RANGE_PAST_DAYS = "time_range_past_days"
+        val DEFAULT_TIME_RANGE_PAST_DAYS = 90
+
+        /* Whether DAVdroid sets the local calendar color to the value from service DB at every sync
+           value = null (not existing)     true (default)
+                   "0"                     false */
+        val KEY_MANAGE_CALENDAR_COLORS = "manage_calendar_colors"
+
+        /* Whether DAVdroid populates and uses CalendarContract.Colors
+           value = null (not existing)     false (default)
+                   "1"                     true */
+        val KEY_EVENT_COLORS = "event_colors"
+
+        /** Contact group method:
+        value = null (not existing)     groups as separate VCards (default)
+        "CATEGORIES"            groups are per-contact CATEGORIES
+         */
+        val KEY_CONTACT_GROUP_METHOD = "contact_group_method"
+
+        @JvmField
+        val SYNC_INTERVAL_MANUALLY = -1L
+
+        fun initialUserData(userName: String): Bundle {
+            val bundle = Bundle(2)
+            bundle.putString(KEY_SETTINGS_VERSION, CURRENT_VERSION.toString())
+            bundle.putString(KEY_USERNAME, userName)
+            return bundle
+        }
+
+    }
+
+
+    val accountManager: AccountManager = AccountManager.get(context)
+
+    init {
+        synchronized(AccountSettings::class.java) {
+            val versionStr = accountManager.getUserData(account, KEY_SETTINGS_VERSION) ?: throw InvalidAccountException(account)
+            var version = 0
+            try {
+                version = Integer.parseInt(versionStr)
+            } catch (e: NumberFormatException) {
+            }
+            Logger.log.fine("Account ${account.name} has version $version, current version: $CURRENT_VERSION")
+
+            if (version < CURRENT_VERSION)
+                update(version)
+        }
+    }
+
+
+    // authentication settings
+
+    fun username(): String? = accountManager.getUserData(account, KEY_USERNAME)
+    fun username(userName: String) = accountManager.setUserData(account, KEY_USERNAME, userName)
+
+    fun password(): String? = accountManager.getPassword(account)
+    fun password(password: String) = accountManager.setPassword(account, password)
+
+
+    // sync. settings
+
+    fun getSyncInterval(authority: String): Long? {
+        if (ContentResolver.getIsSyncable(account, authority) <= 0)
+            return null
+
+        return if (ContentResolver.getSyncAutomatically(account, authority))
+            ContentResolver.getPeriodicSyncs(account, authority).firstOrNull()?.period ?: SYNC_INTERVAL_MANUALLY
+        else
+            SYNC_INTERVAL_MANUALLY
+    }
+
+    fun setSyncInterval(authority: String, seconds: Long) {
+        if (seconds == SYNC_INTERVAL_MANUALLY) {
+            ContentResolver.setSyncAutomatically(account, authority, false)
+        } else {
+            ContentResolver.setSyncAutomatically(account, authority, true)
+            ContentResolver.addPeriodicSync(account, authority, Bundle(), seconds)
+        }
+    }
+
+    fun getSyncWifiOnly() = if (settings.has(KEY_WIFI_ONLY))
+            settings.getBoolean(KEY_WIFI_ONLY, false)
+                else
+            accountManager.getUserData(account, KEY_WIFI_ONLY) != null
+    fun setSyncWiFiOnly(wiFiOnly: Boolean) =
+            accountManager.setUserData(account, KEY_WIFI_ONLY, if (wiFiOnly) "1" else null)
+
+    fun getSyncWifiOnlySSIDs(): List<String>? = (if (settings.has(KEY_WIFI_ONLY_SSIDS))
+                settings.getString(KEY_WIFI_ONLY_SSIDS, null)
+            else
+                accountManager.getUserData(account, KEY_WIFI_ONLY_SSIDS))?.split(',')
+    fun setSyncWifiOnlySSIDs(ssids: List<String>?) =
+            accountManager.setUserData(account, KEY_WIFI_ONLY_SSIDS, StringUtils.trimToNull(ssids?.joinToString(",")))
+
+
+    // CalDAV settings
+
+    fun getTimeRangePastDays(): Int? {
+        val strDays = accountManager.getUserData(account, KEY_TIME_RANGE_PAST_DAYS)
+        if (strDays != null) {
+            val days = Integer.valueOf(strDays)
+            return if (days < 0) null else days
+        } else
+            return DEFAULT_TIME_RANGE_PAST_DAYS
+    }
+
+    fun setTimeRangePastDays(days: Int?) =
+            accountManager.setUserData(account, KEY_TIME_RANGE_PAST_DAYS, (days ?: -1).toString())
+
+    fun getManageCalendarColors() = if (settings.has(KEY_MANAGE_CALENDAR_COLORS))
+        settings.getBoolean(KEY_MANAGE_CALENDAR_COLORS, false)
+    else
+        accountManager.getUserData(account, KEY_MANAGE_CALENDAR_COLORS) == null
+    fun setManageCalendarColors(manage: Boolean) =
+            accountManager.setUserData(account, KEY_MANAGE_CALENDAR_COLORS, if (manage) null else "0")
+
+    fun getEventColors() = if (settings.has(KEY_EVENT_COLORS))
+            settings.getBoolean(KEY_EVENT_COLORS, false)
+                else
+            accountManager.getUserData(account, KEY_EVENT_COLORS) != null
+    fun setEventColors(useColors: Boolean) =
+            accountManager.setUserData(account, KEY_EVENT_COLORS, if (useColors) "1" else null)
+
+    // CardDAV settings
+
+    fun getGroupMethod(): GroupMethod {
+        val name = settings.getString(KEY_CONTACT_GROUP_METHOD, null) ?:
+                accountManager.getUserData(account, KEY_CONTACT_GROUP_METHOD)
+        if (name != null)
+            try {
+                return GroupMethod.valueOf(name)
+            }
+            catch (e: IllegalArgumentException) {
+            }
+        return GroupMethod.GROUP_VCARDS
+    }
+
+    fun setGroupMethod(method: GroupMethod) {
+        accountManager.setUserData(account, KEY_CONTACT_GROUP_METHOD, method.name)
+    }
+
+
+    // update from previous account settings
+
+    private fun update(baseVersion: Int) {
+        for (toVersion in baseVersion+1 .. CURRENT_VERSION) {
+            val fromVersion = toVersion-1
+            Logger.log.info("Updating account ${account.name} from version $fromVersion to $toVersion")
+            try {
+                val updateProc = this::class.java.getDeclaredMethod("update_${fromVersion}_$toVersion")
+                updateProc.invoke(this)
+                accountManager.setUserData(account, KEY_SETTINGS_VERSION, toVersion.toString())
+            } catch (e: Exception) {
+                Logger.log.log(Level.SEVERE, "Couldn't update account settings", e)
+            }
+        }
+    }
+
+    @Suppress("unused")
+    private fun update_6_7() {
+        // add calendar colors
+        context.contentResolver.acquireContentProviderClient(CalendarContract.AUTHORITY)?.let { provider ->
+            try {
+                AndroidCalendar.insertColors(provider, account)
+            } finally {
+                if (Build.VERSION.SDK_INT >= 24)
+                    provider.close()
+                else
+                    provider.release()
+            }
+        }
+
+        // update allowed WiFi settings key
+        val onlySSID = accountManager.getUserData(account, "wifi_only_ssid")
+        accountManager.setUserData(account, KEY_WIFI_ONLY_SSIDS, onlySSID)
+        accountManager.setUserData(account, "wifi_only_ssid", null)
+    }
+
+    @Suppress("unused")
+    private fun update_5_6() {
+        context.contentResolver.acquireContentProviderClient(ContactsContract.AUTHORITY)?.let { provider ->
+            val parcel = Parcel.obtain()
+            try {
+                // don't run syncs during the migration
+                ContentResolver.setIsSyncable(account, ContactsContract.AUTHORITY, 0)
+                ContentResolver.setIsSyncable(account, context.getString(R.string.address_books_authority), 0)
+                ContentResolver.cancelSync(account, null)
+
+                // get previous address book settings (including URL)
+                val raw = ContactsContract.SyncState.get(provider, account)
+                if (raw == null)
+                    Logger.log.info("No contacts sync state, ignoring account")
+                else {
+                    parcel.unmarshall(raw, 0, raw.size)
+                    parcel.setDataPosition(0)
+                    val params = parcel.readBundle()
+                    val url = params.getString("url")
+                    if (url == null)
+                        Logger.log.info("No address book URL, ignoring account")
+                    else {
+                        // create new address book
+                        val info = CollectionInfo(url)
+                        info.type = CollectionInfo.Type.ADDRESS_BOOK
+                        info.displayName = account.name
+                        Logger.log.log(Level.INFO, "Creating new address book account", url)
+                        val addressBookAccount = Account(LocalAddressBook.accountName(account, info), context.getString(R.string.account_type_address_book))
+                        if (!accountManager.addAccountExplicitly(addressBookAccount, null, LocalAddressBook.initialUserData(account, info.url)))
+                            throw ContactsStorageException("Couldn't create address book account")
+
+                        // move contacts to new address book
+                        Logger.log.info("Moving contacts from $account to $addressBookAccount")
+                        val newAccount = ContentValues(2)
+                        newAccount.put(ContactsContract.RawContacts.ACCOUNT_NAME, addressBookAccount.name)
+                        newAccount.put(ContactsContract.RawContacts.ACCOUNT_TYPE, addressBookAccount.type)
+                        val affected = provider.update(ContactsContract.RawContacts.CONTENT_URI.buildUpon()
+                                .appendQueryParameter(ContactsContract.RawContacts.ACCOUNT_NAME, account.name)
+                                .appendQueryParameter(ContactsContract.RawContacts.ACCOUNT_TYPE, account.type)
+                                .appendQueryParameter(ContactsContract.CALLER_IS_SYNCADAPTER, "true").build(),
+                                newAccount,
+                                "${ContactsContract.RawContacts.ACCOUNT_NAME}=? AND ${ContactsContract.RawContacts.ACCOUNT_TYPE}=?",
+                                arrayOf(account.name, account.type))
+                        Logger.log.info("$affected contacts moved to new address book")
+                    }
+
+                    ContactsContract.SyncState.set(provider, account, null)
+                }
+            } catch(e: RemoteException) {
+                throw ContactsStorageException("Couldn't migrate contacts to new address book", e)
+            } finally {
+                parcel.recycle()
+                if (Build.VERSION.SDK_INT >= 24)
+                    provider.close()
+                else
+                    provider.release()
+            }
+        }
+
+        // update version number so that further syncs don't repeat the migration
+        accountManager.setUserData(account, KEY_SETTINGS_VERSION, "6")
+
+        // request sync of new address book account
+        ContentResolver.setIsSyncable(account, context.getString(R.string.address_books_authority), 1)
+        setSyncInterval(context.getString(R.string.address_books_authority), Constants.DEFAULT_SYNC_INTERVAL)
+    }
+
+    /* Android 7.1.1 OpenTasks fix */
+    @Suppress("unused")
+    private fun update_4_5() {
+        // call PackageChangedReceiver which then enables/disables OpenTasks sync when it's (not) available
+        PackageChangedReceiver.updateTaskSync(context)
+    }
+
+    @Suppress("unused")
+    private fun update_3_4() {
+        setGroupMethod(GroupMethod.CATEGORIES)
+    }
+
+    @Suppress("unused")
+    private fun update_2_3() {
+        // Don't show a warning for Android updates anymore
+        accountManager.setUserData(account, "last_android_version", null)
+
+        var serviceCardDAV: Long? = null
+        var serviceCalDAV: Long? = null
+
+        ServiceDB.OpenHelper(context).use { dbHelper ->
+            val db = dbHelper.writableDatabase
+            // we have to create the WebDAV Service database only from the old address book, calendar and task list URLs
+
+            // CardDAV: migrate address books
+            context.contentResolver.acquireContentProviderClient(ContactsContract.AUTHORITY)?.let { client ->
+                try {
+                    val addrBook = LocalAddressBook(context, account, client)
+                    val url = addrBook.getURL()
+                    Logger.log.fine("Migrating address book $url")
+
+                    // insert CardDAV service
+                    val values = ContentValues(3)
+                    values.put(Services.ACCOUNT_NAME, account.name)
+                    values.put(Services.SERVICE, Services.SERVICE_CARDDAV)
+                    serviceCardDAV = db.insert(Services._TABLE, null, values)
+
+                    // insert address book
+                    values.clear()
+                    values.put(Collections.SERVICE_ID, serviceCardDAV)
+                    values.put(Collections.URL, url)
+                    values.put(Collections.SYNC, 1)
+                    db.insert(Collections._TABLE, null, values)
+
+                    // insert home set
+                    HttpUrl.parse(url)?.let {
+                        val homeSet = it.resolve("../")
+                        values.clear()
+                        values.put(HomeSets.SERVICE_ID, serviceCardDAV)
+                        values.put(HomeSets.URL, homeSet.toString())
+                        db.insert(HomeSets._TABLE, null, values)
+                    }
+                } catch (e: ContactsStorageException) {
+                    Logger.log.log(Level.SEVERE, "Couldn't migrate address book", e)
+                } finally {
+                    if (Build.VERSION.SDK_INT >= 24)
+                        client.close()
+                    else
+                        @Suppress("deprecation")
+                        client.release()
+                }
+            }
+
+            // CalDAV: migrate calendars + task lists
+            val collections = HashSet<String>()
+            val homeSets = HashSet<HttpUrl>()
+
+            context.contentResolver.acquireContentProviderClient(CalendarContract.AUTHORITY)?.let { client ->
+                try {
+                    val calendars = AndroidCalendar.find(account, client, LocalCalendar.Factory, null, null)
+                    for (calendar in calendars)
+                        calendar.name?.let { url ->
+                            Logger.log.fine("Migrating calendar $url")
+                            collections.add(url)
+                            HttpUrl.parse(url)?.resolve("../")?.let { homeSets.add(it) }
+                        }
+                } catch (e: CalendarStorageException) {
+                    Logger.log.log(Level.SEVERE, "Couldn't migrate calendars", e)
+                } finally {
+                    if (Build.VERSION.SDK_INT >= 24)
+                        client.close()
+                    else
+                        @Suppress("deprecation")
+                        client.release()
+                }
+            }
+
+            AndroidTaskList.acquireTaskProvider(context.contentResolver)?.use { provider ->
+                try {
+                    val taskLists = AndroidTaskList.find(account, provider, LocalTaskList.Factory, null, null)
+                    for (taskList in taskLists)
+                        taskList.syncId?.let { url ->
+                            Logger.log.fine("Migrating task list $url")
+                            collections.add(url)
+                            HttpUrl.parse(url)?.resolve("../")?.let { homeSets.add(it) }
+                        }
+                } catch (e: CalendarStorageException) {
+                    Logger.log.log(Level.SEVERE, "Couldn't migrate task lists", e)
+                }
+            }
+
+            if (!collections.isEmpty()) {
+                // insert CalDAV service
+                val values = ContentValues(3)
+                values.put(Services.ACCOUNT_NAME, account.name)
+                values.put(Services.SERVICE, Services.SERVICE_CALDAV)
+                serviceCalDAV = db.insert(Services._TABLE, null, values)
+
+                // insert collections
+                for (url in collections) {
+                    values.clear()
+                    values.put(Collections.SERVICE_ID, serviceCalDAV)
+                    values.put(Collections.URL, url)
+                    values.put(Collections.SYNC, 1)
+                    db.insert(Collections._TABLE, null, values)
+                }
+
+                // insert home sets
+                for (homeSet in homeSets) {
+                    values.clear()
+                    values.put(HomeSets.SERVICE_ID, serviceCalDAV)
+                    values.put(HomeSets.URL, homeSet.toString())
+                    db.insert(HomeSets._TABLE, null, values)
+                }
+            }
+        }
+
+        // initiate service detection (refresh) to get display names, colors etc.
+        val refresh = Intent(context, DavService::class.java)
+        refresh.action = DavService.ACTION_REFRESH_COLLECTIONS
+        serviceCardDAV?.let {
+            refresh.putExtra(DavService.EXTRA_DAV_SERVICE_ID, it)
+            context.startService(refresh)
+        }
+        serviceCalDAV?.let {
+            refresh.putExtra(DavService.EXTRA_DAV_SERVICE_ID, it)
+            context.startService(refresh)
+        }
+    }
+
+    @Suppress("unused")
+    private fun update_1_2() {
+        /* - KEY_ADDRESSBOOK_URL ("addressbook_url"),
+           - KEY_ADDRESSBOOK_CTAG ("addressbook_ctag"),
+           - KEY_ADDRESSBOOK_VCARD_VERSION ("addressbook_vcard_version") are not used anymore (now stored in ContactsContract.SyncState)
+           - KEY_LAST_ANDROID_VERSION ("last_android_version") has been added
+        */
+
+        // move previous address book info to ContactsContract.SyncState
+        val provider = context.contentResolver.acquireContentProviderClient(ContactsContract.AUTHORITY) ?:
+            throw ContactsStorageException("Couldn't access Contacts provider")
+
+        try {
+            val addr = LocalAddressBook(context, account, provider)
+
+            // until now, ContactsContract.Settings.UNGROUPED_VISIBLE was not set explicitly
+            val values = ContentValues()
+            values.put(ContactsContract.Settings.UNGROUPED_VISIBLE, 1)
+            addr.updateSettings(values)
+
+            val url = accountManager.getUserData(account, "addressbook_url")
+            if (!url.isNullOrEmpty())
+                addr.setURL(url)
+            accountManager.setUserData(account, "addressbook_url", null)
+
+            val cTag = accountManager.getUserData (account, "addressbook_ctag")
+            if (!cTag.isNullOrEmpty())
+                addr.setCTag(cTag)
+            accountManager.setUserData(account, "addressbook_ctag", null)
+        } finally {
+            if (Build.VERSION.SDK_INT >= 24)
+                provider.close()
+            else
+                @Suppress("deprecation")
+                provider.release()
+        }
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/AccountsChangedReceiver.java

@@ -1,46 +0,0 @@
-/*
- * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid;
-
-import android.accounts.AccountManager;
-import android.accounts.OnAccountsUpdateListener;
-import android.content.BroadcastReceiver;
-import android.content.Context;
-import android.content.Intent;
-
-import java.util.LinkedList;
-import java.util.List;
-
-public class AccountsChangedReceiver extends BroadcastReceiver {
-
-    protected static final List<OnAccountsUpdateListener> listeners = new LinkedList<>();
-
-    @Override
-    public void onReceive(Context context, Intent intent) {
-        if (AccountManager.LOGIN_ACCOUNTS_CHANGED_ACTION.equals(intent.getAction())) {
-            Intent serviceIntent = new Intent(context, DavService.class);
-            serviceIntent.setAction(DavService.ACTION_ACCOUNTS_UPDATED);
-            context.startService(serviceIntent);
-
-            for (OnAccountsUpdateListener listener : listeners)
-                listener.onAccountsUpdated(null);
-        }
-    }
-
-    public static void registerListener(OnAccountsUpdateListener listener, boolean callImmediately) {
-        listeners.add(listener);
-        if (callImmediately)
-            listener.onAccountsUpdated(null);
-    }
-
-    public static void unregisterListener(OnAccountsUpdateListener listener) {
-        listeners.remove(listener);
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/AccountsChangedReceiver.kt

@@ -0,0 +1,48 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid
+
+import android.accounts.AccountManager
+import android.accounts.OnAccountsUpdateListener
+import android.content.BroadcastReceiver
+import android.content.Context
+import android.content.Intent
+import java.util.*
+
+class AccountsChangedReceiver: BroadcastReceiver() {
+
+    companion object {
+
+        private val listeners = LinkedList<OnAccountsUpdateListener>()
+
+        @JvmStatic
+        fun registerListener(listener: OnAccountsUpdateListener, callImmediately: Boolean) {
+            listeners += listener
+            if (callImmediately)
+                listener.onAccountsUpdated(null)
+        }
+
+        @JvmStatic
+        fun unregisterListener(listener: OnAccountsUpdateListener) {
+            listeners -= listener
+        }
+    }
+
+    override fun onReceive(context: Context, intent: Intent) {
+        if (intent.action == AccountManager.LOGIN_ACCOUNTS_CHANGED_ACTION) {
+            val serviceIntent = Intent(context, DavService::class.java)
+            serviceIntent.action = DavService.ACTION_ACCOUNTS_UPDATED
+            context.startService(serviceIntent)
+
+            for (listener in listeners)
+                listener.onAccountsUpdated(null)
+        }
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/App.java

@@ -1,189 +0,0 @@
-/*
- * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid;
-
-import android.annotation.SuppressLint;
-import android.annotation.TargetApi;
-import android.app.Application;
-import android.content.BroadcastReceiver;
-import android.content.Context;
-import android.content.Intent;
-import android.graphics.Bitmap;
-import android.graphics.drawable.BitmapDrawable;
-import android.graphics.drawable.Drawable;
-import android.os.Build;
-import android.os.Process;
-import android.support.annotation.NonNull;
-import android.support.annotation.Nullable;
-import android.support.v4.app.NotificationManagerCompat;
-import android.support.v7.app.NotificationCompat;
-import android.util.Log;
-
-import net.fortuna.ical4j.util.UidGenerator;
-
-import org.apache.commons.lang3.time.DateFormatUtils;
-
-import java.io.File;
-import java.io.IOException;
-import java.util.logging.FileHandler;
-import java.util.logging.Handler;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-
-import javax.net.ssl.HostnameVerifier;
-
-import at.bitfire.cert4android.CustomCertManager;
-import at.bitfire.davdroid.log.LogcatHandler;
-import at.bitfire.davdroid.log.PlainTextFormatter;
-import at.bitfire.davdroid.model.ServiceDB;
-import at.bitfire.davdroid.model.Settings;
-import lombok.Cleanup;
-import lombok.Getter;
-import okhttp3.internal.tls.OkHostnameVerifier;
-
-public class App extends Application {
-    public static final String FLAVOR_GOOGLE_PLAY = "gplay";
-
-    public static final String
-            DISTRUST_SYSTEM_CERTIFICATES = "distrustSystemCerts",
-            LOG_TO_EXTERNAL_STORAGE = "logToExternalStorage",
-            OVERRIDE_PROXY = "overrideProxy",
-            OVERRIDE_PROXY_HOST = "overrideProxyHost",
-            OVERRIDE_PROXY_PORT = "overrideProxyPort";
-
-    public static final String OVERRIDE_PROXY_HOST_DEFAULT = "localhost";
-    public static final int OVERRIDE_PROXY_PORT_DEFAULT = 8118;
-
-    @Getter
-    private CustomCertManager certManager;
-
-    @Getter
-    private static SSLSocketFactoryCompat sslSocketFactoryCompat;
-
-    @Getter
-    private static HostnameVerifier hostnameVerifier;
-
-    @Getter
-    private static UidGenerator uidGenerator;
-
-    public final static Logger log = Logger.getLogger("davdroid");
-    static {
-        at.bitfire.dav4android.Constants.log = Logger.getLogger("davdroid.dav4android");
-        at.bitfire.cert4android.Constants.log = Logger.getLogger("davdroid.cert4android");
-    }
-
-    @Override
-    @SuppressLint("HardwareIds")
-    public void onCreate() {
-        super.onCreate();
-        reinitCertManager();
-        reinitLogger();
-
-        uidGenerator = new UidGenerator(null, android.provider.Settings.Secure.getString(getContentResolver(), android.provider.Settings.Secure.ANDROID_ID));
-    }
-
-    public void reinitCertManager() {
-        if (BuildConfig.customCerts) {
-            if (certManager != null)
-                certManager.close();
-
-            @Cleanup ServiceDB.OpenHelper dbHelper = new ServiceDB.OpenHelper(this);
-            Settings settings = new Settings(dbHelper.getReadableDatabase());
-
-            certManager = new CustomCertManager(this, !settings.getBoolean(DISTRUST_SYSTEM_CERTIFICATES, false));
-            sslSocketFactoryCompat = new SSLSocketFactoryCompat(certManager);
-            hostnameVerifier = certManager.hostnameVerifier(OkHostnameVerifier.INSTANCE);
-        }
-    }
-
-    public void reinitLogger() {
-        @Cleanup ServiceDB.OpenHelper dbHelper = new ServiceDB.OpenHelper(this);
-        Settings settings = new Settings(dbHelper.getReadableDatabase());
-
-        boolean logToFile = settings.getBoolean(LOG_TO_EXTERNAL_STORAGE, false),
-                logVerbose = logToFile || Log.isLoggable(log.getName(), Log.DEBUG);
-
-        App.log.info("Verbose logging: " + logVerbose);
-
-        // set logging level according to preferences
-        final Logger rootLogger = Logger.getLogger("");
-        rootLogger.setLevel(logVerbose ? Level.ALL : Level.INFO);
-
-        // remove all handlers and add our own logcat handler
-        rootLogger.setUseParentHandlers(false);
-        for (Handler handler : rootLogger.getHandlers())
-            rootLogger.removeHandler(handler);
-        rootLogger.addHandler(LogcatHandler.INSTANCE);
-
-        NotificationManagerCompat nm = NotificationManagerCompat.from(this);
-        // log to external file according to preferences
-        if (logToFile) {
-            NotificationCompat.Builder builder = new NotificationCompat.Builder(this);
-            builder .setSmallIcon(R.drawable.ic_sd_storage_light)
-                    .setLargeIcon(getLauncherBitmap(this))
-                    .setContentTitle(getString(R.string.logging_davdroid_file_logging))
-                    .setLocalOnly(true);
-
-            File dir = getExternalFilesDir(null);
-            if (dir != null)
-                try {
-                    String fileName = new File(dir, "davdroid-" + Process.myPid() + "-" +
-                            DateFormatUtils.format(System.currentTimeMillis(), "yyyyMMdd-HHmmss") + ".txt").toString();
-                    log.info("Logging to " + fileName);
-
-                    FileHandler fileHandler = new FileHandler(fileName);
-                    fileHandler.setFormatter(PlainTextFormatter.DEFAULT);
-                    log.addHandler(fileHandler);
-                    builder .setContentText(dir.getPath())
-                            .setSubText(getString(R.string.logging_to_external_storage_warning))
-                            .setCategory(NotificationCompat.CATEGORY_STATUS)
-                            .setPriority(NotificationCompat.PRIORITY_HIGH)
-                            .setStyle(new NotificationCompat.BigTextStyle()
-                                    .bigText(getString(R.string.logging_to_external_storage, dir.getPath())))
-                            .setOngoing(true);
-
-                } catch (IOException e) {
-                    log.log(Level.SEVERE, "Couldn't create external log file", e);
-
-                    builder .setContentText(getString(R.string.logging_couldnt_create_file, e.getLocalizedMessage()))
-                            .setCategory(NotificationCompat.CATEGORY_ERROR);
-                }
-            else
-                builder.setContentText(getString(R.string.logging_no_external_storage));
-
-            nm.notify(Constants.NOTIFICATION_EXTERNAL_FILE_LOGGING, builder.build());
-        } else
-            nm.cancel(Constants.NOTIFICATION_EXTERNAL_FILE_LOGGING);
-    }
-
-    @Nullable
-    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
-    public static Bitmap getLauncherBitmap(@NonNull Context context) {
-        Bitmap bitmapLogo = null;
-        Drawable drawableLogo = android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP ?
-                context.getDrawable(R.mipmap.ic_launcher) :
-                context.getResources().getDrawable(R.mipmap.ic_launcher);
-        if (drawableLogo instanceof BitmapDrawable)
-            bitmapLogo = ((BitmapDrawable)drawableLogo).getBitmap();
-        return bitmapLogo;
-    }
-
-
-    public static class ReinitLoggingReceiver extends BroadcastReceiver {
-
-        @Override
-        public void onReceive(Context context, Intent intent) {
-            log.info("Received broadcast: re-initializing logger");
-
-            App app = (App)context.getApplicationContext();
-            app.reinitLogger();
-        }
-
-    }
-}

app/src/main/java/at/bitfire/davdroid/App.kt

@@ -0,0 +1,56 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid
+
+import android.app.Application
+import android.content.Context
+import android.graphics.Bitmap
+import android.graphics.drawable.BitmapDrawable
+import android.os.Build
+import android.support.v7.app.AppCompatDelegate
+import at.bitfire.davdroid.log.Logger
+
+class App: Application() {
+
+    companion object {
+
+        @JvmField val DISTRUST_SYSTEM_CERTIFICATES = "distrust_system_certs"
+        @JvmField val OVERRIDE_PROXY = "override_proxy"
+        @JvmField val OVERRIDE_PROXY_HOST = "override_proxy_host"
+        @JvmField val OVERRIDE_PROXY_PORT = "override_proxy_port"
+
+        @JvmField val OVERRIDE_PROXY_HOST_DEFAULT = "localhost"
+        @JvmField val OVERRIDE_PROXY_PORT_DEFAULT = 8118
+
+
+        @JvmStatic
+        fun getLauncherBitmap(context: Context): Bitmap? {
+            val drawableLogo = if (android.os.Build.VERSION.SDK_INT >= 21)
+                    context.getDrawable(R.mipmap.ic_launcher)
+                else
+                    @Suppress("deprecation")
+                    context.resources.getDrawable(R.mipmap.ic_launcher)
+            return if (drawableLogo is BitmapDrawable)
+                drawableLogo.bitmap
+            else
+                null
+        }
+
+    }
+
+
+    override fun onCreate() {
+        super.onCreate()
+        Logger.initialize(this)
+
+        if (Build.VERSION.SDK_INT <= 21)
+            AppCompatDelegate.setCompatVectorFromResourcesEnabled(true)
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/ArrayUtils.java

@@ -1,33 +0,0 @@
-/*
- * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-package at.bitfire.davdroid;
-
-import java.lang.reflect.Array;
-
-public class ArrayUtils {
-
-	@SuppressWarnings("unchecked")
-	public static <T> T[][] partition(T[] bigArray, int max) {
-		int nItems = bigArray.length;
-		int nPartArrays = (nItems + max-1)/max;
-		
-		T[][] partArrays = (T[][])Array.newInstance(bigArray.getClass().getComponentType(), nPartArrays, 0); 
-		
-		// nItems is now the number of remaining items
-		for (int i = 0; nItems > 0; i++) {
-			int n = (nItems < max) ? nItems : max;
-			partArrays[i] = (T[])Array.newInstance(bigArray.getClass().getComponentType(), n); 
-			System.arraycopy(bigArray, i*max, partArrays[i], 0, n);
-			
-			nItems -= n;
-		}
-		
-		return partArrays;
-	}
-	
-}

app/src/main/java/at/bitfire/davdroid/Constants.java

@@ -1,30 +0,0 @@
-/*
- * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-package at.bitfire.davdroid;
-
-import android.net.Uri;
-
-public class Constants {
-
-	public static final String
-		ACCOUNT_TYPE = "bitfire.at.davdroid";
-
-    // notification IDs
-    public final static int
-            NOTIFICATION_EXTERNAL_FILE_LOGGING = 1,
-            NOTIFICATION_REFRESH_COLLECTIONS = 2,
-            NOTIFICATION_CONTACTS_SYNC = 10,
-            NOTIFICATION_CALENDAR_SYNC = 11,
-            NOTIFICATION_TASK_SYNC = 12,
-            NOTIFICATION_PERMISSIONS = 20;
-
-    public static final Uri webUri = Uri.parse("https://davdroid.bitfire.at/?pk_campaign=davdroid-app");
-
-    public static final int DEFAULT_SYNC_INTERVAL = 4 * 3600;  // 4 hours
-
-}

app/src/main/java/at/bitfire/davdroid/Constants.kt

@@ -0,0 +1,23 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+package at.bitfire.davdroid;
+
+object Constants {
+
+    // notification IDs
+    @JvmField val NOTIFICATION_EXTERNAL_FILE_LOGGING = 1
+    @JvmField val NOTIFICATION_REFRESH_COLLECTIONS = 2
+    @JvmField val NOTIFICATION_CONTACTS_SYNC = 10
+    @JvmField val NOTIFICATION_CALENDAR_SYNC = 11
+    @JvmField val NOTIFICATION_TASK_SYNC = 12
+    @JvmField val NOTIFICATION_PERMISSIONS = 20
+
+    @JvmField
+    val DEFAULT_SYNC_INTERVAL = 4 * 3600L    // 4 hours
+
+}

app/src/main/java/at/bitfire/davdroid/DavService.java

@@ -1,428 +0,0 @@
-/*
- * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid;
-
-import android.accounts.Account;
-import android.accounts.AccountManager;
-import android.annotation.SuppressLint;
-import android.app.Notification;
-import android.app.PendingIntent;
-import android.app.Service;
-import android.content.ContentValues;
-import android.content.Intent;
-import android.database.Cursor;
-import android.database.DatabaseUtils;
-import android.database.sqlite.SQLiteDatabase;
-import android.os.Binder;
-import android.os.IBinder;
-import android.support.annotation.NonNull;
-import android.support.annotation.Nullable;
-import android.support.v4.app.NotificationManagerCompat;
-import android.support.v7.app.NotificationCompat;
-import android.text.TextUtils;
-
-import org.apache.commons.collections4.iterators.IteratorChain;
-import org.apache.commons.collections4.iterators.SingletonIterator;
-
-import java.io.IOException;
-import java.lang.ref.WeakReference;
-import java.util.HashSet;
-import java.util.Iterator;
-import java.util.LinkedHashMap;
-import java.util.LinkedHashSet;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import java.util.logging.Level;
-
-import at.bitfire.dav4android.DavResource;
-import at.bitfire.dav4android.UrlUtils;
-import at.bitfire.dav4android.exception.DavException;
-import at.bitfire.dav4android.exception.HttpException;
-import at.bitfire.dav4android.property.AddressbookHomeSet;
-import at.bitfire.dav4android.property.CalendarHomeSet;
-import at.bitfire.dav4android.property.CalendarProxyReadFor;
-import at.bitfire.dav4android.property.CalendarProxyWriteFor;
-import at.bitfire.dav4android.property.GroupMembership;
-import at.bitfire.davdroid.model.CollectionInfo;
-import at.bitfire.davdroid.model.ServiceDB.Collections;
-import at.bitfire.davdroid.model.ServiceDB.HomeSets;
-import at.bitfire.davdroid.model.ServiceDB.OpenHelper;
-import at.bitfire.davdroid.model.ServiceDB.Services;
-import at.bitfire.davdroid.ui.DebugInfoActivity;
-import lombok.Cleanup;
-import okhttp3.HttpUrl;
-import okhttp3.OkHttpClient;
-
-public class DavService extends Service {
-
-    public static final String
-            ACTION_ACCOUNTS_UPDATED = "accountsUpdated",
-            ACTION_REFRESH_COLLECTIONS = "refreshCollections",
-            EXTRA_DAV_SERVICE_ID = "davServiceID";
-
-    private final IBinder binder = new InfoBinder();
-
-    private final Set<Long> runningRefresh = new HashSet<>();
-    private final List<WeakReference<RefreshingStatusListener>> refreshingStatusListeners = new LinkedList<>();
-
-
-    @Override
-    public int onStartCommand(Intent intent, int flags, int startId) {
-        if (intent != null) {
-            String action = intent.getAction();
-            long id = intent.getLongExtra(EXTRA_DAV_SERVICE_ID, -1);
-
-            switch (action) {
-                case ACTION_ACCOUNTS_UPDATED:
-                    cleanupAccounts();
-                    break;
-                case ACTION_REFRESH_COLLECTIONS:
-                    if (runningRefresh.add(id)) {
-                        new Thread(new RefreshCollections(id)).start();
-                        for (WeakReference<RefreshingStatusListener> ref : refreshingStatusListeners) {
-                            RefreshingStatusListener listener = ref.get();
-                            if (listener != null)
-                                listener.onDavRefreshStatusChanged(id, true);
-                        }
-                    }
-                    break;
-            }
-        }
-
-        return START_NOT_STICKY;
-    }
-
-
-    /* BOUND SERVICE PART
-       for communicating with the activities
-    */
-
-    @Override
-    public IBinder onBind(Intent intent) {
-        return binder;
-    }
-
-    public interface RefreshingStatusListener {
-        void onDavRefreshStatusChanged(long id, boolean refreshing);
-    }
-
-    public class InfoBinder extends Binder {
-        public boolean isRefreshing(long id) {
-            return runningRefresh.contains(id);
-        }
-
-        public void addRefreshingStatusListener(@NonNull RefreshingStatusListener listener, boolean callImmediate) {
-            refreshingStatusListeners.add(new WeakReference<>(listener));
-            if (callImmediate)
-                for (long id : runningRefresh)
-                    listener.onDavRefreshStatusChanged(id, true);
-        }
-
-        public void removeRefreshingStatusListener(@NonNull RefreshingStatusListener listener) {
-            for (Iterator<WeakReference<RefreshingStatusListener>> iterator = refreshingStatusListeners.iterator(); iterator.hasNext(); ) {
-                RefreshingStatusListener item = iterator.next().get();
-                if (listener.equals(item))
-                    iterator.remove();
-            }
-        }
-    }
-
-
-    /* ACTION RUNNABLES
-       which actually do the work
-     */
-
-    @SuppressLint("MissingPermission")
-    void cleanupAccounts() {
-        App.log.info("Cleaning up orphaned accounts");
-
-        final OpenHelper dbHelper = new OpenHelper(this);
-        try {
-            SQLiteDatabase db = dbHelper.getWritableDatabase();
-
-            List<String> sqlAccountNames = new LinkedList<>();
-            AccountManager am = AccountManager.get(this);
-            for (Account account : am.getAccountsByType(Constants.ACCOUNT_TYPE))
-                sqlAccountNames.add(DatabaseUtils.sqlEscapeString(account.name));
-
-            if (sqlAccountNames.isEmpty())
-                db.delete(Services._TABLE, null, null);
-            else
-                db.delete(Services._TABLE, Services.ACCOUNT_NAME + " NOT IN (" + TextUtils.join(",", sqlAccountNames) + ")", null);
-        } finally {
-            dbHelper.close();
-        }
-    }
-
-    private class RefreshCollections implements Runnable {
-        final long service;
-        final OpenHelper dbHelper;
-        SQLiteDatabase db;
-
-        RefreshCollections(long davServiceId) {
-            this.service = davServiceId;
-            dbHelper = new OpenHelper(DavService.this);
-        }
-
-        @Override
-        public void run() {
-            Account account = null;
-
-            try {
-                db = dbHelper.getWritableDatabase();
-
-                String serviceType = serviceType();
-                App.log.info("Refreshing " + serviceType + " collections of service #" + service);
-
-                // get account
-                account = account();
-
-                // create authenticating OkHttpClient (credentials taken from account settings)
-                OkHttpClient httpClient = HttpClient.create(DavService.this, account);
-
-                // refresh home sets: principal
-                Set<HttpUrl> homeSets = readHomeSets();
-                HttpUrl principal = readPrincipal();
-                if (principal != null) {
-                    App.log.fine("Querying principal for home sets");
-                    DavResource dav = new DavResource(httpClient, principal);
-                    queryHomeSets(serviceType, dav, homeSets);
-
-                    // refresh home sets: calendar-proxy-read/write-for
-                    CalendarProxyReadFor proxyRead = (CalendarProxyReadFor)dav.properties.get(CalendarProxyReadFor.NAME);
-                    if (proxyRead != null)
-                        for (String href : proxyRead.principals) {
-                            App.log.fine("Principal is a read-only proxy for " + href + ", checking for home sets");
-                            queryHomeSets(serviceType, new DavResource(httpClient, dav.location.resolve(href)), homeSets);
-                        }
-                    CalendarProxyWriteFor proxyWrite = (CalendarProxyWriteFor)dav.properties.get(CalendarProxyWriteFor.NAME);
-                    if (proxyWrite != null)
-                        for (String href : proxyWrite.principals) {
-                            App.log.fine("Principal is a read-write proxy for " + href + ", checking for home sets");
-                            queryHomeSets(serviceType, new DavResource(httpClient, dav.location.resolve(href)), homeSets);
-                        }
-
-                    // refresh home sets: direct group memberships
-                    GroupMembership groupMembership = (GroupMembership)dav.properties.get(GroupMembership.NAME);
-                    if (groupMembership != null)
-                        for (String href : groupMembership.hrefs) {
-                            App.log.fine("Principal is member of group " + href + ", checking for home sets");
-                            DavResource group = new DavResource(httpClient, dav.location.resolve(href));
-                            try {
-                                queryHomeSets(serviceType, group, homeSets);
-                            } catch(HttpException|DavException e) {
-                                App.log.log(Level.WARNING, "Couldn't query member group ", e);
-                            }
-                        }
-                }
-
-                // now refresh collections (taken from home sets)
-                Map<HttpUrl, CollectionInfo> collections = readCollections();
-
-                // (remember selections before)
-                Set<HttpUrl> selectedCollections = new HashSet<>();
-                for (CollectionInfo info : collections.values())
-                    if (info.selected)
-                        selectedCollections.add(HttpUrl.parse(info.url));
-
-                for (Iterator<HttpUrl> itHomeSets = homeSets.iterator(); itHomeSets.hasNext(); ) {
-                    HttpUrl homeSet = itHomeSets.next();
-                    App.log.fine("Listing home set " + homeSet);
-
-                    DavResource dav = new DavResource(httpClient, homeSet);
-                    try {
-                        dav.propfind(1, CollectionInfo.DAV_PROPERTIES);
-                        IteratorChain<DavResource> itCollections = new IteratorChain<>(dav.members.iterator(), new SingletonIterator(dav));
-                        while (itCollections.hasNext()) {
-                            DavResource member = itCollections.next();
-                            CollectionInfo info = CollectionInfo.fromDavResource(member);
-                            info.confirmed = true;
-                            App.log.log(Level.FINE, "Found collection", info);
-
-                            if ((serviceType.equals(Services.SERVICE_CARDDAV) && info.type == CollectionInfo.Type.ADDRESS_BOOK) ||
-                                (serviceType.equals(Services.SERVICE_CALDAV) && info.type == CollectionInfo.Type.CALENDAR))
-                                collections.put(member.location, info);
-                        }
-                    } catch(HttpException e) {
-                        if (e.status == 403 || e.status == 404 || e.status == 410)
-                            // delete home set only if it was not accessible (40x)
-                            itHomeSets.remove();
-                    }
-                }
-
-                // check/refresh unconfirmed collections
-                for (Iterator<Map.Entry<HttpUrl, CollectionInfo>> iterator = collections.entrySet().iterator(); iterator.hasNext(); ) {
-                    Map.Entry<HttpUrl, CollectionInfo> entry = iterator.next();
-                    HttpUrl url = entry.getKey();
-                    CollectionInfo info = entry.getValue();
-
-                    if (!info.confirmed)
-                        try {
-                            DavResource dav = new DavResource(httpClient, url);
-                            dav.propfind(0, CollectionInfo.DAV_PROPERTIES);
-                            info = CollectionInfo.fromDavResource(dav);
-                            info.confirmed = true;
-
-                            // remove unusable collections
-                            if ((serviceType.equals(Services.SERVICE_CARDDAV) && info.type != CollectionInfo.Type.ADDRESS_BOOK) ||
-                                (serviceType.equals(Services.SERVICE_CALDAV) && info.type != CollectionInfo.Type.CALENDAR))
-                                iterator.remove();
-                        } catch(HttpException e) {
-                            if (e.status == 403 || e.status == 404 || e.status == 410)
-                                // delete collection only if it was not accessible (40x)
-                                iterator.remove();
-                            else
-                                throw e;
-                        }
-                }
-
-                // restore selections
-                for (HttpUrl url : selectedCollections) {
-                    CollectionInfo info = collections.get(url);
-                    if (info != null)
-                        info.selected = true;
-                }
-
-                db.beginTransactionNonExclusive();
-                try {
-                    saveHomeSets(homeSets);
-                    saveCollections(collections.values());
-                    db.setTransactionSuccessful();
-                } finally {
-                    db.endTransaction();
-                }
-
-            } catch(InvalidAccountException e) {
-                App.log.log(Level.SEVERE, "Invalid account", e);
-            } catch(IOException|HttpException|DavException e) {
-                App.log.log(Level.SEVERE, "Couldn't refresh collection list", e);
-
-                Intent debugIntent = new Intent(DavService.this, DebugInfoActivity.class);
-                debugIntent.putExtra(DebugInfoActivity.KEY_THROWABLE, e);
-                if (account != null)
-                    debugIntent.putExtra(DebugInfoActivity.KEY_ACCOUNT, account);
-
-                NotificationManagerCompat nm = NotificationManagerCompat.from(DavService.this);
-                Notification notify = new NotificationCompat.Builder(DavService.this)
-                        .setSmallIcon(R.drawable.ic_error_light)
-                        .setLargeIcon(App.getLauncherBitmap(DavService.this))
-                        .setContentTitle(getString(R.string.dav_service_refresh_failed))
-                        .setContentText(getString(R.string.dav_service_refresh_couldnt_refresh))
-                        .setContentIntent(PendingIntent.getActivity(DavService.this, 0, debugIntent, PendingIntent.FLAG_UPDATE_CURRENT))
-                        .build();
-                nm.notify(Constants.NOTIFICATION_REFRESH_COLLECTIONS, notify);
-            } finally {
-                dbHelper.close();
-
-                runningRefresh.remove(service);
-                for (WeakReference<RefreshingStatusListener> ref : refreshingStatusListeners) {
-                    RefreshingStatusListener listener = ref.get();
-                    if (listener != null)
-                        listener.onDavRefreshStatusChanged(service, false);
-                }
-            }
-        }
-
-        /**
-         * Checks if the given URL defines home sets and adds them to the home set list.
-         * @param serviceType       CalDAV/CardDAV (calendar home set / addressbook home set)
-         * @param dav               DavResource to check
-         * @param homeSets          set where found home set URLs will be put into
-         */
-        private void queryHomeSets(String serviceType, DavResource dav, Set<HttpUrl> homeSets) throws IOException, HttpException, DavException {
-            if (Services.SERVICE_CARDDAV.equals(serviceType)) {
-                dav.propfind(0, AddressbookHomeSet.NAME, GroupMembership.NAME);
-                AddressbookHomeSet addressbookHomeSet = (AddressbookHomeSet)dav.properties.get(AddressbookHomeSet.NAME);
-                if (addressbookHomeSet != null)
-                    for (String href : addressbookHomeSet.hrefs)
-                        homeSets.add(UrlUtils.withTrailingSlash(dav.location.resolve(href)));
-            } else if (Services.SERVICE_CALDAV.equals(serviceType)) {
-                dav.propfind(0, CalendarHomeSet.NAME, CalendarProxyReadFor.NAME, CalendarProxyWriteFor.NAME, GroupMembership.NAME);
-                CalendarHomeSet calendarHomeSet = (CalendarHomeSet)dav.properties.get(CalendarHomeSet.NAME);
-                if (calendarHomeSet != null)
-                    for (String href : calendarHomeSet.hrefs)
-                        homeSets.add(UrlUtils.withTrailingSlash(dav.location.resolve(href)));
-            }
-        }
-
-
-        @NonNull
-        private Account account() {
-            @Cleanup Cursor cursor = db.query(Services._TABLE, new String[] { Services.ACCOUNT_NAME }, Services.ID + "=?", new String[] { String.valueOf(service) }, null, null, null);
-            if (cursor.moveToNext()) {
-                return new Account(cursor.getString(0), Constants.ACCOUNT_TYPE);
-            } else
-                throw new IllegalArgumentException("Service not found");
-        }
-
-        @NonNull
-        private String serviceType() {
-            @Cleanup Cursor cursor = db.query(Services._TABLE, new String[] { Services.SERVICE }, Services.ID + "=?", new String[] { String.valueOf(service) }, null, null, null);
-            if (cursor.moveToNext())
-                return cursor.getString(0);
-            else
-                throw new IllegalArgumentException("Service not found");
-        }
-
-        @Nullable
-        private HttpUrl readPrincipal() {
-            @Cleanup Cursor cursor = db.query(Services._TABLE, new String[] { Services.PRINCIPAL }, Services.ID + "=?", new String[] { String.valueOf(service) }, null, null, null);
-            if (cursor.moveToNext()) {
-                String principal = cursor.getString(0);
-                if (principal != null)
-                    return HttpUrl.parse(cursor.getString(0));
-            }
-            return null;
-        }
-
-        @NonNull
-        private Set<HttpUrl> readHomeSets() {
-            Set<HttpUrl> homeSets = new LinkedHashSet<>();
-            @Cleanup Cursor cursor = db.query(HomeSets._TABLE, new String[] { HomeSets.URL }, HomeSets.SERVICE_ID + "=?", new String[] { String.valueOf(service) }, null, null, null);
-            while (cursor.moveToNext())
-                homeSets.add(HttpUrl.parse(cursor.getString(0)));
-            return homeSets;
-        }
-
-        private void saveHomeSets(Set<HttpUrl> homeSets) {
-            db.delete(HomeSets._TABLE, HomeSets.SERVICE_ID + "=?", new String[] { String.valueOf(service) });
-            for (HttpUrl homeSet : homeSets) {
-                ContentValues values = new ContentValues(1);
-                values.put(HomeSets.SERVICE_ID, service);
-                values.put(HomeSets.URL, homeSet.toString());
-                db.insertOrThrow(HomeSets._TABLE, null, values);
-            }
-        }
-
-        @NonNull
-        private Map<HttpUrl, CollectionInfo> readCollections() {
-            Map<HttpUrl, CollectionInfo> collections = new LinkedHashMap<>();
-            @Cleanup Cursor cursor = db.query(Collections._TABLE, null, Collections.SERVICE_ID + "=?", new String[]{String.valueOf(service)}, null, null, null);
-            while (cursor.moveToNext()) {
-                ContentValues values = new ContentValues();
-                DatabaseUtils.cursorRowToContentValues(cursor, values);
-                collections.put(HttpUrl.parse(values.getAsString(Collections.URL)), CollectionInfo.fromDB(values));
-            }
-            return collections;
-        }
-
-        private void saveCollections(Iterable<CollectionInfo> collections) {
-            db.delete(Collections._TABLE, HomeSets.SERVICE_ID + "=?", new String[] { String.valueOf(service) });
-            for (CollectionInfo collection : collections) {
-                ContentValues values = collection.toDB();
-                App.log.log(Level.FINE, "Saving collection", values);
-                values.put(Collections.SERVICE_ID, service);
-                db.insertWithOnConflict(Collections._TABLE, null, values, SQLiteDatabase.CONFLICT_REPLACE);
-            }
-        }
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/DavService.kt

@@ -0,0 +1,382 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid
+
+import android.accounts.Account
+import android.accounts.AccountManager
+import android.annotation.SuppressLint
+import android.app.PendingIntent
+import android.app.Service
+import android.content.ContentValues
+import android.content.Intent
+import android.database.DatabaseUtils
+import android.database.sqlite.SQLiteDatabase
+import android.os.Binder
+import android.support.v4.app.NotificationManagerCompat
+import android.support.v7.app.NotificationCompat
+import at.bitfire.dav4android.DavResource
+import at.bitfire.dav4android.UrlUtils
+import at.bitfire.dav4android.exception.DavException
+import at.bitfire.dav4android.exception.HttpException
+import at.bitfire.dav4android.property.*
+import at.bitfire.davdroid.log.Logger
+import at.bitfire.davdroid.model.CollectionInfo
+import at.bitfire.davdroid.model.ServiceDB.*
+import at.bitfire.davdroid.model.ServiceDB.Collections
+import at.bitfire.davdroid.resource.LocalAddressBook
+import at.bitfire.davdroid.ui.DebugInfoActivity
+import at.bitfire.vcard4android.ContactsStorageException
+import okhttp3.HttpUrl
+import org.apache.commons.collections4.iterators.IteratorChain
+import org.apache.commons.collections4.iterators.SingletonIterator
+import java.io.IOException
+import java.lang.ref.WeakReference
+import java.util.*
+import java.util.logging.Level
+import kotlin.concurrent.thread
+
+class DavService: Service() {
+
+    companion object {
+        @JvmField val ACTION_ACCOUNTS_UPDATED = "accountsUpdated"
+        @JvmField val ACTION_REFRESH_COLLECTIONS = "refreshCollections"
+        @JvmField val EXTRA_DAV_SERVICE_ID = "davServiceID"
+    }
+
+    private val runningRefresh = HashSet<Long>()
+    private val refreshingStatusListeners = LinkedList<WeakReference<RefreshingStatusListener>>()
+
+
+    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
+        intent?.let {
+            val id = intent.getLongExtra(EXTRA_DAV_SERVICE_ID, -1)
+
+            when (intent.action) {
+                ACTION_ACCOUNTS_UPDATED ->
+                    cleanupAccounts()
+                ACTION_REFRESH_COLLECTIONS ->
+                    if (runningRefresh.add(id)) {
+                        thread { refreshCollections(id) }
+                        refreshingStatusListeners.forEach { it.get()?.onDavRefreshStatusChanged(id, true) }
+                    }
+            }
+        }
+
+        return START_NOT_STICKY
+    }
+
+
+    /* BOUND SERVICE PART
+       for communicating with the activities
+    */
+
+    interface RefreshingStatusListener {
+        fun onDavRefreshStatusChanged(id: Long, refreshing: Boolean)
+    }
+
+    private val binder = InfoBinder()
+
+    inner class InfoBinder: Binder() {
+        fun isRefreshing(id: Long) = runningRefresh.contains(id)
+
+        fun addRefreshingStatusListener(listener: RefreshingStatusListener, callImmediate: Boolean) {
+            refreshingStatusListeners += WeakReference<RefreshingStatusListener>(listener)
+            if (callImmediate)
+                runningRefresh.forEach { id -> listener.onDavRefreshStatusChanged(id, true) }
+        }
+
+        fun removeRefreshingStatusListener(listener: RefreshingStatusListener) {
+            val iter = refreshingStatusListeners.iterator()
+            while (iter.hasNext()) {
+                val item = iter.next().get()
+                if (listener == item)
+                    iter.remove()
+            }
+        }
+    }
+
+    override fun onBind(intent: Intent?) = binder
+
+
+
+    /* ACTION RUNNABLES
+       which actually do the work
+     */
+
+    @SuppressLint("MissingPermission")
+    fun cleanupAccounts() {
+        Logger.log.info("Cleaning up orphaned accounts")
+
+        OpenHelper(this).use { dbHelper ->
+            val db = dbHelper.writableDatabase
+
+            val sqlAccountNames = LinkedList<String>()
+            val accountNames = HashSet<String>()
+            val accountManager = AccountManager.get(this)
+            for (account in accountManager.getAccountsByType(getString(R.string.account_type))) {
+                sqlAccountNames.add(DatabaseUtils.sqlEscapeString(account.name))
+                accountNames += account.name
+            }
+
+            // delete orphaned address book accounts
+            accountManager.getAccountsByType(getString(R.string.account_type_address_book))
+                    .map { LocalAddressBook(this, it, null) }
+                    .forEach {
+                        try {
+                            if (!accountNames.contains(it.getMainAccount().name))
+                                it.delete()
+                        } catch(e: ContactsStorageException) {
+                            Logger.log.log(Level.SEVERE, "Couldn't get address book main account", e)
+                        }
+                    }
+
+            // delete orphaned services in DB
+            if (sqlAccountNames.isEmpty())
+                db.delete(Services._TABLE, null, null)
+            else
+                db.delete(Services._TABLE, "${Services.ACCOUNT_NAME} NOT IN (${sqlAccountNames.joinToString(",")})", null)
+        }
+    }
+
+    fun refreshCollections(service: Long) {
+        OpenHelper(this@DavService).use { dbHelper ->
+            val db = dbHelper.writableDatabase
+
+            val serviceType by lazy {
+                db.query(Services._TABLE, arrayOf(Services.SERVICE), "${Services.ID}=?", arrayOf(service.toString()), null, null, null)?.use { cursor ->
+                    if (cursor.moveToNext())
+                        return@lazy cursor.getString(0)
+                } ?: throw IllegalArgumentException("Service not found")
+            }
+
+            val account by lazy {
+                db.query(Services._TABLE, arrayOf(Services.ACCOUNT_NAME), "${Services.ID}=?", arrayOf(service.toString()), null, null, null)?.use { cursor ->
+                    if (cursor.moveToNext())
+                        return@lazy Account(cursor.getString(0), getString(R.string.account_type))
+                }
+                throw IllegalArgumentException("Account not found")
+            }
+
+            val homeSets by lazy {
+                val homeSets = mutableSetOf<HttpUrl>()
+                db.query(HomeSets._TABLE, arrayOf(HomeSets.URL), "${HomeSets.SERVICE_ID}=?", arrayOf(service.toString()), null, null, null)?.use { cursor ->
+                    while (cursor.moveToNext())
+                        HttpUrl.parse(cursor.getString(0))?.let { homeSets += it }
+                }
+                homeSets
+            }
+
+            val collections by lazy {
+                val collections = mutableMapOf<HttpUrl, CollectionInfo>()
+                db.query(Collections._TABLE, null, "${Collections.SERVICE_ID}=?", arrayOf(service.toString()), null, null, null)?.use { cursor ->
+                    while (cursor.moveToNext()) {
+                        val values = ContentValues()
+                        DatabaseUtils.cursorRowToContentValues(cursor, values)
+                        values.getAsString(Collections.URL)?.let { url ->
+                            HttpUrl.parse(url)?.let { collections.put(it, CollectionInfo(values)) }
+                        }
+                    }
+                }
+                collections
+            }
+
+            fun readPrincipal(): HttpUrl? {
+                db.query(Services._TABLE, arrayOf(Services.PRINCIPAL), "${Services.ID}=?", arrayOf(service.toString()), null, null, null)?.use { cursor ->
+                    if (cursor.moveToNext())
+                        cursor.getString(0)?.let { return HttpUrl.parse(it) }
+                }
+                return null
+            }
+
+            /**
+             * Checks if the given URL defines home sets and adds them to the home set list.
+             * @param dav               DavResource to check
+             */
+            @Throws(IOException::class, HttpException::class, DavException::class)
+            fun queryHomeSets(dav: DavResource) {
+                when (serviceType) {
+                    Services.SERVICE_CARDDAV -> {
+                        dav.propfind(0, AddressbookHomeSet.NAME, GroupMembership.NAME)
+                        for ((resource, addressbookHomeSet) in dav.findProperties(AddressbookHomeSet.NAME) as List<Pair<DavResource, AddressbookHomeSet>>)
+                            for (href in addressbookHomeSet.hrefs)
+                                resource.location.resolve(href)?.let { homeSets += UrlUtils.withTrailingSlash(it) }
+                    }
+                    Services.SERVICE_CALDAV -> {
+                        dav.propfind(0, CalendarHomeSet.NAME, CalendarProxyReadFor.NAME, CalendarProxyWriteFor.NAME, GroupMembership.NAME)
+                        for ((resource, calendarHomeSet) in dav.findProperties(CalendarHomeSet.NAME) as List<Pair<DavResource, CalendarHomeSet>>)
+                            for (href in calendarHomeSet.hrefs)
+                                resource.location.resolve(href)?.let { homeSets.add(UrlUtils.withTrailingSlash(it)) }
+                    }
+                }
+            }
+
+            fun saveHomeSets() {
+                db.delete(HomeSets._TABLE, "${HomeSets.SERVICE_ID}=?", arrayOf(service.toString()))
+                for (homeSet in homeSets) {
+                    val values = ContentValues(2)
+                    values.put(HomeSets.SERVICE_ID, service)
+                    values.put(HomeSets.URL, homeSet.toString())
+                    db.insertOrThrow(HomeSets._TABLE, null, values)
+                }
+            }
+
+            fun saveCollections() {
+                db.delete(Collections._TABLE, "${HomeSets.SERVICE_ID}=?", arrayOf(service.toString()))
+                for ((_,collection) in collections) {
+                    val values = collection.toDB()
+                    Logger.log.log(Level.FINE, "Saving collection", values)
+                    values.put(Collections.SERVICE_ID, service)
+                    db.insertWithOnConflict(Collections._TABLE, null, values, SQLiteDatabase.CONFLICT_REPLACE)
+                }
+            }
+
+
+            try {
+                Logger.log.info("Refreshing $serviceType collections of service #$service")
+
+                // create authenticating OkHttpClient (credentials taken from account settings)
+                HttpClient.Builder(this@DavService, account)
+                        .setForeground(true)
+                        .build().use { client ->
+                    val httpClient = client.okHttpClient
+
+                    // refresh home set list (from principal)
+                    readPrincipal()?.let { principalUrl ->
+                        Logger.log.fine("Querying principal $principalUrl for home sets")
+                        val principal = DavResource(httpClient, principalUrl)
+                        queryHomeSets(principal)
+
+                        // refresh home sets: calendar-proxy-read/write-for
+                        for ((resource, proxyRead) in principal.findProperties(CalendarProxyReadFor.NAME) as List<Pair<DavResource, CalendarProxyReadFor>>)
+                            for (href in proxyRead.hrefs) {
+                                Logger.log.fine("Principal is a read-only proxy for $href, checking for home sets")
+                                resource.location.resolve(href)?.let { queryHomeSets(DavResource(httpClient, it)) }
+                            }
+                        for ((resource, proxyWrite) in principal.findProperties(CalendarProxyWriteFor.NAME) as List<Pair<DavResource, CalendarProxyWriteFor>>)
+                            for (href in proxyWrite.hrefs) {
+                                Logger.log.fine("Principal is a read/write proxy for $href, checking for home sets")
+                                resource.location.resolve(href)?.let { queryHomeSets(DavResource(httpClient, it)) }
+                            }
+
+                        // refresh home sets: direct group memberships
+                        (principal.properties[GroupMembership.NAME] as GroupMembership?)?.let { groupMembership ->
+                            for (href in groupMembership.hrefs) {
+                                Logger.log.fine("Principal is member of group $href, checking for home sets")
+                                principal.location.resolve(href)?.let { url ->
+                                    try {
+                                        queryHomeSets(DavResource(httpClient, url))
+                                    } catch(e: HttpException) {
+                                        Logger.log.log(Level.WARNING, "Couldn't query member group", e)
+                                    } catch(e: DavException) {
+                                        Logger.log.log(Level.WARNING, "Couldn't query member group", e)
+                                    }
+                                }
+                            }
+                        }
+                    }
+
+                    // remember selected collections
+                    val selectedCollections = HashSet<HttpUrl>()
+                    collections.values
+                            .filter { it.selected }
+                            .forEach { (url,_) -> HttpUrl.parse(url)?.let { selectedCollections.add(it) } }
+
+                    // now refresh collections (taken from home sets)
+                    val itHomeSets = homeSets.iterator()
+                    while (itHomeSets.hasNext()) {
+                        val homeSetUrl = itHomeSets.next()
+                        Logger.log.fine("Listing home set $homeSetUrl")
+
+                        val homeSet = DavResource(httpClient, homeSetUrl)
+                        try {
+                            homeSet.propfind(1, *CollectionInfo.DAV_PROPERTIES)
+                            val itCollections = IteratorChain<DavResource>(homeSet.members.iterator(), homeSet.related.iterator(), SingletonIterator(homeSet))
+                            while (itCollections.hasNext()) {
+                                val member = itCollections.next()
+                                val info = CollectionInfo(member)
+                                info.confirmed = true
+                                Logger.log.log(Level.FINE, "Found collection", info)
+
+                                if ((serviceType == Services.SERVICE_CARDDAV && info.type == CollectionInfo.Type.ADDRESS_BOOK) ||
+                                    (serviceType == Services.SERVICE_CALDAV && arrayOf(CollectionInfo.Type.CALENDAR, CollectionInfo.Type.WEBCAL).contains(info.type)))
+                                    collections[member.location] = info
+                            }
+                        } catch(e: HttpException) {
+                            if (e.status in arrayOf(403, 404, 410))
+                                // delete home set only if it was not accessible (40x)
+                                itHomeSets.remove()
+                        }
+                    }
+
+                    // check/refresh unconfirmed collections
+                    val itCollections = collections.entries.iterator()
+                    while (itCollections.hasNext()) {
+                        val (url, info) = itCollections.next()
+                        if (!info.confirmed)
+                            try {
+                                val collection = DavResource(httpClient, url)
+                                collection.propfind(0, *CollectionInfo.DAV_PROPERTIES)
+                                val info = CollectionInfo(collection)
+                                info.confirmed = true
+
+                                // remove unusable collections
+                                if ((serviceType == Services.SERVICE_CARDDAV && info.type != CollectionInfo.Type.ADDRESS_BOOK) ||
+                                    (serviceType == Services.SERVICE_CALDAV && !arrayOf(CollectionInfo.Type.CALENDAR, CollectionInfo.Type.WEBCAL).contains(info.type)) ||
+                                    (info.type == CollectionInfo.Type.WEBCAL && info.source == null))
+                                    itCollections.remove()
+                            } catch(e: HttpException) {
+                                if (e.status in arrayOf(403, 404, 410))
+                                    // delete collection only if it was not accessible (40x)
+                                    itCollections.remove()
+                                else
+                                    throw e
+                            }
+                    }
+
+                    // restore selections
+                    for (url in selectedCollections)
+                        collections[url]?.let { it.selected = true }
+                }
+
+                db.beginTransactionNonExclusive()
+                try {
+                    saveHomeSets()
+                    saveCollections()
+                    db.setTransactionSuccessful()
+                } finally {
+                    db.endTransaction()
+                }
+
+            } catch(e: InvalidAccountException) {
+                Logger.log.log(Level.SEVERE, "Invalid account", e)
+            } catch(e: Exception) {
+                Logger.log.log(Level.SEVERE, "Couldn't refresh collection list", e)
+
+                val debugIntent = Intent(this@DavService, DebugInfoActivity::class.java)
+                debugIntent.putExtra(DebugInfoActivity.KEY_THROWABLE, e)
+                debugIntent.putExtra(DebugInfoActivity.KEY_ACCOUNT, account)
+
+                val nm = NotificationManagerCompat.from(this@DavService)
+                val notify = NotificationCompat.Builder(this@DavService)
+                        .setSmallIcon(R.drawable.ic_error_light)
+                        .setLargeIcon(App.getLauncherBitmap(this@DavService))
+                        .setContentTitle(getString(R.string.dav_service_refresh_failed))
+                        .setContentText(getString(R.string.dav_service_refresh_couldnt_refresh))
+                        .setContentIntent(PendingIntent.getActivity(this@DavService, 0, debugIntent, PendingIntent.FLAG_UPDATE_CURRENT))
+                        .build()
+                nm.notify(Constants.NOTIFICATION_REFRESH_COLLECTIONS, notify)
+            } finally {
+                runningRefresh.remove(service)
+                refreshingStatusListeners.forEach { it.get()?.onDavRefreshStatusChanged(service, false) }
+            }
+        }
+
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/DavUtils.java

@@ -1,41 +0,0 @@
-/*
- * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid;
-
-import android.support.annotation.NonNull;
-
-import org.apache.commons.lang3.StringUtils;
-
-import java.util.Collections;
-import java.util.LinkedList;
-import java.util.List;
-
-import okhttp3.HttpUrl;
-
-public class DavUtils {
-
-    public static String ARGBtoCalDAVColor(int colorWithAlpha) {
-        byte alpha = (byte)(colorWithAlpha >> 24);
-        int color = colorWithAlpha & 0xFFFFFF;
-        return String.format("#%06X%02X", color, alpha);
-    }
-
-    public static String lastSegmentOfUrl(@NonNull String url) {
-        // the list returned by HttpUrl.pathSegments() is unmodifiable, so we have to create a copy
-        List<String> segments = new LinkedList<>(HttpUrl.parse(url).pathSegments());
-        Collections.reverse(segments);
-
-        for (String segment : segments)
-            if (!StringUtils.isEmpty(segment))
-                return segment;
-
-        return "/";
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/DavUtils.kt

@@ -0,0 +1,38 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid;
+
+import okhttp3.HttpUrl
+import java.util.*
+
+object DavUtils {
+
+    @JvmStatic
+    fun ARGBtoCalDAVColor(colorWithAlpha: Int): String {
+        val alpha = (colorWithAlpha shr 24) and 0xFF
+        val color = colorWithAlpha and 0xFFFFFF
+        return String.format("#%06X%02X", color, alpha)
+    }
+
+    @JvmStatic
+    fun lastSegmentOfUrl(url: String): String {
+        val httpUrl = HttpUrl.parse(url) ?: throw IllegalArgumentException("url not parsable")
+
+        // the list returned by HttpUrl.pathSegments() is unmodifiable, so we have to create a copy
+        val segments = LinkedList<String>(httpUrl.pathSegments())
+        Collections.reverse(segments)
+
+        for (segment in segments)
+            if (segment.isNotEmpty())
+                return segment
+
+        return "/"
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/HttpClient.java

@@ -1,169 +0,0 @@
-/*
- * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid;
-
-import android.accounts.Account;
-import android.content.Context;
-import android.database.sqlite.SQLiteOpenHelper;
-import android.os.Build;
-import android.support.annotation.NonNull;
-import android.support.annotation.Nullable;
-
-import java.io.IOException;
-import java.net.InetSocketAddress;
-import java.net.Proxy;
-import java.text.SimpleDateFormat;
-import java.util.Date;
-import java.util.Locale;
-import java.util.concurrent.TimeUnit;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-
-import at.bitfire.dav4android.BasicDigestAuthHandler;
-import at.bitfire.dav4android.UrlUtils;
-import at.bitfire.davdroid.model.ServiceDB;
-import at.bitfire.davdroid.model.Settings;
-import okhttp3.Interceptor;
-import okhttp3.OkHttpClient;
-import okhttp3.Request;
-import okhttp3.Response;
-import okhttp3.logging.HttpLoggingInterceptor;
-
-public class HttpClient {
-    private static final OkHttpClient client = new OkHttpClient();
-    private static final UserAgentInterceptor userAgentInterceptor = new UserAgentInterceptor();
-
-    private static final String userAgent;
-    static {
-        String date = new SimpleDateFormat("yyyy/MM/dd", Locale.US).format(new Date(BuildConfig.buildTime));
-        userAgent = "DAVdroid/" + BuildConfig.VERSION_NAME + " (" + date + "; dav4android; okhttp3) Android/" + Build.VERSION.RELEASE;
-    }
-
-    private HttpClient() {
-    }
-
-    public static OkHttpClient create(@Nullable Context context, @NonNull Account account, @NonNull final Logger logger) throws InvalidAccountException {
-        OkHttpClient.Builder builder = defaultBuilder(context, logger);
-
-        // use account settings for authentication
-        AccountSettings settings = new AccountSettings(context, account);
-        builder = addAuthentication(builder, null, settings.username(), settings.password());
-
-        return builder.build();
-    }
-
-    public static OkHttpClient create(@NonNull Context context, @NonNull Logger logger) {
-        return defaultBuilder(context, logger).build();
-    }
-
-    public static OkHttpClient create(@NonNull Context context, @NonNull Account account) throws InvalidAccountException {
-        return create(context, account, App.log);
-    }
-
-    public static OkHttpClient create(@Nullable Context context) {
-        return create(context, App.log);
-    }
-
-
-    private static OkHttpClient.Builder defaultBuilder(@Nullable Context context, @NonNull final Logger logger) {
-        OkHttpClient.Builder builder = client.newBuilder();
-
-        // use MemorizingTrustManager to manage self-signed certificates
-        if (context != null) {
-            App app = (App)context.getApplicationContext();
-            if (App.getSslSocketFactoryCompat() != null && app.getCertManager() != null)
-                builder.sslSocketFactory(App.getSslSocketFactoryCompat(), app.getCertManager());
-            if (App.getHostnameVerifier() != null)
-                builder.hostnameVerifier(App.getHostnameVerifier());
-        }
-
-        // set timeouts
-        builder.connectTimeout(30, TimeUnit.SECONDS);
-        builder.writeTimeout(30, TimeUnit.SECONDS);
-        builder.readTimeout(120, TimeUnit.SECONDS);
-
-        // don't allow redirects, because it would break PROPFIND handling
-        builder.followRedirects(false);
-
-        // custom proxy support
-        if (context != null) {
-            SQLiteOpenHelper dbHelper = new ServiceDB.OpenHelper(context);
-            try {
-                Settings settings = new Settings(dbHelper.getReadableDatabase());
-                if (settings.getBoolean(App.OVERRIDE_PROXY, false)) {
-                    InetSocketAddress address = new InetSocketAddress(
-                            settings.getString(App.OVERRIDE_PROXY_HOST, App.OVERRIDE_PROXY_HOST_DEFAULT),
-                            settings.getInt(App.OVERRIDE_PROXY_PORT, App.OVERRIDE_PROXY_PORT_DEFAULT)
-                    );
-
-                    Proxy proxy = new Proxy(Proxy.Type.HTTP, address);
-                    builder.proxy(proxy);
-                    App.log.log(Level.INFO, "Using proxy", proxy);
-                }
-            } catch(IllegalArgumentException|NullPointerException e) {
-                App.log.log(Level.SEVERE, "Can't set proxy, ignoring", e);
-            } finally {
-                dbHelper.close();
-            }
-        }
-
-        // add User-Agent to every request
-        builder.addNetworkInterceptor(userAgentInterceptor);
-
-        // add cookie store for non-persistent cookies (some services like Horde use cookies for session tracking)
-        builder.cookieJar(new MemoryCookieStore());
-
-        // add network logging, if requested
-        if (logger.isLoggable(Level.FINEST)) {
-            HttpLoggingInterceptor loggingInterceptor = new HttpLoggingInterceptor(new HttpLoggingInterceptor.Logger() {
-                @Override
-                public void log(String message) {
-                    logger.finest(message);
-                }
-            });
-            loggingInterceptor.setLevel(HttpLoggingInterceptor.Level.BODY);
-            builder.addInterceptor(loggingInterceptor);
-        }
-
-        return builder;
-    }
-
-    private static OkHttpClient.Builder addAuthentication(@NonNull OkHttpClient.Builder builder, @Nullable String host, @NonNull String username, @NonNull String password) {
-        BasicDigestAuthHandler authHandler = new BasicDigestAuthHandler(UrlUtils.hostToDomain(host), username, password);
-        return builder
-                .addNetworkInterceptor(authHandler)
-                .authenticator(authHandler);
-    }
-
-    public static OkHttpClient addAuthentication(@NonNull OkHttpClient client, @NonNull String username, @NonNull String password) {
-        OkHttpClient.Builder builder = client.newBuilder();
-        addAuthentication(builder, null, username, password);
-        return builder.build();
-    }
-
-    public static OkHttpClient addAuthentication(@NonNull OkHttpClient client, @NonNull String host, @NonNull String username, @NonNull String password) {
-        OkHttpClient.Builder builder = client.newBuilder();
-        addAuthentication(builder, host, username, password);
-        return builder.build();
-    }
-
-
-    static class UserAgentInterceptor implements Interceptor {
-        @Override
-        public Response intercept(Chain chain) throws IOException {
-            Locale locale = Locale.getDefault();
-            Request request = chain.request().newBuilder()
-                    .header("User-Agent", userAgent)
-                    .header("Accept-Language", locale.getLanguage() + "-" + locale.getCountry() + ", " + locale.getLanguage() + ";q=0.7, *;q=0.5")
-                    .build();
-            return chain.proceed(request);
-        }
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/HttpClient.kt

@@ -0,0 +1,170 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid;
+
+import android.accounts.Account
+import android.content.Context
+import android.os.Build
+import at.bitfire.cert4android.CustomCertManager
+import at.bitfire.dav4android.BasicDigestAuthHandler
+import at.bitfire.dav4android.UrlUtils
+import at.bitfire.davdroid.log.Logger
+import at.bitfire.davdroid.settings.Settings
+import okhttp3.Cache
+import okhttp3.Interceptor
+import okhttp3.OkHttpClient
+import okhttp3.Response
+import okhttp3.internal.tls.OkHostnameVerifier
+import okhttp3.logging.HttpLoggingInterceptor
+import java.io.Closeable
+import java.io.File
+import java.net.InetSocketAddress
+import java.net.Proxy
+import java.text.SimpleDateFormat
+import java.util.*
+import java.util.concurrent.TimeUnit
+import java.util.logging.Level
+
+class HttpClient private constructor(
+        val okHttpClient: OkHttpClient,
+        private val certManager: CustomCertManager?
+): Closeable {
+
+    override fun close() {
+        certManager?.close()
+    }
+
+
+    class Builder @JvmOverloads constructor(
+            val context: Context? = null,
+            account: Account? = null,
+            accountSettings: AccountSettings? = null,
+            logger: java.util.logging.Logger = Logger.log
+    ) {
+        var certManager: CustomCertManager? = null
+        private val orig = OkHttpClient.Builder()
+
+        init {
+            // set timeouts
+            orig.connectTimeout(30, TimeUnit.SECONDS)
+            orig.writeTimeout(30, TimeUnit.SECONDS)
+            orig.readTimeout(120, TimeUnit.SECONDS)
+
+            // don't allow redirects by default, because it would break PROPFIND handling
+            orig.followRedirects(false)
+
+            // add User-Agent to every request
+            orig.addNetworkInterceptor(UserAgentInterceptor)
+
+            // add cookie store for non-persistent cookies (some services like Horde use cookies for session tracking)
+            orig.cookieJar(MemoryCookieStore())
+
+            // add network logging, if requested
+            if (logger.isLoggable(Level.FINEST)) {
+                val loggingInterceptor = HttpLoggingInterceptor(HttpLoggingInterceptor.Logger {
+                    message -> logger.finest(message)
+                })
+                loggingInterceptor.level = HttpLoggingInterceptor.Level.BODY
+                orig.addInterceptor(loggingInterceptor)
+            }
+
+            context?.let {
+                Settings.getInstance(context)?.use { settings ->
+                    // custom proxy support
+                    try {
+                        if (settings.getBoolean(App.OVERRIDE_PROXY, false)) {
+                            val address = InetSocketAddress(
+                                    settings.getString(App.OVERRIDE_PROXY_HOST, App.OVERRIDE_PROXY_HOST_DEFAULT),
+                                    settings.getInt(App.OVERRIDE_PROXY_PORT, App.OVERRIDE_PROXY_PORT_DEFAULT)
+                            )
+
+                            val proxy = Proxy(Proxy.Type.HTTP, address)
+                            orig.proxy(proxy)
+                            Logger.log.log(Level.INFO, "Using proxy", proxy)
+                        }
+                    } catch(e: Exception) {
+                        Logger.log.log(Level.SEVERE, "Can't set proxy, ignoring", e)
+                    }
+
+                    if (BuildConfig.customCerts)
+                        customCertManager(CustomCertManager(context, !settings.getBoolean(App.DISTRUST_SYSTEM_CERTIFICATES, false)))
+
+                    // use account settings for authentication
+                    val accountSettings = accountSettings ?: account?.let { AccountSettings(context, settings, it) }
+                    accountSettings?.let {
+                        val userName = accountSettings.username()
+                        val password = accountSettings.password()
+                        if (userName != null && password != null)
+                            addAuthentication(null, userName, password)
+                    }
+                }
+            }
+        }
+
+        constructor(context: Context, host: String?, username: String, password: String): this(context) {
+            addAuthentication(host, username, password)
+        }
+
+        fun withDiskCache(): Builder {
+            val context = context ?: throw IllegalArgumentException("Context is required to find the cache directory")
+            for (dir in arrayOf(context.externalCacheDir, context.cacheDir)) {
+                if (dir.exists() && dir.canWrite()) {
+                    val cacheDir = File(dir, "HttpClient")
+                    cacheDir.mkdir()
+                    Logger.log.fine("Using disk cache: $cacheDir")
+                    orig.cache(Cache(cacheDir, 10*1024*1024))
+                    break
+                }
+            }
+            return this
+        }
+
+        fun followRedirects(follow: Boolean): Builder {
+            orig.followRedirects(follow)
+            return this
+        }
+
+        fun customCertManager(manager: CustomCertManager) {
+            certManager = manager
+            orig.sslSocketFactory(SSLSocketFactoryCompat(manager), manager)
+            orig.hostnameVerifier(manager.hostnameVerifier(OkHostnameVerifier.INSTANCE))
+        }
+        fun setForeground(foreground: Boolean): Builder {
+            certManager?.appInForeground = foreground
+            return this
+        }
+
+        fun addAuthentication(host: String?, username: String, password: String): Builder {
+            val authHandler = BasicDigestAuthHandler(UrlUtils.hostToDomain(host), username, password)
+            orig    .addNetworkInterceptor(authHandler)
+                    .authenticator(authHandler)
+            return this
+        }
+
+        fun build() = HttpClient(orig.build(), certManager)
+    }
+
+
+    private object UserAgentInterceptor: Interceptor {
+
+        private val userAgentDate = SimpleDateFormat("yyyy/MM/dd", Locale.US).format(Date(BuildConfig.buildTime))
+        private val userAgent = "DAVdroid/${BuildConfig.VERSION_NAME} ($userAgentDate; dav4android; okhttp3) Android/${Build.VERSION.RELEASE}"
+
+        override fun intercept(chain: Interceptor.Chain): Response {
+            val locale = Locale.getDefault()
+            val request = chain.request().newBuilder()
+                    .header("User-Agent", userAgent)
+                    .header("Accept-Language", "${locale.language}-${locale.country}, ${locale.language};q=0.7, *;q=0.5")
+                    .build()
+            return chain.proceed(request)
+        }
+
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/InvalidAccountException.java

@@ -1,19 +0,0 @@
-/*
- * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid;
-
-import android.accounts.Account;
-
-public class InvalidAccountException extends Exception {
-
-    public InvalidAccountException(Account account) {
-        super("Invalid account: " + account);
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/InvalidAccountException.kt

@@ -0,0 +1,13 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid
+
+import android.accounts.Account
+
+class InvalidAccountException(account: Account): Exception("Invalid account: $account")

app/src/main/java/at/bitfire/davdroid/MemoryCookieStore.java

@@ -1,69 +0,0 @@
-/*
- * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid;
-
-import org.apache.commons.collections4.MapIterator;
-import org.apache.commons.collections4.keyvalue.MultiKey;
-import org.apache.commons.collections4.map.HashedMap;
-import org.apache.commons.collections4.map.MultiKeyMap;
-
-import java.util.LinkedList;
-import java.util.List;
-
-import okhttp3.Cookie;
-import okhttp3.CookieJar;
-import okhttp3.HttpUrl;
-
-/**
- * Primitive cookie store that stores cookies in a (volatile) hash map.
- * Will be sufficient for session cookies.
- */
-public class MemoryCookieStore implements CookieJar {
-
-    /**
-     * Stored cookies. The multi-key consists of three parts: name, domain, and path.
-     * This ensures that cookies can be overwritten. [RFC 6265 5.3 Storage Model]
-     * Not thread-safe!
-     */
-    protected final MultiKeyMap<String, Cookie> storage = MultiKeyMap.multiKeyMap(new HashedMap<MultiKey<? extends String>, Cookie>());
-
-    @Override
-    public void saveFromResponse(HttpUrl url, List<Cookie> cookies) {
-        synchronized(storage) {
-            for (Cookie cookie : cookies)
-                storage.put(cookie.name(), cookie.domain(), cookie.path(), cookie);
-        }
-    }
-
-    @Override
-    public List<Cookie> loadForRequest(HttpUrl url) {
-        List<Cookie> cookies = new LinkedList<>();
-
-        synchronized(storage) {
-            MapIterator<MultiKey<? extends String>, Cookie> iter = storage.mapIterator();
-            while (iter.hasNext()) {
-                iter.next();
-                Cookie cookie = iter.getValue();
-
-                // remove expired cookies
-                if (cookie.expiresAt() <= System.currentTimeMillis()) {
-                    iter.remove();
-                    continue;
-                }
-
-                // add applicable cookies
-                if (cookie.matches(url))
-                    cookies.add(cookie);
-            }
-        }
-
-        return cookies;
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/MemoryCookieStore.kt

@@ -0,0 +1,63 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid
+
+import okhttp3.Cookie
+import okhttp3.CookieJar
+import okhttp3.HttpUrl
+import org.apache.commons.collections4.keyvalue.MultiKey
+import org.apache.commons.collections4.map.HashedMap
+import org.apache.commons.collections4.map.MultiKeyMap
+import java.util.*
+
+/**
+ * Primitive cookie store that stores cookies in a (volatile) hash map.
+ * Will be sufficient for session cookies.
+ */
+class MemoryCookieStore: CookieJar {
+
+    /**
+     * Stored cookies. The multi-key consists of three parts: name, domain, and path.
+     * This ensures that cookies can be overwritten. [RFC 6265 5.3 Storage Model]
+     * Not thread-safe!
+     */
+    val storage = MultiKeyMap.multiKeyMap(HashedMap<MultiKey<out String>, Cookie>())!!
+
+    override fun saveFromResponse(url: HttpUrl, cookies: List<Cookie>) {
+        synchronized(storage) {
+            for (cookie in cookies)
+                storage.put(cookie.name(), cookie.domain(), cookie.path(), cookie)
+        }
+    }
+
+    override fun loadForRequest(url: HttpUrl): List<Cookie> {
+        val cookies = LinkedList<Cookie>()
+
+        synchronized(storage) {
+            val iter = storage.mapIterator()
+            while (iter.hasNext()) {
+                iter.next()
+                val cookie = iter.value
+
+                // remove expired cookies
+                if (cookie.expiresAt() <= System.currentTimeMillis()) {
+                    iter.remove()
+                    continue
+                }
+
+                // add applicable cookies
+                if (cookie.matches(url))
+                    cookies += cookie
+            }
+        }
+
+        return cookies
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/PackageChangedReceiver.java

@@ -1,63 +0,0 @@
-/*
- * Copyright © Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid;
-
-import android.accounts.Account;
-import android.annotation.SuppressLint;
-import android.content.BroadcastReceiver;
-import android.content.ContentResolver;
-import android.content.Context;
-import android.content.Intent;
-import android.database.Cursor;
-import android.database.sqlite.SQLiteDatabase;
-import android.os.Bundle;
-import android.support.annotation.NonNull;
-
-import at.bitfire.davdroid.model.ServiceDB;
-import at.bitfire.davdroid.model.ServiceDB.Services;
-import at.bitfire.davdroid.resource.LocalTaskList;
-import at.bitfire.ical4android.TaskProvider;
-import lombok.Cleanup;
-
-public class PackageChangedReceiver extends BroadcastReceiver {
-
-    @Override
-    @SuppressLint("MissingPermission")
-    public void onReceive(Context context, Intent intent) {
-        if (Intent.ACTION_PACKAGE_ADDED.equals(intent.getAction()) ||
-            Intent.ACTION_PACKAGE_FULLY_REMOVED.equals(intent.getAction()))
-            updateTaskSync(context);
-    }
-
-    static void updateTaskSync(@NonNull Context context) {
-        boolean tasksInstalled = LocalTaskList.tasksProviderAvailable(context);
-        App.log.info("Package (un)installed; OpenTasks provider now available = " + tasksInstalled);
-
-        // check all accounts and (de)activate OpenTasks if a CalDAV service is defined
-        @Cleanup ServiceDB.OpenHelper dbHelper = new ServiceDB.OpenHelper(context);
-        SQLiteDatabase db = dbHelper.getReadableDatabase();
-
-        @Cleanup Cursor cursor = db.query(Services._TABLE, new String[] { Services.ACCOUNT_NAME },
-                Services.SERVICE + "=?", new String[] { Services.SERVICE_CALDAV }, null, null, null);
-        while (cursor.moveToNext()) {
-            Account account = new Account(cursor.getString(0), Constants.ACCOUNT_TYPE);
-
-            if (tasksInstalled) {
-                if (ContentResolver.getIsSyncable(account, TaskProvider.ProviderName.OpenTasks.authority) <= 0) {
-                    ContentResolver.setIsSyncable(account, TaskProvider.ProviderName.OpenTasks.authority, 1);
-                    ContentResolver.setSyncAutomatically(account, TaskProvider.ProviderName.OpenTasks.authority, true);
-                    ContentResolver.addPeriodicSync(account, TaskProvider.ProviderName.OpenTasks.authority, new Bundle(), Constants.DEFAULT_SYNC_INTERVAL);
-                }
-            } else
-                ContentResolver.setIsSyncable(account, TaskProvider.ProviderName.OpenTasks.authority, 0);
-
-        }
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/PackageChangedReceiver.kt

@@ -0,0 +1,65 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid
+
+import android.accounts.Account
+import android.annotation.SuppressLint
+import android.content.BroadcastReceiver
+import android.content.ContentResolver
+import android.content.Context
+import android.content.Intent
+import android.os.Bundle
+import at.bitfire.davdroid.log.Logger
+import at.bitfire.davdroid.model.ServiceDB
+import at.bitfire.davdroid.model.ServiceDB.Services
+import at.bitfire.davdroid.resource.LocalTaskList
+import at.bitfire.ical4android.TaskProvider
+
+class PackageChangedReceiver: BroadcastReceiver() {
+
+    @SuppressLint("MissingPermission")
+    override fun onReceive(context: Context, intent: Intent) {
+        if (intent.action == Intent.ACTION_PACKAGE_ADDED || intent.action == Intent.ACTION_PACKAGE_FULLY_REMOVED)
+            updateTaskSync(context)
+    }
+
+
+    companion object {
+
+        @JvmStatic
+        fun updateTaskSync(context: Context) {
+            val tasksInstalled = LocalTaskList.tasksProviderAvailable(context)
+            Logger.log.info("Package (un)installed; OpenTasks provider now available = $tasksInstalled")
+
+            // check all accounts and (de)activate OpenTasks if a CalDAV service is defined
+            ServiceDB.OpenHelper(context).use { dbHelper ->
+                val db = dbHelper.readableDatabase
+
+                db.query(Services._TABLE, arrayOf(Services.ACCOUNT_NAME),
+                        "${Services.SERVICE}=?", arrayOf(Services.SERVICE_CALDAV), null, null, null)?.use { cursor ->
+                    while (cursor.moveToNext()) {
+                        val account = Account(cursor.getString(0), context.getString(R.string.account_type))
+
+                        if (tasksInstalled) {
+                            if (ContentResolver.getIsSyncable(account, TaskProvider.ProviderName.OpenTasks.authority) <= 0) {
+                                ContentResolver.setIsSyncable(account, TaskProvider.ProviderName.OpenTasks.authority, 1)
+                                ContentResolver.setSyncAutomatically(account, TaskProvider.ProviderName.OpenTasks.authority, true)
+                                ContentResolver.addPeriodicSync(account, TaskProvider.ProviderName.OpenTasks.authority, Bundle(), Constants.DEFAULT_SYNC_INTERVAL.toLong())
+                            }
+                        } else
+                            ContentResolver.setIsSyncable(account, TaskProvider.ProviderName.OpenTasks.authority, 0)
+
+                    }
+                }
+            }
+        }
+
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/SSLSocketFactoryCompat.java

@@ -1,170 +0,0 @@
-/*
- * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid;
-
-import android.os.Build;
-import android.support.annotation.NonNull;
-import android.text.TextUtils;
-
-import java.io.IOException;
-import java.net.InetAddress;
-import java.net.Socket;
-import java.security.GeneralSecurityException;
-import java.util.Arrays;
-import java.util.HashSet;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Locale;
-
-import javax.net.ssl.SSLContext;
-import javax.net.ssl.SSLSocket;
-import javax.net.ssl.SSLSocketFactory;
-import javax.net.ssl.X509TrustManager;
-
-import lombok.Cleanup;
-
-public class SSLSocketFactoryCompat extends SSLSocketFactory {
-
-    private SSLSocketFactory delegate;
-
-    // Android 5.0+ (API level21) provides reasonable default settings
-    // but it still allows SSLv3
-    // https://developer.android.com/reference/javax/net/ssl/SSLSocket.html
-    static String protocols[] = null, cipherSuites[] = null;
-    static {
-        try {
-            @Cleanup SSLSocket socket = (SSLSocket)SSLSocketFactory.getDefault().createSocket();
-            if (socket != null) {
-                /* set reasonable protocol versions */
-                // - enable all supported protocols (enables TLSv1.1 and TLSv1.2 on Android <5.0)
-                // - remove all SSL versions (especially SSLv3) because they're insecure now
-                List<String> protocols = new LinkedList<>();
-                for (String protocol : socket.getSupportedProtocols())
-                    if (!protocol.toUpperCase(Locale.US).contains("SSL"))
-                        protocols.add(protocol);
-                App.log.info("Setting allowed TLS protocols: " + TextUtils.join(", ", protocols));
-                SSLSocketFactoryCompat.protocols = protocols.toArray(new String[protocols.size()]);
-
-                /* set up reasonable cipher suites */
-                if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
-                    // choose known secure cipher suites
-                    List<String> allowedCiphers = Arrays.asList(
-                            // TLS 1.2
-                            "TLS_RSA_WITH_AES_256_GCM_SHA384",
-                            "TLS_RSA_WITH_AES_128_GCM_SHA256",
-                            "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256",
-                            "TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256",
-                            "TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384",
-                            "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256",
-                            "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256",
-                            // maximum interoperability
-                            "TLS_RSA_WITH_3DES_EDE_CBC_SHA",
-                            "TLS_RSA_WITH_AES_128_CBC_SHA",
-                            // additionally
-                            "TLS_RSA_WITH_AES_256_CBC_SHA",
-                            "TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA",
-                            "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA",
-                            "TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA",
-                            "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA");
-                    List<String> availableCiphers = Arrays.asList(socket.getSupportedCipherSuites());
-                    App.log.info("Available cipher suites: " + TextUtils.join(", ", availableCiphers));
-                    App.log.info("Cipher suites enabled by default: " + TextUtils.join(", ", socket.getEnabledCipherSuites()));
-
-                    // take all allowed ciphers that are available and put them into preferredCiphers
-                    HashSet<String> preferredCiphers = new HashSet<>(allowedCiphers);
-                    preferredCiphers.retainAll(availableCiphers);
-
-                    /* For maximum security, preferredCiphers should *replace* enabled ciphers (thus disabling
-                     * ciphers which are enabled by default, but have become unsecure), but I guess for
-                     * the security level of DAVdroid and maximum compatibility, disabling of insecure
-                     * ciphers should be a server-side task */
-
-                    // add preferred ciphers to enabled ciphers
-                    HashSet<String> enabledCiphers = preferredCiphers;
-                    enabledCiphers.addAll(new HashSet<>(Arrays.asList(socket.getEnabledCipherSuites())));
-
-                    App.log.info("Enabling (only) those TLS ciphers: " + TextUtils.join(", ", enabledCiphers));
-                    SSLSocketFactoryCompat.cipherSuites = enabledCiphers.toArray(new String[enabledCiphers.size()]);
-                }
-            }
-        } catch (IOException e) {
-            App.log.severe("Couldn't determine default TLS settings");
-        }
-    }
-
-    public SSLSocketFactoryCompat(@NonNull X509TrustManager trustManager) {
-        try {
-            SSLContext sslContext = SSLContext.getInstance("TLS");
-            sslContext.init(null, new X509TrustManager[] { trustManager }, null);
-            delegate = sslContext.getSocketFactory();
-        } catch (GeneralSecurityException e) {
-            throw new AssertionError(); // The system has no TLS. Just give up.
-        }
-    }
-
-    private void upgradeTLS(SSLSocket ssl) {
-        if (protocols != null)
-            ssl.setEnabledProtocols(protocols);
-
-        if (cipherSuites != null)
-            ssl.setEnabledCipherSuites(cipherSuites);
-    }
-
-
-    @Override
-    public String[] getDefaultCipherSuites() {
-        return cipherSuites;
-    }
-
-    @Override
-    public String[] getSupportedCipherSuites() {
-        return cipherSuites;
-    }
-
-    @Override
-    public Socket createSocket(Socket s, String host, int port, boolean autoClose) throws IOException {
-        Socket ssl = delegate.createSocket(s, host, port, autoClose);
-        if (ssl instanceof SSLSocket)
-            upgradeTLS((SSLSocket)ssl);
-        return ssl;
-    }
-
-    @Override
-    public Socket createSocket(String host, int port) throws IOException {
-        Socket ssl = delegate.createSocket(host, port);
-        if (ssl instanceof SSLSocket)
-            upgradeTLS((SSLSocket)ssl);
-        return ssl;
-    }
-
-    @Override
-    public Socket createSocket(String host, int port, InetAddress localHost, int localPort) throws IOException {
-        Socket ssl = delegate.createSocket(host, port, localHost, localPort);
-        if (ssl instanceof SSLSocket)
-            upgradeTLS((SSLSocket)ssl);
-        return ssl;
-    }
-
-    @Override
-    public Socket createSocket(InetAddress host, int port) throws IOException {
-        Socket ssl = delegate.createSocket(host, port);
-        if (ssl instanceof SSLSocket)
-            upgradeTLS((SSLSocket)ssl);
-        return ssl;
-    }
-
-    @Override
-    public Socket createSocket(InetAddress address, int port, InetAddress localAddress, int localPort) throws IOException {
-        Socket ssl = delegate.createSocket(address, port, localAddress, localPort);
-        if (ssl instanceof SSLSocket)
-            upgradeTLS((SSLSocket)ssl);
-        return ssl;
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/SSLSocketFactoryCompat.kt

@@ -0,0 +1,160 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid
+
+import android.os.Build
+import at.bitfire.davdroid.log.Logger
+import java.io.IOException
+import java.net.InetAddress
+import java.net.Socket
+import java.security.GeneralSecurityException
+import java.util.*
+import javax.net.ssl.SSLContext
+import javax.net.ssl.SSLSocket
+import javax.net.ssl.SSLSocketFactory
+import javax.net.ssl.X509TrustManager
+
+class SSLSocketFactoryCompat(trustManager: X509TrustManager): SSLSocketFactory() {
+
+    private var delegate: SSLSocketFactory
+
+    companion object {
+        // Android 5.0+ (API level 21) provides reasonable default settings
+        // but it still allows SSLv3
+        // https://developer.android.com/reference/javax/net/ssl/SSLSocket.html
+        var protocols: Array<String>? = null
+        var cipherSuites: Array<String>? = null
+        init {
+            if (Build.VERSION.SDK_INT >= 23) {
+                // Since Android 6.0 (API level 23),
+                // - TLSv1.1 and TLSv1.2 is enabled by default
+                // - SSLv3 is disabled by default
+                // - all modern ciphers are activated by default
+                protocols = null
+                cipherSuites = null
+                Logger.log.fine("Using device default TLS protocols/ciphers")
+            } else {
+                val socket = SSLSocketFactory.getDefault().createSocket() as SSLSocket?
+                try {
+                    socket?.let {
+                        /* set reasonable protocol versions */
+                        // - enable all supported protocols (enables TLSv1.1 and TLSv1.2 on Android <5.0)
+                        // - remove all SSL versions (especially SSLv3) because they're insecure now
+                        val _protocols = LinkedList<String>()
+                        for (protocol in socket.supportedProtocols.filterNot { it.contains("SSL", true) })
+                            _protocols += protocol
+                        Logger.log.info("Enabling (only) these TLS protocols: ${_protocols.joinToString(", ")}")
+                        protocols = _protocols.toTypedArray()
+
+                        /* set up reasonable cipher suites */
+                       val knownCiphers = arrayOf<String>(
+                                // TLS 1.2
+                                "TLS_RSA_WITH_AES_256_GCM_SHA384",
+                                "TLS_RSA_WITH_AES_128_GCM_SHA256",
+                                "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256",
+                                "TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256",
+                                "TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384",
+                                "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256",
+                                "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256",
+                                // maximum interoperability
+                                "TLS_RSA_WITH_3DES_EDE_CBC_SHA",
+                                "SSL_RSA_WITH_3DES_EDE_CBC_SHA",
+                                "TLS_RSA_WITH_AES_128_CBC_SHA",
+                                // additionally
+                                "TLS_RSA_WITH_AES_256_CBC_SHA",
+                                "TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA",
+                                "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA",
+                                "TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA",
+                                "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA"
+                        )
+                        val availableCiphers = socket.supportedCipherSuites
+                        Logger.log.info("Available cipher suites: ${availableCiphers.joinToString(", ")}")
+
+                        /* For maximum security, preferredCiphers should *replace* enabled ciphers (thus
+                         * disabling ciphers which are enabled by default, but have become unsecure), but for
+                         * the security level of DAVdroid and maximum compatibility, disabling of insecure
+                         * ciphers should be a server-side task */
+
+                        // for the final set of enabled ciphers, take the ciphers enabled by default, ...
+                        val _cipherSuites = LinkedList<String>()
+                        _cipherSuites.addAll(socket.enabledCipherSuites)
+                        Logger.log.fine("Cipher suites enabled by default: ${_cipherSuites.joinToString(", ")}")
+                        // ... add explicitly allowed ciphers ...
+                        _cipherSuites.addAll(knownCiphers)
+                        // ... and keep only those which are actually available
+                        _cipherSuites.retainAll(availableCiphers)
+
+                        Logger.log.info("Enabling (only) these TLS ciphers: " + _cipherSuites.joinToString(", "))
+                        cipherSuites = _cipherSuites.toTypedArray()
+                    }
+                } catch(e: IOException) {
+                    Logger.log.severe("Couldn't determine default TLS settings")
+                } finally {
+                    socket?.close()     // doesn't implement Closeable on all supported Android versions
+                }
+            }
+        }
+    }
+
+
+    init {
+        try {
+            val sslContext = SSLContext.getInstance("TLS")
+            sslContext.init(null, arrayOf(trustManager), null)
+            delegate = sslContext.socketFactory
+        } catch (e: GeneralSecurityException) {
+            throw IllegalStateException()      // system has no TLS
+        }
+    }
+
+    override fun getDefaultCipherSuites(): Array<String>? = cipherSuites ?: delegate.defaultCipherSuites
+    override fun getSupportedCipherSuites(): Array<String>? = cipherSuites ?: delegate.supportedCipherSuites
+
+    override fun createSocket(s: Socket, host: String, port: Int, autoClose: Boolean): Socket {
+        val ssl = delegate.createSocket(s, host, port, autoClose)
+        if (ssl is SSLSocket)
+            upgradeTLS(ssl)
+        return ssl
+    }
+
+    override fun createSocket(host: String, port: Int): Socket {
+        val ssl = delegate.createSocket(host, port)
+        if (ssl is SSLSocket)
+            upgradeTLS(ssl)
+        return ssl
+    }
+
+    override fun createSocket(host: String, port: Int, localHost: InetAddress, localPort: Int): Socket {
+        val ssl = delegate.createSocket(host, port, localHost, localPort)
+        if (ssl is SSLSocket)
+            upgradeTLS(ssl)
+        return ssl
+    }
+
+    override fun createSocket(host: InetAddress, port: Int): Socket {
+        val ssl = delegate.createSocket(host, port)
+        if (ssl is SSLSocket)
+            upgradeTLS(ssl)
+        return ssl
+    }
+
+    override fun createSocket(address: InetAddress, port: Int, localAddress: InetAddress, localPort: Int): Socket {
+        val ssl = delegate.createSocket(address, port, localAddress, localPort)
+        if (ssl is SSLSocket)
+            upgradeTLS(ssl)
+        return ssl
+    }
+
+
+    private fun upgradeTLS(ssl: SSLSocket) {
+        protocols?.let { ssl.enabledProtocols = it }
+        cipherSuites?.let { ssl.enabledCipherSuites = it }
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/log/LogcatHandler.java

@@ -1,59 +0,0 @@
-/*
- * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.log;
-
-import android.util.Log;
-
-import org.apache.commons.lang3.math.NumberUtils;
-
-import java.util.logging.Handler;
-import java.util.logging.Level;
-import java.util.logging.LogRecord;
-
-public class LogcatHandler extends Handler {
-    private static final int MAX_LINE_LENGTH = 3000;
-    public static final LogcatHandler INSTANCE = new LogcatHandler();
-
-    private LogcatHandler() {
-        super();
-        setFormatter(PlainTextFormatter.LOGCAT);
-        setLevel(Level.ALL);
-    }
-
-    @Override
-    public void publish(LogRecord r) {
-        String text = getFormatter().format(r);
-        int level = r.getLevel().intValue();
-
-        int end = text.length();
-        for (int pos = 0; pos < end; pos += MAX_LINE_LENGTH) {
-            String line = text.substring(pos, NumberUtils.min(pos + MAX_LINE_LENGTH, end));
-
-            if (level >= Level.SEVERE.intValue())
-                Log.e(r.getLoggerName(), line);
-            else if (level >= Level.WARNING.intValue())
-                Log.w(r.getLoggerName(), line);
-            else if (level >= Level.CONFIG.intValue())
-                Log.i(r.getLoggerName(), line);
-            else if (level >= Level.FINER.intValue())
-                Log.d(r.getLoggerName(), line);
-            else
-                Log.v(r.getLoggerName(), line);
-        }
-    }
-
-    @Override
-    public void flush() {
-    }
-
-    @Override
-    public void close() {
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/log/LogcatHandler.kt

@@ -0,0 +1,50 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.log
+
+import android.util.Log
+
+import org.apache.commons.lang3.math.NumberUtils
+
+import java.util.logging.Handler
+import java.util.logging.Level
+import java.util.logging.LogRecord
+
+object LogcatHandler: Handler() {
+
+    private val MAX_LINE_LENGTH = 3000
+
+    init {
+        formatter = PlainTextFormatter.LOGCAT
+        level = Level.ALL
+    }
+
+    override fun publish(r: LogRecord) {
+        val text = formatter.format(r)
+        val level = r.level.intValue()
+
+        val end = text.length
+        var pos = 0
+        while (pos < end) {
+            val line = text.substring(pos, NumberUtils.min(pos + MAX_LINE_LENGTH, end))
+            when {
+                level >= Level.SEVERE.intValue()  -> Log.e(r.loggerName, line)
+                level >= Level.WARNING.intValue() -> Log.w(r.loggerName, line)
+                level >= Level.CONFIG.intValue()  -> Log.i(r.loggerName, line)
+                level >= Level.FINER.intValue()   -> Log.d(r.loggerName, line)
+                else                              -> Log.v(r.loggerName, line)
+            }
+            pos += MAX_LINE_LENGTH
+        }
+    }
+
+    override fun flush() {}
+    override fun close() {}
+
+}

app/src/main/java/at/bitfire/davdroid/log/Logger.kt

@@ -0,0 +1,112 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.log
+
+import android.app.PendingIntent
+import android.content.Context
+import android.content.Intent
+import android.content.SharedPreferences
+import android.os.Process
+import android.preference.PreferenceManager
+import android.support.v4.app.NotificationCompat
+import android.support.v4.app.NotificationManagerCompat
+import android.util.Log
+import at.bitfire.davdroid.App
+import at.bitfire.davdroid.Constants
+import at.bitfire.davdroid.R
+import at.bitfire.davdroid.ui.AppSettingsActivity
+import org.apache.commons.lang3.time.DateFormatUtils
+import java.io.File
+import java.io.IOException
+import java.util.logging.FileHandler
+import java.util.logging.Level
+
+object Logger {
+
+    val LOG_TO_EXTERNAL_STORAGE = "log_to_external_storage"
+
+    @JvmField
+    val log = java.util.logging.Logger.getLogger("davdroid")!!
+
+
+    lateinit var context: Context
+    lateinit var preferences: SharedPreferences
+
+    fun initialize(context: Context) {
+        this.context = context
+
+        preferences = PreferenceManager.getDefaultSharedPreferences(context)
+        preferences.registerOnSharedPreferenceChangeListener { _, s ->
+            if (s == LOG_TO_EXTERNAL_STORAGE)
+                reinitialize()
+        }
+
+        reinitialize()
+    }
+
+    private fun reinitialize() {
+        val logToFile = preferences.getBoolean(LOG_TO_EXTERNAL_STORAGE, false)
+        val logVerbose = logToFile || Log.isLoggable(log.name, Log.DEBUG)
+
+        log.info("Verbose logging: $logVerbose; to file: $logToFile")
+
+        // set logging level according to preferences
+        val rootLogger = java.util.logging.Logger.getLogger("")
+        rootLogger.level = if (logVerbose) Level.ALL else Level.INFO
+
+        // remove all handlers and add our own logcat handler
+        rootLogger.useParentHandlers = false
+        rootLogger.handlers.forEach { rootLogger.removeHandler(it) }
+        rootLogger.addHandler(LogcatHandler)
+
+        val nm = NotificationManagerCompat.from(context)
+        // log to external file according to preferences
+        if (logToFile) {
+            val builder = NotificationCompat.Builder(context)
+            builder .setSmallIcon(R.drawable.ic_sd_storage_light)
+                    .setLargeIcon(App.getLauncherBitmap(context))
+                    .setContentTitle(context.getString(R.string.logging_davdroid_file_logging))
+                    .setLocalOnly(true)
+
+            val dir = context.getExternalFilesDir(null)
+            if (dir != null)
+                try {
+                    val fileName = File(dir, "davdroid-${Process.myPid()}-${DateFormatUtils.format(System.currentTimeMillis(), "yyyyMMdd-HHmmss")}.txt").toString()
+                    log.info("Logging to $fileName")
+
+                    val fileHandler = FileHandler(fileName)
+                    fileHandler.formatter = PlainTextFormatter.DEFAULT
+                    rootLogger.addHandler(fileHandler)
+
+                    val prefIntent = Intent(context, AppSettingsActivity::class.java)
+                    prefIntent.putExtra(AppSettingsActivity.EXTRA_SCROLL_TO, LOG_TO_EXTERNAL_STORAGE)
+
+                    builder .setContentText(dir.path)
+                            .setCategory(NotificationCompat.CATEGORY_STATUS)
+                            .setPriority(NotificationCompat.PRIORITY_HIGH)
+                            .setContentIntent(PendingIntent.getActivity(context, 0, prefIntent, PendingIntent.FLAG_UPDATE_CURRENT))
+                            .setStyle(NotificationCompat.BigTextStyle()
+                                    .bigText(context.getString(R.string.logging_to_external_storage, dir.path)))
+                            .setOngoing(true)
+
+                } catch(e: IOException) {
+                    log.log(Level.SEVERE, "Couldn't create external log file", e)
+
+                    builder .setContentText(context.getString(R.string.logging_couldnt_create_file, e.localizedMessage))
+                            .setCategory(NotificationCompat.CATEGORY_ERROR)
+                }
+            else
+                builder.setContentText(context.getString(R.string.logging_no_external_storage))
+
+            nm.notify(Constants.NOTIFICATION_EXTERNAL_FILE_LOGGING, builder.build())
+        } else
+            nm.cancel(Constants.NOTIFICATION_EXTERNAL_FILE_LOGGING)
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/log/PlainTextFormatter.java

@@ -1,64 +0,0 @@
-/*
- * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.log;
-
-import org.apache.commons.lang3.StringUtils;
-import org.apache.commons.lang3.exception.ExceptionUtils;
-import org.apache.commons.lang3.time.DateFormatUtils;
-
-import java.util.logging.Formatter;
-import java.util.logging.LogRecord;
-
-public class PlainTextFormatter extends Formatter {
-    public final static PlainTextFormatter
-            LOGCAT = new PlainTextFormatter(true),
-            DEFAULT = new PlainTextFormatter(false);
-
-    private final boolean logcat;
-
-    private PlainTextFormatter(boolean onLogcat) {
-        this.logcat = onLogcat;
-    }
-
-    @Override
-    @SuppressWarnings("ThrowableResultOfMethodCallIgnored")
-    public String format(LogRecord r) {
-        StringBuilder builder = new StringBuilder();
-
-        if (!logcat)
-            builder .append(DateFormatUtils.format(r.getMillis(), "yyyy-MM-dd HH:mm:ss"))
-                    .append(" ").append(r.getThreadID()).append(" ");
-
-        if (!r.getSourceClassName().replaceFirst("\\$.*", "").equals(r.getLoggerName()))
-            builder.append("[").append(shortClassName(r.getSourceClassName())).append("] ");
-
-        builder.append(r.getMessage());
-
-        if (r.getThrown() != null)
-            builder .append("\nEXCEPTION ")
-                    .append(ExceptionUtils.getStackTrace(r.getThrown()));
-
-        if (r.getParameters() != null) {
-            int idx = 1;
-            for (Object param : r.getParameters())
-                builder.append("\n\tPARAMETER #").append(idx++).append(" = ").append(param);
-        }
-
-        if (!logcat)
-            builder.append("\n");
-
-        return builder.toString();
-    }
-
-    private String shortClassName(String className) {
-        String s = StringUtils.replace(className, "at.bitfire.davdroid.", "");
-        return StringUtils.replace(s, "at.bitfire.", "");
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/log/PlainTextFormatter.kt

@@ -0,0 +1,61 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.log
+
+import org.apache.commons.lang3.StringUtils
+import org.apache.commons.lang3.exception.ExceptionUtils
+import org.apache.commons.lang3.time.DateFormatUtils
+import java.util.logging.Formatter
+import java.util.logging.LogRecord
+
+class PlainTextFormatter private constructor(
+        private val logcat: Boolean
+): Formatter() {
+
+    companion object {
+        @JvmField val LOGCAT = PlainTextFormatter(true)
+        @JvmField val DEFAULT = PlainTextFormatter(false)
+
+        val MAX_MESSAGE_LENGTH = 20000
+    }
+
+    override fun format(r: LogRecord): String {
+        val builder = StringBuilder()
+
+        if (!logcat)
+            builder .append(DateFormatUtils.format(r.millis, "yyyy-MM-dd HH:mm:ss"))
+                    .append(" ").append(r.threadID).append(" ")
+
+        val className = shortClassName(r.sourceClassName)
+        if (className != r.loggerName)
+            builder.append("[").append(className).append("] ")
+
+        builder.append(StringUtils.abbreviate(r.message, MAX_MESSAGE_LENGTH))
+
+        r.thrown?.let {
+            builder .append("\nEXCEPTION ")
+                    .append(ExceptionUtils.getStackTrace(it))
+        }
+
+        r.parameters?.let {
+            for ((idx, param) in it.withIndex())
+                builder.append("\n\tPARAMETER #").append(idx).append(" = ").append(param)
+        }
+
+        if (!logcat)
+            builder.append("\n")
+
+        return builder.toString()
+    }
+
+    private fun shortClassName(className: String) = className
+            .replace(Regex("^at\\.bitfire\\.(dav|cert4an|dav4an|ical4an|vcard4an)droid\\."), "")
+            .replace(Regex("\\$.*$"), "")
+
+}

app/src/main/java/at/bitfire/davdroid/log/StringHandler.java

@@ -1,40 +0,0 @@
-/*
- * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.log;
-
-import java.util.logging.Handler;
-import java.util.logging.LogRecord;
-
-public class StringHandler extends Handler {
-
-    StringBuilder builder = new StringBuilder();
-
-    public StringHandler() {
-        super();
-        setFormatter(PlainTextFormatter.DEFAULT);
-    }
-
-    @Override
-    public void publish(LogRecord record) {
-        builder.append(getFormatter().format(record));
-    }
-
-    @Override
-    public void flush() {
-    }
-
-    @Override
-    public void close() {
-    }
-
-    @Override
-    public String toString() {
-        return builder.toString();
-    }
-}

app/src/main/java/at/bitfire/davdroid/log/StringHandler.kt

@@ -0,0 +1,31 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.log
+
+import java.util.logging.Handler;
+import java.util.logging.LogRecord;
+
+class StringHandler: Handler() {
+
+    val builder = StringBuilder()
+
+    init {
+        formatter = PlainTextFormatter.DEFAULT
+    }
+
+    override fun publish(record: LogRecord) {
+        builder.append(formatter.format(record))
+    }
+
+    override fun flush() {}
+    override fun close() {}
+
+    override fun toString() = builder.toString()
+
+}

app/src/main/java/at/bitfire/davdroid/model/CollectionInfo.java

@@ -1,163 +0,0 @@
-/*
- * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.model;
-
-import android.content.ContentValues;
-
-import org.apache.commons.lang3.StringUtils;
-
-import java.io.Serializable;
-
-import at.bitfire.dav4android.DavResource;
-import at.bitfire.dav4android.Property;
-import at.bitfire.dav4android.property.AddressbookDescription;
-import at.bitfire.dav4android.property.CalendarColor;
-import at.bitfire.dav4android.property.CalendarDescription;
-import at.bitfire.dav4android.property.CalendarTimezone;
-import at.bitfire.dav4android.property.CurrentUserPrivilegeSet;
-import at.bitfire.dav4android.property.DisplayName;
-import at.bitfire.dav4android.property.ResourceType;
-import at.bitfire.dav4android.property.SupportedAddressData;
-import at.bitfire.dav4android.property.SupportedCalendarComponentSet;
-import at.bitfire.davdroid.model.ServiceDB.Collections;
-import lombok.ToString;
-
-@ToString
-public class CollectionInfo implements Serializable {
-    public long id;
-    public Long serviceID;
-
-    public enum Type {
-        ADDRESS_BOOK,
-        CALENDAR
-    }
-    public Type type;
-
-    public String url;
-
-    public boolean readOnly;
-    public String displayName, description;
-    public Integer color;
-
-    public String timeZone;
-    public Boolean supportsVEVENT;
-    public Boolean supportsVTODO;
-
-    public boolean selected;
-
-    // non-persistent properties
-    public boolean confirmed;
-
-
-    public static final Property.Name[] DAV_PROPERTIES = {
-            ResourceType.NAME,
-            CurrentUserPrivilegeSet.NAME,
-            DisplayName.NAME,
-            AddressbookDescription.NAME, SupportedAddressData.NAME,
-            CalendarDescription.NAME, CalendarColor.NAME, SupportedCalendarComponentSet.NAME
-    };
-
-    public static CollectionInfo fromDavResource(DavResource dav) {
-        CollectionInfo info = new CollectionInfo();
-        info.url = dav.location.toString();
-
-        ResourceType type = (ResourceType)dav.properties.get(ResourceType.NAME);
-        if (type != null) {
-            if (type.types.contains(ResourceType.ADDRESSBOOK))
-                info.type = Type.ADDRESS_BOOK;
-            else if (type.types.contains(ResourceType.CALENDAR))
-                info.type = Type.CALENDAR;
-        }
-
-        info.readOnly = false;
-        CurrentUserPrivilegeSet privilegeSet = (CurrentUserPrivilegeSet)dav.properties.get(CurrentUserPrivilegeSet.NAME);
-        if (privilegeSet != null)
-            info.readOnly = !privilegeSet.mayWriteContent;
-
-        DisplayName displayName = (DisplayName)dav.properties.get(DisplayName.NAME);
-        if (displayName != null && !StringUtils.isEmpty(displayName.displayName))
-            info.displayName = displayName.displayName;
-
-        if (info.type == Type.ADDRESS_BOOK) {
-            AddressbookDescription addressbookDescription = (AddressbookDescription)dav.properties.get(AddressbookDescription.NAME);
-            if (addressbookDescription != null)
-                info.description = addressbookDescription.description;
-
-        } else if (info.type == Type.CALENDAR) {
-            CalendarDescription calendarDescription = (CalendarDescription)dav.properties.get(CalendarDescription.NAME);
-            if (calendarDescription != null)
-                info.description = calendarDescription.description;
-
-            CalendarColor calendarColor = (CalendarColor)dav.properties.get(CalendarColor.NAME);
-            if (calendarColor != null)
-                info.color = calendarColor.color;
-
-            CalendarTimezone timeZone = (CalendarTimezone)dav.properties.get(CalendarTimezone.NAME);
-            if (timeZone != null)
-                info.timeZone = timeZone.vTimeZone;
-
-            info.supportsVEVENT = info.supportsVTODO = true;
-            SupportedCalendarComponentSet supportedCalendarComponentSet = (SupportedCalendarComponentSet)dav.properties.get(SupportedCalendarComponentSet.NAME);
-            if (supportedCalendarComponentSet != null) {
-                info.supportsVEVENT = supportedCalendarComponentSet.supportsEvents;
-                info.supportsVTODO = supportedCalendarComponentSet.supportsTasks;
-            }
-        }
-
-        return info;
-    }
-
-
-    public static CollectionInfo fromDB(ContentValues values) {
-        CollectionInfo info = new CollectionInfo();
-        info.id = values.getAsLong(Collections.ID);
-        info.serviceID = values.getAsLong(Collections.SERVICE_ID);
-
-        info.url = values.getAsString(Collections.URL);
-        info.readOnly = values.getAsInteger(Collections.READ_ONLY) != 0;
-        info.displayName = values.getAsString(Collections.DISPLAY_NAME);
-        info.description = values.getAsString(Collections.DESCRIPTION);
-
-        info.color = values.getAsInteger(Collections.COLOR);
-
-        info.timeZone = values.getAsString(Collections.TIME_ZONE);
-        info.supportsVEVENT = getAsBooleanOrNull(values, Collections.SUPPORTS_VEVENT);
-        info.supportsVTODO = getAsBooleanOrNull(values, Collections.SUPPORTS_VTODO);
-
-        info.selected = values.getAsInteger(Collections.SYNC) != 0;
-        return info;
-    }
-
-    public ContentValues toDB() {
-        ContentValues values = new ContentValues();
-        // Collections.SERVICE_ID is never changed
-
-        values.put(Collections.URL, url);
-        values.put(Collections.READ_ONLY, readOnly ? 1 : 0);
-        values.put(Collections.DISPLAY_NAME, displayName);
-        values.put(Collections.DESCRIPTION, description);
-        values.put(Collections.COLOR, color);
-
-        values.put(Collections.TIME_ZONE, timeZone);
-        if (supportsVEVENT != null)
-            values.put(Collections.SUPPORTS_VEVENT, supportsVEVENT ? 1 : 0);
-        if (supportsVTODO != null)
-            values.put(Collections.SUPPORTS_VTODO, supportsVTODO ? 1 : 0);
-
-        values.put(Collections.SYNC, selected ? 1 : 0);
-        return values;
-    }
-
-
-    private static Boolean getAsBooleanOrNull(ContentValues values, String field) {
-        Integer i = values.getAsInteger(field);
-        return (i == null) ? null : (i != 0);
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/model/CollectionInfo.kt

@@ -0,0 +1,159 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.model
+
+import android.content.ContentValues
+import at.bitfire.dav4android.DavResource
+import at.bitfire.dav4android.property.*
+import at.bitfire.davdroid.model.ServiceDB.Collections
+import java.io.Serializable
+
+data class CollectionInfo @JvmOverloads constructor(
+        val url: String,
+
+        var id: Long? = null,
+        var serviceID: Long? = null,
+
+        var type: Type? = null,
+
+        var readOnly: Boolean = false,
+        var displayName: String? = null,
+        var description: String? = null,
+        var color: Int? = null,
+
+        var timeZone: String? = null,
+        var supportsVEVENT: Boolean = false,
+        var supportsVTODO: Boolean = false,
+        var selected: Boolean = false,
+
+        // subscriptions
+        var source: String? = null,
+
+        // non-persistent properties
+        var confirmed: Boolean = false
+): Serializable {
+
+    enum class Type {
+        ADDRESS_BOOK,
+        CALENDAR,
+        WEBCAL          // iCalendar subscription
+    }
+
+    companion object {
+
+        @JvmField
+        val DAV_PROPERTIES = arrayOf(
+            ResourceType.NAME,
+            CurrentUserPrivilegeSet.NAME,
+            DisplayName.NAME,
+            AddressbookDescription.NAME, SupportedAddressData.NAME,
+            CalendarDescription.NAME, CalendarColor.NAME, SupportedCalendarComponentSet.NAME,
+            Source.NAME
+        )
+
+    }
+
+
+    constructor(dav: DavResource): this(dav.location.toString()) {
+        (dav.properties[ResourceType.NAME] as ResourceType?)?.let { type ->
+            when {
+                type.types.contains(ResourceType.ADDRESSBOOK) -> this.type = Type.ADDRESS_BOOK
+                type.types.contains(ResourceType.CALENDAR)    -> this.type = Type.CALENDAR
+                type.types.contains(ResourceType.SUBSCRIBED)  -> this.type = Type.WEBCAL
+            }
+        }
+
+        (dav.properties[CurrentUserPrivilegeSet.NAME] as CurrentUserPrivilegeSet?)?.let { privilegeSet ->
+            readOnly = !privilegeSet.mayWriteContent
+        }
+
+        (dav.properties[DisplayName.NAME] as DisplayName?)?.let {
+            if (!it.displayName.isNullOrEmpty())
+                displayName = it.displayName
+        }
+
+        when (type) {
+            Type.ADDRESS_BOOK -> {
+                (dav.properties[AddressbookDescription.NAME] as AddressbookDescription?)?.let { description = it.description }
+            }
+            Type.CALENDAR -> {
+                (dav.properties[CalendarDescription.NAME] as CalendarDescription?)?.let { description = it.description }
+                (dav.properties[CalendarColor.NAME] as CalendarColor?)?.let { color = it.color }
+                (dav.properties[CalendarTimezone.NAME] as CalendarTimezone?)?.let { timeZone = it.vTimeZone }
+
+                supportsVEVENT = true
+                supportsVTODO = true
+                (dav.properties[SupportedCalendarComponentSet.NAME] as SupportedCalendarComponentSet?)?.let {
+                    supportsVEVENT = it.supportsEvents
+                    supportsVTODO = it.supportsTasks
+                }
+            }
+            Type.WEBCAL -> {
+                (dav.properties[Source.NAME] as Source?)?.let { source = it.hrefs.firstOrNull() }
+                supportsVEVENT = true
+            }
+        }
+    }
+
+
+    constructor(values: ContentValues): this(values.getAsString(Collections.URL)) {
+        id = values.getAsLong(Collections.ID)
+        serviceID = values.getAsLong(Collections.SERVICE_ID)
+        type = try {
+            Type.valueOf(values.getAsString(Collections.TYPE))
+        } catch (e: Exception) {
+            null
+        }
+
+        readOnly = values.getAsInteger(Collections.READ_ONLY) != 0
+        displayName = values.getAsString(Collections.DISPLAY_NAME)
+        description = values.getAsString(Collections.DESCRIPTION)
+
+        color = values.getAsInteger(Collections.COLOR)
+
+        timeZone = values.getAsString(Collections.TIME_ZONE)
+        supportsVEVENT = getAsBooleanOrNull(values, Collections.SUPPORTS_VEVENT) ?: false
+        supportsVTODO = getAsBooleanOrNull(values, Collections.SUPPORTS_VTODO) ?: false
+
+        source = values.getAsString(Collections.SOURCE)
+
+        selected = values.getAsInteger(Collections.SYNC) != 0
+    }
+
+    fun toDB(): ContentValues {
+        val values = ContentValues()
+        // Collections.SERVICE_ID is never changed
+        type?.let { values.put(Collections.TYPE, it.name) }
+
+        values.put(Collections.URL, url)
+        values.put(Collections.READ_ONLY, if (readOnly) 1 else 0)
+        values.put(Collections.DISPLAY_NAME, displayName)
+        values.put(Collections.DESCRIPTION, description)
+        values.put(Collections.COLOR, color)
+
+        values.put(Collections.TIME_ZONE, timeZone)
+        values.put(Collections.SUPPORTS_VEVENT, if (supportsVEVENT) 1 else 0)
+        values.put(Collections.SUPPORTS_VTODO, if (supportsVTODO) 1 else 0)
+
+        values.put(Collections.SOURCE, source)
+
+        values.put(Collections.SYNC, if (selected) 1 else 0)
+        return values
+    }
+
+
+    private fun getAsBooleanOrNull(values: ContentValues, field: String): Boolean? {
+        val i = values.getAsInteger(field)
+        return if (i == null)
+            null
+        else
+            (i != 0)
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/model/ServiceDB.java

@@ -1,195 +0,0 @@
-/*
- * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.model;
-
-import android.content.ContentValues;
-import android.content.Context;
-import android.database.Cursor;
-import android.database.sqlite.SQLiteDatabase;
-import android.database.sqlite.SQLiteException;
-import android.database.sqlite.SQLiteOpenHelper;
-import android.os.Build;
-import android.support.annotation.NonNull;
-import android.support.annotation.RequiresApi;
-
-import at.bitfire.davdroid.App;
-import lombok.Cleanup;
-
-public class ServiceDB {
-
-    public static class Settings {
-        public static final String
-                _TABLE = "settings",
-                NAME = "setting",
-                VALUE = "value";
-    }
-
-    public static class Services {
-        public static final String
-                _TABLE = "services",
-                ID = "_id",
-                ACCOUNT_NAME = "accountName",
-                SERVICE = "service",
-                PRINCIPAL = "principal";
-
-        // allowed values for SERVICE column
-        public static final String
-                SERVICE_CALDAV = "caldav",
-                SERVICE_CARDDAV = "carddav";
-    }
-
-    public static class HomeSets {
-        public static final String
-                _TABLE = "homesets",
-                ID = "_id",
-                SERVICE_ID = "serviceID",
-                URL = "url";
-    }
-
-    public static class Collections {
-        public static final String
-                _TABLE = "collections",
-                ID = "_id",
-                SERVICE_ID = "serviceID",
-                URL = "url",
-                READ_ONLY = "readOnly",
-                DISPLAY_NAME = "displayName",
-                DESCRIPTION = "description",
-                COLOR = "color",
-                TIME_ZONE = "timezone",
-                SUPPORTS_VEVENT = "supportsVEVENT",
-                SUPPORTS_VTODO = "supportsVTODO",
-                SYNC = "sync";
-    }
-
-
-    public static class OpenHelper extends SQLiteOpenHelper {
-        private static final String DATABASE_NAME = "services.db";
-        private static final int DATABASE_VERSION = 1;
-
-        public OpenHelper(Context context) {
-            super(context, DATABASE_NAME, null, DATABASE_VERSION);
-        }
-
-        @Override
-        public void onOpen(SQLiteDatabase db) {
-            if (Build.VERSION.SDK_INT < 16)
-                db.execSQL("PRAGMA foreign_keys=ON;");
-        }
-
-        @Override
-        @RequiresApi(16)
-        public void onConfigure(SQLiteDatabase db) {
-            setWriteAheadLoggingEnabled(true);
-            db.setForeignKeyConstraintsEnabled(true);
-        }
-
-        @Override
-        public void onCreate(SQLiteDatabase db) {
-            App.log.info("Creating database " + db.getPath());
-
-            db.execSQL("CREATE TABLE " + Settings._TABLE + "(" +
-                    Settings.NAME + " TEXT NOT NULL," +
-                    Settings.VALUE + " TEXT NOT NULL" +
-            ")");
-            db.execSQL("CREATE UNIQUE INDEX settings_name ON " + Settings._TABLE + " (" + Settings.NAME + ")");
-
-            db.execSQL("CREATE TABLE " + Services._TABLE + "(" +
-                    Services.ID + " INTEGER PRIMARY KEY AUTOINCREMENT," +
-                    Services.ACCOUNT_NAME + " TEXT NOT NULL," +
-                    Services.SERVICE + " TEXT NOT NULL," +
-                    Services.PRINCIPAL + " TEXT NULL" +
-            ")");
-            db.execSQL("CREATE UNIQUE INDEX services_account ON " + Services._TABLE + " (" + Services.ACCOUNT_NAME + "," + Services.SERVICE + ")");
-
-            db.execSQL("CREATE TABLE " + HomeSets._TABLE + "(" +
-                    HomeSets.ID + " INTEGER PRIMARY KEY AUTOINCREMENT," +
-                    HomeSets.SERVICE_ID + " INTEGER NOT NULL REFERENCES " + Services._TABLE +" ON DELETE CASCADE," +
-                    HomeSets.URL + " TEXT NOT NULL" +
-             ")");
-            db.execSQL("CREATE UNIQUE INDEX homesets_service_url ON " + HomeSets._TABLE + "(" + HomeSets.SERVICE_ID + "," + HomeSets.URL + ")");
-
-            db.execSQL("CREATE TABLE " + Collections._TABLE + "(" +
-                    Collections.ID + " INTEGER PRIMARY KEY AUTOINCREMENT," +
-                    Collections.SERVICE_ID + " INTEGER NOT NULL REFERENCES " + Services._TABLE +" ON DELETE CASCADE," +
-                    Collections.URL + " TEXT NOT NULL," +
-                    Collections.READ_ONLY + " INTEGER DEFAULT 0 NOT NULL," +
-                    Collections.DISPLAY_NAME + " TEXT NULL," +
-                    Collections.DESCRIPTION + " TEXT NULL," +
-                    Collections.COLOR + " INTEGER NULL," +
-                    Collections.TIME_ZONE + " TEXT NULL," +
-                    Collections.SUPPORTS_VEVENT + " INTEGER NULL," +
-                    Collections.SUPPORTS_VTODO + " INTEGER NULL," +
-                    Collections.SYNC + " INTEGER DEFAULT 0 NOT NULL" +
-            ")");
-            db.execSQL("CREATE UNIQUE INDEX collections_service_url ON " + Collections._TABLE + "(" + Collections.SERVICE_ID + "," + Collections.URL + ")");
-        }
-
-        @Override
-        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
-            // no different versions yet
-        }
-
-
-        public void dump(StringBuilder sb) {
-            SQLiteDatabase db = getReadableDatabase();
-            db.beginTransactionNonExclusive();
-
-            // iterate through all tables
-            @Cleanup Cursor cursorTables = db.query("sqlite_master", new String[] { "name" }, "type='table'", null, null, null, null);
-            while (cursorTables.moveToNext()) {
-                String table = cursorTables.getString(0);
-                sb.append(table).append("\n");
-                @Cleanup Cursor cursor = db.query(table, null, null, null, null, null, null);
-
-                // print columns
-                int cols = cursor.getColumnCount();
-                sb.append("\t| ");
-                for (int i = 0; i < cols; i++) {
-                    sb.append(" ");
-                    sb.append(cursor.getColumnName(i));
-                    sb.append(" |");
-                }
-                sb.append("\n");
-
-                // print rows
-                while (cursor.moveToNext()) {
-                    sb.append("\t| ");
-                    for (int i = 0; i < cols; i++) {
-                        sb.append(" ");
-                        try {
-                            String value = cursor.getString(i);
-                            if (value != null)
-                                sb.append(value
-                                        .replace("\r", "<CR>")
-                                        .replace("\n", "<LF>"));
-                            else
-                                sb.append("<null>");
-
-                        } catch (SQLiteException e) {
-                            sb.append("<unprintable>");
-                        }
-                        sb.append(" |");
-                    }
-                    sb.append("\n");
-                }
-                sb.append("----------\n");
-            }
-            db.endTransaction();
-        }
-    }
-
-
-    public static void onRenameAccount(@NonNull SQLiteDatabase db, @NonNull String oldName, @NonNull String newName) {
-        ContentValues values = new ContentValues(1);
-        values.put(Services.ACCOUNT_NAME, newName);
-        db.update(Services._TABLE, values, Services.ACCOUNT_NAME + "=?", new String[] { oldName });
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/model/ServiceDB.kt

@@ -0,0 +1,224 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.model
+
+import android.content.ContentValues
+import android.content.Context
+import android.database.sqlite.SQLiteDatabase
+import android.database.sqlite.SQLiteException
+import android.database.sqlite.SQLiteOpenHelper
+import android.preference.PreferenceManager
+import at.bitfire.davdroid.App
+import at.bitfire.davdroid.log.Logger
+import at.bitfire.davdroid.ui.StartupDialogFragment
+import java.io.Closeable
+import java.util.logging.Level
+
+class ServiceDB {
+
+    /*object Settings {
+        @JvmField val _TABLE = "settings"
+        @JvmField val NAME = "setting"
+        @JvmField val VALUE = "value"
+    }*/
+
+    object Services {
+        @JvmField val _TABLE = "services"
+        @JvmField val ID = "_id"
+        @JvmField val ACCOUNT_NAME = "accountName"
+        @JvmField val SERVICE = "service"
+        @JvmField val PRINCIPAL = "principal"
+
+        // allowed values for SERVICE column
+        @JvmField val SERVICE_CALDAV = "caldav"
+        @JvmField val SERVICE_CARDDAV = "carddav"
+    }
+
+    object HomeSets {
+        @JvmField val _TABLE = "homesets"
+        @JvmField val ID = "_id"
+        @JvmField val SERVICE_ID = "serviceID"
+        @JvmField val URL = "url"
+    }
+
+    object Collections {
+        @JvmField val _TABLE = "collections"
+        @JvmField val ID = "_id"
+        @JvmField val TYPE = "type"
+        @JvmField val SERVICE_ID = "serviceID"
+        @JvmField val URL = "url"
+        @JvmField val READ_ONLY = "readOnly"
+        @JvmField val DISPLAY_NAME = "displayName"
+        @JvmField val DESCRIPTION = "description"
+        @JvmField val COLOR = "color"
+        @JvmField val TIME_ZONE = "timezone"
+        @JvmField val SUPPORTS_VEVENT = "supportsVEVENT"
+        @JvmField val SUPPORTS_VTODO = "supportsVTODO"
+        @JvmField val SOURCE = "source"
+        @JvmField val SYNC = "sync"
+    }
+
+    companion object {
+
+        @JvmStatic
+        fun onRenameAccount(db: SQLiteDatabase, oldName: String, newName: String) {
+            val values = ContentValues(1)
+            values.put(Services.ACCOUNT_NAME, newName)
+            db.updateWithOnConflict(Services._TABLE, values, Services.ACCOUNT_NAME + "=?", arrayOf(oldName), SQLiteDatabase.CONFLICT_REPLACE)
+        }
+
+    }
+
+
+    class OpenHelper(
+            val context: Context
+    ): SQLiteOpenHelper(context, DATABASE_NAME, null, DATABASE_VERSION), Closeable {
+
+        companion object {
+            val DATABASE_NAME = "services.db"
+            val DATABASE_VERSION = 3
+        }
+
+        override fun onConfigure(db: SQLiteDatabase) {
+            setWriteAheadLoggingEnabled(true)
+            db.setForeignKeyConstraintsEnabled(true)
+        }
+
+        override fun onCreate(db: SQLiteDatabase) {
+            Logger.log.info("Creating database " + db.path)
+
+            db.execSQL("CREATE TABLE ${Services._TABLE}(" +
+                    "${Services.ID} INTEGER PRIMARY KEY AUTOINCREMENT," +
+                    "${Services.ACCOUNT_NAME} TEXT NOT NULL," +
+                    "${Services.SERVICE} TEXT NOT NULL," +
+                    "${Services.PRINCIPAL} TEXT NULL)")
+            db.execSQL("CREATE UNIQUE INDEX services_account ON ${Services._TABLE} (${Services.ACCOUNT_NAME},${Services.SERVICE})")
+
+            db.execSQL("CREATE TABLE ${HomeSets._TABLE}(" +
+                    "${HomeSets.ID} INTEGER PRIMARY KEY AUTOINCREMENT," +
+                    "${HomeSets.SERVICE_ID} INTEGER NOT NULL REFERENCES ${Services._TABLE} ON DELETE CASCADE," +
+                    "${HomeSets.URL} TEXT NOT NULL)")
+            db.execSQL("CREATE UNIQUE INDEX homesets_service_url ON ${HomeSets._TABLE}(${HomeSets.SERVICE_ID},${HomeSets.URL})")
+
+            db.execSQL("CREATE TABLE ${Collections._TABLE}(" +
+                    "${Collections.ID} INTEGER PRIMARY KEY AUTOINCREMENT," +
+                    "${Collections.SERVICE_ID} INTEGER NOT NULL REFERENCES ${Services._TABLE} ON DELETE CASCADE," +
+                    "${Collections.TYPE} TEXT NOT NULL," +
+                    "${Collections.URL} TEXT NOT NULL," +
+                    "${Collections.READ_ONLY} INTEGER DEFAULT 0 NOT NULL," +
+                    "${Collections.DISPLAY_NAME} TEXT NULL," +
+                    "${Collections.DESCRIPTION} TEXT NULL," +
+                    "${Collections.COLOR} INTEGER NULL," +
+                    "${Collections.TIME_ZONE} TEXT NULL," +
+                    "${Collections.SUPPORTS_VEVENT} INTEGER NULL," +
+                    "${Collections.SUPPORTS_VTODO} INTEGER NULL," +
+                    "${Collections.SOURCE} TEXT NULL," +
+                    "${Collections.SYNC} INTEGER DEFAULT 0 NOT NULL)")
+            db.execSQL("CREATE UNIQUE INDEX collections_service_url ON ${Collections._TABLE}(${Collections.SERVICE_ID},${Collections.URL})")
+        }
+
+        override fun onUpgrade(db: SQLiteDatabase, oldVersion: Int, newVersion: Int) {
+            for (upgradeFrom in oldVersion until newVersion) {
+                val upgradeTo = oldVersion + 1
+                Logger.log.info("Upgrading database from version $upgradeFrom to $upgradeTo")
+                try {
+                    val upgradeProc = this::class.java.getDeclaredMethod("upgrade_${upgradeFrom}_$upgradeTo", SQLiteDatabase::class.java)
+                    upgradeProc.invoke(this, db)
+                } catch(e: Exception) {
+                    Logger.log.log(Level.SEVERE, "Couldn't upgrade database", e)
+                }
+            }
+        }
+
+        @Suppress("unused")
+        private fun upgrade_2_3(db: SQLiteDatabase) {
+            val edit = PreferenceManager.getDefaultSharedPreferences(context).edit()
+            try {
+                db.query("settings", arrayOf("setting", "value"), null, null, null, null, null).use { cursor ->
+                    while (cursor.moveToNext()) {
+                        when (cursor.getString(0)) {
+                            "distrustSystemCerts" -> edit.putBoolean(App.DISTRUST_SYSTEM_CERTIFICATES, cursor.getInt(1) != 0)
+                            "overrideProxy" -> edit.putBoolean(App.OVERRIDE_PROXY, cursor.getInt(1) != 0)
+                            "overrideProxyHost" -> edit.putString(App.OVERRIDE_PROXY_HOST, cursor.getString(1))
+                            "overrideProxyPort" -> edit.putInt(App.OVERRIDE_PROXY_PORT, cursor.getInt(1))
+
+                            StartupDialogFragment.HINT_GOOGLE_PLAY_ACCOUNTS_REMOVED ->
+                                edit.putBoolean(StartupDialogFragment.HINT_GOOGLE_PLAY_ACCOUNTS_REMOVED, cursor.getInt(1) != 0)
+                            StartupDialogFragment.HINT_OPENTASKS_NOT_INSTALLED ->
+                                edit.putBoolean(StartupDialogFragment.HINT_OPENTASKS_NOT_INSTALLED, cursor.getInt(1) != 0)
+                        }
+                    }
+                }
+                db.execSQL("DROP TABLE settings")
+            } finally {
+                edit.apply()
+            }
+        }
+
+        @Suppress("unused")
+        private fun upgrade_1_2(db: SQLiteDatabase) {
+            db.execSQL("ALTER TABLE ${Collections._TABLE} ADD COLUMN ${Collections.TYPE} TEXT NOT NULL DEFAULT ''")
+            db.execSQL("ALTER TABLE ${Collections._TABLE} ADD COLUMN ${Collections.SOURCE} TEXT NULL")
+            db.execSQL("UPDATE ${Collections._TABLE} SET ${Collections.TYPE}=(" +
+                    "SELECT CASE ${Services.SERVICE} WHEN ? THEN ? ELSE ? END " +
+                    "FROM ${Services._TABLE} WHERE ${Services.ID}=${Collections._TABLE}.${Collections.SERVICE_ID}" +
+                    ")",
+                    arrayOf(Services.SERVICE_CALDAV, CollectionInfo.Type.CALENDAR, CollectionInfo.Type.ADDRESS_BOOK))
+        }
+
+
+        fun dump(sb: StringBuilder) {
+            val db = readableDatabase
+            db.beginTransactionNonExclusive()
+
+            // iterate through all tables
+            db.query("sqlite_master", arrayOf("name"), "type='table'", null, null, null, null).use { cursorTables ->
+                while (cursorTables.moveToNext()) {
+                    val table = cursorTables.getString(0)
+                    sb.append(table).append("\n")
+                    db.query(table, null, null, null, null, null, null).use { cursor ->
+                        // print columns
+                        val cols = cursor.columnCount
+                        sb.append("\t| ")
+                        for (i in 0 .. cols-1)
+                            sb  .append(" ")
+                                .append(cursor.getColumnName(i))
+                                .append(" |")
+                        sb.append("\n")
+
+                        // print rows
+                        while (cursor.moveToNext()) {
+                            sb.append("\t| ")
+                            for (i in 0 .. cols-1) {
+                                sb.append(" ")
+                                try {
+                                    val value = cursor.getString(i)
+                                    if (value != null)
+                                        sb.append(value
+                                                .replace("\r", "<CR>")
+                                                .replace("\n", "<LF>"))
+                                    else
+                                        sb.append("<null>")
+
+                                } catch (e: SQLiteException) {
+                                    sb.append("<unprintable>")
+                                }
+                                sb.append(" |")
+                            }
+                            sb.append("\n")
+                        }
+                        sb.append("----------\n")
+                    }
+                }
+                db.endTransaction()
+            }
+        }
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/model/Settings.java

@@ -1,83 +0,0 @@
-/*
- * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.model;
-
-import android.content.ContentValues;
-import android.database.Cursor;
-import android.database.sqlite.SQLiteDatabase;
-import android.support.annotation.Nullable;
-
-import lombok.Cleanup;
-
-public class Settings {
-
-    final SQLiteDatabase db;
-
-    public Settings(SQLiteDatabase db) {
-        this.db = db;
-    }
-
-
-    public boolean getBoolean(String name, boolean defaultValue) {
-        @Cleanup Cursor cursor = db.query(ServiceDB.Settings._TABLE, new String[] { ServiceDB.Settings.VALUE },
-                ServiceDB.Settings.NAME + "=?", new String[] { name }, null, null, null);
-        if (cursor.moveToNext() && !cursor.isNull(0))
-            return cursor.getInt(0) != 0;
-        else
-            return defaultValue;
-    }
-
-    public void putBoolean(String name, boolean value) {
-        ContentValues values = new ContentValues(2);
-        values.put(ServiceDB.Settings.NAME, name);
-        values.put(ServiceDB.Settings.VALUE, value ? 1 : 0);
-        db.insertWithOnConflict(ServiceDB.Settings._TABLE, null, values, SQLiteDatabase.CONFLICT_REPLACE);
-    }
-
-
-    public int getInt(String name, int defaultValue) {
-        @Cleanup Cursor cursor = db.query(ServiceDB.Settings._TABLE, new String[] { ServiceDB.Settings.VALUE },
-                ServiceDB.Settings.NAME + "=?", new String[] { name }, null, null, null);
-        if (cursor.moveToNext() && !cursor.isNull(0))
-            return cursor.isNull(0) ? defaultValue : cursor.getInt(0);
-        else
-            return defaultValue;
-    }
-
-    public void putInt(String name, int value) {
-        ContentValues values = new ContentValues(2);
-        values.put(ServiceDB.Settings.NAME, name);
-        values.put(ServiceDB.Settings.VALUE, value);
-        db.insertWithOnConflict(ServiceDB.Settings._TABLE, null, values, SQLiteDatabase.CONFLICT_REPLACE);
-    }
-
-
-    @Nullable
-    public String getString(String name, @Nullable String defaultValue) {
-        @Cleanup Cursor cursor = db.query(ServiceDB.Settings._TABLE, new String[] { ServiceDB.Settings.VALUE },
-                ServiceDB.Settings.NAME + "=?", new String[] { name }, null, null, null);
-        if (cursor.moveToNext())
-            return cursor.getString(0);
-        else
-            return defaultValue;
-    }
-
-    public void putString(String name, @Nullable String value) {
-        ContentValues values = new ContentValues(2);
-        values.put(ServiceDB.Settings.NAME, name);
-        values.put(ServiceDB.Settings.VALUE, value);
-        db.insertWithOnConflict(ServiceDB.Settings._TABLE, null, values, SQLiteDatabase.CONFLICT_REPLACE);
-    }
-
-
-    public void remove(String name) {
-        db.delete(ServiceDB.Settings._TABLE, ServiceDB.Settings.NAME + "=?", new String[] { name });
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/model/UnknownProperties.java

@@ -1,22 +0,0 @@
-/*
- * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.model;
-
-import android.provider.ContactsContract.RawContacts;
-
-public class UnknownProperties {
-
-    public static final String CONTENT_ITEM_TYPE = "x.davdroid/unknown-properties";
-
-    public static final String
-            MIMETYPE = RawContacts.Data.MIMETYPE,
-            RAW_CONTACT_ID = RawContacts.Data.RAW_CONTACT_ID,
-            UNKNOWN_PROPERTIES = RawContacts.Data.DATA1;
-
-}

app/src/main/java/at/bitfire/davdroid/model/UnknownProperties.kt

@@ -0,0 +1,28 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.model;
+
+import android.provider.ContactsContract.RawContacts;
+
+object UnknownProperties {
+
+    @JvmField
+    val CONTENT_ITEM_TYPE = "x.davdroid/unknown-properties"
+
+
+    @JvmField
+    val MIMETYPE = RawContacts.Data.MIMETYPE
+
+    @JvmField
+    val RAW_CONTACT_ID = RawContacts.Data.RAW_CONTACT_ID
+
+    @JvmField
+    val UNKNOWN_PROPERTIES = RawContacts.Data.DATA1
+
+}

app/src/main/java/at/bitfire/davdroid/resource/LocalAddressBook.java

@@ -1,319 +0,0 @@
-/*
- * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-package at.bitfire.davdroid.resource;
-
-import android.accounts.Account;
-import android.content.ContentProviderClient;
-import android.content.ContentResolver;
-import android.content.ContentUris;
-import android.content.ContentValues;
-import android.database.Cursor;
-import android.net.Uri;
-import android.os.Build;
-import android.os.Bundle;
-import android.os.Parcel;
-import android.os.RemoteException;
-import android.provider.ContactsContract;
-import android.provider.ContactsContract.CommonDataKinds.GroupMembership;
-import android.provider.ContactsContract.Groups;
-import android.provider.ContactsContract.RawContacts;
-import android.support.annotation.NonNull;
-
-import java.io.FileNotFoundException;
-import java.util.Collections;
-import java.util.HashSet;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Set;
-import java.util.logging.Level;
-
-import at.bitfire.davdroid.App;
-import at.bitfire.vcard4android.AndroidAddressBook;
-import at.bitfire.vcard4android.AndroidContact;
-import at.bitfire.vcard4android.AndroidGroup;
-import at.bitfire.vcard4android.CachedGroupMembership;
-import at.bitfire.vcard4android.ContactsStorageException;
-import lombok.Cleanup;
-
-
-public class LocalAddressBook extends AndroidAddressBook implements LocalCollection {
-
-    protected static final String
-            SYNC_STATE_CTAG = "ctag",
-            SYNC_STATE_URL = "url";
-
-    private final Bundle syncState = new Bundle();
-
-    /**
-     * Whether contact groups (LocalGroup resources) are included in query results for
-     * {@link #getAll()}, {@link #getDeleted()}, {@link #getDirty()} and
-     * {@link #getWithoutFileName()}.
-     */
-    public boolean includeGroups = true;
-
-
-    public LocalAddressBook(Account account, ContentProviderClient provider) {
-        super(account, provider, LocalGroup.Factory.INSTANCE, LocalContact.Factory.INSTANCE);
-    }
-
-    @NonNull
-    public LocalContact findContactByUID(String uid) throws ContactsStorageException, FileNotFoundException {
-        LocalContact[] contacts = (LocalContact[])queryContacts(LocalContact.COLUMN_UID + "=?", new String[] { uid });
-        if (contacts.length == 0)
-            throw new FileNotFoundException();
-        return contacts[0];
-    }
-
-    @Override
-    @NonNull
-    public LocalResource[] getAll() throws ContactsStorageException {
-        List<LocalResource> all = new LinkedList<>();
-        Collections.addAll(all, (LocalResource[])queryContacts(null, null));
-        if (includeGroups)
-            Collections.addAll(all, (LocalResource[])queryGroups(null, null));
-        return all.toArray(new LocalResource[all.size()]);
-    }
-
-    /**
-     * Returns an array of local contacts/groups which have been deleted locally. (DELETED != 0).
-     */
-    @Override
-    @NonNull
-    public LocalResource[] getDeleted() throws ContactsStorageException {
-        List<LocalResource> deleted = new LinkedList<>();
-        Collections.addAll(deleted, getDeletedContacts());
-        if (includeGroups)
-            Collections.addAll(deleted, getDeletedGroups());
-        return deleted.toArray(new LocalResource[deleted.size()]);
-    }
-
-    /**
-     * Queries all contacts with DIRTY flag and checks whether their data checksum has changed, i.e.
-     * if they're "really dirty" (= data has changed, not only metadata, which is not hashed).
-     * The DIRTY flag is removed from contacts which are not "really dirty", i.e. from contacts
-     * whose contact data checksum has not changed.
-     * @return number of "really dirty" contacts
-     */
-    public int verifyDirty() throws ContactsStorageException {
-        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N)
-            App.log.severe("verifyDirty() should not be called on Android <7");
-
-        int reallyDirty = 0;
-        for (LocalContact contact : getDirtyContacts()) {
-            try {
-                int lastHash = contact.getLastHashCode(),
-                    currentHash = contact.dataHashCode();
-                if (lastHash == currentHash) {
-                    // hash is code still the same, contact is not "really dirty" (only metadata been have changed)
-                    App.log.log(Level.FINE, "Contact data hash has not changed, resetting dirty flag", contact);
-                    contact.resetDirty();
-                } else {
-                    App.log.log(Level.FINE, "Contact data has changed from hash " + lastHash + " to " + currentHash, contact);
-                    reallyDirty++;
-                }
-            } catch(FileNotFoundException e) {
-                throw new ContactsStorageException("Couldn't calculate hash code", e);
-            }
-        }
-
-        if (includeGroups)
-            reallyDirty += getDirtyGroups().length;
-
-        return reallyDirty;
-    }
-
-    /**
-     * Returns an array of local contacts/groups which have been changed locally (DIRTY != 0).
-     */
-    @Override
-    @NonNull
-    public LocalResource[] getDirty() throws ContactsStorageException {
-        List<LocalResource> dirty = new LinkedList<>();
-        Collections.addAll(dirty, getDirtyContacts());
-        if (includeGroups)
-            Collections.addAll(dirty, getDirtyGroups());
-        return dirty.toArray(new LocalResource[dirty.size()]);
-    }
-
-    /**
-     * Returns an array of local contacts which don't have a file name yet.
-     */
-    @Override
-    @NonNull
-    public LocalResource[] getWithoutFileName() throws ContactsStorageException {
-        List<LocalResource> nameless = new LinkedList<>();
-        Collections.addAll(nameless, (LocalContact[])queryContacts(AndroidContact.COLUMN_FILENAME + " IS NULL", null));
-        if (includeGroups)
-            Collections.addAll(nameless, (LocalGroup[])queryGroups(AndroidGroup.COLUMN_FILENAME + " IS NULL", null));
-        return nameless.toArray(new LocalResource[nameless.size()]);
-    }
-
-
-    @NonNull
-    public LocalContact[] getDeletedContacts() throws ContactsStorageException {
-        return (LocalContact[])queryContacts(RawContacts.DELETED + "!= 0", null);
-    }
-
-    @NonNull
-    public LocalContact[] getDirtyContacts() throws ContactsStorageException {
-        return (LocalContact[])queryContacts(RawContacts.DIRTY + "!= 0", null);
-    }
-
-    @NonNull
-    public LocalGroup[] getDeletedGroups() throws ContactsStorageException {
-        return (LocalGroup[])queryGroups(Groups.DELETED + "!= 0", null);
-    }
-
-    @NonNull
-    public LocalGroup[] getDirtyGroups() throws ContactsStorageException {
-        return (LocalGroup[])queryGroups(Groups.DIRTY + "!= 0", null);
-    }
-
-    @NonNull LocalContact[] getByGroupMembership(long groupID) throws ContactsStorageException {
-        try {
-            @Cleanup Cursor cursor = provider.query(syncAdapterURI(ContactsContract.Data.CONTENT_URI),
-                    new String[] { RawContacts.Data.RAW_CONTACT_ID },
-                    "(" + GroupMembership.MIMETYPE + "=? AND " + GroupMembership.GROUP_ROW_ID + "=?) OR (" + CachedGroupMembership.MIMETYPE + "=? AND " + CachedGroupMembership.GROUP_ID + "=?)",
-                    new String[] { GroupMembership.CONTENT_ITEM_TYPE, String.valueOf(groupID), CachedGroupMembership.CONTENT_ITEM_TYPE, String.valueOf(groupID) },
-                    null);
-
-            Set<Long> ids = new HashSet<>();
-            while (cursor != null && cursor.moveToNext())
-                ids.add(cursor.getLong(0));
-
-            LocalContact[] contacts = new LocalContact[ids.size()];
-            int i = 0;
-            for (Long id : ids)
-                contacts[i++] = new LocalContact(this, id, null, null);
-            return contacts;
-        } catch (RemoteException e) {
-            throw new ContactsStorageException("Couldn't query contacts", e);
-        }
-    }
-
-
-    public void deleteAll() throws ContactsStorageException {
-        try {
-            provider.delete(syncAdapterURI(RawContacts.CONTENT_URI), null, null);
-            provider.delete(syncAdapterURI(Groups.CONTENT_URI), null, null);
-        } catch(RemoteException e) {
-            throw new ContactsStorageException("Couldn't delete all local contacts and groups", e);
-        }
-    }
-
-
-    /**
-     * Finds the first group with the given title. If there is no group with this
-     * title, a new group is created.
-     * @param title     title of the group to look for
-     * @return          id of the group with given title
-     * @throws ContactsStorageException on contact provider errors
-     */
-    public long findOrCreateGroup(@NonNull String title) throws ContactsStorageException {
-        try {
-            @Cleanup Cursor cursor = provider.query(syncAdapterURI(Groups.CONTENT_URI),
-                    new String[] { Groups._ID  },
-                    Groups.TITLE + "=?", new String[] { title },
-                    null);
-            if (cursor != null && cursor.moveToNext())
-                return cursor.getLong(0);
-
-            ContentValues values = new ContentValues();
-            values.put(Groups.TITLE, title);
-            Uri uri = provider.insert(syncAdapterURI(Groups.CONTENT_URI), values);
-            return ContentUris.parseId(uri);
-        } catch(RemoteException e) {
-            throw new ContactsStorageException("Couldn't find local contact group", e);
-        }
-    }
-
-    public void removeEmptyGroups() throws ContactsStorageException {
-        // find groups without members
-        /** should be done using {@link Groups.SUMMARY_COUNT}, but it's not implemented in Android yet */
-        for (LocalGroup group : (LocalGroup[])queryGroups(null, null))
-            if (group.getMembers().length == 0) {
-                App.log.log(Level.FINE, "Deleting group", group);
-                group.delete();
-            }
-    }
-
-    public void removeGroups() throws ContactsStorageException {
-        try {
-            provider.delete(syncAdapterURI(Groups.CONTENT_URI), null, null);
-        } catch(RemoteException e) {
-            throw new ContactsStorageException("Couldn't remove all groups", e);
-        }
-    }
-
-
-    // SYNC STATE
-
-    @SuppressWarnings("ParcelClassLoader,Recycle")
-    protected void readSyncState() throws ContactsStorageException {
-        @Cleanup("recycle") Parcel parcel = Parcel.obtain();
-        byte[] raw = getSyncState();
-        syncState.clear();
-        if (raw != null) {
-            parcel.unmarshall(raw, 0, raw.length);
-            parcel.setDataPosition(0);
-            syncState.putAll(parcel.readBundle());
-        }
-    }
-
-    @SuppressWarnings("Recycle")
-    protected void writeSyncState() throws ContactsStorageException {
-        @Cleanup("recycle") Parcel parcel = Parcel.obtain();
-        parcel.writeBundle(syncState);
-        setSyncState(parcel.marshall());
-    }
-
-    public String getURL() throws ContactsStorageException {
-        synchronized (syncState) {
-            readSyncState();
-            return syncState.getString(SYNC_STATE_URL);
-        }
-    }
-
-    public void setURL(String url) throws ContactsStorageException {
-        synchronized (syncState) {
-            readSyncState();
-            syncState.putString(SYNC_STATE_URL, url);
-            writeSyncState();
-        }
-    }
-
-    @Override
-    public String getCTag() throws ContactsStorageException {
-        synchronized (syncState) {
-            readSyncState();
-            return syncState.getString(SYNC_STATE_CTAG);
-        }
-    }
-
-    @Override
-    public void setCTag(String cTag) throws ContactsStorageException {
-        synchronized (syncState) {
-            readSyncState();
-            syncState.putString(SYNC_STATE_CTAG, cTag);
-            writeSyncState();
-        }
-    }
-
-
-    // HELPERS
-
-    public static void onRenameAccount(@NonNull ContentResolver resolver, @NonNull String oldName, @NonNull String newName) throws RemoteException {
-        @Cleanup("release") ContentProviderClient client = resolver.acquireContentProviderClient(ContactsContract.AUTHORITY);
-        if (client != null) {
-            ContentValues values = new ContentValues(1);
-            values.put(RawContacts.ACCOUNT_NAME, newName);
-            client.update(RawContacts.CONTENT_URI, values, RawContacts.ACCOUNT_NAME + "=?", new String[]{oldName});
-        }
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/resource/LocalAddressBook.kt

@@ -0,0 +1,359 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+package at.bitfire.davdroid.resource
+
+import android.accounts.Account
+import android.accounts.AccountManager
+import android.content.*
+import android.os.Build
+import android.os.Bundle
+import android.os.RemoteException
+import android.provider.ContactsContract
+import android.provider.ContactsContract.CommonDataKinds.GroupMembership
+import android.provider.ContactsContract.Groups
+import android.provider.ContactsContract.RawContacts
+import android.util.Base64
+import at.bitfire.davdroid.DavUtils
+import at.bitfire.davdroid.R
+import at.bitfire.davdroid.log.Logger
+import at.bitfire.davdroid.model.CollectionInfo
+import at.bitfire.vcard4android.*
+import java.io.ByteArrayOutputStream
+import java.io.FileNotFoundException
+import java.util.*
+import java.util.logging.Level
+
+class LocalAddressBook(
+        private val context: Context,
+        account: Account,
+        provider: ContentProviderClient?
+): AndroidAddressBook<LocalContact, LocalGroup>(account, provider, LocalContact.Factory, LocalGroup.Factory), LocalCollection<LocalResource> {
+
+    companion object {
+
+        val USER_DATA_MAIN_ACCOUNT_TYPE = "real_account_type"
+        val USER_DATA_MAIN_ACCOUNT_NAME = "real_account_name"
+        val USER_DATA_URL = "url"
+        val USER_DATA_READ_ONLY = "read_only"
+        val USER_DATA_CTAG = "ctag"
+
+        @JvmStatic
+        @Throws(ContactsStorageException::class)
+        fun create(context: Context, provider: ContentProviderClient, mainAccount: Account, info: CollectionInfo): LocalAddressBook {
+            val accountManager = AccountManager.get(context)
+
+            val account = Account(accountName(mainAccount, info), context.getString(R.string.account_type_address_book))
+            if (!accountManager.addAccountExplicitly(account, null, initialUserData(mainAccount, info.url)))
+                throw ContactsStorageException("Couldn't create address book account")
+
+            val addressBook = LocalAddressBook(context, account, provider)
+            ContentResolver.setSyncAutomatically(account, ContactsContract.AUTHORITY, true)
+            return addressBook
+        }
+
+        @JvmStatic
+        @Throws(ContactsStorageException::class)
+        fun find(context: Context, provider: ContentProviderClient, mainAccount: Account?): List<LocalAddressBook> {
+            val accountManager = AccountManager.get(context)
+
+            val result = LinkedList<LocalAddressBook>()
+            accountManager.getAccountsByType(context.getString(R.string.account_type_address_book))
+                    .map { LocalAddressBook(context, it, provider) }
+                    .filter { mainAccount == null || it.getMainAccount() == mainAccount }
+                    .forEach { result += it }
+
+            return result
+        }
+
+        @JvmStatic
+        fun accountName(mainAccount: Account, info: CollectionInfo): String {
+            val baos = ByteArrayOutputStream()
+            baos.write(info.url.hashCode())
+            val hash = Base64.encodeToString(baos.toByteArray(), Base64.NO_WRAP or Base64.NO_PADDING)
+
+            val sb = StringBuilder(if (info.displayName.isNullOrEmpty()) DavUtils.lastSegmentOfUrl(info.url) else info.displayName)
+            sb      .append(" (")
+                    .append(mainAccount.name)
+                    .append(" ")
+                    .append(hash)
+                    .append(")")
+            return sb.toString()
+        }
+
+        @JvmStatic
+        fun initialUserData(mainAccount: Account, url: String): Bundle {
+            val bundle = Bundle(3)
+            bundle.putString(USER_DATA_MAIN_ACCOUNT_NAME, mainAccount.name)
+            bundle.putString(USER_DATA_MAIN_ACCOUNT_TYPE, mainAccount.type)
+            bundle.putString(USER_DATA_URL, url)
+            return bundle
+        }
+
+    }
+
+    /**
+     * Whether contact groups (LocalGroup resources) are included in query results for
+     * {@link #getAll()}, {@link #getDeleted()}, {@link #getDirty()} and
+     * {@link #getWithoutFileName()}.
+     */
+    var includeGroups = true
+
+
+    /* operations on the collection (address book) itself */
+
+    @Throws(ContactsStorageException::class)
+    fun update(info: CollectionInfo) {
+        val newAccountName = accountName(getMainAccount(), info)
+        if (account.name != newAccountName && Build.VERSION.SDK_INT >= 21) {
+            val accountManager = AccountManager.get(context)
+            val future = accountManager.renameAccount(account, newAccountName, {
+                try {
+                    // update raw contacts to new account name
+                    provider?.let { provider ->
+                        val values = ContentValues(1)
+                        values.put(RawContacts.ACCOUNT_NAME, newAccountName)
+                        provider.update(syncAdapterURI(RawContacts.CONTENT_URI), values, "${RawContacts.ACCOUNT_NAME}=?", arrayOf(account.name))
+                    }
+                } catch(e: RemoteException) {
+                    Logger.log.log(Level.WARNING, "Couldn't re-assign contacts to new account name", e)
+                }
+            }, null)
+            account = future.result
+        }
+
+        Constants.log.info("Address book read-only? = ${info.readOnly}")
+        setReadOnly(info.readOnly)
+
+        // make sure it will still be synchronized when contacts are updated
+        ContentResolver.setSyncAutomatically(account, ContactsContract.AUTHORITY, true)
+    }
+
+    @Throws(ContactsStorageException::class)
+    fun delete() {
+        val accountManager = AccountManager.get(context)
+        try {
+            if (Build.VERSION.SDK_INT >= 22)
+                accountManager.removeAccount(account, null, null, null)
+            else
+                @Suppress("deprecation")
+                accountManager.removeAccount(account, null, null)
+        } catch(e: Exception) {
+            throw ContactsStorageException("Couldn't remove address book", e)
+        }
+    }
+
+
+    /* operations on members (contacts/groups) */
+
+    @Throws(ContactsStorageException::class, FileNotFoundException::class)
+    fun findContactByUID(uid: String): LocalContact {
+        val contacts = queryContacts("${AndroidContact.COLUMN_UID}=?", arrayOf(uid))
+        if (contacts.isEmpty())
+            throw FileNotFoundException()
+        return contacts.first()
+    }
+
+    @Throws(ContactsStorageException::class)
+    override fun getAll(): List<LocalResource> {
+        val all = LinkedList<LocalResource>()
+        all.addAll(queryContacts(null, null))
+        if (includeGroups)
+            all.addAll(queryGroups(null, null))
+        return all
+    }
+
+    /**
+     * Returns an array of local contacts/groups which have been deleted locally. (DELETED != 0).
+     */
+    @Throws(ContactsStorageException::class)
+    override fun getDeleted(): List<LocalResource> {
+        val deleted = LinkedList<LocalResource>()
+        deleted.addAll(getDeletedContacts())
+        if (includeGroups)
+            deleted.addAll(getDeletedGroups())
+        return deleted
+    }
+
+    /**
+     * Queries all contacts with DIRTY flag and checks whether their data checksum has changed, i.e.
+     * if they're "really dirty" (= data has changed, not only metadata, which is not hashed).
+     * The DIRTY flag is removed from contacts which are not "really dirty", i.e. from contacts
+     * whose contact data checksum has not changed.
+     * @return number of "really dirty" contacts
+     */
+    @Throws(ContactsStorageException::class)
+    fun verifyDirty(): Int {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N || Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
+            throw IllegalStateException("verifyDirty() should not be called on Android != 7")
+
+        var reallyDirty = 0
+        for (contact in getDirtyContacts())
+            try {
+                val lastHash = contact.getLastHashCode()
+                val currentHash = contact.dataHashCode()
+                if (lastHash == currentHash) {
+                    // hash is code still the same, contact is not "really dirty" (only metadata been have changed)
+                    Logger.log.log(Level.FINE, "Contact data hash has not changed, resetting dirty flag", contact)
+                    contact.resetDirty()
+                } else {
+                    Logger.log.log(Level.FINE, "Contact data has changed from hash $lastHash to $currentHash", contact)
+                    reallyDirty++
+                }
+            } catch(e: FileNotFoundException) {
+                throw ContactsStorageException("Couldn't calculate hash code", e)
+            }
+
+        if (includeGroups)
+            reallyDirty += getDirtyGroups().size
+
+        return reallyDirty
+    }
+
+    /**
+     * Returns an array of local contacts/groups which have been changed locally (DIRTY != 0).
+     */
+    @Throws(ContactsStorageException::class)
+    override fun getDirty(): List<LocalResource> {
+        val dirty = LinkedList<LocalResource>()
+        dirty.addAll(getDirtyContacts())
+        if (includeGroups)
+            dirty.addAll(getDirtyGroups())
+        return dirty
+    }
+
+    /**
+     * Returns an array of local contacts which don't have a file name yet.
+     */
+    @Throws(ContactsStorageException::class)
+    override fun getWithoutFileName(): List<LocalResource> {
+        val nameless = LinkedList<LocalResource>()
+        nameless.addAll(queryContacts("${AndroidContact.COLUMN_FILENAME} IS NULL", null))
+        if (includeGroups)
+            nameless.addAll(queryGroups("${AndroidGroup.COLUMN_FILENAME} IS NULL", null))
+        return nameless
+    }
+
+    @Throws(ContactsStorageException::class)
+    fun getDeletedContacts() = queryContacts("${RawContacts.DELETED} != 0", null)
+
+    @Throws(ContactsStorageException::class)
+    fun getDirtyContacts() = queryContacts("${RawContacts.DIRTY} != 0", null)
+
+    @Throws(ContactsStorageException::class)
+    fun getDeletedGroups() = queryGroups("${Groups.DELETED} != 0", null)
+
+    @Throws(ContactsStorageException::class)
+    fun getDirtyGroups() = queryGroups("${Groups.DIRTY} != 0", null)
+
+    @Throws(ContactsStorageException::class)
+    fun getByGroupMembership(groupID: Long): List<LocalContact> {
+        try {
+            val ids = HashSet<Long>()
+
+            provider!!.query(syncAdapterURI(ContactsContract.Data.CONTENT_URI),
+                    arrayOf(RawContacts.Data.RAW_CONTACT_ID),
+                    "(${GroupMembership.MIMETYPE}=? AND ${GroupMembership.GROUP_ROW_ID}=?) OR (${CachedGroupMembership.MIMETYPE}=? AND ${CachedGroupMembership.GROUP_ID}=?)",
+                    arrayOf(GroupMembership.CONTENT_ITEM_TYPE, groupID.toString(), CachedGroupMembership.CONTENT_ITEM_TYPE, groupID.toString()),
+                    null)?.use { cursor ->
+                while (cursor.moveToNext())
+                    ids += cursor.getLong(0)
+            }
+
+            return ids.map { id -> LocalContact(this, id, null, null) }
+        } catch (e: RemoteException) {
+            throw ContactsStorageException("Couldn't query contacts", e)
+        }
+    }
+
+
+    /* special group operations */
+
+    /**
+     * Finds the first group with the given title. If there is no group with this
+     * title, a new group is created.
+     * @param title     title of the group to look for
+     * @return          id of the group with given title
+     * @throws ContactsStorageException on contact provider errors
+     */
+    @Throws(ContactsStorageException::class)
+    fun findOrCreateGroup(title: String): Long {
+        try {
+            provider!!.query(syncAdapterURI(Groups.CONTENT_URI), arrayOf(Groups._ID),
+                    "${Groups.TITLE}=?", arrayOf(title), null)?.use { cursor ->
+                if (cursor.moveToNext())
+                    return cursor.getLong(0)
+            }
+
+            val values = ContentValues(1)
+            values.put(Groups.TITLE, title)
+            val uri = provider.insert(syncAdapterURI(Groups.CONTENT_URI), values)
+            return ContentUris.parseId(uri)
+        } catch(e: RemoteException) {
+            throw ContactsStorageException("Couldn't find local contact group", e)
+        }
+    }
+
+    @Throws(ContactsStorageException::class)
+    fun removeEmptyGroups() {
+        // find groups without members
+        /** should be done using {@link Groups.SUMMARY_COUNT}, but it's not implemented in Android yet */
+        queryGroups(null, null).filter { it.getMembers().isEmpty() }.forEach { group ->
+            Logger.log.log(Level.FINE, "Deleting group", group)
+            group.delete()
+        }
+    }
+
+    @Throws(ContactsStorageException::class)
+    fun removeGroups() {
+        try {
+            provider!!.delete(syncAdapterURI(Groups.CONTENT_URI), null, null)
+        } catch(e: RemoteException) {
+            throw ContactsStorageException("Couldn't remove all groups", e)
+        }
+    }
+
+
+    // SETTINGS
+
+    @Throws(ContactsStorageException::class)
+    fun getMainAccount(): Account {
+        val accountManager = AccountManager.get(context)
+        val name = accountManager.getUserData(account, USER_DATA_MAIN_ACCOUNT_NAME)
+        val type = accountManager.getUserData(account, USER_DATA_MAIN_ACCOUNT_TYPE)
+        if (name != null && type != null)
+            return Account(name, type)
+        else
+            throw ContactsStorageException("Address book doesn't exist anymore")
+    }
+
+    fun setMainAccount(mainAccount: Account) {
+        val accountManager = AccountManager.get(context)
+        accountManager.setUserData(account, USER_DATA_MAIN_ACCOUNT_NAME, mainAccount.name)
+        accountManager.setUserData(account, USER_DATA_MAIN_ACCOUNT_TYPE, mainAccount.type)
+    }
+
+    @Throws(ContactsStorageException::class)
+    fun getURL() =
+            AccountManager.get(context).getUserData(account, USER_DATA_URL) ?: throw ContactsStorageException("Address book has no URL")
+
+    fun setURL(url: String) =
+            AccountManager.get(context).setUserData(account, USER_DATA_URL, url)
+
+    fun getReadOnly() =
+            AccountManager.get(context).getUserData(account, USER_DATA_READ_ONLY) != null
+
+    fun setReadOnly(readOnly: Boolean) =
+            AccountManager.get(context).setUserData(account, USER_DATA_READ_ONLY, if (readOnly) "1" else null)
+
+    override fun getCTag(): String? =
+            AccountManager.get(context).getUserData(account, USER_DATA_CTAG)
+
+    override fun setCTag(cTag: String?) =
+            AccountManager.get(context).setUserData(account, USER_DATA_CTAG, cTag)
+
+}

app/src/main/java/at/bitfire/davdroid/resource/LocalCalendar.java

@@ -1,255 +0,0 @@
-/*
- * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.resource;
-
-import android.accounts.Account;
-import android.content.ContentProviderClient;
-import android.content.ContentProviderOperation;
-import android.content.ContentUris;
-import android.content.ContentValues;
-import android.database.Cursor;
-import android.net.Uri;
-import android.os.RemoteException;
-import android.provider.CalendarContract;
-import android.provider.CalendarContract.Calendars;
-import android.provider.CalendarContract.Events;
-import android.provider.CalendarContract.Reminders;
-import android.support.annotation.NonNull;
-import android.text.TextUtils;
-
-import net.fortuna.ical4j.model.component.VTimeZone;
-
-import org.apache.commons.lang3.StringUtils;
-
-import java.io.FileNotFoundException;
-import java.util.LinkedList;
-import java.util.List;
-
-import at.bitfire.davdroid.App;
-import at.bitfire.davdroid.DavUtils;
-import at.bitfire.davdroid.model.CollectionInfo;
-import at.bitfire.ical4android.AndroidCalendar;
-import at.bitfire.ical4android.AndroidCalendarFactory;
-import at.bitfire.ical4android.BatchOperation;
-import at.bitfire.ical4android.CalendarStorageException;
-import at.bitfire.ical4android.DateUtils;
-import at.bitfire.vcard4android.ContactsStorageException;
-import lombok.Cleanup;
-
-public class LocalCalendar extends AndroidCalendar implements LocalCollection {
-
-    public static final int defaultColor = 0xFF8bc34a;     // light green 500
-
-    public static final String COLUMN_CTAG = Calendars.CAL_SYNC1;
-
-    static String[] BASE_INFO_COLUMNS = new String[] {
-            Events._ID,
-            Events._SYNC_ID,
-            LocalEvent.COLUMN_ETAG
-    };
-
-    @Override
-    protected String[] eventBaseInfoColumns() {
-        return BASE_INFO_COLUMNS;
-    }
-
-
-    protected LocalCalendar(Account account, ContentProviderClient provider, long id) {
-        super(account, provider, LocalEvent.Factory.INSTANCE, id);
-    }
-
-    public static Uri create(@NonNull Account account, @NonNull ContentProviderClient provider, @NonNull CollectionInfo info) throws CalendarStorageException {
-        ContentValues values = valuesFromCollectionInfo(info, true);
-
-        // ACCOUNT_NAME and ACCOUNT_TYPE are required (see docs)! If it's missing, other apps will crash.
-        values.put(Calendars.ACCOUNT_NAME, account.name);
-        values.put(Calendars.ACCOUNT_TYPE, account.type);
-        values.put(Calendars.OWNER_ACCOUNT, account.name);
-
-        // flag as visible & synchronizable at creation, might be changed by user at any time
-        values.put(Calendars.VISIBLE, 1);
-        values.put(Calendars.SYNC_EVENTS, 1);
-
-        return create(account, provider, values);
-    }
-
-    public void update(CollectionInfo info, boolean updateColor) throws CalendarStorageException {
-        update(valuesFromCollectionInfo(info, updateColor));
-    }
-
-    private static ContentValues valuesFromCollectionInfo(CollectionInfo info, boolean withColor) {
-        ContentValues values = new ContentValues();
-        values.put(Calendars.NAME, info.url);
-        values.put(Calendars.CALENDAR_DISPLAY_NAME, !TextUtils.isEmpty(info.displayName) ? info.displayName : DavUtils.lastSegmentOfUrl(info.url));
-
-        if (withColor)
-            values.put(Calendars.CALENDAR_COLOR, info.color != null ? info.color : defaultColor);
-
-        if (info.readOnly)
-            values.put(Calendars.CALENDAR_ACCESS_LEVEL, Calendars.CAL_ACCESS_READ);
-        else {
-            values.put(Calendars.CALENDAR_ACCESS_LEVEL, Calendars.CAL_ACCESS_OWNER);
-            values.put(Calendars.CAN_MODIFY_TIME_ZONE, 1);
-            values.put(Calendars.CAN_ORGANIZER_RESPOND, 1);
-        }
-
-        if (!TextUtils.isEmpty(info.timeZone)) {
-            VTimeZone timeZone = DateUtils.parseVTimeZone(info.timeZone);
-            if (timeZone != null && timeZone.getTimeZoneId() != null)
-                values.put(Calendars.CALENDAR_TIME_ZONE, DateUtils.findAndroidTimezoneID(timeZone.getTimeZoneId().getValue()));
-        }
-        values.put(Calendars.ALLOWED_REMINDERS, Reminders.METHOD_ALERT);
-        values.put(Calendars.ALLOWED_AVAILABILITY, StringUtils.join(new int[] { Reminders.AVAILABILITY_TENTATIVE, Reminders.AVAILABILITY_FREE, Reminders.AVAILABILITY_BUSY }, ","));
-        values.put(Calendars.ALLOWED_ATTENDEE_TYPES, StringUtils.join(new int[] { CalendarContract.Attendees.TYPE_OPTIONAL, CalendarContract.Attendees.TYPE_REQUIRED, CalendarContract.Attendees.TYPE_RESOURCE }, ", "));
-        return values;
-    }
-
-
-    @Override
-    public LocalResource[] getAll() throws CalendarStorageException, ContactsStorageException {
-        return (LocalEvent[])queryEvents(Events.ORIGINAL_ID + " IS NULL", null);
-    }
-
-    @Override
-    public LocalEvent[] getDeleted() throws CalendarStorageException {
-        return (LocalEvent[])queryEvents(Events.DELETED + "!=0 AND " + Events.ORIGINAL_ID + " IS NULL", null);
-    }
-
-    @Override
-    public LocalEvent[] getWithoutFileName() throws CalendarStorageException {
-        return (LocalEvent[])queryEvents(Events._SYNC_ID + " IS NULL AND " + Events.ORIGINAL_ID + " IS NULL", null);
-    }
-
-    @Override
-    public LocalResource[] getDirty() throws CalendarStorageException, FileNotFoundException {
-        List<LocalResource> dirty = new LinkedList<>();
-
-        // get dirty events which are required to have an increased SEQUENCE value
-        for (LocalEvent event : (LocalEvent[])queryEvents(Events.DIRTY + "!=0 AND " + Events.ORIGINAL_ID + " IS NULL", null)) {
-            if (event.getEvent().sequence == null)      // sequence has not been assigned yet (i.e. this event was just locally created)
-                event.getEvent().sequence = 0;
-            else if (event.weAreOrganizer)
-                event.getEvent().sequence++;
-            dirty.add(event);
-        }
-
-        return dirty.toArray(new LocalResource[dirty.size()]);
-    }
-
-
-    @Override
-    @SuppressWarnings("Recycle")
-    public String getCTag() throws CalendarStorageException {
-        try {
-            @Cleanup Cursor cursor = provider.query(calendarSyncURI(), new String[] { COLUMN_CTAG }, null, null, null);
-            if (cursor != null && cursor.moveToNext())
-                return cursor.getString(0);
-        } catch (RemoteException e) {
-            throw new CalendarStorageException("Couldn't read local (last known) CTag", e);
-        }
-        return null;
-    }
-
-    @Override
-    public void setCTag(String cTag) throws CalendarStorageException, ContactsStorageException {
-        try {
-            ContentValues values = new ContentValues(1);
-            values.put(COLUMN_CTAG, cTag);
-            provider.update(calendarSyncURI(), values, null, null);
-        } catch (RemoteException e) {
-            throw new CalendarStorageException("Couldn't write local (last known) CTag", e);
-        }
-    }
-
-    @SuppressWarnings("Recycle")
-    public void processDirtyExceptions() throws CalendarStorageException {
-        // process deleted exceptions
-        App.log.info("Processing deleted exceptions");
-        try {
-            @Cleanup Cursor cursor = provider.query(
-                    syncAdapterURI(Events.CONTENT_URI),
-                    new String[] { Events._ID, Events.ORIGINAL_ID, LocalEvent.COLUMN_SEQUENCE },
-                    Events.DELETED + "!=0 AND " + Events.ORIGINAL_ID + " IS NOT NULL", null, null);
-            while (cursor != null && cursor.moveToNext()) {
-                App.log.fine("Found deleted exception, removing; then re-schuling original event");
-                long    id = cursor.getLong(0),             // can't be null (by definition)
-                        originalID = cursor.getLong(1);     // can't be null (by query)
-
-                // get original event's SEQUENCE
-                @Cleanup Cursor cursor2 = provider.query(
-                        syncAdapterURI(ContentUris.withAppendedId(Events.CONTENT_URI, originalID)),
-                        new String[] { LocalEvent.COLUMN_SEQUENCE },
-                        null, null, null);
-                int originalSequence = (cursor2 == null || cursor2.isNull(0)) ? 0 : cursor2.getInt(0);
-
-                BatchOperation batch = new BatchOperation(provider);
-                // re-schedule original event and set it to DIRTY
-                batch.enqueue(new BatchOperation.Operation(
-                        ContentProviderOperation.newUpdate(syncAdapterURI(ContentUris.withAppendedId(Events.CONTENT_URI, originalID)))
-                                .withValue(LocalEvent.COLUMN_SEQUENCE, originalSequence + 1)
-                                .withValue(Events.DIRTY, 1)
-                ));
-                // remove exception
-                batch.enqueue(new BatchOperation.Operation(
-                        ContentProviderOperation.newDelete(syncAdapterURI(ContentUris.withAppendedId(Events.CONTENT_URI, id)))
-                ));
-                batch.commit();
-            }
-        } catch (RemoteException e) {
-            throw new CalendarStorageException("Couldn't process locally modified exception", e);
-        }
-
-        // process dirty exceptions
-        App.log.info("Processing dirty exceptions");
-        try {
-            @Cleanup Cursor cursor = provider.query(
-                    syncAdapterURI(Events.CONTENT_URI),
-                    new String[] { Events._ID, Events.ORIGINAL_ID, LocalEvent.COLUMN_SEQUENCE },
-                    Events.DIRTY + "!=0 AND " + Events.ORIGINAL_ID + " IS NOT NULL", null, null);
-            while (cursor != null && cursor.moveToNext()) {
-                App.log.fine("Found dirty exception, increasing SEQUENCE to re-schedule");
-                long    id = cursor.getLong(0),             // can't be null (by definition)
-                        originalID = cursor.getLong(1);     // can't be null (by query)
-                int sequence = cursor.isNull(2) ? 0 : cursor.getInt(2);
-
-                BatchOperation batch = new BatchOperation(provider);
-                // original event to DIRTY
-                batch.enqueue(new BatchOperation.Operation(
-                        ContentProviderOperation.newUpdate(syncAdapterURI(ContentUris.withAppendedId(Events.CONTENT_URI, originalID)))
-                                .withValue(Events.DIRTY, 1)
-                ));
-                // increase SEQUENCE and set DIRTY to 0
-                batch.enqueue(new BatchOperation.Operation(
-                        ContentProviderOperation.newUpdate(syncAdapterURI(ContentUris.withAppendedId(Events.CONTENT_URI, id)))
-                                .withValue(LocalEvent.COLUMN_SEQUENCE, sequence + 1)
-                                .withValue(Events.DIRTY, 0)
-                ));
-                batch.commit();
-            }
-        } catch (RemoteException e) {
-            throw new CalendarStorageException("Couldn't process locally modified exception", e);
-        }
-    }
-
-
-    public static class Factory implements AndroidCalendarFactory {
-        public static final Factory INSTANCE = new Factory();
-
-        @Override
-        public AndroidCalendar newInstance(Account account, ContentProviderClient provider, long id) {
-            return new LocalCalendar(account, provider, id);
-        }
-
-        @Override
-        public AndroidCalendar[] newArray(int size) {
-            return new LocalCalendar[size];
-        }
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/resource/LocalCalendar.kt

@@ -0,0 +1,238 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.resource
+
+import android.accounts.Account
+import android.content.ContentProviderClient
+import android.content.ContentProviderOperation
+import android.content.ContentUris
+import android.content.ContentValues
+import android.net.Uri
+import android.os.RemoteException
+import android.provider.CalendarContract
+import android.provider.CalendarContract.*
+import at.bitfire.davdroid.DavUtils
+import at.bitfire.davdroid.log.Logger
+import at.bitfire.davdroid.model.CollectionInfo
+import at.bitfire.ical4android.*
+import java.io.FileNotFoundException
+import java.util.*
+import java.util.logging.Level
+
+class LocalCalendar private constructor(
+        account: Account,
+        provider: ContentProviderClient,
+        id: Long
+): AndroidCalendar<LocalEvent>(account, provider, LocalEvent.Factory, id), LocalCollection<LocalEvent> {
+
+    companion object {
+
+        val defaultColor = 0xFF8bc34a.toInt()     // light green 500
+
+        val COLUMN_CTAG = Calendars.CAL_SYNC1
+
+        val BASE_INFO_COLUMNS = arrayOf(
+            Events._ID,
+            Events._SYNC_ID,
+            LocalEvent.COLUMN_ETAG
+        )
+
+
+        @Throws(CalendarStorageException::class)
+        fun create(account: Account, provider: ContentProviderClient, info: CollectionInfo): Uri {
+            val values = valuesFromCollectionInfo(info, true)
+
+            // ACCOUNT_NAME and ACCOUNT_TYPE are required (see docs)! If it's missing, other apps will crash.
+            values.put(Calendars.ACCOUNT_NAME, account.name)
+            values.put(Calendars.ACCOUNT_TYPE, account.type)
+            values.put(Calendars.OWNER_ACCOUNT, account.name)
+
+            // flag as visible & synchronizable at creation, might be changed by user at any time
+            values.put(Calendars.VISIBLE, 1)
+            values.put(Calendars.SYNC_EVENTS, 1)
+            val uri = create(account, provider, values)
+
+            return uri
+        }
+
+        private fun valuesFromCollectionInfo(info: CollectionInfo, withColor: Boolean): ContentValues {
+            val values = ContentValues()
+            values.put(Calendars.NAME, info.url)
+            values.put(Calendars.CALENDAR_DISPLAY_NAME, if (info.displayName.isNullOrBlank()) DavUtils.lastSegmentOfUrl(info.url) else info.displayName)
+
+            if (withColor)
+                values.put(Calendars.CALENDAR_COLOR, info.color ?: defaultColor)
+
+            if (info.readOnly)
+                values.put(Calendars.CALENDAR_ACCESS_LEVEL, Calendars.CAL_ACCESS_READ)
+            else {
+                values.put(Calendars.CALENDAR_ACCESS_LEVEL, Calendars.CAL_ACCESS_OWNER)
+                values.put(Calendars.CAN_MODIFY_TIME_ZONE, 1)
+                values.put(Calendars.CAN_ORGANIZER_RESPOND, 1)
+            }
+
+            info.timeZone?.let { tzData ->
+                try {
+                    val timeZone = DateUtils.parseVTimeZone(tzData)
+                    timeZone.timeZoneId?.let { tzId ->
+                        values.put(Calendars.CALENDAR_TIME_ZONE, DateUtils.findAndroidTimezoneID(tzId.value))
+                    }
+                } catch(e: IllegalArgumentException) {
+                    Logger.log.log(Level.WARNING, "Couldn't parse calendar default time zone", e)
+                }
+            }
+            values.put(Calendars.ALLOWED_REMINDERS, "${Reminders.METHOD_ALERT},${Reminders.METHOD_EMAIL}")
+            values.put(Calendars.ALLOWED_AVAILABILITY, "${Reminders.AVAILABILITY_TENTATIVE},${Reminders.AVAILABILITY_FREE},${Reminders.AVAILABILITY_BUSY}")
+            values.put(Calendars.ALLOWED_ATTENDEE_TYPES, "${CalendarContract.Attendees.TYPE_OPTIONAL},${CalendarContract.Attendees.TYPE_REQUIRED},${CalendarContract.Attendees.TYPE_RESOURCE}")
+            return values
+        }
+
+    }
+
+
+    override fun eventBaseInfoColumns() = BASE_INFO_COLUMNS
+
+
+    @Throws(CalendarStorageException::class)
+    fun update(info: CollectionInfo, updateColor: Boolean) =
+            update(valuesFromCollectionInfo(info, updateColor))
+
+    @Throws(CalendarStorageException::class)
+    override fun getAll(): List<LocalEvent> =
+            queryEvents("${Events.ORIGINAL_ID} IS NULL", null)
+
+    @Throws(CalendarStorageException::class)
+    override fun getDeleted() =
+            queryEvents("${Events.DELETED}!=0 AND ${Events.ORIGINAL_ID} IS NULL", null)
+
+    @Throws(CalendarStorageException::class)
+    override fun getWithoutFileName() =
+            queryEvents("${Events._SYNC_ID} IS NULL AND ${Events.ORIGINAL_ID} IS NULL", null)
+
+    @Throws(FileNotFoundException::class, CalendarStorageException::class)
+    override fun getDirty(): List<LocalEvent> {
+        val dirty = LinkedList<LocalEvent>()
+
+        // get dirty events which are required to have an increased SEQUENCE value
+        for (localEvent in queryEvents("${Events.DIRTY}!=0 AND ${Events.ORIGINAL_ID} IS NULL", null)) {
+            val event = localEvent.event!!
+            val sequence = event.sequence
+            if (event.sequence == null)      // sequence has not been assigned yet (i.e. this event was just locally created)
+                event.sequence = 0
+            else if (localEvent.weAreOrganizer)
+                event.sequence = sequence!! + 1
+            dirty += localEvent
+        }
+
+        return dirty
+    }
+
+    @Throws(CalendarStorageException::class)
+    override fun getCTag(): String? =
+        try {
+            provider.query(calendarSyncURI(), arrayOf(COLUMN_CTAG), null, null, null)?.use { cursor ->
+                if (cursor.moveToNext())
+                    return cursor.getString(0)
+            }
+            null
+        } catch (e: RemoteException) {
+            throw CalendarStorageException("Couldn't read local (last known) CTag", e)
+        }
+
+    @Throws(CalendarStorageException::class)
+    override fun setCTag(cTag: String?) {
+        try {
+            val values = ContentValues(1)
+            values.put(COLUMN_CTAG, cTag)
+            provider.update(calendarSyncURI(), values, null, null)
+        } catch (e: RemoteException) {
+            throw CalendarStorageException("Couldn't write local (last known) CTag", e)
+        }
+    }
+
+    @Throws(CalendarStorageException::class)
+    fun processDirtyExceptions() {
+        try {
+            // process deleted exceptions
+            Logger.log.info("Processing deleted exceptions")
+            provider.query(
+                    syncAdapterURI(Events.CONTENT_URI),
+                    arrayOf(Events._ID, Events.ORIGINAL_ID, LocalEvent.COLUMN_SEQUENCE),
+                    "${Events.DELETED}!=0 AND ${Events.ORIGINAL_ID} IS NOT NULL", null, null)?.use { cursor ->
+                while (cursor.moveToNext()) {
+                    Logger.log.fine("Found deleted exception, removing; then re-scheduling original event")
+                    val id = cursor.getLong(0)             // can't be null (by definition)
+                    val originalID = cursor.getLong(1)     // can't be null (by query)
+
+                    val batch = BatchOperation(provider)
+
+                    // get original event's SEQUENCE
+                    provider.query(
+                            syncAdapterURI(ContentUris.withAppendedId(Events.CONTENT_URI, originalID)),
+                            arrayOf(LocalEvent.COLUMN_SEQUENCE),
+                            null, null, null)?.use { cursor2 ->
+                        val originalSequence = if (cursor2.isNull(0)) 0 else cursor2.getInt(0)
+
+                        // re-schedule original event and set it to DIRTY
+                        batch.enqueue(BatchOperation.Operation(
+                                ContentProviderOperation.newUpdate(syncAdapterURI(ContentUris.withAppendedId(Events.CONTENT_URI, originalID)))
+                                        .withValue(LocalEvent.COLUMN_SEQUENCE, originalSequence + 1)
+                                        .withValue(Events.DIRTY, 1)
+                        ))
+                    }
+
+                    // remove exception
+                    batch.enqueue(BatchOperation.Operation(
+                            ContentProviderOperation.newDelete(syncAdapterURI(ContentUris.withAppendedId(Events.CONTENT_URI, id)))
+                    ))
+                    batch.commit()
+                }
+            }
+
+            // process dirty exceptions
+            Logger.log.info("Processing dirty exceptions")
+            provider.query(
+                    syncAdapterURI(Events.CONTENT_URI),
+                    arrayOf(Events._ID, Events.ORIGINAL_ID, LocalEvent.COLUMN_SEQUENCE),
+                    "${Events.DIRTY}!=0 AND ${Events.ORIGINAL_ID} IS NOT NULL", null, null)?.use { cursor ->
+                while (cursor.moveToNext()) {
+                    Logger.log.fine("Found dirty exception, increasing SEQUENCE to re-schedule")
+                    val id = cursor.getLong(0)             // can't be null (by definition)
+                    val originalID = cursor.getLong(1)     // can't be null (by query)
+                    val sequence = if (cursor.isNull(2)) 0 else cursor.getInt(2)
+
+                    val batch = BatchOperation(provider)
+                    // original event to DIRTY
+                    batch.enqueue(BatchOperation.Operation (
+                            ContentProviderOperation.newUpdate(syncAdapterURI(ContentUris.withAppendedId(Events.CONTENT_URI, originalID)))
+                                    .withValue(Events.DIRTY, 1)
+                    ))
+                    // increase SEQUENCE and set DIRTY to 0
+                    batch.enqueue(BatchOperation.Operation (
+                            ContentProviderOperation.newUpdate(syncAdapterURI(ContentUris.withAppendedId(Events.CONTENT_URI, id)))
+                                    .withValue(LocalEvent.COLUMN_SEQUENCE, sequence + 1)
+                                    .withValue(Events.DIRTY, 0)
+                    ))
+                    batch.commit()
+                }
+            }
+        } catch (e: RemoteException) {
+            throw CalendarStorageException("Couldn't process locally modified exception", e)
+        }
+    }
+
+
+    object Factory: AndroidCalendarFactory<LocalCalendar> {
+
+        override fun newInstance(account: Account, provider: ContentProviderClient, id: Long) =
+            LocalCalendar(account, provider, id)
+
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/resource/LocalCollection.java

@@ -1,26 +0,0 @@
-/*
- * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.resource;
-
-import java.io.FileNotFoundException;
-
-import at.bitfire.ical4android.CalendarStorageException;
-import at.bitfire.vcard4android.ContactsStorageException;
-
-public interface LocalCollection {
-
-    LocalResource[] getDeleted() throws CalendarStorageException, ContactsStorageException;
-    LocalResource[] getWithoutFileName()  throws CalendarStorageException, ContactsStorageException;
-    LocalResource[] getDirty() throws CalendarStorageException, ContactsStorageException, FileNotFoundException;
-
-    LocalResource[] getAll() throws CalendarStorageException, ContactsStorageException;
-
-    String getCTag() throws CalendarStorageException, ContactsStorageException;
-    void setCTag(String cTag) throws CalendarStorageException, ContactsStorageException;
-}

app/src/main/java/at/bitfire/davdroid/resource/LocalCollection.kt

@@ -0,0 +1,35 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.resource
+
+import at.bitfire.ical4android.CalendarStorageException
+import at.bitfire.vcard4android.ContactsStorageException
+import java.io.FileNotFoundException
+
+interface LocalCollection<out T: LocalResource> {
+
+    @Throws(CalendarStorageException::class, ContactsStorageException::class)
+    fun getDeleted(): List<T>
+
+    @Throws(CalendarStorageException::class, ContactsStorageException::class)
+    fun getWithoutFileName(): List<T>
+
+    @Throws(CalendarStorageException::class, ContactsStorageException::class, FileNotFoundException::class)
+    fun getDirty(): List<T>
+
+    @Throws(CalendarStorageException::class, ContactsStorageException::class)
+    fun getAll(): List<T>
+
+    @Throws(CalendarStorageException::class, ContactsStorageException::class)
+    fun getCTag(): String?
+
+    @Throws(CalendarStorageException::class, ContactsStorageException::class)
+    fun setCTag(cTag: String?)
+
+}

app/src/main/java/at/bitfire/davdroid/resource/LocalContact.java

@@ -1,284 +0,0 @@
-/*
- * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.resource;
-
-import android.content.ContentProviderOperation;
-import android.content.ContentValues;
-import android.database.Cursor;
-import android.os.Build;
-import android.os.RemoteException;
-import android.provider.ContactsContract;
-import android.provider.ContactsContract.CommonDataKinds.GroupMembership;
-import android.provider.ContactsContract.RawContacts.Data;
-import android.support.annotation.NonNull;
-import android.support.annotation.Nullable;
-
-import java.io.FileNotFoundException;
-import java.util.HashSet;
-import java.util.Set;
-import java.util.UUID;
-
-import at.bitfire.davdroid.App;
-import at.bitfire.davdroid.BuildConfig;
-import at.bitfire.davdroid.model.UnknownProperties;
-import at.bitfire.vcard4android.AndroidAddressBook;
-import at.bitfire.vcard4android.AndroidContact;
-import at.bitfire.vcard4android.AndroidContactFactory;
-import at.bitfire.vcard4android.BatchOperation;
-import at.bitfire.vcard4android.CachedGroupMembership;
-import at.bitfire.vcard4android.Contact;
-import at.bitfire.vcard4android.ContactsStorageException;
-import ezvcard.Ezvcard;
-import lombok.Cleanup;
-
-public class LocalContact extends AndroidContact implements LocalResource {
-    static {
-        Contact.productID = "+//IDN bitfire.at//DAVdroid/" + BuildConfig.VERSION_NAME + " vcard4android ez-vcard/" + Ezvcard.VERSION;
-    }
-    public static final String COLUMN_HASHCODE = ContactsContract.RawContacts.SYNC3;
-
-    protected final Set<Long>
-            cachedGroupMemberships = new HashSet<>(),
-            groupMemberships = new HashSet<>();
-
-
-    protected LocalContact(AndroidAddressBook addressBook, long id, String fileName, String eTag) {
-        super(addressBook, id, fileName, eTag);
-    }
-
-    public LocalContact(AndroidAddressBook addressBook, Contact contact, String fileName, String eTag) {
-        super(addressBook, contact, fileName, eTag);
-    }
-
-    public void resetDirty() throws ContactsStorageException {
-        ContentValues values = new ContentValues(1);
-        values.put(ContactsContract.RawContacts.DIRTY, 0);
-        try {
-            addressBook.provider.update(rawContactSyncURI(), values, null, null);
-        } catch(RemoteException e) {
-            throw new ContactsStorageException("Couldn't clear dirty flag", e);
-        }
-    }
-
-    public void clearDirty(String eTag) throws ContactsStorageException {
-        try {
-            ContentValues values = new ContentValues(3);
-            values.put(COLUMN_ETAG, eTag);
-            values.put(ContactsContract.RawContacts.DIRTY, 0);
-
-            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
-                // workaround for Android 7 which sets DIRTY flag when only meta-data is changed
-                int hashCode = dataHashCode();
-                values.put(COLUMN_HASHCODE, hashCode);
-                App.log.finer("Clearing dirty flag with eTag = " + eTag + ", contact hash = " + hashCode);
-            }
-
-            addressBook.provider.update(rawContactSyncURI(), values, null, null);
-
-            this.eTag = eTag;
-        } catch (FileNotFoundException|RemoteException e) {
-            throw new ContactsStorageException("Couldn't clear dirty flag", e);
-        }
-    }
-
-    public void prepareForUpload() throws ContactsStorageException {
-        try {
-            final String uid = UUID.randomUUID().toString();
-            final String newFileName = uid + ".vcf";
-
-            ContentValues values = new ContentValues(2);
-            values.put(COLUMN_FILENAME, newFileName);
-            values.put(COLUMN_UID, uid);
-            addressBook.provider.update(rawContactSyncURI(), values, null, null);
-
-            fileName = newFileName;
-        } catch (RemoteException e) {
-            throw new ContactsStorageException("Couldn't update UID", e);
-        }
-    }
-
-
-    @Override
-    protected void populateData(String mimeType, ContentValues row) {
-        switch (mimeType) {
-            case CachedGroupMembership.CONTENT_ITEM_TYPE:
-                cachedGroupMemberships.add(row.getAsLong(CachedGroupMembership.GROUP_ID));
-                break;
-            case GroupMembership.CONTENT_ITEM_TYPE:
-                groupMemberships.add(row.getAsLong(GroupMembership.GROUP_ROW_ID));
-                break;
-            case UnknownProperties.CONTENT_ITEM_TYPE:
-                contact.unknownProperties = row.getAsString(UnknownProperties.UNKNOWN_PROPERTIES);
-                break;
-        }
-    }
-
-    @Override
-    protected void insertDataRows(BatchOperation batch) throws ContactsStorageException {
-        super.insertDataRows(batch);
-
-        if (contact.unknownProperties != null) {
-            final BatchOperation.Operation op;
-            final ContentProviderOperation.Builder builder = ContentProviderOperation.newInsert(dataSyncURI());
-            if (id == null) {
-                op = new BatchOperation.Operation(builder, UnknownProperties.RAW_CONTACT_ID, 0);
-            } else {
-                op = new BatchOperation.Operation(builder);
-                builder.withValue(UnknownProperties.RAW_CONTACT_ID, id);
-            }
-            builder .withValue(UnknownProperties.MIMETYPE, UnknownProperties.CONTENT_ITEM_TYPE)
-                    .withValue(UnknownProperties.UNKNOWN_PROPERTIES, contact.unknownProperties);
-            batch.enqueue(op);
-        }
-
-    }
-
-
-    /**
-     * Calculates a hash code from the contact's data (VCard) and group memberships.
-     * Attention: re-reads {@link #contact} from the database, discarding all changes in memory
-     * @return hash code of contact data (including group memberships)
-     */
-    protected int dataHashCode() throws FileNotFoundException, ContactsStorageException {
-        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N)
-            App.log.severe("dataHashCode() should not be called on Android <7");
-
-        // reset contact so that getContact() reads from database
-        contact = null;
-
-        // groupMemberships is filled by getContact()
-        int dataHash = getContact().hashCode(),
-            groupHash = groupMemberships.hashCode();
-        App.log.finest("Calculated data hash = " + dataHash + ", group memberships hash = " + groupHash);
-        return dataHash ^ groupHash;
-    }
-
-    public void updateHashCode(@Nullable BatchOperation batch) throws ContactsStorageException {
-        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N)
-            App.log.severe("updateHashCode() should not be called on Android <7");
-
-        ContentValues values = new ContentValues(1);
-        try {
-            int hashCode = dataHashCode();
-            App.log.fine("Storing contact hash = " + hashCode);
-            values.put(COLUMN_HASHCODE, hashCode);
-
-            if (batch == null)
-                addressBook.provider.update(rawContactSyncURI(), values, null, null);
-            else {
-                ContentProviderOperation.Builder builder = ContentProviderOperation
-                        .newUpdate(rawContactSyncURI())
-                        .withValues(values);
-                batch.enqueue(new BatchOperation.Operation(builder));
-            }
-        } catch(FileNotFoundException|RemoteException e) {
-            throw new ContactsStorageException("Couldn't store contact checksum", e);
-        }
-    }
-
-    public int getLastHashCode() throws ContactsStorageException {
-        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N)
-            App.log.severe("getLastHashCode() should not be called on Android <7");
-
-        try {
-            @Cleanup Cursor c = addressBook.provider.query(rawContactSyncURI(), new String[] { COLUMN_HASHCODE }, null, null, null);
-            if (c == null || !c.moveToNext() || c.isNull(0))
-                return 0;
-            return c.getInt(0);
-        } catch(RemoteException e) {
-            throw new ContactsStorageException("Could't read last hash code", e);
-        }
-    }
-
-
-    public void addToGroup(BatchOperation batch, long groupID) {
-        assertID();
-
-        batch.enqueue(new BatchOperation.Operation(
-                ContentProviderOperation.newInsert(dataSyncURI())
-                        .withValue(GroupMembership.MIMETYPE, GroupMembership.CONTENT_ITEM_TYPE)
-                        .withValue(GroupMembership.RAW_CONTACT_ID, id)
-                        .withValue(GroupMembership.GROUP_ROW_ID, groupID)
-        ));
-        groupMemberships.add(groupID);
-
-        batch.enqueue(new BatchOperation.Operation(
-                ContentProviderOperation.newInsert(dataSyncURI())
-                        .withValue(CachedGroupMembership.MIMETYPE, CachedGroupMembership.CONTENT_ITEM_TYPE)
-                        .withValue(CachedGroupMembership.RAW_CONTACT_ID, id)
-                        .withValue(CachedGroupMembership.GROUP_ID, groupID)
-                        .withYieldAllowed(true)
-        ));
-        cachedGroupMemberships.add(groupID);
-    }
-
-    public void removeGroupMemberships(BatchOperation batch) {
-        assertID();
-        batch.enqueue(new BatchOperation.Operation(
-                ContentProviderOperation.newDelete(dataSyncURI())
-                        .withSelection(
-                                Data.RAW_CONTACT_ID + "=? AND " + Data.MIMETYPE + " IN (?,?)",
-                                new String[] { String.valueOf(id), GroupMembership.CONTENT_ITEM_TYPE, CachedGroupMembership.CONTENT_ITEM_TYPE }
-                        )
-                        .withYieldAllowed(true)
-        ));
-        groupMemberships.clear();
-        cachedGroupMemberships.clear();
-    }
-
-    /**
-     * Returns the IDs of all groups the contact was member of (cached memberships).
-     * Cached memberships are kept in sync with memberships by DAVdroid and are used to determine
-     * whether a membership has been deleted/added when a raw contact is dirty.
-     * @return set of {@link GroupMembership#GROUP_ROW_ID} (may be empty)
-     * @throws ContactsStorageException   on contact provider errors
-     * @throws FileNotFoundException      if the current contact can't be found
-     */
-    @NonNull
-    public Set<Long> getCachedGroupMemberships() throws ContactsStorageException, FileNotFoundException {
-        getContact();
-        return cachedGroupMemberships;
-    }
-
-    /**
-     * Returns the IDs of all groups the contact is member of.
-     * @return set of {@link GroupMembership#GROUP_ROW_ID}s (may be empty)
-     * @throws ContactsStorageException   on contact provider errors
-     * @throws FileNotFoundException      if the current contact can't be found
-     */
-    @NonNull
-    public Set<Long> getGroupMemberships() throws ContactsStorageException, FileNotFoundException {
-        getContact();
-        return groupMemberships;
-    }
-
-
-    // factory
-
-    static class Factory extends AndroidContactFactory {
-        static final Factory INSTANCE = new Factory();
-
-        @Override
-        public LocalContact newInstance(AndroidAddressBook addressBook, long id, String fileName, String eTag) {
-            return new LocalContact(addressBook, id, fileName, eTag);
-        }
-
-        @Override
-        public LocalContact newInstance(AndroidAddressBook addressBook, Contact contact, String fileName, String eTag) {
-            return new LocalContact(addressBook, contact, fileName, eTag);
-        }
-
-        @Override
-        public LocalContact[] newArray(int size) {
-            return new LocalContact[size];
-        }
-
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/resource/LocalContact.kt

@@ -0,0 +1,284 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.resource
+
+import android.content.ContentProviderOperation
+import android.content.ContentValues
+import android.os.Build
+import android.os.RemoteException
+import android.provider.ContactsContract
+import android.provider.ContactsContract.CommonDataKinds.GroupMembership
+import android.provider.ContactsContract.RawContacts.Data
+import at.bitfire.davdroid.BuildConfig
+import at.bitfire.davdroid.log.Logger
+import at.bitfire.davdroid.model.UnknownProperties
+import at.bitfire.vcard4android.*
+import ezvcard.Ezvcard
+import java.io.FileNotFoundException
+import java.util.*
+
+class LocalContact: AndroidContact, LocalResource {
+
+    companion object {
+
+        init {
+            Contact.productID = "+//IDN bitfire.at//DAVdroid/" + BuildConfig.VERSION_NAME + " ez-vcard/" + Ezvcard.VERSION
+        }
+
+        val COLUMN_HASHCODE = ContactsContract.RawContacts.SYNC3
+
+    }
+
+    private val cachedGroupMemberships = HashSet<Long>()
+    private val groupMemberships = HashSet<Long>()
+
+
+    constructor(addressBook: AndroidAddressBook<LocalContact,*>, id: Long, fileName: String?, eTag: String?):
+            super(addressBook, id, fileName, eTag)
+
+    constructor(addressBook: AndroidAddressBook<LocalContact,*>, contact: Contact, fileName: String?, eTag: String?):
+            super(addressBook, contact, fileName, eTag)
+
+
+    @Throws(ContactsStorageException::class)
+    fun resetDeleted() {
+        val values = ContentValues(1)
+        values.put(ContactsContract.RawContacts.DELETED, 0)
+        try {
+            addressBook.provider!!.update(rawContactSyncURI(), values, null, null)
+        } catch(e: RemoteException) {
+            throw ContactsStorageException("Couldn't clear deleted flag", e)
+        }
+    }
+
+    @Throws(ContactsStorageException::class)
+    fun resetDirty() {
+        val values = ContentValues(1)
+        values.put(ContactsContract.RawContacts.DIRTY, 0)
+        try {
+            addressBook.provider!!.update(rawContactSyncURI(), values, null, null)
+        } catch(e: RemoteException) {
+            throw ContactsStorageException("Couldn't clear dirty flag", e)
+        }
+    }
+
+    @Throws(ContactsStorageException::class)
+    override fun clearDirty(eTag: String?) {
+        try {
+            val values = ContentValues(3)
+            values.put(COLUMN_ETAG, eTag)
+            values.put(ContactsContract.RawContacts.DIRTY, 0)
+
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N && Build.VERSION.SDK_INT < Build.VERSION_CODES.O) {
+                // workaround for Android 7 which sets DIRTY flag when only meta-data is changed
+                val hashCode = dataHashCode()
+                values.put(COLUMN_HASHCODE, hashCode)
+                Logger.log.finer("Clearing dirty flag with eTag = $eTag, contact hash = $hashCode")
+            }
+
+            addressBook.provider!!.update(rawContactSyncURI(), values, null, null)
+
+            this.eTag = eTag
+        } catch(e: Exception) {
+            throw ContactsStorageException("Couldn't clear dirty flag", e)
+        }
+    }
+
+    @Throws(ContactsStorageException::class)
+    override fun prepareForUpload() {
+        try {
+            val uid = UUID.randomUUID().toString()
+            val newFileName = uid + ".vcf"
+
+            val values = ContentValues(2)
+            values.put(COLUMN_FILENAME, newFileName)
+            values.put(COLUMN_UID, uid)
+            addressBook.provider!!.update(rawContactSyncURI(), values, null, null)
+
+            fileName = newFileName
+        } catch(e: RemoteException) {
+            throw ContactsStorageException("Couldn't update UID", e)
+        }
+    }
+
+
+    @Throws(ContactsStorageException::class)
+    override fun populateData(mimeType: String, row: ContentValues) {
+        when (mimeType) {
+            CachedGroupMembership.CONTENT_ITEM_TYPE ->
+                cachedGroupMemberships.add(row.getAsLong(CachedGroupMembership.GROUP_ID))
+            GroupMembership.CONTENT_ITEM_TYPE ->
+                groupMemberships.add(row.getAsLong(GroupMembership.GROUP_ROW_ID))
+            UnknownProperties.CONTENT_ITEM_TYPE ->
+                try {
+                    contact!!.unknownProperties = row.getAsString(UnknownProperties.UNKNOWN_PROPERTIES)
+                } catch(e: FileNotFoundException) {
+                    throw ContactsStorageException("Couldn't fetch data rows", e)
+                }
+        }
+    }
+
+    @Throws(ContactsStorageException::class)
+    override fun insertDataRows(batch: BatchOperation) {
+        super.insertDataRows(batch)
+
+        try {
+            contact!!.unknownProperties?.let { unknownProperties ->
+                val op: BatchOperation.Operation
+                val builder = ContentProviderOperation.newInsert(dataSyncURI())
+                if (id == null)
+                    op = BatchOperation.Operation(builder, UnknownProperties.RAW_CONTACT_ID, 0)
+                else {
+                    op = BatchOperation.Operation(builder)
+                    builder.withValue(UnknownProperties.RAW_CONTACT_ID, id)
+                }
+                builder .withValue(UnknownProperties.MIMETYPE, UnknownProperties.CONTENT_ITEM_TYPE)
+                        .withValue(UnknownProperties.UNKNOWN_PROPERTIES, unknownProperties)
+                batch.enqueue(op)
+            }
+        } catch(e: FileNotFoundException) {
+            throw ContactsStorageException("Couldn't insert data rows", e)
+        }
+
+    }
+
+
+    /**
+     * Calculates a hash code from the contact's data (VCard) and group memberships.
+     * Attention: re-reads {@link #contact} from the database, discarding all changes in memory
+     * @return hash code of contact data (including group memberships)
+     */
+    @Throws(FileNotFoundException::class, ContactsStorageException::class)
+    internal fun dataHashCode(): Int {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N || Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
+            throw IllegalStateException("dataHashCode() should not be called on Android != 7")
+
+        // reset contact so that getContact() reads from database
+        contact = null
+
+        // groupMemberships is filled by getContact()
+        val dataHash = contact!!.hashCode()
+        val groupHash = groupMemberships.hashCode()
+        Logger.log.finest("Calculated data hash = $dataHash, group memberships hash = $groupHash")
+        return dataHash xor groupHash
+    }
+
+    @Throws(ContactsStorageException::class)
+    fun updateHashCode(batch: BatchOperation?) {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N || Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
+            throw IllegalStateException("updateHashCode() should not be called on Android != 7")
+
+        val values = ContentValues(1)
+        try {
+            val hashCode = dataHashCode()
+            Logger.log.fine("Storing contact hash = $hashCode")
+            values.put(COLUMN_HASHCODE, hashCode)
+
+            if (batch == null)
+                addressBook.provider!!.update(rawContactSyncURI(), values, null, null)
+            else {
+                val builder = ContentProviderOperation
+                        .newUpdate(rawContactSyncURI())
+                        .withValues(values)
+                batch.enqueue(BatchOperation.Operation(builder))
+            }
+        } catch(e: Exception) {
+            throw ContactsStorageException("Couldn't store contact checksum", e)
+        }
+    }
+
+    @Throws(ContactsStorageException::class)
+    fun getLastHashCode(): Int {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N || Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
+            throw IllegalStateException("getLastHashCode() should not be called on Android != 7")
+
+        try {
+            addressBook.provider!!.query(rawContactSyncURI(), arrayOf(COLUMN_HASHCODE), null, null, null)?.use { c ->
+                if (c.moveToNext() && !c.isNull(0))
+                    return c.getInt(0)
+            }
+            return 0
+        } catch(e: RemoteException) {
+            throw ContactsStorageException("Could't read last hash code", e)
+        }
+    }
+
+
+    fun addToGroup(batch: BatchOperation, groupID: Long) {
+        batch.enqueue(BatchOperation.Operation(
+                ContentProviderOperation.newInsert(dataSyncURI())
+                        .withValue(GroupMembership.MIMETYPE, GroupMembership.CONTENT_ITEM_TYPE)
+                        .withValue(GroupMembership.RAW_CONTACT_ID, id)
+                        .withValue(GroupMembership.GROUP_ROW_ID, groupID)
+        ))
+        groupMemberships.add(groupID)
+
+        batch.enqueue(BatchOperation.Operation(
+                ContentProviderOperation.newInsert(dataSyncURI())
+                        .withValue(CachedGroupMembership.MIMETYPE, CachedGroupMembership.CONTENT_ITEM_TYPE)
+                        .withValue(CachedGroupMembership.RAW_CONTACT_ID, id)
+                        .withValue(CachedGroupMembership.GROUP_ID, groupID)
+                        .withYieldAllowed(true)
+        ))
+        cachedGroupMemberships.add(groupID)
+    }
+
+    fun removeGroupMemberships(batch: BatchOperation) {
+        batch.enqueue(BatchOperation.Operation(
+                ContentProviderOperation.newDelete(dataSyncURI())
+                        .withSelection(
+                                Data.RAW_CONTACT_ID + "=? AND " + Data.MIMETYPE + " IN (?,?)",
+                                arrayOf(id.toString(), GroupMembership.CONTENT_ITEM_TYPE, CachedGroupMembership.CONTENT_ITEM_TYPE)
+                        )
+                        .withYieldAllowed(true)
+        ))
+        groupMemberships.clear()
+        cachedGroupMemberships.clear()
+    }
+
+    /**
+     * Returns the IDs of all groups the contact was member of (cached memberships).
+     * Cached memberships are kept in sync with memberships by DAVdroid and are used to determine
+     * whether a membership has been deleted/added when a raw contact is dirty.
+     * @return set of {@link GroupMembership#GROUP_ROW_ID} (may be empty)
+     * @throws ContactsStorageException   on contact provider errors
+     * @throws FileNotFoundException      if the current contact can't be found
+     */
+    @Throws(FileNotFoundException::class, ContactsStorageException::class)
+    fun getCachedGroupMemberships(): Set<Long> {
+        contact
+        return cachedGroupMemberships
+    }
+
+    /**
+     * Returns the IDs of all groups the contact is member of.
+     * @return set of {@link GroupMembership#GROUP_ROW_ID}s (may be empty)
+     * @throws ContactsStorageException   on contact provider errors
+     * @throws FileNotFoundException      if the current contact can't be found
+     */
+    @Throws(FileNotFoundException::class, ContactsStorageException::class)
+    fun getGroupMemberships(): Set<Long> {
+        contact
+        return groupMemberships
+    }
+
+
+    // factory
+
+    object Factory: AndroidContactFactory<LocalContact> {
+
+        override fun newInstance(addressBook: AndroidAddressBook<LocalContact, *>, id: Long, fileName: String?, eTag: String?) =
+                LocalContact(addressBook, id, fileName, eTag)
+
+        override fun newInstance(addressBook: AndroidAddressBook<LocalContact, *>, contact: Contact, fileName: String?, eTag: String?) =
+                LocalContact(addressBook, contact, fileName, eTag)
+
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/resource/LocalEvent.java

@@ -1,166 +0,0 @@
-/*
- * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.resource;
-
-import android.annotation.TargetApi;
-import android.content.ContentProviderOperation;
-import android.content.ContentValues;
-import android.database.Cursor;
-import android.os.Build;
-import android.os.RemoteException;
-import android.provider.CalendarContract;
-import android.provider.CalendarContract.Events;
-import android.support.annotation.NonNull;
-
-import net.fortuna.ical4j.model.property.ProdId;
-
-import at.bitfire.davdroid.App;
-import at.bitfire.davdroid.BuildConfig;
-import at.bitfire.ical4android.AndroidCalendar;
-import at.bitfire.ical4android.AndroidEvent;
-import at.bitfire.ical4android.AndroidEventFactory;
-import at.bitfire.ical4android.CalendarStorageException;
-import at.bitfire.ical4android.Event;
-import lombok.Cleanup;
-import lombok.Getter;
-import lombok.Setter;
-import lombok.ToString;
-
-@TargetApi(17)
-@ToString(of={ "fileName","eTag" }, callSuper=true)
-public class LocalEvent extends AndroidEvent implements LocalResource {
-    static {
-        Event.prodId = new ProdId("+//IDN bitfire.at//DAVdroid/" + BuildConfig.VERSION_NAME + " ical4android ical4j/2.x");
-    }
-
-    static final String COLUMN_ETAG = CalendarContract.Events.SYNC_DATA1,
-                        COLUMN_UID = Build.VERSION.SDK_INT >= 17 ? Events.UID_2445 : Events.SYNC_DATA2,
-                        COLUMN_SEQUENCE = CalendarContract.Events.SYNC_DATA3;
-
-    @Getter protected String fileName;
-    @Getter @Setter protected String eTag;
-
-    public boolean weAreOrganizer = true;
-
-    public LocalEvent(@NonNull AndroidCalendar calendar, Event event, String fileName, String eTag) {
-        super(calendar, event);
-        this.fileName = fileName;
-        this.eTag = eTag;
-    }
-
-    protected LocalEvent(@NonNull AndroidCalendar calendar, long id, ContentValues baseInfo) {
-        super(calendar, id, baseInfo);
-        if (baseInfo != null) {
-            fileName = baseInfo.getAsString(Events._SYNC_ID);
-            eTag = baseInfo.getAsString(COLUMN_ETAG);
-        }
-    }
-
-
-    /* process LocalEvent-specific fields */
-
-    @Override
-    protected void populateEvent(ContentValues values) {
-        super.populateEvent(values);
-        fileName = values.getAsString(Events._SYNC_ID);
-        eTag = values.getAsString(COLUMN_ETAG);
-        event.uid = values.getAsString(COLUMN_UID);
-
-        event.sequence = values.getAsInteger(COLUMN_SEQUENCE);
-        if (Build.VERSION.SDK_INT >= 17)
-            weAreOrganizer = values.getAsInteger(Events.IS_ORGANIZER) != 0;
-        else {
-            String organizer = values.getAsString(Events.ORGANIZER);
-            weAreOrganizer = organizer == null || organizer.equals(calendar.account.name);
-        }
-    }
-
-    @Override
-    protected void buildEvent(Event recurrence, ContentProviderOperation.Builder builder) {
-        super.buildEvent(recurrence, builder);
-
-        boolean buildException = recurrence != null;
-        Event eventToBuild = buildException ? recurrence : event;
-
-        builder .withValue(COLUMN_UID, event.uid)
-                .withValue(COLUMN_SEQUENCE, eventToBuild.sequence)
-                .withValue(CalendarContract.Events.DIRTY, 0)
-                .withValue(CalendarContract.Events.DELETED, 0);
-
-        if (buildException)
-            builder.withValue(Events.ORIGINAL_SYNC_ID, fileName);
-        else
-            builder .withValue(Events._SYNC_ID, fileName)
-                    .withValue(COLUMN_ETAG, eTag);
-    }
-
-
-    /* custom queries */
-
-    public void prepareForUpload() throws CalendarStorageException {
-        try {
-            String uid = null;
-            @Cleanup Cursor c = calendar.provider.query(eventSyncURI(), new String[] { COLUMN_UID }, null, null, null);
-            if (c.moveToNext())
-                uid = c.getString(0);
-            if (uid == null)
-                uid = App.getUidGenerator().generateUid().getValue();
-
-            final String newFileName = uid + ".ics";
-
-            ContentValues values = new ContentValues(2);
-            values.put(Events._SYNC_ID, newFileName);
-            values.put(COLUMN_UID, uid);
-            calendar.provider.update(eventSyncURI(), values, null, null);
-
-            fileName = newFileName;
-            if (event != null)
-                event.uid = uid;
-
-        } catch (RemoteException e) {
-            throw new CalendarStorageException("Couldn't update UID", e);
-        }
-    }
-
-    @Override
-    public void clearDirty(String eTag) throws CalendarStorageException {
-        try {
-            ContentValues values = new ContentValues(2);
-            values.put(CalendarContract.Events.DIRTY, 0);
-            values.put(COLUMN_ETAG, eTag);
-            if (event != null)
-                values.put(COLUMN_SEQUENCE, event.sequence);
-            calendar.provider.update(eventSyncURI(), values, null, null);
-
-            this.eTag = eTag;
-        } catch (RemoteException e) {
-            throw new CalendarStorageException("Couldn't update UID", e);
-        }
-    }
-
-
-    static class Factory implements AndroidEventFactory {
-        static final Factory INSTANCE = new Factory();
-
-        @Override
-        public AndroidEvent newInstance(AndroidCalendar calendar, long id, ContentValues baseInfo) {
-            return new LocalEvent(calendar, id, baseInfo);
-        }
-
-        @Override
-        public AndroidEvent newInstance(AndroidCalendar calendar, Event event) {
-            return new LocalEvent(calendar, event, null, null);
-        }
-
-        @Override
-        public AndroidEvent[] newArray(int size) {
-            return new LocalEvent[size];
-        }
-    }
-}

app/src/main/java/at/bitfire/davdroid/resource/LocalEvent.kt

@@ -0,0 +1,148 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.resource
+
+import android.content.ContentProviderOperation
+import android.content.ContentValues
+import android.os.Build
+import android.provider.CalendarContract
+import android.provider.CalendarContract.Events
+import at.bitfire.davdroid.BuildConfig
+import at.bitfire.ical4android.*
+import net.fortuna.ical4j.model.property.ProdId
+import java.io.FileNotFoundException
+import java.util.*
+
+class LocalEvent: AndroidEvent, LocalResource {
+
+    companion object {
+        init {
+            iCalendar.prodId = ProdId("+//IDN bitfire.at//DAVdroid/" + BuildConfig.VERSION_NAME + " ical4j/2.x")
+        }
+
+        val COLUMN_ETAG = CalendarContract.Events.SYNC_DATA1
+        val COLUMN_UID = if (Build.VERSION.SDK_INT >= 17) Events.UID_2445 else Events.SYNC_DATA2
+        val COLUMN_SEQUENCE = CalendarContract.Events.SYNC_DATA3
+    }
+
+    override var fileName: String? = null
+    override var eTag: String? = null
+
+    var weAreOrganizer = true
+
+
+    constructor(calendar: AndroidCalendar<*>, event: Event, fileName: String?, eTag: String?): super(calendar, event) {
+        this.fileName = fileName
+        this.eTag = eTag
+    }
+
+    private constructor(calendar: AndroidCalendar<*>, id: Long, baseInfo: ContentValues?): super(calendar, id, baseInfo) {
+        baseInfo?.let {
+            fileName = it.getAsString(Events._SYNC_ID)
+            eTag = it.getAsString(COLUMN_ETAG)
+        }
+    }
+
+
+    /* process LocalEvent-specific fields */
+
+    @Throws(FileNotFoundException::class, CalendarStorageException::class)
+    override fun populateEvent(row: ContentValues) {
+        super.populateEvent(row)
+        val event = requireNotNull(event)
+
+        fileName = row.getAsString(Events._SYNC_ID)
+        eTag = row.getAsString(COLUMN_ETAG)
+        event.uid = row.getAsString(COLUMN_UID)
+
+        event.sequence = row.getAsInteger(COLUMN_SEQUENCE)
+        if (Build.VERSION.SDK_INT >= 17) {
+            val isOrganizer = row.getAsInteger(Events.IS_ORGANIZER)
+            weAreOrganizer = isOrganizer != null && isOrganizer != 0
+        } else {
+            val organizer = row.getAsString(Events.ORGANIZER)
+            weAreOrganizer = organizer == null || organizer == calendar.account.name
+        }
+    }
+
+    @Throws(FileNotFoundException::class, CalendarStorageException::class)
+    override fun buildEvent(recurrence: Event?, builder: ContentProviderOperation.Builder) {
+        super.buildEvent(recurrence, builder)
+        val event = requireNotNull(event)
+
+        val buildException = recurrence != null
+        val eventToBuild = recurrence ?: event
+
+        builder .withValue(COLUMN_UID, event.uid)
+                .withValue(COLUMN_SEQUENCE, eventToBuild.sequence)
+                .withValue(CalendarContract.Events.DIRTY, 0)
+                .withValue(CalendarContract.Events.DELETED, 0)
+
+        if (buildException)
+            builder .withValue(Events.ORIGINAL_SYNC_ID, fileName)
+        else
+            builder .withValue(Events._SYNC_ID, fileName)
+                    .withValue(COLUMN_ETAG, eTag)
+    }
+
+
+    /* custom queries */
+
+    @Throws(CalendarStorageException::class)
+    override fun prepareForUpload() {
+        try {
+            var uid: String? = null
+            calendar.provider.query(eventSyncURI(), arrayOf(COLUMN_UID), null, null, null)?.use { cursor ->
+                if (cursor.moveToNext())
+                    uid = cursor.getString(0)
+            }
+            if (uid == null)
+                uid = UUID.randomUUID().toString()
+
+            val newFileName = "$uid.ics"
+
+            val values = ContentValues(2)
+            values.put(Events._SYNC_ID, newFileName)
+            values.put(COLUMN_UID, uid)
+            calendar.provider.update(eventSyncURI(), values, null, null)
+
+            fileName = newFileName
+            event!!.uid = uid
+
+        } catch(e: Exception) {
+            throw CalendarStorageException("Couldn't update UID", e)
+        }
+    }
+
+    @Throws(CalendarStorageException::class)
+    override fun clearDirty(eTag: String?) {
+        try {
+            val values = ContentValues(2)
+            values.put(CalendarContract.Events.DIRTY, 0)
+            values.put(COLUMN_ETAG, eTag)
+            values.put(COLUMN_SEQUENCE, event!!.sequence);
+            calendar.provider.update(eventSyncURI(), values, null, null)
+
+            this.eTag = eTag
+        } catch (e: Exception) {
+            throw CalendarStorageException("Couldn't update UID", e)
+        }
+    }
+
+
+    object Factory: AndroidEventFactory<LocalEvent> {
+
+        override fun newInstance(calendar: AndroidCalendar<*>, id: Long, baseInfo: ContentValues?) =
+                LocalEvent(calendar, id, baseInfo)
+
+        override fun newInstance(calendar: AndroidCalendar<*>, event: Event) =
+                LocalEvent(calendar, event, null, null)
+
+    }
+}

app/src/main/java/at/bitfire/davdroid/resource/LocalGroup.java

@@ -1,260 +0,0 @@
-/*
- * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.resource;
-
-import android.content.ContentProviderOperation;
-import android.content.ContentUris;
-import android.content.ContentValues;
-import android.database.Cursor;
-import android.os.Build;
-import android.os.Parcel;
-import android.os.RemoteException;
-import android.provider.ContactsContract;
-import android.provider.ContactsContract.CommonDataKinds.GroupMembership;
-import android.provider.ContactsContract.Groups;
-import android.provider.ContactsContract.RawContacts;
-import android.provider.ContactsContract.RawContacts.Data;
-
-import org.apache.commons.lang3.ArrayUtils;
-
-import java.io.FileNotFoundException;
-import java.util.HashSet;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Set;
-import java.util.UUID;
-import java.util.logging.Level;
-
-import at.bitfire.dav4android.Constants;
-import at.bitfire.vcard4android.AndroidAddressBook;
-import at.bitfire.vcard4android.AndroidGroup;
-import at.bitfire.vcard4android.AndroidGroupFactory;
-import at.bitfire.vcard4android.BatchOperation;
-import at.bitfire.vcard4android.CachedGroupMembership;
-import at.bitfire.vcard4android.Contact;
-import at.bitfire.vcard4android.ContactsStorageException;
-import lombok.Cleanup;
-import lombok.ToString;
-
-@ToString(callSuper=true)
-public class LocalGroup extends AndroidGroup implements LocalResource {
-    /** marshalled list of member UIDs, as sent by server */
-    public static final String COLUMN_PENDING_MEMBERS = Groups.SYNC3;
-
-    public LocalGroup(AndroidAddressBook addressBook, long id, String fileName, String eTag) {
-        super(addressBook, id, fileName, eTag);
-    }
-
-    public LocalGroup(AndroidAddressBook addressBook, Contact contact, String fileName, String eTag) {
-        super(addressBook, contact, fileName, eTag);
-    }
-
-
-    @Override
-    public void clearDirty(String eTag) throws ContactsStorageException {
-        assertID();
-
-        ContentValues values = new ContentValues(2);
-        values.put(Groups.DIRTY, 0);
-        values.put(COLUMN_ETAG, this.eTag = eTag);
-        update(values);
-
-        // update cached group memberships
-        BatchOperation batch = new BatchOperation(addressBook.provider);
-
-        // delete cached group memberships
-        batch.enqueue(new BatchOperation.Operation(
-                ContentProviderOperation.newDelete(addressBook.syncAdapterURI(ContactsContract.Data.CONTENT_URI))
-                        .withSelection(
-                                CachedGroupMembership.MIMETYPE + "=? AND " + CachedGroupMembership.GROUP_ID + "=?",
-                                new String[] { CachedGroupMembership.CONTENT_ITEM_TYPE, String.valueOf(id) }
-                        )
-        ));
-
-        // insert updated cached group memberships
-        for (long member : getMembers())
-            batch.enqueue(new BatchOperation.Operation(
-                    ContentProviderOperation.newInsert(addressBook.syncAdapterURI(ContactsContract.Data.CONTENT_URI))
-                            .withValue(CachedGroupMembership.MIMETYPE, CachedGroupMembership.CONTENT_ITEM_TYPE)
-                            .withValue(CachedGroupMembership.RAW_CONTACT_ID, member)
-                            .withValue(CachedGroupMembership.GROUP_ID, id)
-                            .withYieldAllowed(true)
-            ));
-
-        batch.commit();
-    }
-
-    @Override
-    public void prepareForUpload() throws ContactsStorageException {
-        final String uid = UUID.randomUUID().toString();
-        final String newFileName = uid + ".vcf";
-
-        ContentValues values = new ContentValues(2);
-        values.put(COLUMN_FILENAME, newFileName);
-        values.put(COLUMN_UID, uid);
-        update(values);
-
-        fileName = newFileName;
-    }
-
-    @Override
-    protected ContentValues contentValues() {
-        ContentValues values = super.contentValues();
-
-        @Cleanup("recycle") Parcel members = Parcel.obtain();
-        members.writeStringList(contact.members);
-        values.put(COLUMN_PENDING_MEMBERS, members.marshall());
-
-        return values;
-    }
-
-
-    /**
-     * Marks all members of the current group as dirty.
-     */
-    public void markMembersDirty() throws ContactsStorageException {
-        assertID();
-        BatchOperation batch = new BatchOperation(addressBook.provider);
-
-        for (long member : getMembers())
-            batch.enqueue(new BatchOperation.Operation(
-                    ContentProviderOperation.newUpdate(addressBook.syncAdapterURI(ContentUris.withAppendedId(RawContacts.CONTENT_URI, member)))
-                            .withValue(RawContacts.DIRTY, 1)
-                            .withYieldAllowed(true)
-            ));
-
-        batch.commit();
-    }
-
-    /**
-     * Processes all groups with non-null {@link #COLUMN_PENDING_MEMBERS}: the pending memberships
-     * are (if possible) applied, keeping cached memberships in sync.
-     * @param addressBook    address book to take groups from
-     * @throws ContactsStorageException on contact provider errors
-     */
-    public static void applyPendingMemberships(LocalAddressBook addressBook) throws ContactsStorageException {
-        try {
-            @Cleanup Cursor cursor = addressBook.provider.query(
-                    addressBook.syncAdapterURI(Groups.CONTENT_URI),
-                    new String[] { Groups._ID, COLUMN_PENDING_MEMBERS },
-                    COLUMN_PENDING_MEMBERS + " IS NOT NULL", new String[] {},
-                    null
-            );
-
-            BatchOperation batch = new BatchOperation(addressBook.provider);
-            while (cursor != null && cursor.moveToNext()) {
-                long id = cursor.getLong(0);
-                Constants.log.fine("Assigning members to group " + id);
-
-                // required for workaround for Android 7 which sets DIRTY flag when only meta-data is changed
-                Set<Long> changeContactIDs = new HashSet<>();
-
-                // delete all memberships and cached memberships for this group
-                for (LocalContact contact : addressBook.getByGroupMembership(id)) {
-                    contact.removeGroupMemberships(batch);
-                    changeContactIDs.add(contact.getId());
-                }
-
-                // extract list of member UIDs
-                List<String> members = new LinkedList<>();
-                byte[] raw = cursor.getBlob(1);
-                @Cleanup("recycle") Parcel parcel = Parcel.obtain();
-                parcel.unmarshall(raw, 0, raw.length);
-                parcel.setDataPosition(0);
-                parcel.readStringList(members);
-
-                // insert memberships
-                for (String uid : members) {
-                    Constants.log.fine("Assigning member: " + uid);
-                    try {
-                        LocalContact member = addressBook.findContactByUID(uid);
-                        member.addToGroup(batch, id);
-                        changeContactIDs.add(member.getId());
-                    } catch(FileNotFoundException e) {
-                        Constants.log.log(Level.WARNING, "Group member not found: " + uid, e);
-                    }
-                }
-
-                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N)
-                    // workaround for Android 7 which sets DIRTY flag when only meta-data is changed
-                    for (Long contactID : changeContactIDs) {
-                        LocalContact contact = new LocalContact(addressBook, contactID, null, null);
-                        contact.updateHashCode(batch);
-                    }
-
-                // remove pending memberships
-                batch.enqueue(new BatchOperation.Operation(
-                        ContentProviderOperation.newUpdate(addressBook.syncAdapterURI(ContentUris.withAppendedId(Groups.CONTENT_URI, id)))
-                                .withValue(COLUMN_PENDING_MEMBERS, null)
-                                .withYieldAllowed(true)
-                ));
-
-                batch.commit();
-            }
-        } catch(RemoteException e) {
-            throw new ContactsStorageException("Couldn't get pending memberships", e);
-        }
-    }
-
-
-    // helpers
-
-    private void assertID() {
-        if (id == null)
-            throw new IllegalStateException("Group has not been saved yet");
-    }
-
-    /**
-     * Lists all members of this group.
-     * @return list of all members' raw contact IDs
-     * @throws ContactsStorageException on contact provider errors
-     */
-    protected long[] getMembers() throws ContactsStorageException {
-        assertID();
-        List<Long> members = new LinkedList<>();
-        try {
-            @Cleanup Cursor cursor = addressBook.provider.query(
-                    addressBook.syncAdapterURI(ContactsContract.Data.CONTENT_URI),
-                    new String[] { Data.RAW_CONTACT_ID },
-                    GroupMembership.MIMETYPE + "=? AND " + GroupMembership.GROUP_ROW_ID + "=?",
-                    new String[] { GroupMembership.CONTENT_ITEM_TYPE, String.valueOf(id) },
-                    null
-            );
-            while (cursor != null && cursor.moveToNext())
-                members.add(cursor.getLong(0));
-        } catch(RemoteException e) {
-            throw new ContactsStorageException("Couldn't list group members", e);
-        }
-        return ArrayUtils.toPrimitive(members.toArray(new Long[members.size()]));
-    }
-
-
-    // factory
-
-    static class Factory extends AndroidGroupFactory {
-        static final Factory INSTANCE = new Factory();
-
-        @Override
-        public LocalGroup newInstance(AndroidAddressBook addressBook, long id, String fileName, String eTag) {
-            return new LocalGroup(addressBook, id, fileName, eTag);
-        }
-
-        @Override
-        public LocalGroup newInstance(AndroidAddressBook addressBook, Contact contact, String fileName, String eTag) {
-            return new LocalGroup(addressBook, contact, fileName, eTag);
-        }
-
-        @Override
-        public LocalGroup[] newArray(int size) {
-            return new LocalGroup[size];
-        }
-
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/resource/LocalGroup.kt

@@ -0,0 +1,255 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.resource
+
+import android.content.ContentProviderOperation
+import android.content.ContentUris
+import android.content.ContentValues
+import android.os.Build
+import android.os.Parcel
+import android.os.RemoteException
+import android.provider.ContactsContract
+import android.provider.ContactsContract.CommonDataKinds.GroupMembership
+import android.provider.ContactsContract.Groups
+import android.provider.ContactsContract.RawContacts
+import android.provider.ContactsContract.RawContacts.Data
+import at.bitfire.dav4android.Constants
+import at.bitfire.vcard4android.*
+import java.io.FileNotFoundException
+import java.util.*
+import java.util.logging.Level
+
+class LocalGroup: AndroidGroup, LocalResource {
+
+    companion object {
+
+        /** marshaled list of member UIDs, as sent by server */
+        val COLUMN_PENDING_MEMBERS = Groups.SYNC3
+
+        /**
+         * Processes all groups with non-null {@link #COLUMN_PENDING_MEMBERS}: the pending memberships
+         * are (if possible) applied, keeping cached memberships in sync.
+         * @param addressBook    address book to take groups from
+         * @throws ContactsStorageException on contact provider errors
+         */
+        @JvmStatic
+        @Throws(ContactsStorageException::class)
+        fun applyPendingMemberships(addressBook: LocalAddressBook) {
+            try {
+                addressBook.provider!!.query(
+                        addressBook.syncAdapterURI(Groups.CONTENT_URI),
+                        arrayOf(Groups._ID, COLUMN_PENDING_MEMBERS),
+                        "$COLUMN_PENDING_MEMBERS IS NOT NULL", null,
+                        null
+                )?.use { cursor ->
+                    val batch = BatchOperation(addressBook.provider)
+                    while (cursor.moveToNext()) {
+                        val id = cursor.getLong(0)
+                        Constants.log.fine("Assigning members to group $id")
+
+                        // required for workaround for Android 7 which sets DIRTY flag when only meta-data is changed
+                        val changeContactIDs = HashSet<Long>()
+
+                        // delete all memberships and cached memberships for this group
+                        for (contact in addressBook.getByGroupMembership(id)) {
+                            contact.removeGroupMemberships(batch)
+                            changeContactIDs.add(contact.id!!)
+                        }
+
+                        // extract list of member UIDs
+                        val members = LinkedList<String>()
+                        val raw = cursor.getBlob(1)
+                        val parcel = Parcel.obtain()
+                        try {
+                            parcel.unmarshall(raw, 0, raw.size)
+                            parcel.setDataPosition(0)
+                            parcel.readStringList(members)
+                        } finally {
+                            parcel.recycle()
+                        }
+
+                        // insert memberships
+                        for (uid in members) {
+                            Constants.log.fine("Assigning member: $uid")
+                            try {
+                                val member = addressBook.findContactByUID(uid)
+                                member.addToGroup(batch, id)
+                                changeContactIDs.add(member.id!!)
+                            } catch(e: FileNotFoundException) {
+                                Constants.log.log(Level.WARNING, "Group member not found: $uid", e)
+                            }
+                        }
+
+                        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N && Build.VERSION.SDK_INT < Build.VERSION_CODES.O)
+                            // workaround for Android 7 which sets DIRTY flag when only meta-data is changed
+                            changeContactIDs
+                                    .map { LocalContact(addressBook, it, null, null) }
+                                    .forEach { it.updateHashCode(batch) }
+
+                        // remove pending memberships
+                        batch.enqueue(BatchOperation.Operation(
+                                ContentProviderOperation.newUpdate(addressBook.syncAdapterURI(ContentUris.withAppendedId(Groups.CONTENT_URI, id)))
+                                        .withValue(COLUMN_PENDING_MEMBERS, null)
+                                        .withYieldAllowed(true)
+                                ))
+
+                        batch.commit()
+                    }
+                }
+            } catch(e: RemoteException) {
+                throw ContactsStorageException("Couldn't get pending memberships", e)
+            }
+        }
+
+    }
+
+
+    constructor(addressBook: AndroidAddressBook<out AndroidContact, LocalGroup>, id: Long, fileName: String?, eTag: String?):
+        super(addressBook, id, fileName, eTag)
+
+    constructor(addressBook: AndroidAddressBook<out AndroidContact, LocalGroup>, contact: Contact, fileName: String?, eTag: String?):
+        super(addressBook, contact, fileName, eTag)
+
+
+    @Throws(ContactsStorageException::class)
+    fun resetDeleted() {
+        val uri = ContentUris.withAppendedId(addressBook.syncAdapterURI(ContactsContract.Groups.CONTENT_URI), requireNotNull(id))
+
+        val values = ContentValues(1)
+        values.put(ContactsContract.Groups.DELETED, 0)
+        try {
+            addressBook.provider!!.update(uri, values, null, null)
+        } catch(e: RemoteException) {
+            throw ContactsStorageException("Couldn't clear deleted flag", e)
+        }
+    }
+
+    @Throws(ContactsStorageException::class)
+    override fun clearDirty(eTag: String?) {
+        val id = requireNotNull(id)
+
+        val values = ContentValues(2)
+        values.put(Groups.DIRTY, 0)
+        values.put(COLUMN_ETAG, eTag)
+        this.eTag = eTag
+        update(values)
+
+        // update cached group memberships
+        val batch = BatchOperation(addressBook.provider!!)
+
+        // delete cached group memberships
+        batch.enqueue(BatchOperation.Operation(
+                ContentProviderOperation.newDelete(addressBook.syncAdapterURI(ContactsContract.Data.CONTENT_URI))
+                        .withSelection(
+                                CachedGroupMembership.MIMETYPE + "=? AND " + CachedGroupMembership.GROUP_ID + "=?",
+                                arrayOf(CachedGroupMembership.CONTENT_ITEM_TYPE, id.toString())
+                        )
+        ))
+
+        // insert updated cached group memberships
+        for (member in getMembers())
+            batch.enqueue(BatchOperation.Operation(
+                    ContentProviderOperation.newInsert(addressBook.syncAdapterURI(ContactsContract.Data.CONTENT_URI))
+                            .withValue(CachedGroupMembership.MIMETYPE, CachedGroupMembership.CONTENT_ITEM_TYPE)
+                            .withValue(CachedGroupMembership.RAW_CONTACT_ID, member)
+                            .withValue(CachedGroupMembership.GROUP_ID, id)
+                            .withYieldAllowed(true)
+            ))
+
+        batch.commit()
+    }
+
+    @Throws(ContactsStorageException::class)
+    override fun prepareForUpload() {
+        val uid = UUID.randomUUID().toString()
+        val newFileName = "$uid.vcf"
+
+        val values = ContentValues(2)
+        values.put(COLUMN_FILENAME, newFileName)
+        values.put(COLUMN_UID, uid)
+        update(values)
+
+        fileName = newFileName
+    }
+
+    @Throws(FileNotFoundException::class, ContactsStorageException::class)
+    override fun contentValues(): ContentValues  {
+        val values = super.contentValues()
+
+        val members = Parcel.obtain()
+        try {
+            members.writeStringList(contact!!.members)
+            values.put(COLUMN_PENDING_MEMBERS, members.marshall())
+        } finally {
+            members.recycle()
+        }
+        return values
+    }
+
+
+    /**
+     * Marks all members of the current group as dirty.
+     */
+    @Throws(ContactsStorageException::class)
+    fun markMembersDirty() {
+        val batch = BatchOperation(addressBook.provider!!)
+
+        for (member in getMembers())
+            batch.enqueue(BatchOperation.Operation(
+                    ContentProviderOperation.newUpdate(addressBook.syncAdapterURI(ContentUris.withAppendedId(RawContacts.CONTENT_URI, member)))
+                            .withValue(RawContacts.DIRTY, 1)
+                            .withYieldAllowed(true)
+            ))
+
+        batch.commit()
+    }
+
+
+    // helpers
+
+    /**
+     * Lists all members of this group.
+     * @return list of all members' raw contact IDs
+     * @throws ContactsStorageException on contact provider errorst
+     */
+    @Throws(ContactsStorageException::class)
+    internal fun getMembers(): List<Long> {
+        val id = requireNotNull(id)
+        val members = LinkedList<Long>()
+        try {
+            addressBook.provider!!.query(
+                    addressBook.syncAdapterURI(ContactsContract.Data.CONTENT_URI),
+                    arrayOf(Data.RAW_CONTACT_ID),
+                    "${GroupMembership.MIMETYPE}=? AND ${GroupMembership.GROUP_ROW_ID}=?",
+                    arrayOf(GroupMembership.CONTENT_ITEM_TYPE, id.toString()),
+                    null
+            )?.use { cursor ->
+                while (cursor.moveToNext())
+                    members.add(cursor.getLong(0))
+            }
+        } catch(e: RemoteException) {
+            throw ContactsStorageException("Couldn't list group members", e)
+        }
+        return members
+    }
+
+
+    // factory
+
+    object Factory: AndroidGroupFactory<LocalGroup> {
+
+        override fun newInstance(addressBook: AndroidAddressBook<out AndroidContact, LocalGroup>, id: Long, fileName: String?, eTag: String?) =
+                LocalGroup(addressBook, id, fileName, eTag)
+
+        override fun newInstance(addressBook: AndroidAddressBook<out AndroidContact, LocalGroup>, contact: Contact, fileName: String?, eTag: String?) =
+                LocalGroup(addressBook, contact, fileName, eTag)
+
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/resource/LocalResource.java

@@ -1,26 +0,0 @@
-/*
- * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.resource;
-
-import at.bitfire.ical4android.CalendarStorageException;
-import at.bitfire.vcard4android.ContactsStorageException;
-
-public interface LocalResource {
-
-    Long getId();
-
-    String getFileName();
-    String getETag();
-
-    int delete() throws CalendarStorageException, ContactsStorageException;
-
-    void prepareForUpload() throws CalendarStorageException, ContactsStorageException;
-    void clearDirty(String eTag) throws CalendarStorageException, ContactsStorageException;
-
-}

app/src/main/java/at/bitfire/davdroid/resource/LocalResource.kt

@@ -0,0 +1,30 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.resource
+
+import at.bitfire.ical4android.CalendarStorageException
+import at.bitfire.vcard4android.ContactsStorageException
+
+interface LocalResource {
+
+    val id: Long?
+
+    var fileName: String?
+    var eTag: String?
+
+    @Throws(CalendarStorageException::class, ContactsStorageException::class)
+    fun delete(): Int
+
+    @Throws(CalendarStorageException::class, ContactsStorageException::class)
+    fun prepareForUpload()
+
+    @Throws(CalendarStorageException::class, ContactsStorageException::class)
+    fun clearDirty(eTag: String?)
+
+}

app/src/main/java/at/bitfire/davdroid/resource/LocalTask.java

@@ -1,142 +0,0 @@
-/*
- * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.resource;
-
-import android.content.ContentProviderOperation;
-import android.content.ContentValues;
-import android.os.RemoteException;
-import android.provider.CalendarContract.Events;
-import android.support.annotation.NonNull;
-
-import net.fortuna.ical4j.model.property.ProdId;
-
-import org.dmfs.provider.tasks.TaskContract.Tasks;
-
-import java.io.FileNotFoundException;
-import java.text.ParseException;
-
-import at.bitfire.davdroid.App;
-import at.bitfire.davdroid.BuildConfig;
-import at.bitfire.ical4android.AndroidTask;
-import at.bitfire.ical4android.AndroidTaskFactory;
-import at.bitfire.ical4android.AndroidTaskList;
-import at.bitfire.ical4android.CalendarStorageException;
-import at.bitfire.ical4android.Task;
-import lombok.Getter;
-import lombok.Setter;
-import lombok.ToString;
-
-@ToString(of={ "fileName","eTag" }, callSuper=true)
-public class LocalTask extends AndroidTask implements LocalResource {
-    static {
-        Task.prodId = new ProdId("+//IDN bitfire.at//DAVdroid/" + BuildConfig.VERSION_NAME + " ical4android ical4j/2.x");
-    }
-
-    static final String COLUMN_ETAG = Tasks.SYNC1,
-                        COLUMN_UID = Tasks.SYNC2,
-                        COLUMN_SEQUENCE = Tasks.SYNC3;
-
-    @Getter protected String fileName;
-    @Getter @Setter protected String eTag;
-
-    public LocalTask(@NonNull AndroidTaskList taskList, Task task, String fileName, String eTag) {
-        super(taskList, task);
-        this.fileName = fileName;
-        this.eTag = eTag;
-    }
-
-    protected LocalTask(@NonNull AndroidTaskList taskList, long id, ContentValues baseInfo) {
-        super(taskList, id);
-        if (baseInfo != null) {
-            fileName = baseInfo.getAsString(Events._SYNC_ID);
-            eTag = baseInfo.getAsString(COLUMN_ETAG);
-        }
-    }
-
-
-    /* process LocalTask-specific fields */
-
-    @Override
-    protected void populateTask(ContentValues values) throws FileNotFoundException, RemoteException, ParseException {
-        super.populateTask(values);
-
-        fileName = values.getAsString(Events._SYNC_ID);
-        eTag = values.getAsString(COLUMN_ETAG);
-        task.uid = values.getAsString(COLUMN_UID);
-
-        task.sequence = values.getAsInteger(COLUMN_SEQUENCE);
-    }
-
-    @Override
-    protected void buildTask(ContentProviderOperation.Builder builder, boolean update) {
-        super.buildTask(builder, update);
-        builder .withValue(Tasks._SYNC_ID, fileName)
-                .withValue(COLUMN_UID, task.uid)
-                .withValue(COLUMN_SEQUENCE, task.sequence)
-                .withValue(COLUMN_ETAG, eTag);
-    }
-
-
-    /* custom queries */
-
-    public void prepareForUpload() throws CalendarStorageException {
-        try {
-            final String uid = App.getUidGenerator().generateUid().getValue();
-            final String newFileName = uid + ".ics";
-
-            ContentValues values = new ContentValues(2);
-            values.put(Tasks._SYNC_ID, newFileName);
-            values.put(COLUMN_UID, uid);
-            taskList.provider.client.update(taskSyncURI(), values, null, null);
-
-            fileName = newFileName;
-            if (task != null)
-                task.uid = uid;
-
-        } catch (RemoteException e) {
-            throw new CalendarStorageException("Couldn't update UID", e);
-        }
-    }
-
-    @Override
-    public void clearDirty(String eTag) throws CalendarStorageException {
-        try {
-            ContentValues values = new ContentValues(2);
-            values.put(Tasks._DIRTY, 0);
-            values.put(COLUMN_ETAG, eTag);
-            if (task != null)
-                values.put(COLUMN_SEQUENCE, task.sequence);
-            taskList.provider.client.update(taskSyncURI(), values, null, null);
-
-            this.eTag = eTag;
-        } catch (RemoteException e) {
-            throw new CalendarStorageException("Couldn't update _DIRTY/ETag/SEQUENCE", e);
-        }
-    }
-
-
-    static class Factory implements AndroidTaskFactory {
-        static final Factory INSTANCE = new Factory();
-
-        @Override
-        public LocalTask newInstance(AndroidTaskList taskList, long id, ContentValues baseInfo) {
-            return new LocalTask(taskList, id, baseInfo);
-        }
-
-        @Override
-        public LocalTask newInstance(AndroidTaskList taskList, Task task) {
-            return new LocalTask(taskList, task, null, null);
-        }
-
-        @Override
-        public LocalTask[] newArray(int size) {
-            return new LocalTask[size];
-        }
-    }
-}

app/src/main/java/at/bitfire/davdroid/resource/LocalTask.kt

@@ -0,0 +1,117 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.resource
+
+import android.content.ContentProviderOperation
+import android.content.ContentValues
+import android.provider.CalendarContract.Events
+import at.bitfire.ical4android.*
+import org.dmfs.provider.tasks.TaskContract.Tasks
+import java.io.FileNotFoundException
+import java.text.ParseException
+import java.util.*
+
+class LocalTask: AndroidTask, LocalResource {
+
+    companion object {
+        val COLUMN_ETAG = Tasks.SYNC1
+        val COLUMN_UID = Tasks.SYNC2
+        val COLUMN_SEQUENCE = Tasks.SYNC3
+    }
+
+    override var fileName: String? = null
+    override var eTag: String? = null
+
+    constructor(taskList: AndroidTaskList<*>, task: Task, fileName: String?, eTag: String?): super(taskList, task) {
+        this.fileName = fileName
+        this.eTag = eTag
+    }
+
+    private constructor(taskList: AndroidTaskList<*>, id: Long, baseInfo: ContentValues?): super(taskList, id) {
+        baseInfo?.let {
+            fileName = it.getAsString(Events._SYNC_ID)
+            eTag = it.getAsString(COLUMN_ETAG)
+        }
+    }
+
+
+    /* process LocalTask-specific fields */
+
+    @Throws(ParseException::class)
+    override fun populateTask(values: ContentValues) {
+        super.populateTask(values)
+
+        fileName = values.getAsString(Events._SYNC_ID)
+        eTag = values.getAsString(COLUMN_ETAG)
+
+        val task = requireNotNull(task)
+        task.uid = values.getAsString(COLUMN_UID)
+        task.sequence = values.getAsInteger(COLUMN_SEQUENCE)
+    }
+
+    @Throws(FileNotFoundException::class, CalendarStorageException::class)
+    override fun buildTask(builder: ContentProviderOperation.Builder, update: Boolean) {
+        super.buildTask(builder, update)
+        val task = requireNotNull(task)
+
+        builder .withValue(Tasks._SYNC_ID, fileName)
+                .withValue(COLUMN_UID, task.uid)
+                .withValue(COLUMN_SEQUENCE, task.sequence)
+                .withValue(COLUMN_ETAG, eTag)
+    }
+
+
+    /* custom queries */
+
+    @Throws(CalendarStorageException::class)
+    override fun prepareForUpload() {
+        try {
+            val uid = UUID.randomUUID().toString()
+            val newFileName = uid + ".ics"
+
+            val values = ContentValues(2)
+            values.put(Tasks._SYNC_ID, newFileName)
+            values.put(COLUMN_UID, uid)
+            taskList.provider.client.update(taskSyncURI(), values, null, null)
+
+            fileName = newFileName
+
+            task!!.uid = uid
+        } catch (e: Exception) {
+            throw CalendarStorageException("Couldn't update UID", e)
+        }
+    }
+
+    @Throws(CalendarStorageException::class)
+    override fun clearDirty(eTag: String?) {
+        try {
+            val values = ContentValues(2)
+            values.put(Tasks._DIRTY, 0)
+            values.put(COLUMN_ETAG, eTag)
+
+            values.put(COLUMN_SEQUENCE, task!!.sequence)
+            taskList.provider.client.update(taskSyncURI(), values, null, null)
+
+            this.eTag = eTag
+        } catch (e: Exception) {
+            throw CalendarStorageException("Couldn't update _DIRTY/ETag/SEQUENCE", e)
+        }
+    }
+
+
+    object Factory: AndroidTaskFactory<LocalTask> {
+
+        override fun newInstance(calendar: AndroidTaskList<*>, id: Long, baseInfo: ContentValues?) =
+                LocalTask(calendar, id, baseInfo)
+
+        override fun newInstance(calendar: AndroidTaskList<*>, task: Task) =
+                LocalTask(calendar, task, null, null)
+
+    }
+}

app/src/main/java/at/bitfire/davdroid/resource/LocalTaskList.java

@@ -1,175 +0,0 @@
-/*
- * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.resource;
-
-import android.accounts.Account;
-import android.content.ContentProviderClient;
-import android.content.ContentResolver;
-import android.content.ContentValues;
-import android.content.Context;
-import android.database.Cursor;
-import android.net.Uri;
-import android.os.Build;
-import android.os.RemoteException;
-import android.support.annotation.NonNull;
-import android.text.TextUtils;
-
-import org.dmfs.provider.tasks.TaskContract.TaskLists;
-import org.dmfs.provider.tasks.TaskContract.Tasks;
-
-import java.io.FileNotFoundException;
-
-import at.bitfire.davdroid.DavUtils;
-import at.bitfire.davdroid.model.CollectionInfo;
-import at.bitfire.ical4android.AndroidTaskList;
-import at.bitfire.ical4android.AndroidTaskListFactory;
-import at.bitfire.ical4android.CalendarStorageException;
-import at.bitfire.ical4android.TaskProvider;
-import lombok.Cleanup;
-
-public class LocalTaskList extends AndroidTaskList implements LocalCollection {
-
-    public static final int defaultColor = 0xFFC3EA6E;     // "DAVdroid green"
-
-    public static final String COLUMN_CTAG = TaskLists.SYNC_VERSION;
-
-    static String[] BASE_INFO_COLUMNS = new String[] {
-            Tasks._ID,
-            Tasks._SYNC_ID,
-            LocalTask.COLUMN_ETAG
-    };
-
-
-    @Override
-    protected String[] taskBaseInfoColumns() {
-        return BASE_INFO_COLUMNS;
-    }
-
-
-    protected LocalTaskList(Account account, TaskProvider provider, long id) {
-        super(account, provider, LocalTask.Factory.INSTANCE, id);
-    }
-
-    public static Uri create(Account account, TaskProvider provider, CollectionInfo info) throws CalendarStorageException {
-        ContentValues values = valuesFromCollectionInfo(info, true);
-        values.put(TaskLists.OWNER, account.name);
-        values.put(TaskLists.SYNC_ENABLED, 1);
-        values.put(TaskLists.VISIBLE, 1);
-        return create(account, provider, values);
-    }
-
-    public void update(CollectionInfo info, boolean updateColor) throws CalendarStorageException {
-        update(valuesFromCollectionInfo(info, updateColor));
-    }
-
-    private static ContentValues valuesFromCollectionInfo(CollectionInfo info, boolean withColor) {
-        ContentValues values = new ContentValues();
-        values.put(TaskLists._SYNC_ID, info.url);
-        values.put(TaskLists.LIST_NAME, !TextUtils.isEmpty(info.displayName) ? info.displayName : DavUtils.lastSegmentOfUrl(info.url));
-
-        if (withColor)
-            values.put(TaskLists.LIST_COLOR, info.color != null ? info.color : defaultColor);
-
-        return values;
-    }
-
-
-    @Override
-    public LocalTask[] getAll() throws CalendarStorageException {
-        return (LocalTask[])queryTasks(null, null);
-    }
-
-    @Override
-    public LocalTask[] getDeleted() throws CalendarStorageException {
-        return (LocalTask[])queryTasks(Tasks._DELETED + "!=0", null);
-    }
-
-    @Override
-    public LocalTask[] getWithoutFileName() throws CalendarStorageException {
-        return (LocalTask[])queryTasks(Tasks._SYNC_ID + " IS NULL", null);
-    }
-
-    @Override
-    public LocalResource[] getDirty() throws CalendarStorageException, FileNotFoundException {
-        LocalTask[] tasks = (LocalTask[])queryTasks(Tasks._DIRTY + "!=0", null);
-        if (tasks != null)
-        for (LocalTask task : tasks) {
-            if (task.getTask().sequence == null)    // sequence has not been assigned yet (i.e. this task was just locally created)
-                task.getTask().sequence = 0;
-            else
-                task.getTask().sequence++;
-        }
-        return tasks;
-    }
-
-
-    @Override
-    @SuppressWarnings("Recycle")
-    public String getCTag() throws CalendarStorageException {
-        try {
-            @Cleanup Cursor cursor = provider.client.query(taskListSyncUri(), new String[] { COLUMN_CTAG }, null, null, null);
-            if (cursor != null && cursor.moveToNext())
-                return cursor.getString(0);
-        } catch (RemoteException e) {
-            throw new CalendarStorageException("Couldn't read local (last known) CTag", e);
-        }
-        return null;
-    }
-
-    @Override
-    public void setCTag(String cTag) throws CalendarStorageException {
-        try {
-            ContentValues values = new ContentValues(1);
-            values.put(COLUMN_CTAG, cTag);
-            provider.client.update(taskListSyncUri(), values, null, null);
-        } catch (RemoteException e) {
-            throw new CalendarStorageException("Couldn't write local (last known) CTag", e);
-        }
-    }
-
-
-    // helpers
-
-    public static boolean tasksProviderAvailable(@NonNull Context context) {
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M)
-            return context.getPackageManager().resolveContentProvider(TaskProvider.ProviderName.OpenTasks.authority, 0) != null;
-        else {
-            @Cleanup TaskProvider provider = TaskProvider.acquire(context.getContentResolver(), TaskProvider.ProviderName.OpenTasks);
-            return provider != null;
-        }
-    }
-
-
-    public static class Factory implements AndroidTaskListFactory {
-        public static final Factory INSTANCE = new Factory();
-
-        @Override
-        public AndroidTaskList newInstance(Account account, TaskProvider provider, long id) {
-            return new LocalTaskList(account, provider, id);
-        }
-
-        @Override
-        public AndroidTaskList[] newArray(int size) {
-            return new LocalTaskList[size];
-        }
-    }
-
-
-    // HELPERS
-
-    public static void onRenameAccount(@NonNull ContentResolver resolver, @NonNull String oldName, @NonNull String newName) throws RemoteException {
-        @Cleanup("release") ContentProviderClient client = resolver.acquireContentProviderClient(TaskProvider.ProviderName.OpenTasks.authority);
-        if (client != null) {
-            ContentValues values = new ContentValues(1);
-            values.put(Tasks.ACCOUNT_NAME, newName);
-            client.update(Tasks.getContentUri(TaskProvider.ProviderName.OpenTasks.authority), values, Tasks.ACCOUNT_NAME + "=?", new String[]{oldName});
-        }
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/resource/LocalTaskList.kt

@@ -0,0 +1,164 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.resource
+
+import android.accounts.Account
+import android.content.ContentProviderClient
+import android.content.ContentResolver
+import android.content.ContentValues
+import android.content.Context
+import android.net.Uri
+import android.os.Build
+import at.bitfire.davdroid.DavUtils
+import at.bitfire.davdroid.model.CollectionInfo
+import at.bitfire.ical4android.AndroidTaskList
+import at.bitfire.ical4android.AndroidTaskListFactory
+import at.bitfire.ical4android.CalendarStorageException
+import at.bitfire.ical4android.TaskProvider
+import org.dmfs.provider.tasks.TaskContract.TaskLists
+import org.dmfs.provider.tasks.TaskContract.Tasks
+import java.io.FileNotFoundException
+
+class LocalTaskList private constructor(
+        account: Account,
+        provider: TaskProvider,
+        id: Long
+): AndroidTaskList<LocalTask>(account, provider, LocalTask.Factory, id), LocalCollection<LocalTask> {
+
+    companion object {
+
+        val defaultColor = 0xFFC3EA6E.toInt()     // "DAVdroid green"
+
+        val COLUMN_CTAG = TaskLists.SYNC_VERSION
+
+        val BASE_INFO_COLUMNS = arrayOf(
+            Tasks._ID,
+            Tasks._SYNC_ID,
+            LocalTask.COLUMN_ETAG
+        )
+
+        @JvmStatic
+        fun tasksProviderAvailable(context: Context): Boolean {
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M)
+                return context.packageManager.resolveContentProvider(TaskProvider.ProviderName.OpenTasks.authority, 0) != null
+            else {
+                val provider = TaskProvider.acquire(context.contentResolver, TaskProvider.ProviderName.OpenTasks)
+                provider?.use { return true }
+                return false
+            }
+        }
+
+        @JvmStatic
+        @Throws(CalendarStorageException::class)
+        fun create(account: Account, provider: TaskProvider, info: CollectionInfo): Uri {
+            val values = valuesFromCollectionInfo(info, true)
+            values.put(TaskLists.OWNER, account.name)
+            values.put(TaskLists.SYNC_ENABLED, 1)
+            values.put(TaskLists.VISIBLE, 1)
+            return create(account, provider, values)
+        }
+
+        @JvmStatic
+        @Throws(Exception::class)
+        fun onRenameAccount(resolver: ContentResolver, oldName: String, newName: String) {
+            var client: ContentProviderClient? = null
+            try {
+                client = resolver.acquireContentProviderClient(TaskProvider.ProviderName.OpenTasks.authority)
+                client?.use {
+                    val values = ContentValues(1)
+                    values.put(Tasks.ACCOUNT_NAME, newName)
+                    it.update(Tasks.getContentUri(TaskProvider.ProviderName.OpenTasks.authority), values, "${Tasks.ACCOUNT_NAME}=?", arrayOf(oldName))
+                }
+            } finally {
+                if (Build.VERSION.SDK_INT >= 24)
+                    client?.close()
+                else
+                    client?.release()
+            }
+        }
+
+        private fun valuesFromCollectionInfo(info: CollectionInfo, withColor: Boolean): ContentValues {
+            val values = ContentValues(3)
+            values.put(TaskLists._SYNC_ID, info.url)
+            values.put(TaskLists.LIST_NAME, if (info.displayName.isNullOrBlank()) DavUtils.lastSegmentOfUrl(info.url) else info.displayName)
+
+            if (withColor)
+                values.put(TaskLists.LIST_COLOR, info.color ?: defaultColor)
+
+            return values
+        }
+
+    }
+
+
+    override fun taskBaseInfoColumns() = BASE_INFO_COLUMNS
+
+
+    @Throws(CalendarStorageException::class)
+    fun update(info: CollectionInfo, updateColor: Boolean) {
+        update(valuesFromCollectionInfo(info, updateColor));
+    }
+
+
+    @Throws(CalendarStorageException::class)
+    override fun getAll() = queryTasks(null, null)
+
+    @Throws(CalendarStorageException::class)
+    override fun getDeleted() = queryTasks("${Tasks._DELETED}!=0", null)
+
+    @Throws(CalendarStorageException::class)
+    override fun getWithoutFileName() = queryTasks("${Tasks._SYNC_ID} IS NULL", null)
+
+    @Throws(FileNotFoundException::class, CalendarStorageException::class)
+    override fun getDirty(): List<LocalTask> {
+        val tasks = queryTasks("${Tasks._DIRTY}!=0", null)
+        for (localTask in tasks) {
+            val task = requireNotNull(localTask.task)
+            val sequence = task.sequence
+            if (sequence == null)    // sequence has not been assigned yet (i.e. this task was just locally created)
+                task.sequence = 0
+            else
+                task.sequence = sequence + 1
+        }
+        return tasks
+    }
+
+
+    @Throws(CalendarStorageException::class)
+    override fun getCTag(): String? =
+        try {
+            provider.client.query(taskListSyncUri(), arrayOf(COLUMN_CTAG), null, null, null)?.use { cursor ->
+                if (cursor.moveToNext())
+                    return cursor.getString(0)
+            }
+            null
+        } catch(e: Exception) {
+            throw CalendarStorageException("Couldn't read local (last known) CTag", e)
+        }
+
+    @Throws(CalendarStorageException::class)
+    override fun setCTag(cTag: String?) {
+        try {
+            val values = ContentValues(1)
+            values.put(COLUMN_CTAG, cTag)
+            provider.client.update(taskListSyncUri(), values, null, null)
+        } catch (e: Exception) {
+            throw CalendarStorageException("Couldn't write local (last known) CTag", e)
+        }
+    }
+
+
+    object Factory: AndroidTaskListFactory<LocalTaskList> {
+
+        override fun newInstance(account: Account, provider: TaskProvider, id: Long) =
+                LocalTaskList(account, provider, id)
+
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/settings/DefaultsProvider.kt

@@ -0,0 +1,74 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.settings
+
+import at.bitfire.davdroid.App
+
+open class DefaultsProvider(
+        private val allowOverride: Boolean = true
+): Provider {
+
+    open val booleanDefaults = mapOf<String, Boolean>(
+            Pair(App.DISTRUST_SYSTEM_CERTIFICATES, false),
+            Pair(App.OVERRIDE_PROXY, false)
+    )
+
+    open val intDefaults = mapOf<String, Int>(
+            Pair(App.OVERRIDE_PROXY_PORT, App.OVERRIDE_PROXY_PORT_DEFAULT)
+    )
+
+    open val longDefaults = mapOf<String, Long>()
+
+    open val stringDefaults = mapOf<String, String>(
+            Pair(App.OVERRIDE_PROXY_HOST, App.OVERRIDE_PROXY_HOST_DEFAULT)
+    )
+
+
+    override fun close() {
+    }
+
+    override fun forceReload() {
+    }
+
+
+    private fun hasKey(key: String) =
+            booleanDefaults.containsKey(key) ||
+            intDefaults.containsKey(key) ||
+            longDefaults.containsKey(key) ||
+            stringDefaults.containsKey(key)
+
+    override fun has(key: String): Pair<Boolean, Boolean> {
+        val has = hasKey(key)
+        return Pair(has, allowOverride || !has)
+    }
+
+
+    override fun getBoolean(key: String) =
+            Pair(booleanDefaults[key], allowOverride || !booleanDefaults.containsKey(key))
+
+    override fun getInt(key: String) =
+            Pair(intDefaults[key], allowOverride || !intDefaults.containsKey(key))
+
+    override fun getLong(key: String) =
+            Pair(longDefaults[key], allowOverride || !longDefaults.containsKey(key))
+
+    override fun getString(key: String) =
+            Pair(stringDefaults[key], allowOverride || !stringDefaults.containsKey(key))
+
+
+    override fun isWritable(key: String) = Pair(false, allowOverride || !hasKey(key))
+
+    override fun putBoolean(key: String, value: Boolean?) = false
+    override fun putInt(key: String, value: Int?) = false
+    override fun putLong(key: String, value: Long?) = false
+    override fun putString(key: String, value: String?) = false
+
+    override fun remove(key: String) = false
+
+}

app/src/main/java/at/bitfire/davdroid/settings/Provider.kt

@@ -0,0 +1,38 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.settings
+
+import java.io.Closeable
+
+interface Provider: Closeable {
+
+    fun forceReload()
+
+    fun has(key: String): Pair<Boolean, Boolean>
+
+    fun getBoolean(key: String): Pair<Boolean?, Boolean>
+    fun getInt(key: String): Pair<Int?, Boolean>
+    fun getLong(key: String): Pair<Long?, Boolean>
+    fun getString(key: String): Pair<String?, Boolean>
+
+    fun isWritable(key: String): Pair<Boolean, Boolean>
+
+    fun putBoolean(key: String, value: Boolean?): Boolean
+    fun putInt(key: String, value: Int?): Boolean
+    fun putLong(key: String, value: Long?): Boolean
+    fun putString(key: String, value: String?): Boolean
+
+    fun remove(key: String): Boolean
+
+
+    interface Observer {
+        fun onReload()
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/settings/Settings.kt

@@ -0,0 +1,276 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.settings
+
+import android.annotation.TargetApi
+import android.app.Service
+import android.content.ComponentName
+import android.content.Context
+import android.content.Intent
+import android.content.ServiceConnection
+import android.os.Build
+import android.os.Handler
+import android.os.IBinder
+import android.os.Looper
+import at.bitfire.davdroid.log.Logger
+import java.io.Closeable
+import java.lang.ref.WeakReference
+import java.util.*
+import java.util.logging.Level
+
+class Settings: Service(), Provider.Observer {
+
+    private val providers = LinkedList<Provider>()
+    private val observers = LinkedList<WeakReference<ISettingsObserver>>()
+
+    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
+    override fun onCreate() {
+        Logger.log.info("Initializing Settings service")
+
+        // always add a defaults provider first
+        providers.add(DefaultsProvider())
+
+        // always add a provider for local preferences
+        providers.add(SharedPreferencesProvider(this))
+    }
+
+    override fun onDestroy() {
+        Logger.log.info("Shutting down Settings service")
+        providers.forEach { it.close() }
+        providers.clear()
+    }
+
+    override fun onTrimMemory(level: Int) {
+        stopSelf()
+    }
+
+
+    fun forceReload() {
+        providers.forEach { it.forceReload() }
+    }
+
+    override fun onReload() {
+        observers.forEach {
+            Handler(Looper.getMainLooper()).post {
+                it.get()?.onSettingsChanged()
+            }
+        }
+    }
+
+
+    private fun has(key: String): Boolean {
+        Logger.log.fine("Looking for setting $key")
+        var result = false
+        for (provider in providers)
+            try {
+                val (value, further) = provider.has(key)
+                Logger.log.finer("${provider::class.java.simpleName}: has $key = $value, continue: $further")
+                if (value) {
+                    result = true
+                    break
+                }
+                if (!further)
+                    break
+            } catch(e: Exception) {
+                Logger.log.log(Level.SEVERE, "Couldn't look up setting in $provider", e)
+            }
+        Logger.log.fine("Looking for setting $key -> $result")
+        return result
+    }
+
+    private fun<T> getValue(key: String, reader: (Provider) -> Pair<T?, Boolean>): T? {
+        Logger.log.fine("Looking up setting $key")
+        var result: T? = null
+        for (provider in providers)
+            try {
+                val (value, further) = reader(provider)
+                Logger.log.finer("${provider::class.java.simpleName}: value = $value, continue: $further")
+                value?.let { result = it }
+                if (!further)
+                    break
+            } catch(e: Exception) {
+                Logger.log.log(Level.SEVERE, "Couldn't read setting from $provider", e)
+            }
+        Logger.log.fine("Looked up setting $key -> $result")
+        return result
+    }
+
+    fun getBoolean(key: String) =
+            getValue(key, { provider -> provider.getBoolean(key) })
+
+    fun getInt(key: String) =
+            getValue(key, { provider -> provider.getInt(key) })
+
+    fun getLong(key: String) =
+            getValue(key, { provider -> provider.getLong(key) })
+
+    fun getString(key: String) =
+            getValue(key, { provider -> provider.getString(key) })
+
+
+    fun isWritable(key: String): Boolean {
+        for (provider in providers) {
+            val (value, further) = provider.isWritable(key)
+            if (value)
+                return true
+            if (!further)
+                return false
+        }
+        return false
+    }
+
+    private fun<T> putValue(key: String, value: T?, writer: (Provider) -> Boolean): Boolean {
+        Logger.log.fine("Trying to write setting $key = $value")
+        for (provider in providers) {
+            val (writable, further) = provider.isWritable(key)
+            Logger.log.finer("${provider::class.java.simpleName}: writable = $writable, continue: $further")
+            if (writable)
+                return try {
+                    writer(provider)
+                } catch (e: Exception) {
+                    Logger.log.log(Level.SEVERE, "Couldn't write setting to $provider", e)
+                    false
+                }
+            if (!further)
+                return false
+        }
+        return false
+    }
+
+    fun putBoolean(key: String, value: Boolean?) =
+            putValue(key, value, { provider -> provider.putBoolean(key, value) })
+
+    fun putInt(key: String, value: Int?) =
+            putValue(key, value, { provider -> provider.putInt(key, value) })
+
+    fun putLong(key: String, value: Long?) =
+            putValue(key, value, { provider -> provider.putLong(key, value) })
+
+    fun putString(key: String, value: String?) =
+            putValue(key, value, { provider -> provider.putString(key, value) })
+
+    fun remove(key: String): Boolean {
+        var deleted = false
+        providers.forEach { deleted = deleted || it.remove(key) }
+        return deleted
+    }
+
+
+    val binder = object: ISettings.Stub() {
+
+        override fun forceReload() =
+               this@Settings.forceReload()
+
+        override fun has(key: String) =
+                this@Settings.has(key)
+
+        override fun getBoolean(key: String, defaultValue: Boolean) =
+                this@Settings.getBoolean(key) ?: defaultValue
+
+        override fun getInt(key: String, defaultValue: Int) =
+                this@Settings.getInt(key) ?: defaultValue
+
+        override fun getLong(key: String, defaultValue: Long) =
+                this@Settings.getLong(key) ?: defaultValue
+
+        override fun getString(key: String, defaultValue: String?) =
+                this@Settings.getString(key) ?: defaultValue
+
+        override fun isWritable(key: String) =
+                this@Settings.isWritable(key)
+
+        override fun remove(key: String) =
+                this@Settings.remove(key)
+
+        override fun putBoolean(key: String, value: Boolean) =
+                this@Settings.putBoolean(key, value)
+
+        override fun putString(key: String, value: String?) =
+                this@Settings.putString(key, value)
+
+        override fun putInt(key: String, value: Int) =
+                this@Settings.putInt(key, value)
+
+        override fun putLong(key: String, value: Long) =
+                this@Settings.putLong(key, value)
+
+        override fun registerObserver(observer: ISettingsObserver) {
+            observers += WeakReference(observer)
+        }
+
+        override fun unregisterObserver(observer: ISettingsObserver) {
+            observers.removeAll { it.get() == observer }
+        }
+
+    }
+
+    override fun onBind(intent: Intent?) = binder
+
+
+    class Stub(
+            delegate: ISettings,
+            private val context: Context,
+            private val serviceConn: ServiceConnection
+    ): ISettings by delegate, Closeable {
+
+        override fun close() {
+            try {
+                context.unbindService(serviceConn)
+            } catch(e: Exception) {
+                Logger.log.log(Level.SEVERE, "Couldn't unbind Settings service", e)
+            }
+        }
+
+    }
+
+    companion object {
+
+        fun getInstance(context: Context): Stub? {
+            if (Looper.getMainLooper().thread == Thread.currentThread())
+                throw IllegalStateException("Must not be called from main thread")
+
+            var service: ISettings? = null
+            val serviceLock = Object()
+            val serviceConn = object: ServiceConnection {
+                override fun onServiceConnected(name: ComponentName, binder: IBinder) {
+                    synchronized(serviceLock) {
+                        service = ISettings.Stub.asInterface(binder)
+                        serviceLock.notify()
+                    }
+                }
+                override fun onServiceDisconnected(name: ComponentName) {
+                    service = null
+                }
+            }
+
+            if (!context.bindService(Intent(context, Settings::class.java), serviceConn, Context.BIND_AUTO_CREATE or Context.BIND_IMPORTANT))
+                return null
+
+            synchronized(serviceLock) {
+                if (service == null)
+                    try {
+                        serviceLock.wait()
+                    } catch(e: InterruptedException) {
+                    }
+
+                if (service == null) {
+                    try {
+                        context.unbindService(serviceConn)
+                    } catch (e: IllegalArgumentException) {
+                    }
+                    return null
+                }
+            }
+
+            return Stub(service!!, context, serviceConn)
+        }
+
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/settings/SharedPreferencesProvider.kt

@@ -0,0 +1,120 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.settings
+
+import android.content.Context
+import android.content.Context.MODE_PRIVATE
+import android.content.SharedPreferences
+import android.preference.PreferenceManager
+import at.bitfire.davdroid.log.Logger
+import at.bitfire.davdroid.model.ServiceDB
+
+class SharedPreferencesProvider(
+        context: Context
+): Provider {
+
+    companion object {
+        private val META_VERSION = "version"
+        private val CURRENT_VERSION = 0
+    }
+
+    private val preferences = PreferenceManager.getDefaultSharedPreferences(context)
+
+    init {
+        val meta = context.getSharedPreferences("meta", MODE_PRIVATE)
+        val version = meta.getInt(META_VERSION, -1)
+        if (version == -1) {
+            // first call, check whether to migrate from SQLite database (DAVdroid <1.9)
+            firstCall(context)
+            meta.edit().putInt(META_VERSION, CURRENT_VERSION).apply()
+        }
+    }
+
+    override fun close() {
+    }
+
+    override fun forceReload() {
+    }
+
+
+    override fun has(key: String) =
+            Pair(preferences.contains(key), true)
+
+    private fun<T> getValue(key: String, reader: (SharedPreferences) -> T): Pair<T?, Boolean> {
+        if (preferences.contains(key))
+            return Pair(
+                    try { reader(preferences) } catch(e: ClassCastException) { null },
+                    true)
+
+        return Pair(null, true)
+    }
+
+    override fun getBoolean(key: String): Pair<Boolean?, Boolean> =
+            getValue(key, { preferences -> preferences.getBoolean(key, /* will never be used: */ false) })
+
+    override fun getInt(key: String): Pair<Int?, Boolean> =
+            getValue(key, { preferences -> preferences.getInt(key, /* will never be used: */ -1) })
+
+    override fun getLong(key: String): Pair<Long?, Boolean> =
+            getValue(key, { preferences -> preferences.getLong(key, /* will never be used: */ -1) })
+
+    override fun getString(key: String): Pair<String?, Boolean> =
+            getValue(key, { preferences -> preferences.getString(key, /* will never be used: */ null) })
+
+
+    override fun isWritable(key: String) =
+            Pair(true, true)
+
+    private fun<T> putValue(key: String, value: T?, writer: (SharedPreferences.Editor, T) -> Unit): Boolean {
+        if (value == null)
+            return remove(key)
+        else {
+            Logger.log.fine("Writing setting $key = $value")
+            val edit = preferences.edit()
+            writer(edit, value)
+            edit.apply()
+            return true
+        }
+    }
+
+    override fun putBoolean(key: String, value: Boolean?) =
+            putValue(key, value, { editor, v -> editor.putBoolean(key, v) })
+
+    override fun putInt(key: String, value: Int?) =
+            putValue(key, value, { editor, v -> editor.putInt(key, v) })
+
+    override fun putLong(key: String, value: Long?) =
+            putValue(key, value, { editor, v -> editor.putLong(key, v) })
+
+    override fun putString(key: String, value: String?) =
+            putValue(key, value, { editor, v -> editor.putString(key, v) })
+
+    override fun remove(key: String): Boolean {
+        Logger.log.fine("Removing setting $key")
+        preferences.edit()
+                .remove(key)
+                .apply()
+        return true
+    }
+
+
+    private fun firstCall(context: Context) {
+        // remove possible artifacts from DAVdroid <1.9
+        val edit = preferences.edit()
+        edit.remove("override_proxy")
+        edit.remove("proxy_host")
+        edit.remove("proxy_port")
+        edit.remove("log_to_external_storage")
+        edit.apply()
+
+        // open ServiceDB to upgrade it and possibly migrate settings
+        ServiceDB.OpenHelper(context).use { it.readableDatabase }
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/syncadapter/AccountAuthenticatorService.java

@@ -1,89 +0,0 @@
-/*
- * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-package at.bitfire.davdroid.syncadapter;
-
-import android.accounts.AbstractAccountAuthenticator;
-import android.accounts.Account;
-import android.accounts.AccountAuthenticatorResponse;
-import android.accounts.AccountManager;
-import android.accounts.NetworkErrorException;
-import android.app.Service;
-import android.content.Context;
-import android.content.Intent;
-import android.os.Bundle;
-import android.os.IBinder;
-
-import at.bitfire.davdroid.ui.setup.LoginActivity;
-
-public class AccountAuthenticatorService extends Service {
-
-    private AccountAuthenticator accountAuthenticator;
-
-    @Override
-    public void onCreate() {
-        accountAuthenticator = new AccountAuthenticator(this);
-    }
-
-    @Override
-    public IBinder onBind(Intent intent) {
-        if (intent.getAction().equals(android.accounts.AccountManager.ACTION_AUTHENTICATOR_INTENT))
-            return accountAuthenticator.getIBinder();
-        return null;
-    }
-
-
-    private static class AccountAuthenticator extends AbstractAccountAuthenticator {
-        final Context context;
-
-        public AccountAuthenticator(Context context) {
-            super(context);
-            this.context = context;
-        }
-
-        @Override
-        public Bundle addAccount(AccountAuthenticatorResponse response, String accountType, String authTokenType,
-                String[] requiredFeatures, Bundle options) throws NetworkErrorException {
-            Intent intent = new Intent(context, LoginActivity.class);
-            intent.putExtra(AccountManager.KEY_ACCOUNT_AUTHENTICATOR_RESPONSE, response);
-            Bundle bundle = new Bundle();
-            bundle.putParcelable(AccountManager.KEY_INTENT, intent);
-            return bundle;
-        }
-
-        @Override
-        public Bundle confirmCredentials(AccountAuthenticatorResponse response, Account account, Bundle options) throws NetworkErrorException {
-            return null;
-        }
-
-        @Override
-        public Bundle editProperties(AccountAuthenticatorResponse response, String accountType) {
-            return null;
-        }
-
-        @Override
-        public Bundle getAuthToken(AccountAuthenticatorResponse response, Account account, String authTokenType, Bundle options) throws NetworkErrorException {
-            return null;
-        }
-
-        @Override
-        public String getAuthTokenLabel(String authTokenType) {
-            return null;
-        }
-
-        @Override
-        public Bundle hasFeatures(AccountAuthenticatorResponse response, Account account, String[] features) throws NetworkErrorException {
-            return null;
-        }
-
-        @Override
-        public Bundle updateCredentials(AccountAuthenticatorResponse response, Account account, String authTokenType, Bundle options) throws NetworkErrorException {
-            return null;
-        }
-
-    }
-}

app/src/main/java/at/bitfire/davdroid/syncadapter/AccountAuthenticatorService.kt

@@ -0,0 +1,52 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+package at.bitfire.davdroid.syncadapter
+
+import android.accounts.AbstractAccountAuthenticator
+import android.accounts.Account
+import android.accounts.AccountAuthenticatorResponse
+import android.accounts.AccountManager
+import android.app.Service
+import android.content.Context
+import android.content.Intent
+import android.os.Bundle
+import at.bitfire.davdroid.ui.setup.LoginActivity
+
+class AccountAuthenticatorService: Service() {
+
+    private lateinit var accountAuthenticator: AccountAuthenticator
+
+    override fun onCreate() {
+        accountAuthenticator = AccountAuthenticator(this)
+    }
+
+    override fun onBind(intent: Intent?) =
+            accountAuthenticator.iBinder.takeIf { intent?.action == android.accounts.AccountManager.ACTION_AUTHENTICATOR_INTENT }
+
+
+    private class AccountAuthenticator(
+            val context: Context
+    ): AbstractAccountAuthenticator(context) {
+
+        override fun addAccount(response: AccountAuthenticatorResponse?, accountType: String?, authTokenType: String?, requiredFeatures: Array<String>?, options: Bundle?): Bundle {
+            val intent = Intent(context, LoginActivity::class.java)
+            intent.putExtra(AccountManager.KEY_ACCOUNT_AUTHENTICATOR_RESPONSE, response)
+            val bundle = Bundle(1)
+            bundle.putParcelable(AccountManager.KEY_INTENT, intent)
+            return bundle
+        }
+
+        override fun editProperties(response: AccountAuthenticatorResponse?, accountType: String?)  = null
+        override fun getAuthTokenLabel(p0: String?) = null
+        override fun confirmCredentials(p0: AccountAuthenticatorResponse?, p1: Account?, p2: Bundle?) = null
+        override fun updateCredentials(p0: AccountAuthenticatorResponse?, p1: Account?, p2: String?, p3: Bundle?) = null
+        override fun getAuthToken(p0: AccountAuthenticatorResponse?, p1: Account?, p2: String?, p3: Bundle?) = null
+        override fun hasFeatures(p0: AccountAuthenticatorResponse?, p1: Account?, p2: Array<out String>?) = null
+
+    }
+}

app/src/main/java/at/bitfire/davdroid/syncadapter/AddressBookProvider.kt

@@ -0,0 +1,24 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.syncadapter
+
+import android.content.ContentProvider
+import android.content.ContentValues
+import android.net.Uri
+
+class AddressBookProvider: ContentProvider() {
+
+    override fun onCreate() = false
+    override fun insert(p0: Uri?, p1: ContentValues?) = null
+    override fun query(p0: Uri?, p1: Array<out String>?, p2: String?, p3: Array<out String>?, p4: String?) = null
+    override fun update(p0: Uri?, p1: ContentValues?, p2: String?, p3: Array<out String>?) = 0
+    override fun delete(p0: Uri?, p1: String?, p2: Array<out String>?) = 0
+    override fun getType(p0: Uri?) = null
+
+}

app/src/main/java/at/bitfire/davdroid/syncadapter/AddressBooksSyncAdapterService.kt

@@ -0,0 +1,135 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+package at.bitfire.davdroid.syncadapter
+
+import android.accounts.Account
+import android.accounts.AccountManager
+import android.content.*
+import android.database.DatabaseUtils
+import android.os.Bundle
+import android.provider.ContactsContract
+import at.bitfire.davdroid.AccountSettings
+import at.bitfire.davdroid.R
+import at.bitfire.davdroid.log.Logger
+import at.bitfire.davdroid.model.CollectionInfo
+import at.bitfire.davdroid.model.ServiceDB
+import at.bitfire.davdroid.model.ServiceDB.Collections
+import at.bitfire.davdroid.resource.LocalAddressBook
+import at.bitfire.davdroid.settings.ISettings
+import at.bitfire.vcard4android.ContactsStorageException
+import java.util.logging.Level
+
+class AddressBooksSyncAdapterService: SyncAdapterService() {
+
+    override fun syncAdapter() = AddressBooksSyncAdapter(this)
+
+
+	protected class AddressBooksSyncAdapter(
+            context: Context
+    ): SyncAdapter(context) {
+
+        override fun sync(settings: ISettings, account: Account, extras: Bundle, authority: String, addressBooksProvider: ContentProviderClient, syncResult: SyncResult) {
+            val contactsProvider = context.contentResolver.acquireContentProviderClient(ContactsContract.AUTHORITY)
+            if (contactsProvider == null) {
+                Logger.log.severe("Couldn't access contacts provider")
+                syncResult.databaseError = true
+                return
+            }
+
+            try {
+                val accountSettings = AccountSettings(context, settings, account)
+
+                /* don't run sync if
+                   - sync conditions (e.g. "sync only in WiFi") are not met AND
+                   - this is is an automatic sync (i.e. manual syncs are run regardless of sync conditions)
+                 */
+                if (!extras.containsKey(ContentResolver.SYNC_EXTRAS_MANUAL) && !checkSyncConditions(accountSettings))
+                    return
+
+                updateLocalAddressBooks(contactsProvider, account)
+
+                val accountManager = AccountManager.get(context)
+                for (addressBookAccount in accountManager.getAccountsByType(context.getString(R.string.account_type_address_book))) {
+                    Logger.log.log(Level.INFO, "Running sync for address book", addressBookAccount)
+                    val syncExtras = Bundle(extras)
+                    syncExtras.putBoolean(ContentResolver.SYNC_EXTRAS_IGNORE_SETTINGS, true)
+                    syncExtras.putBoolean(ContentResolver.SYNC_EXTRAS_IGNORE_BACKOFF, true)
+                    ContentResolver.requestSync(addressBookAccount, ContactsContract.AUTHORITY, syncExtras)
+                }
+            } catch(e: Exception) {
+                Logger.log.log(Level.SEVERE, "Couldn't sync address books", e)
+            }
+
+            Logger.log.info("Address book sync complete")
+        }
+
+        private fun updateLocalAddressBooks(provider: ContentProviderClient, account: Account) {
+            ServiceDB.OpenHelper(context).use { dbHelper ->
+                val db = dbHelper.readableDatabase
+
+                fun getService() =
+                        db.query(ServiceDB.Services._TABLE, arrayOf(ServiceDB.Services.ID),
+                            "${ServiceDB.Services.ACCOUNT_NAME}=? AND ${ServiceDB.Services.SERVICE}=?",
+                            arrayOf(account.name, ServiceDB.Services.SERVICE_CARDDAV), null, null, null)?.use { c ->
+                            if (c.moveToNext())
+                                c.getLong(0)
+                            else
+                                null
+                        }
+
+                fun remoteAddressBooks(service: Long?): MutableMap<String, CollectionInfo> {
+                    val collections = mutableMapOf<String, CollectionInfo>()
+                    service?.let {
+                        db.query(Collections._TABLE, null,
+                            Collections.SERVICE_ID + "=? AND " + Collections.SYNC, arrayOf(service.toString()), null, null, null)?.use { cursor ->
+                            while (cursor.moveToNext()) {
+                                val values = ContentValues(cursor.columnCount)
+                                DatabaseUtils.cursorRowToContentValues(cursor, values)
+                                val info = CollectionInfo(values)
+                                collections[info.url] = info
+                            }
+                        }
+                    }
+                    return collections
+                }
+
+                // enumerate remote and local address books
+                val service = getService()
+                val remote = remoteAddressBooks(service)
+
+                // delete/update local address books
+                for (addressBook in LocalAddressBook.find(context, provider, account)) {
+                    val url = addressBook.getURL()
+                    val info = remote[url]
+                    if (info == null) {
+                        Logger.log.log(Level.INFO, "Deleting obsolete local address book", url)
+                        addressBook.delete()
+                    } else {
+                        // remote CollectionInfo found for this local collection, update data
+                        try {
+                            Logger.log.log(Level.FINE, "Updating local address book $url", info)
+                            addressBook.update(info)
+                        } catch(e: ContactsStorageException) {
+                            Logger.log.log(Level.WARNING, "Couldn't rename address book account", e)
+                        }
+                        // we already have a local address book for this remote collection, don't take into consideration anymore
+                        remote -= url
+                    }
+                }
+
+                // create new local address books
+                for ((_, info) in remote) {
+                    Logger.log.log(Level.INFO, "Adding local address book", info)
+                    LocalAddressBook.create(context, provider, account, info)
+                }
+            }
+        }
+
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/syncadapter/CalendarSyncManager.java

@@ -1,252 +0,0 @@
-/*
- * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.syncadapter;
-
-import android.accounts.Account;
-import android.content.Context;
-import android.content.SyncResult;
-import android.os.Bundle;
-
-import org.apache.commons.codec.Charsets;
-import org.apache.commons.lang3.StringUtils;
-
-import java.io.ByteArrayInputStream;
-import java.io.ByteArrayOutputStream;
-import java.io.IOException;
-import java.io.InputStream;
-import java.nio.charset.Charset;
-import java.util.Calendar;
-import java.util.Date;
-import java.util.HashMap;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.logging.Level;
-
-import at.bitfire.dav4android.DavCalendar;
-import at.bitfire.dav4android.DavResource;
-import at.bitfire.dav4android.exception.DavException;
-import at.bitfire.dav4android.exception.HttpException;
-import at.bitfire.dav4android.property.CalendarData;
-import at.bitfire.dav4android.property.GetCTag;
-import at.bitfire.dav4android.property.GetContentType;
-import at.bitfire.dav4android.property.GetETag;
-import at.bitfire.davdroid.AccountSettings;
-import at.bitfire.davdroid.App;
-import at.bitfire.davdroid.ArrayUtils;
-import at.bitfire.davdroid.Constants;
-import at.bitfire.davdroid.InvalidAccountException;
-import at.bitfire.davdroid.R;
-import at.bitfire.davdroid.resource.LocalCalendar;
-import at.bitfire.davdroid.resource.LocalEvent;
-import at.bitfire.davdroid.resource.LocalResource;
-import at.bitfire.ical4android.CalendarStorageException;
-import at.bitfire.ical4android.Event;
-import at.bitfire.ical4android.InvalidCalendarException;
-import at.bitfire.vcard4android.ContactsStorageException;
-import lombok.Cleanup;
-import okhttp3.HttpUrl;
-import okhttp3.MediaType;
-import okhttp3.RequestBody;
-import okhttp3.ResponseBody;
-
-/**
- * Synchronization manager for CalDAV collections; handles events ({@code VEVENT}).
- */
-public class CalendarSyncManager extends SyncManager {
-
-    protected static final int MAX_MULTIGET = 20;
-
-
-    public CalendarSyncManager(Context context, Account account, AccountSettings settings, Bundle extras, String authority, SyncResult result, LocalCalendar calendar) throws InvalidAccountException {
-        super(context, account, settings, extras, authority, result, "calendar/" + calendar.getId());
-        localCollection = calendar;
-    }
-
-    @Override
-    protected int notificationId() {
-        return Constants.NOTIFICATION_CALENDAR_SYNC;
-    }
-
-    @Override
-    protected String getSyncErrorTitle() {
-        return context.getString(R.string.sync_error_calendar, account.name);
-    }
-
-
-    @Override
-    protected boolean prepare() {
-        collectionURL = HttpUrl.parse(localCalendar().getName());
-        davCollection = new DavCalendar(httpClient, collectionURL);
-        return true;
-    }
-
-    @Override
-    protected void queryCapabilities() throws DavException, IOException, HttpException {
-        davCollection.propfind(0, GetCTag.NAME);
-    }
-
-    @Override
-    protected void prepareDirty() throws CalendarStorageException, ContactsStorageException {
-        super.prepareDirty();
-
-        localCalendar().processDirtyExceptions();
-    }
-
-    @Override
-    protected RequestBody prepareUpload(LocalResource resource) throws IOException, CalendarStorageException {
-        LocalEvent local = (LocalEvent)resource;
-        App.log.log(Level.FINE, "Preparing upload of event " + local.getFileName(), local.getEvent());
-
-        ByteArrayOutputStream os = new ByteArrayOutputStream();
-        local.getEvent().write(os);
-
-        return RequestBody.create(
-                DavCalendar.MIME_ICALENDAR,
-                os.toByteArray()
-        );
-    }
-
-    @Override
-    protected void listRemote() throws IOException, HttpException, DavException {
-        // calculate time range limits
-        Date limitStart = null;
-        Integer pastDays = settings.getTimeRangePastDays();
-        if (pastDays != null) {
-            Calendar calendar = Calendar.getInstance();
-            calendar.add(Calendar.DAY_OF_MONTH, -pastDays);
-            limitStart = calendar.getTime();
-        }
-
-        // fetch list of remote VEVENTs and build hash table to index file name
-        final DavCalendar calendar = davCalendar();
-        currentDavResource = calendar;
-        calendar.calendarQuery("VEVENT", limitStart, null);
-
-        remoteResources = new HashMap<>(davCollection.members.size());
-        for (DavResource iCal : davCollection.members) {
-            String fileName = iCal.fileName();
-            App.log.fine("Found remote VEVENT: " + fileName);
-            remoteResources.put(fileName, iCal);
-        }
-
-        currentDavResource = null;
-    }
-
-    @Override
-    protected void downloadRemote() throws IOException, HttpException, DavException, CalendarStorageException {
-        App.log.info("Downloading " + toDownload.size() + " events (" + MAX_MULTIGET + " at once)");
-
-        // download new/updated iCalendars from server
-        for (DavResource[] bunch : ArrayUtils.partition(toDownload.toArray(new DavResource[toDownload.size()]), MAX_MULTIGET)) {
-            if (Thread.interrupted())
-                return;
-            App.log.info("Downloading " + StringUtils.join(bunch, ", "));
-
-            if (bunch.length == 1) {
-                // only one contact, use GET
-                final DavResource remote = bunch[0];
-                currentDavResource = remote;
-
-                ResponseBody body = remote.get("text/calendar");
-
-                // CalDAV servers MUST return ETag on GET [https://tools.ietf.org/html/rfc4791#section-5.3.4]
-                GetETag eTag = (GetETag)remote.properties.get(GetETag.NAME);
-                if (eTag == null || StringUtils.isEmpty(eTag.eTag))
-                    throw new DavException("Received CalDAV GET response without ETag for " + remote.location);
-
-                Charset charset = Charsets.UTF_8;
-                MediaType contentType = body.contentType();
-                if (contentType != null)
-                    charset = contentType.charset(Charsets.UTF_8);
-
-                @Cleanup InputStream stream = body.byteStream();
-                processVEvent(remote.fileName(), eTag.eTag, stream, charset);
-
-            } else {
-                // multiple contacts, use multi-get
-                List<HttpUrl> urls = new LinkedList<>();
-                for (DavResource remote : bunch)
-                    urls.add(remote.location);
-
-                final DavCalendar calendar = davCalendar();
-                currentDavResource = calendar;
-                calendar.multiget(urls.toArray(new HttpUrl[urls.size()]));
-
-                // process multiget results
-                for (final DavResource remote : davCollection.members) {
-                    currentDavResource = remote;
-
-                    String eTag;
-                    GetETag getETag = (GetETag)remote.properties.get(GetETag.NAME);
-                    if (getETag != null)
-                        eTag = getETag.eTag;
-                    else
-                        throw new DavException("Received multi-get response without ETag");
-
-                    Charset charset = Charsets.UTF_8;
-                    GetContentType getContentType = (GetContentType)remote.properties.get(GetContentType.NAME);
-                    if (getContentType != null && getContentType.type != null) {
-                        MediaType type = MediaType.parse(getContentType.type);
-                        if (type != null)
-                            charset = type.charset(Charsets.UTF_8);
-                    }
-
-                    CalendarData calendarData = (CalendarData)remote.properties.get(CalendarData.NAME);
-                    if (calendarData == null || calendarData.iCalendar == null)
-                        throw new DavException("Received multi-get response without address data");
-
-                    @Cleanup InputStream stream = new ByteArrayInputStream(calendarData.iCalendar.getBytes());
-                    processVEvent(remote.fileName(), eTag, stream, charset);
-                }
-            }
-
-            currentDavResource = null;
-        }
-    }
-
-
-    // helpers
-
-    private LocalCalendar localCalendar() { return ((LocalCalendar)localCollection); }
-    private DavCalendar davCalendar() { return (DavCalendar)davCollection; }
-
-    private void processVEvent(String fileName, String eTag, InputStream stream, Charset charset) throws IOException, CalendarStorageException {
-        Event[] events;
-        try {
-            events = Event.fromStream(stream, charset);
-        } catch (InvalidCalendarException e) {
-            App.log.log(Level.SEVERE, "Received invalid iCalendar, ignoring", e);
-            return;
-        }
-
-        if (events.length == 1) {
-            Event newData = events[0];
-
-            // delete local event, if it exists
-            LocalEvent localEvent = (LocalEvent)localResources.get(fileName);
-            currentLocalResource = localEvent;
-            if (localEvent != null) {
-                App.log.info("Updating " + fileName + " in local calendar");
-                localEvent.setETag(eTag);
-                localEvent.update(newData);
-                syncResult.stats.numUpdates++;
-            } else {
-                App.log.info("Adding " + fileName + " to local calendar");
-                localEvent = new LocalEvent(localCalendar(), newData, fileName, eTag);
-                currentLocalResource = localEvent;
-                localEvent.add();
-                syncResult.stats.numInserts++;
-            }
-        } else
-            App.log.severe("Received VCALENDAR with not exactly one VEVENT with UID, but without RECURRENCE-ID; ignoring " + fileName);
-
-        currentLocalResource = null;
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/syncadapter/CalendarSyncManager.kt

@@ -0,0 +1,209 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.syncadapter
+
+import android.accounts.Account
+import android.content.ContentProviderClient
+import android.content.Context
+import android.content.SyncResult
+import android.os.Bundle
+import at.bitfire.dav4android.DavCalendar
+import at.bitfire.dav4android.DavResource
+import at.bitfire.dav4android.exception.DavException
+import at.bitfire.dav4android.property.CalendarData
+import at.bitfire.dav4android.property.GetCTag
+import at.bitfire.dav4android.property.GetETag
+import at.bitfire.davdroid.AccountSettings
+import at.bitfire.davdroid.Constants
+import at.bitfire.davdroid.R
+import at.bitfire.davdroid.log.Logger
+import at.bitfire.davdroid.resource.LocalCalendar
+import at.bitfire.davdroid.resource.LocalEvent
+import at.bitfire.davdroid.resource.LocalResource
+import at.bitfire.ical4android.Event
+import at.bitfire.ical4android.InvalidCalendarException
+import okhttp3.HttpUrl
+import okhttp3.RequestBody
+import org.apache.commons.collections4.ListUtils
+import java.io.ByteArrayOutputStream
+import java.io.Reader
+import java.io.StringReader
+import java.util.*
+import java.util.logging.Level
+
+/**
+ * Synchronization manager for CalDAV collections; handles events ({@code VEVENT}).
+ */
+class CalendarSyncManager(
+        context: Context,
+        account: Account,
+        settings: AccountSettings,
+        extras: Bundle,
+        authority: String,
+        syncResult: SyncResult,
+        val provider: ContentProviderClient,
+        val localCalendar: LocalCalendar
+): SyncManager(context, account, settings, extras, authority, syncResult, "calendar/${localCalendar.id}") {
+
+    val MAX_MULTIGET = 20
+
+    init {
+        localCollection = localCalendar
+    }
+
+    override fun notificationId() = Constants.NOTIFICATION_CALENDAR_SYNC
+
+    override fun getSyncErrorTitle() = context.getString(R.string.sync_error_calendar, account.name)!!
+
+
+    override fun prepare(): Boolean {
+        collectionURL = HttpUrl.parse(localCalendar.name ?: return false) ?: return false
+        davCollection = DavCalendar(httpClient.okHttpClient, collectionURL)
+        return true
+    }
+
+    override fun queryCapabilities() {
+        davCollection.propfind(0, GetCTag.NAME)
+    }
+
+    override fun prepareDirty() {
+        super.prepareDirty()
+        localCalendar.processDirtyExceptions()
+    }
+
+    override fun prepareUpload(resource: LocalResource): RequestBody {
+        if (resource is LocalEvent) {
+            val event = requireNotNull(resource.event)
+            Logger.log.log(Level.FINE, "Preparing upload of event ${resource.fileName}", event)
+
+            val os = ByteArrayOutputStream()
+            event.write(os)
+
+            return RequestBody.create(
+                    DavCalendar.MIME_ICALENDAR,
+                    os.toByteArray()
+            )
+        } else
+            throw IllegalArgumentException("resource must be a LocalEvent")
+    }
+
+    override fun listRemote() {
+        // calculate time range limits
+        var limitStart: Date? = null
+        settings.getTimeRangePastDays()?.let { pastDays ->
+            val calendar = Calendar.getInstance()
+            calendar.add(Calendar.DAY_OF_MONTH, -pastDays)
+            limitStart = calendar.time
+        }
+
+        // fetch list of remote VEVENTs and build hash table to index file name
+        val calendar = davCalendar()
+        currentDavResource = calendar
+        calendar.calendarQuery("VEVENT", limitStart, null)
+
+        remoteResources = HashMap<String, DavResource>(davCollection.members.size)
+        for (iCal in davCollection.members) {
+            val fileName = iCal.fileName()
+            Logger.log.fine("Found remote VEVENT: $fileName")
+            remoteResources[fileName] = iCal
+        }
+
+        currentDavResource = null
+    }
+
+    override fun downloadRemote() {
+        Logger.log.info("Downloading ${toDownload.size} events ($MAX_MULTIGET at once)")
+
+        // download new/updated iCalendars from server
+        for (bunch in ListUtils.partition(toDownload.toList(), MAX_MULTIGET)) {
+            if (Thread.interrupted())
+                return
+
+            Logger.log.info("Downloading ${bunch.joinToString(", ")}")
+
+            if (bunch.size == 1) {
+                // only one contact, use GET
+                val remote = bunch.first()
+                currentDavResource = remote
+
+                val body = remote.get("text/calendar")
+
+                // CalDAV servers MUST return ETag on GET [https://tools.ietf.org/html/rfc4791#section-5.3.4]
+                val eTag = remote.properties[GetETag.NAME] as GetETag?
+                if (eTag == null || eTag.eTag.isNullOrEmpty())
+                    throw DavException("Received CalDAV GET response without ETag for ${remote.location}")
+
+                body.charStream()?.use { reader ->
+                    processVEvent(remote.fileName(), eTag.eTag!!, reader)
+                }
+
+            } else {
+                // multiple contacts, use multi-get
+                val calendar = davCalendar()
+                currentDavResource = calendar
+                calendar.multiget(bunch.map { it.location })
+
+                // process multiget results
+                for (remote in davCollection.members) {
+                    currentDavResource = remote
+
+                    val eTag = (remote.properties[GetETag.NAME] as GetETag?)?.eTag
+                            ?: throw DavException("Received multi-get response without ETag")
+
+                    val calendarData = remote.properties[CalendarData.NAME] as CalendarData?
+                    val iCalendar = calendarData?.iCalendar
+                            ?: throw DavException("Received multi-get response without event data")
+
+                    processVEvent(remote.fileName(), eTag, StringReader(iCalendar))
+                }
+            }
+
+            currentDavResource = null
+        }
+    }
+
+
+    // helpers
+
+    private fun davCalendar() = davCollection as DavCalendar
+
+    private fun processVEvent(fileName: String, eTag: String, reader: Reader) {
+        val events: List<Event>
+        try {
+            events = Event.fromReader(reader)
+        } catch (e: InvalidCalendarException) {
+            Logger.log.log(Level.SEVERE, "Received invalid iCalendar, ignoring", e)
+            return
+        }
+
+        if (events.size == 1) {
+            val newData = events.first()
+
+            // delete local event, if it exists
+            val localEvent = localResources[fileName] as LocalEvent?
+            currentLocalResource = localEvent
+            if (localEvent != null) {
+                Logger.log.info("Updating $fileName in local calendar")
+                localEvent.eTag = eTag
+                localEvent.update(newData)
+                syncResult.stats.numUpdates++
+            } else {
+                Logger.log.info("Adding $fileName to local calendar")
+                val newEvent = LocalEvent(localCalendar, newData, fileName, eTag)
+                currentLocalResource = newEvent
+                newEvent.add()
+                syncResult.stats.numInserts++
+            }
+        } else
+            Logger.log.severe("Received VCALENDAR with not exactly one VEVENT with UID, but without RECURRENCE-ID; ignoring $fileName")
+
+        currentLocalResource = null
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/syncadapter/CalendarsSyncAdapterService.java

@@ -1,149 +0,0 @@
-/*
- * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-package at.bitfire.davdroid.syncadapter;
-
-import android.accounts.Account;
-import android.content.AbstractThreadedSyncAdapter;
-import android.content.ContentProviderClient;
-import android.content.ContentResolver;
-import android.content.ContentValues;
-import android.content.Context;
-import android.content.SyncResult;
-import android.database.Cursor;
-import android.database.DatabaseUtils;
-import android.database.sqlite.SQLiteDatabase;
-import android.database.sqlite.SQLiteException;
-import android.database.sqlite.SQLiteOpenHelper;
-import android.os.Bundle;
-import android.provider.CalendarContract;
-import android.support.annotation.NonNull;
-import android.support.annotation.Nullable;
-
-import java.util.LinkedHashMap;
-import java.util.Map;
-import java.util.logging.Level;
-
-import at.bitfire.davdroid.AccountSettings;
-import at.bitfire.davdroid.App;
-import at.bitfire.davdroid.InvalidAccountException;
-import at.bitfire.davdroid.model.CollectionInfo;
-import at.bitfire.davdroid.model.ServiceDB;
-import at.bitfire.davdroid.model.ServiceDB.Collections;
-import at.bitfire.davdroid.model.ServiceDB.Services;
-import at.bitfire.davdroid.resource.LocalCalendar;
-import at.bitfire.ical4android.CalendarStorageException;
-import lombok.Cleanup;
-
-public class CalendarsSyncAdapterService extends SyncAdapterService {
-
-    @Override
-    protected AbstractThreadedSyncAdapter syncAdapter() {
-        return new SyncAdapter(this);
-    }
-
-
-	private static class SyncAdapter extends SyncAdapterService.SyncAdapter {
-
-        public SyncAdapter(Context context) {
-            super(context);
-        }
-
-        @Override
-        public void onPerformSync(Account account, Bundle extras, String authority, ContentProviderClient provider, SyncResult syncResult) {
-            super.onPerformSync(account, extras, authority, provider, syncResult);
-
-            try {
-                AccountSettings settings = new AccountSettings(getContext(), account);
-                if (!extras.containsKey(ContentResolver.SYNC_EXTRAS_MANUAL) && !checkSyncConditions(settings))
-                    return;
-
-                updateLocalCalendars(provider, account, settings);
-
-                for (LocalCalendar calendar : (LocalCalendar[])LocalCalendar.find(account, provider, LocalCalendar.Factory.INSTANCE, CalendarContract.Calendars.SYNC_EVENTS + "!=0", null)) {
-                    App.log.info("Synchronizing calendar #"  + calendar.getId() + ", URL: " + calendar.getName());
-                    CalendarSyncManager syncManager = new CalendarSyncManager(getContext(), account, settings, extras, authority, syncResult, calendar);
-                    syncManager.performSync();
-                }
-            } catch(CalendarStorageException|SQLiteException e) {
-                App.log.log(Level.SEVERE, "Couldn't prepare local calendars", e);
-                syncResult.databaseError = true;
-            } catch(InvalidAccountException e) {
-                App.log.log(Level.SEVERE, "Couldn't get account settings", e);
-            }
-
-            App.log.info("Calendar sync complete");
-        }
-
-        private void updateLocalCalendars(ContentProviderClient provider, Account account, AccountSettings settings) throws CalendarStorageException {
-            SQLiteOpenHelper dbHelper = new ServiceDB.OpenHelper(getContext());
-            try {
-                // enumerate remote and local calendars
-                SQLiteDatabase db = dbHelper.getReadableDatabase();
-                Long service = getService(db, account);
-                Map<String, CollectionInfo> remote = remoteCalendars(db, service);
-
-                LocalCalendar[] local = (LocalCalendar[])LocalCalendar.find(account, provider, LocalCalendar.Factory.INSTANCE, null, null);
-
-                boolean updateColors = settings.getManageCalendarColors();
-
-                // delete obsolete local calendar
-                for (LocalCalendar calendar : local) {
-                    String url = calendar.getName();
-                    if (!remote.containsKey(url)) {
-                        App.log.fine("Deleting obsolete local calendar " + url);
-                        calendar.delete();
-                    } else {
-                        // remote CollectionInfo found for this local collection, update data
-                        CollectionInfo info = remote.get(url);
-                        App.log.fine("Updating local calendar " + url + " with " + info);
-                        calendar.update(info, updateColors);
-                        // we already have a local calendar for this remote collection, don't take into consideration anymore
-                        remote.remove(url);
-                    }
-                }
-
-                // create new local calendars
-                for (String url : remote.keySet()) {
-                    CollectionInfo info = remote.get(url);
-                    App.log.info("Adding local calendar list " + info);
-                    LocalCalendar.create(account, provider, info);
-                }
-            } finally {
-                dbHelper.close();
-            }
-        }
-
-        @Nullable
-        Long getService(@NonNull SQLiteDatabase db, @NonNull Account account) {
-            @Cleanup Cursor c = db.query(Services._TABLE, new String[] { Services.ID },
-                    Services.ACCOUNT_NAME + "=? AND " + Services.SERVICE + "=?", new String[] { account.name, Services.SERVICE_CALDAV }, null, null, null);
-            if (c.moveToNext())
-                return c.getLong(0);
-            else
-                return null;
-        }
-
-        @NonNull
-        private Map<String, CollectionInfo> remoteCalendars(@NonNull SQLiteDatabase db, Long service) {
-            Map<String, CollectionInfo> collections = new LinkedHashMap<>();
-            if (service != null) {
-                @Cleanup Cursor cursor = db.query(Collections._TABLE, null,
-                        Collections.SERVICE_ID + "=? AND " + Collections.SUPPORTS_VEVENT + "!=0 AND " + Collections.SYNC,
-                        new String[] { String.valueOf(service) }, null, null, null);
-                while (cursor.moveToNext()) {
-                    ContentValues values = new ContentValues();
-                    DatabaseUtils.cursorRowToContentValues(cursor, values);
-                    CollectionInfo info = CollectionInfo.fromDB(values);
-                    collections.put(info.url, info);
-                }
-            }
-            return collections;
-        }
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/syncadapter/CalendarsSyncAdapterService.kt

@@ -0,0 +1,127 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+package at.bitfire.davdroid.syncadapter
+
+import android.accounts.Account
+import android.content.*
+import android.database.DatabaseUtils
+import android.os.Bundle
+import android.provider.CalendarContract
+import at.bitfire.davdroid.AccountSettings
+import at.bitfire.davdroid.log.Logger
+import at.bitfire.davdroid.model.CollectionInfo
+import at.bitfire.davdroid.model.ServiceDB
+import at.bitfire.davdroid.model.ServiceDB.Collections
+import at.bitfire.davdroid.resource.LocalCalendar
+import at.bitfire.davdroid.settings.ISettings
+import at.bitfire.ical4android.AndroidCalendar
+import java.util.logging.Level
+
+class CalendarsSyncAdapterService: SyncAdapterService() {
+
+    override fun syncAdapter() = SyncAdapter(this)
+
+
+	protected class SyncAdapter(
+            context: Context
+    ): SyncAdapterService.SyncAdapter(context) {
+
+        override fun sync(settings: ISettings, account: Account, extras: Bundle, authority: String, provider: ContentProviderClient, syncResult: SyncResult) {
+            try {
+                val accountSettings = AccountSettings(context, settings, account)
+
+                /* don't run sync if
+                   - sync conditions (e.g. "sync only in WiFi") are not met AND
+                   - this is is an automatic sync (i.e. manual syncs are run regardless of sync conditions)
+                 */
+                if (!extras.containsKey(ContentResolver.SYNC_EXTRAS_MANUAL) && !checkSyncConditions(accountSettings))
+                    return
+
+                if (accountSettings.getEventColors())
+                    AndroidCalendar.insertColors(provider, account)
+                else
+                    AndroidCalendar.removeColors(provider, account)
+
+                updateLocalCalendars(provider, account, accountSettings)
+
+                for (calendar in AndroidCalendar.find(account, provider, LocalCalendar.Factory, "${CalendarContract.Calendars.SYNC_EVENTS}!=0", null)) {
+                    Logger.log.info("Synchronizing calendar #${calendar.id}, URL: ${calendar.name}")
+                    CalendarSyncManager(context, account, accountSettings, extras, authority, syncResult, provider, calendar).use {
+                        it.performSync()
+                    }
+                }
+            } catch(e: Exception) {
+                Logger.log.log(Level.SEVERE, "Couldn't sync calendars", e)
+            }
+            Logger.log.info("Calendar sync complete")
+        }
+
+        private fun updateLocalCalendars(provider: ContentProviderClient, account: Account, settings: AccountSettings) {
+            ServiceDB.OpenHelper(context).use { dbHelper ->
+                val db = dbHelper.readableDatabase
+
+                fun getService() =
+                        db.query(ServiceDB.Services._TABLE, arrayOf(ServiceDB.Services.ID),
+                                "${ServiceDB.Services.ACCOUNT_NAME}=? AND ${ServiceDB.Services.SERVICE}=?",
+                                arrayOf(account.name, ServiceDB.Services.SERVICE_CALDAV), null, null, null)?.use { c ->
+                            if (c.moveToNext())
+                                c.getLong(0)
+                            else
+                                null
+                        }
+
+                fun remoteCalendars(service: Long?): MutableMap<String, CollectionInfo> {
+                    val collections = mutableMapOf<String, CollectionInfo>()
+                    service?.let {
+                        db.query(Collections._TABLE, null,
+                                "${Collections.SERVICE_ID}=? AND ${Collections.SUPPORTS_VEVENT}!=0 AND ${Collections.SYNC}",
+                                arrayOf(service.toString()), null, null, null).use { cursor ->
+                            while (cursor.moveToNext()) {
+                                val values = ContentValues(cursor.columnCount)
+                                DatabaseUtils.cursorRowToContentValues(cursor, values)
+                                val info = CollectionInfo(values)
+                                collections[info.url] = info
+                            }
+                        }
+                    }
+                    return collections
+                }
+
+                // enumerate remote and local calendars
+                val service = getService()
+                val remote = remoteCalendars(service)
+
+                // delete/update local calendars
+                val updateColors = settings.getManageCalendarColors()
+
+                for (calendar in AndroidCalendar.find(account, provider, LocalCalendar.Factory, null, null))
+                    calendar.name?.let { url ->
+                        val info = remote[url]
+                        if (info == null) {
+                            Logger.log.log(Level.INFO, "Deleting obsolete local calendar", url)
+                            calendar.delete()
+                        } else {
+                            // remote CollectionInfo found for this local collection, update data
+                            Logger.log.log(Level.FINE, "Updating local calendar $url", info)
+                            calendar.update(info, updateColors)
+                            // we already have a local calendar for this remote collection, don't take into consideration anymore
+                            remote -= url
+                        }
+                    }
+
+                // create new local calendars
+                for ((_, info) in remote) {
+                    Logger.log.log(Level.INFO, "Adding local calendar", info)
+                    LocalCalendar.create(account, provider, info)
+                }
+            }
+        }
+
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/syncadapter/ContactsSyncAdapterService.java

@@ -1,115 +0,0 @@
-/*
- * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-package at.bitfire.davdroid.syncadapter;
-
-import android.accounts.Account;
-import android.content.AbstractThreadedSyncAdapter;
-import android.content.ContentProviderClient;
-import android.content.ContentResolver;
-import android.content.ContentValues;
-import android.content.Context;
-import android.content.SyncResult;
-import android.database.Cursor;
-import android.database.DatabaseUtils;
-import android.database.sqlite.SQLiteDatabase;
-import android.database.sqlite.SQLiteOpenHelper;
-import android.os.Bundle;
-import android.support.annotation.NonNull;
-import android.support.annotation.Nullable;
-
-import java.util.logging.Level;
-
-import at.bitfire.davdroid.AccountSettings;
-import at.bitfire.davdroid.App;
-import at.bitfire.davdroid.InvalidAccountException;
-import at.bitfire.davdroid.model.CollectionInfo;
-import at.bitfire.davdroid.model.ServiceDB;
-import at.bitfire.davdroid.model.ServiceDB.Collections;
-import at.bitfire.davdroid.resource.LocalAddressBook;
-import at.bitfire.vcard4android.ContactsStorageException;
-import lombok.Cleanup;
-
-public class ContactsSyncAdapterService extends SyncAdapterService {
-
-    @Override
-    protected AbstractThreadedSyncAdapter syncAdapter() {
-        return new ContactsSyncAdapter(this);
-    }
-
-
-	private static class ContactsSyncAdapter extends SyncAdapter {
-
-        public ContactsSyncAdapter(Context context) {
-            super(context);
-        }
-
-        @Override
-        public void onPerformSync(Account account, Bundle extras, String authority, ContentProviderClient provider, SyncResult syncResult) {
-            super.onPerformSync(account, extras, authority, provider, syncResult);
-
-            SQLiteOpenHelper dbHelper = new ServiceDB.OpenHelper(getContext());
-            try {
-                AccountSettings settings = new AccountSettings(getContext(), account);
-                if (!extras.containsKey(ContentResolver.SYNC_EXTRAS_MANUAL) && !checkSyncConditions(settings))
-                    return;
-
-                SQLiteDatabase db = dbHelper.getReadableDatabase();
-                Long service = getService(db, account);
-                if (service != null) {
-                    CollectionInfo remote = remoteAddressBook(db, service);
-                    if (remote != null)
-                        try {
-                            ContactsSyncManager syncManager = new ContactsSyncManager(getContext(), account, settings, extras, authority, provider, syncResult, remote);
-                            syncManager.performSync();
-                        } catch(InvalidAccountException e) {
-                            App.log.log(Level.SEVERE, "Couldn't get account settings", e);
-                        }
-                    else {
-                        App.log.info("No address book collection selected for synchronization, deleting local contacts");
-                        LocalAddressBook localAddressBook = new LocalAddressBook(account, provider);
-                        try {
-                            localAddressBook.deleteAll();
-                        } catch(ContactsStorageException ignored) {
-                        }
-                    }
-                } else
-                    App.log.info("No CardDAV service found in DB");
-            } catch (InvalidAccountException e) {
-                App.log.log(Level.SEVERE, "Couldn't get account settings", e);
-            } finally {
-                dbHelper.close();
-            }
-
-            App.log.info("Address book sync complete");
-        }
-
-        @Nullable
-        private Long getService(@NonNull SQLiteDatabase db, @NonNull Account account) {
-            @Cleanup Cursor c = db.query(ServiceDB.Services._TABLE, new String[] { ServiceDB.Services.ID },
-                    ServiceDB.Services.ACCOUNT_NAME + "=? AND " + ServiceDB.Services.SERVICE + "=?", new String[] { account.name, ServiceDB.Services.SERVICE_CARDDAV }, null, null, null);
-            if (c.moveToNext())
-                return c.getLong(0);
-            else
-                return null;
-        }
-
-        @Nullable
-        private CollectionInfo remoteAddressBook(@NonNull SQLiteDatabase db, long service) {
-            @Cleanup Cursor c = db.query(Collections._TABLE, null,
-                    Collections.SERVICE_ID + "=? AND " + Collections.SYNC, new String[] { String.valueOf(service) }, null, null, null);
-            if (c.moveToNext()) {
-                ContentValues values = new ContentValues();
-                DatabaseUtils.cursorRowToContentValues(c, values);
-                return CollectionInfo.fromDB(values);
-            } else
-                return null;
-        }
-
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/syncadapter/ContactsSyncAdapterService.kt

@@ -0,0 +1,75 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.syncadapter
+
+import android.accounts.Account
+import android.content.ContentProviderClient
+import android.content.ContentResolver
+import android.content.Context
+import android.content.SyncResult
+import android.os.Bundle
+import android.provider.ContactsContract
+import at.bitfire.davdroid.AccountSettings
+import at.bitfire.davdroid.log.Logger
+import at.bitfire.davdroid.resource.LocalAddressBook
+import at.bitfire.davdroid.settings.ISettings
+import java.util.logging.Level
+
+class ContactsSyncAdapterService: SyncAdapterService() {
+
+    companion object {
+        val PREVIOUS_GROUP_METHOD = "previous_group_method"
+    }
+
+    override fun syncAdapter() = ContactsSyncAdapter(this)
+
+
+	protected class ContactsSyncAdapter(
+            context: Context
+    ): SyncAdapter(context) {
+
+        override fun sync(settings: ISettings, account: Account, extras: Bundle, authority: String, provider: ContentProviderClient, syncResult: SyncResult) {
+            try {
+                val addressBook = LocalAddressBook(context, account, provider)
+                val accountSettings = AccountSettings(context, settings, addressBook.getMainAccount())
+
+                // handle group method change
+                val groupMethod = accountSettings.getGroupMethod().name
+                accountSettings.accountManager.getUserData(account, PREVIOUS_GROUP_METHOD)?.let { previousGroupMethod ->
+                    if (previousGroupMethod != groupMethod) {
+                        Logger.log.info("Group method changed, deleting all local contacts/groups")
+
+                        // delete all local contacts and groups so that they will be downloaded again
+                        provider.delete(addressBook.syncAdapterURI(ContactsContract.RawContacts.CONTENT_URI), null, null)
+                        provider.delete(addressBook.syncAdapterURI(ContactsContract.Groups.CONTENT_URI), null, null)
+
+                        // reset CTag
+                        addressBook.setCTag(null)
+                    }
+                }
+                accountSettings.accountManager.setUserData(account, PREVIOUS_GROUP_METHOD, groupMethod)
+
+                if (!extras.containsKey(ContentResolver.SYNC_EXTRAS_MANUAL) && !checkSyncConditions(accountSettings))
+                    return
+
+                Logger.log.info("Synchronizing address book: ${addressBook.getURL()}")
+                Logger.log.info("Taking settings from: ${addressBook.getMainAccount()}")
+
+                ContactsSyncManager(context, account, accountSettings, extras, authority, syncResult, provider, addressBook).use {
+                    it.performSync()
+                }
+            } catch(e: Exception) {
+                Logger.log.log(Level.SEVERE, "Couldn't sync contacts", e)
+            }
+            Logger.log.info("Contacts sync complete")
+        }
+
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/syncadapter/ContactsSyncManager.java

@@ -1,553 +0,0 @@
-/*
- * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.syncadapter;
-
-import android.accounts.Account;
-import android.content.ContentProviderClient;
-import android.content.ContentProviderOperation;
-import android.content.ContentResolver;
-import android.content.ContentUris;
-import android.content.ContentValues;
-import android.content.Context;
-import android.content.SyncResult;
-import android.database.Cursor;
-import android.os.Build;
-import android.os.Bundle;
-import android.os.RemoteException;
-import android.provider.ContactsContract;
-import android.provider.ContactsContract.Groups;
-import android.support.annotation.NonNull;
-import android.text.TextUtils;
-
-import org.apache.commons.codec.Charsets;
-import org.apache.commons.collections4.SetUtils;
-import org.apache.commons.io.IOUtils;
-import org.apache.commons.lang3.StringUtils;
-
-import java.io.ByteArrayInputStream;
-import java.io.ByteArrayOutputStream;
-import java.io.FileNotFoundException;
-import java.io.IOException;
-import java.io.InputStream;
-import java.nio.charset.Charset;
-import java.util.HashMap;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Set;
-import java.util.logging.Level;
-
-import at.bitfire.dav4android.DavAddressBook;
-import at.bitfire.dav4android.DavResource;
-import at.bitfire.dav4android.exception.DavException;
-import at.bitfire.dav4android.exception.HttpException;
-import at.bitfire.dav4android.property.AddressData;
-import at.bitfire.dav4android.property.GetCTag;
-import at.bitfire.dav4android.property.GetContentType;
-import at.bitfire.dav4android.property.GetETag;
-import at.bitfire.dav4android.property.ResourceType;
-import at.bitfire.dav4android.property.SupportedAddressData;
-import at.bitfire.davdroid.AccountSettings;
-import at.bitfire.davdroid.App;
-import at.bitfire.davdroid.ArrayUtils;
-import at.bitfire.davdroid.BuildConfig;
-import at.bitfire.davdroid.Constants;
-import at.bitfire.davdroid.HttpClient;
-import at.bitfire.davdroid.InvalidAccountException;
-import at.bitfire.davdroid.R;
-import at.bitfire.davdroid.model.CollectionInfo;
-import at.bitfire.davdroid.resource.LocalAddressBook;
-import at.bitfire.davdroid.resource.LocalContact;
-import at.bitfire.davdroid.resource.LocalGroup;
-import at.bitfire.davdroid.resource.LocalResource;
-import at.bitfire.ical4android.CalendarStorageException;
-import at.bitfire.vcard4android.BatchOperation;
-import at.bitfire.vcard4android.Contact;
-import at.bitfire.vcard4android.ContactsStorageException;
-import at.bitfire.vcard4android.GroupMethod;
-import ezvcard.VCardVersion;
-import lombok.Cleanup;
-import lombok.RequiredArgsConstructor;
-import okhttp3.HttpUrl;
-import okhttp3.MediaType;
-import okhttp3.OkHttpClient;
-import okhttp3.Request;
-import okhttp3.RequestBody;
-import okhttp3.Response;
-import okhttp3.ResponseBody;
-
-/**
- * <p>Synchronization manager for CardDAV collections; handles contacts and groups.</p>
- *
- * <p></p>Group handling differs according to the {@link #groupMethod}. There are two basic methods to
- * handle/manage groups:</p>
- * <ul>
- *     <li>{@code CATEGORIES}: groups memberships are attached to each contact and represented as
- *     "category". When a group is dirty or has been deleted, all its members have to be set to
- *     dirty, too (because they have to be uploaded without the respective category). This
- *     is done in {@link #prepareDirty()}. Empty groups can be deleted without further processing,
- *     which is done in {@link #postProcess()} because groups may become empty after downloading
- *     updated remoted contacts.</li>
- *     <li>Groups as separate VCards: individual and group contacts (with a list of member UIDs) are
- *     distinguished. When a local group is dirty, its members don't need to be set to dirty.
- *     <ol>
- *         <li>However, when a contact is dirty, it has
- *         to be checked whether its group memberships have changed. In this case, the respective
- *         groups have to be set to dirty. For instance, if contact A is in group G and H, and then
- *         group membership of G is removed, the contact will be set to dirty because of the changed
- *         {@link android.provider.ContactsContract.CommonDataKinds.GroupMembership}. DAVdroid will
- *         then have to check whether the group memberships have actually changed, and if so,
- *         all affected groups have to be set to dirty. To detect changes in group memberships,
- *         DAVdroid always mirrors all {@link android.provider.ContactsContract.CommonDataKinds.GroupMembership}
- *         data rows in respective {@link at.bitfire.vcard4android.CachedGroupMembership} rows.
- *         If the cached group memberships are not the same as the current group member ships, the
- *         difference set (in our example G, because its in the cached memberships, but not in the
- *         actual ones) is marked as dirty. This is done in {@link #prepareDirty()}.</li>
- *         <li>When downloading remote contacts, groups (+ member information) may be received
- *         by the actual members. Thus, the member lists have to be cached until all VCards
- *         are received. This is done by caching the member UIDs of each group in
- *         {@link LocalGroup#COLUMN_PENDING_MEMBERS}. In {@link #postProcess()},
- *         these "pending memberships" are assigned to the actual contacs and then cleaned up.</li>
- *     </ol>
- * </ul>
- */
-public class ContactsSyncManager extends SyncManager {
-    protected static final int MAX_MULTIGET = 10;
-
-    final private ContentProviderClient provider;
-    final private CollectionInfo remote;
-
-    private boolean hasVCard4;
-    private GroupMethod groupMethod;
-
-
-    public ContactsSyncManager(Context context, Account account, AccountSettings settings, Bundle extras, String authority, ContentProviderClient provider, SyncResult result, CollectionInfo remote) throws InvalidAccountException {
-        super(context, account, settings, extras, authority, result, "addressBook");
-        this.provider = provider;
-        this.remote = remote;
-    }
-
-    @Override
-    protected int notificationId() {
-        return Constants.NOTIFICATION_CONTACTS_SYNC;
-    }
-
-    @Override
-    protected String getSyncErrorTitle() {
-        return context.getString(R.string.sync_error_contacts, account.name);
-    }
-
-
-    @Override
-    protected boolean prepare() throws ContactsStorageException {
-        // prepare local address book
-        localCollection = new LocalAddressBook(account, provider);
-        LocalAddressBook localAddressBook = localAddressBook();
-
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
-            // workaround for Android 7 which sets DIRTY flag when only meta-data is changed
-            int reallyDirty = localAddressBook.verifyDirty(),
-                deleted = localAddressBook.getDeleted().length;
-            if (extras.containsKey(ContentResolver.SYNC_EXTRAS_UPLOAD) && reallyDirty == 0 && deleted == 0) {
-                App.log.info("This sync was called to up-sync dirty/deleted contacts, but no contacts have been changed");
-                return false;
-            }
-        }
-
-        String url = remote.url;
-        String lastUrl = localAddressBook.getURL();
-        if (!url.equals(lastUrl)) {
-            App.log.info("Selected address book has changed from " + lastUrl + " to " + url + ", deleting all local contacts");
-            localAddressBook.deleteAll();
-            localAddressBook.setURL(remote.url);
-        }
-
-        // set up Contacts Provider Settings
-        ContentValues values = new ContentValues(2);
-        values.put(ContactsContract.Settings.SHOULD_SYNC, 1);
-        values.put(ContactsContract.Settings.UNGROUPED_VISIBLE, 1);
-        localAddressBook.updateSettings(values);
-
-        collectionURL = HttpUrl.parse(url);
-        davCollection = new DavAddressBook(httpClient, collectionURL);
-
-        return true;
-    }
-
-    @Override
-    protected void queryCapabilities() throws DavException, IOException, HttpException {
-        // prepare remote address book
-        davCollection.propfind(0, SupportedAddressData.NAME, GetCTag.NAME);
-        SupportedAddressData supportedAddressData = (SupportedAddressData)davCollection.properties.get(SupportedAddressData.NAME);
-        hasVCard4 = supportedAddressData != null && supportedAddressData.hasVCard4();
-        App.log.info("Server advertises VCard/4 support: " + hasVCard4);
-
-        groupMethod = settings.getGroupMethod();
-        App.log.info("Contact group method: " + groupMethod);
-
-        localAddressBook().includeGroups = groupMethod == GroupMethod.GROUP_VCARDS;
-    }
-
-    @Override
-    protected void prepareDirty() throws CalendarStorageException, ContactsStorageException {
-        super.prepareDirty();
-
-        LocalAddressBook addressBook = localAddressBook();
-
-        if (groupMethod == GroupMethod.CATEGORIES) {
-            /* groups memberships are represented as contact CATEGORIES */
-
-            // groups with DELETED=1: set all members to dirty, then remove group
-            for (LocalGroup group : addressBook.getDeletedGroups()) {
-                App.log.fine("Finally removing group " + group);
-                // useless because Android deletes group memberships as soon as a group is set to DELETED:
-                // group.markMembersDirty();
-                group.delete();
-            }
-
-            // groups with DIRTY=1: mark all memberships as dirty, then clean DIRTY flag of group
-            for (LocalGroup group : addressBook.getDirtyGroups()) {
-                App.log.fine("Marking members of modified group " + group + " as dirty");
-                group.markMembersDirty();
-                group.clearDirty(null);
-            }
-        } else {
-            /* groups as separate VCards: there are group contacts and individual contacts */
-
-            // mark groups with changed members as dirty
-            BatchOperation batch = new BatchOperation(addressBook.provider);
-            for (LocalContact contact : addressBook.getDirtyContacts())
-                try {
-                    App.log.fine("Looking for changed group memberships of contact " + contact.getFileName());
-                    Set<Long>   cachedGroups = contact.getCachedGroupMemberships(),
-                                currentGroups = contact.getGroupMemberships();
-                    for (Long groupID : SetUtils.disjunction(cachedGroups, currentGroups)) {
-                        App.log.fine("Marking group as dirty: " + groupID);
-                        batch.enqueue(new BatchOperation.Operation(
-                                ContentProviderOperation.newUpdate(addressBook.syncAdapterURI(ContentUris.withAppendedId(Groups.CONTENT_URI, groupID)))
-                                .withValue(Groups.DIRTY, 1)
-                                .withYieldAllowed(true)
-                        ));
-                    }
-                } catch(FileNotFoundException ignored) {
-                }
-            batch.commit();
-        }
-    }
-
-    @Override
-    protected RequestBody prepareUpload(@NonNull LocalResource resource) throws IOException, ContactsStorageException {
-        final Contact contact;
-        if (resource instanceof LocalContact) {
-            LocalContact local = ((LocalContact)resource);
-            contact = local.getContact();
-
-            if (groupMethod == GroupMethod.CATEGORIES) {
-                // add groups as CATEGORIES
-                for (long groupID : local.getGroupMemberships()) {
-                    try {
-                        @Cleanup Cursor c = provider.query(
-                                localAddressBook().syncAdapterURI(ContentUris.withAppendedId(Groups.CONTENT_URI, groupID)),
-                                new String[] { Groups.TITLE },
-                                null, null,
-                                null
-                        );
-                        if (c != null && c.moveToNext()) {
-                            String title = c.getString(0);
-                            if (!TextUtils.isEmpty(title))
-                                contact.categories.add(title);
-                        }
-                    } catch(RemoteException e) {
-                        throw new ContactsStorageException("Couldn't find group for adding CATEGORIES", e);
-                    }
-                }
-            }
-        } else if (resource instanceof LocalGroup)
-            contact = ((LocalGroup)resource).getContact();
-        else
-            throw new IllegalArgumentException("Argument must be LocalContact or LocalGroup");
-
-        App.log.log(Level.FINE, "Preparing upload of VCard " + resource.getFileName(), contact);
-
-        ByteArrayOutputStream os = new ByteArrayOutputStream();
-        contact.write(hasVCard4 ? VCardVersion.V4_0 : VCardVersion.V3_0, groupMethod, os);
-
-        return RequestBody.create(
-                hasVCard4 ? DavAddressBook.MIME_VCARD4 : DavAddressBook.MIME_VCARD3_UTF8,
-                os.toByteArray()
-        );
-    }
-
-    @Override
-    protected void listRemote() throws IOException, HttpException, DavException {
-        final DavAddressBook addressBook = davAddressBook();
-        currentDavResource = addressBook;
-
-        // fetch list of remote VCards and build hash table to index file name
-        addressBook.propfind(1, ResourceType.NAME, GetETag.NAME);
-
-        remoteResources = new HashMap<>(davCollection.members.size());
-        for (DavResource vCard : davCollection.members) {
-            // ignore member collections
-            ResourceType type = (ResourceType)vCard.properties.get(ResourceType.NAME);
-            if (type != null && type.types.contains(ResourceType.COLLECTION))
-                continue;
-
-            String fileName = vCard.fileName();
-            App.log.fine("Found remote VCard: " + fileName);
-            remoteResources.put(fileName, vCard);
-        }
-
-        currentDavResource = null;
-    }
-
-    @Override
-    protected void downloadRemote() throws IOException, HttpException, DavException, ContactsStorageException {
-        App.log.info("Downloading " + toDownload.size() + " contacts (" + MAX_MULTIGET + " at once)");
-
-        // prepare downloader which may be used to download external resource like contact photos
-        Contact.Downloader downloader = new ResourceDownloader(collectionURL);
-
-        // download new/updated VCards from server
-        for (DavResource[] bunch : ArrayUtils.partition(toDownload.toArray(new DavResource[toDownload.size()]), MAX_MULTIGET)) {
-            if (Thread.interrupted())
-                return;
-
-            App.log.info("Downloading " + StringUtils.join(bunch, ", "));
-
-            if (bunch.length == 1) {
-                // only one contact, use GET
-                final DavResource remote = bunch[0];
-                currentDavResource = remote;
-
-                ResponseBody body = remote.get("text/vcard;version=4.0, text/vcard;charset=utf-8;q=0.8, text/vcard;q=0.5");
-
-                // CardDAV servers MUST return ETag on GET [https://tools.ietf.org/html/rfc6352#section-6.3.2.3]
-                GetETag eTag = (GetETag)remote.properties.get(GetETag.NAME);
-                if (eTag == null || StringUtils.isEmpty(eTag.eTag))
-                    throw new DavException("Received CardDAV GET response without ETag for " + remote.location);
-
-                Charset charset = Charsets.UTF_8;
-                MediaType contentType = body.contentType();
-                if (contentType != null)
-                    charset = contentType.charset(Charsets.UTF_8);
-
-                @Cleanup InputStream stream = body.byteStream();
-                processVCard(remote.fileName(), eTag.eTag, stream, charset, downloader);
-
-            } else {
-                // multiple contacts, use multi-get
-                List<HttpUrl> urls = new LinkedList<>();
-                for (DavResource remote : bunch)
-                    urls.add(remote.location);
-
-                final DavAddressBook addressBook = davAddressBook();
-                currentDavResource = addressBook;
-                addressBook.multiget(urls.toArray(new HttpUrl[urls.size()]), hasVCard4);
-
-                // process multi-get results
-                for (final DavResource remote : davCollection.members) {
-                    currentDavResource = remote;
-
-                    String eTag;
-                    GetETag getETag = (GetETag)remote.properties.get(GetETag.NAME);
-                    if (getETag != null)
-                        eTag = getETag.eTag;
-                    else
-                        throw new DavException("Received multi-get response without ETag");
-
-                    Charset charset = Charsets.UTF_8;
-                    GetContentType getContentType = (GetContentType)remote.properties.get(GetContentType.NAME);
-                    if (getContentType != null && getContentType.type != null) {
-                        MediaType type = MediaType.parse(getContentType.type);
-                        if (type != null)
-                            charset = type.charset(Charsets.UTF_8);
-                    }
-
-                    AddressData addressData = (AddressData)remote.properties.get(AddressData.NAME);
-                    if (addressData == null || addressData.vCard == null)
-                        throw new DavException("Received multi-get response without address data");
-
-                    @Cleanup InputStream stream = new ByteArrayInputStream(addressData.vCard.getBytes());
-                    processVCard(remote.fileName(), eTag, stream, charset, downloader);
-                }
-            }
-
-            currentDavResource = null;
-        }
-    }
-
-    @Override
-    protected void postProcess() throws CalendarStorageException, ContactsStorageException {
-        if (groupMethod == GroupMethod.CATEGORIES) {
-            /* VCard3 group handling: groups memberships are represented as contact CATEGORIES */
-
-            // remove empty groups
-            App.log.info("Removing empty groups");
-            localAddressBook().removeEmptyGroups();
-
-        } else {
-            /* VCard4 group handling: there are group contacts and individual contacts */
-            App.log.info("Assigning memberships of downloaded contact groups");
-            LocalGroup.applyPendingMemberships(localAddressBook());
-        }
-    }
-
-
-    // helpers
-
-    private DavAddressBook davAddressBook() { return (DavAddressBook)davCollection; }
-    private LocalAddressBook localAddressBook() { return (LocalAddressBook)localCollection; }
-
-    private void processVCard(String fileName, String eTag, InputStream stream, Charset charset, Contact.Downloader downloader) throws IOException, ContactsStorageException {
-        App.log.info("Processing CardDAV resource " + fileName);
-        Contact[] contacts = Contact.fromStream(stream, charset, downloader);
-        if (contacts.length == 0) {
-            App.log.warning("Received VCard without data, ignoring");
-            return;
-        } else if (contacts.length > 1)
-            App.log.warning("Received multiple VCards, using first one");
-
-        final Contact newData = contacts[0];
-
-        if (groupMethod == GroupMethod.CATEGORIES && newData.group) {
-            groupMethod = GroupMethod.GROUP_VCARDS;
-            App.log.warning("Received group VCard although group method is CATEGORIES. Deleting all groups; new group method: " + groupMethod);
-            localAddressBook().removeGroups();
-            settings.setGroupMethod(groupMethod);
-        }
-
-        // update local contact, if it exists
-        LocalResource local = localResources.get(fileName);
-        currentLocalResource = local;
-        if (local != null) {
-            App.log.log(Level.INFO, "Updating " + fileName + " in local address book", newData);
-
-            if (local instanceof LocalGroup && newData.group) {
-                // update group
-                LocalGroup group = (LocalGroup)local;
-                group.eTag = eTag;
-                group.updateFromServer(newData);
-                syncResult.stats.numUpdates++;
-
-            } else if (local instanceof LocalContact && !newData.group) {
-                // update contact
-                LocalContact contact = (LocalContact)local;
-                contact.eTag = eTag;
-                contact.update(newData);
-                syncResult.stats.numUpdates++;
-
-            } else {
-                // group has become an individual contact or vice versa
-                try {
-                    local.delete();
-                    local = null;
-                } catch(CalendarStorageException e) {
-                    // CalendarStorageException is not used by LocalGroup and LocalContact
-                }
-            }
-        }
-
-        if (local == null) {
-            if (newData.group) {
-                App.log.log(Level.INFO, "Creating local group", newData);
-                LocalGroup group = new LocalGroup(localAddressBook(), newData, fileName, eTag);
-                currentLocalResource = group;
-                group.create();
-
-                local = group;
-            } else {
-                App.log.log(Level.INFO, "Creating local contact", newData);
-                LocalContact contact = new LocalContact(localAddressBook(), newData, fileName, eTag);
-                currentLocalResource = contact;
-                contact.create();
-
-                local = contact;
-            }
-            syncResult.stats.numInserts++;
-        }
-
-        if (groupMethod == GroupMethod.CATEGORIES && local instanceof LocalContact) {
-            // VCard3: update group memberships from CATEGORIES
-            LocalContact contact = (LocalContact)local;
-            currentLocalResource = contact;
-
-            BatchOperation batch = new BatchOperation(provider);
-            App.log.log(Level.FINE, "Removing contact group memberships");
-            contact.removeGroupMemberships(batch);
-
-            for (String category : contact.getContact().categories) {
-                long groupID = localAddressBook().findOrCreateGroup(category);
-                App.log.log(Level.FINE, "Adding membership in group " + category + " (" + groupID + ")");
-                contact.addToGroup(batch, groupID);
-            }
-
-            batch.commit();
-        }
-
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N && local instanceof LocalContact)
-            // workaround for Android 7 which sets DIRTY flag when only meta-data is changed
-            ((LocalContact)local).updateHashCode(null);
-
-        currentLocalResource = null;
-    }
-
-
-    // downloader helper class
-
-    @RequiredArgsConstructor
-    private class ResourceDownloader implements Contact.Downloader {
-        final HttpUrl baseUrl;
-
-        @Override
-        public byte[] download(String url, String accepts) {
-            HttpUrl httpUrl = HttpUrl.parse(url);
-
-            if (httpUrl == null) {
-                App.log.log(Level.SEVERE, "Invalid external resource URL", url);
-                return null;
-            }
-
-            String host = httpUrl.host();
-            if (host == null) {
-                App.log.log(Level.SEVERE, "External resource URL doesn't specify a host name", url);
-                return null;
-            }
-
-            OkHttpClient resourceClient = HttpClient.create(context);
-
-            // authenticate only against a certain host, and only upon request
-            resourceClient = HttpClient.addAuthentication(resourceClient, baseUrl.host(), settings.username(), settings.password());
-
-            // allow redirects
-            resourceClient = resourceClient.newBuilder()
-                    .followRedirects(true)
-                    .build();
-
-            try {
-                Response response = resourceClient.newCall(new Request.Builder()
-                        .get()
-                        .url(httpUrl)
-                        .build()).execute();
-
-                ResponseBody body = response.body();
-                if (body != null) {
-                    @Cleanup InputStream stream = body.byteStream();
-                    if (response.isSuccessful() && stream != null) {
-                        return IOUtils.toByteArray(stream);
-                    } else
-                        App.log.severe("Couldn't download external resource");
-                }
-            } catch(IOException e) {
-                App.log.log(Level.SEVERE, "Couldn't download external resource", e);
-            }
-            return null;
-        }
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/syncadapter/ContactsSyncManager.kt

@@ -0,0 +1,515 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.syncadapter
+
+import android.accounts.Account
+import android.content.*
+import android.os.Build
+import android.os.Bundle
+import android.os.RemoteException
+import android.provider.ContactsContract
+import android.provider.ContactsContract.Groups
+import android.support.v4.app.NotificationCompat
+import android.support.v4.app.NotificationManagerCompat
+import at.bitfire.dav4android.DavAddressBook
+import at.bitfire.dav4android.DavResource
+import at.bitfire.dav4android.exception.DavException
+import at.bitfire.dav4android.property.*
+import at.bitfire.davdroid.*
+import at.bitfire.davdroid.log.Logger
+import at.bitfire.davdroid.resource.LocalAddressBook
+import at.bitfire.davdroid.resource.LocalContact
+import at.bitfire.davdroid.resource.LocalGroup
+import at.bitfire.davdroid.resource.LocalResource
+import at.bitfire.vcard4android.BatchOperation
+import at.bitfire.vcard4android.Contact
+import at.bitfire.vcard4android.ContactsStorageException
+import at.bitfire.vcard4android.GroupMethod
+import ezvcard.VCardVersion
+import okhttp3.HttpUrl
+import okhttp3.Request
+import okhttp3.RequestBody
+import org.apache.commons.collections4.ListUtils
+import java.io.*
+import java.util.*
+import java.util.logging.Level
+
+/**
+ * <p>Synchronization manager for CardDAV collections; handles contacts and groups.</p>
+ *
+ * <p></p>Group handling differs according to the {@link #groupMethod}. There are two basic methods to
+ * handle/manage groups:</p>
+ * <ul>
+ *     <li>{@code CATEGORIES}: groups memberships are attached to each contact and represented as
+ *     "category". When a group is dirty or has been deleted, all its members have to be set to
+ *     dirty, too (because they have to be uploaded without the respective category). This
+ *     is done in {@link #prepareDirty()}. Empty groups can be deleted without further processing,
+ *     which is done in {@link #postProcess()} because groups may become empty after downloading
+ *     updated remote contacts.</li>
+ *     <li>Groups as separate VCards: individual and group contacts (with a list of member UIDs) are
+ *     distinguished. When a local group is dirty, its members don't need to be set to dirty.
+ *     <ol>
+ *         <li>However, when a contact is dirty, it has
+ *         to be checked whether its group memberships have changed. In this case, the respective
+ *         groups have to be set to dirty. For instance, if contact A is in group G and H, and then
+ *         group membership of G is removed, the contact will be set to dirty because of the changed
+ *         {@link android.provider.ContactsContract.CommonDataKinds.GroupMembership}. DAVdroid will
+ *         then have to check whether the group memberships have actually changed, and if so,
+ *         all affected groups have to be set to dirty. To detect changes in group memberships,
+ *         DAVdroid always mirrors all {@link android.provider.ContactsContract.CommonDataKinds.GroupMembership}
+ *         data rows in respective {@link at.bitfire.vcard4android.CachedGroupMembership} rows.
+ *         If the cached group memberships are not the same as the current group member ships, the
+ *         difference set (in our example G, because its in the cached memberships, but not in the
+ *         actual ones) is marked as dirty. This is done in {@link #prepareDirty()}.</li>
+ *         <li>When downloading remote contacts, groups (+ member information) may be received
+ *         by the actual members. Thus, the member lists have to be cached until all VCards
+ *         are received. This is done by caching the member UIDs of each group in
+ *         {@link LocalGroup#COLUMN_PENDING_MEMBERS}. In {@link #postProcess()},
+ *         these "pending memberships" are assigned to the actual contacs and then cleaned up.</li>
+ *     </ol>
+ * </ul>
+ */
+class ContactsSyncManager(
+        context: Context,
+        account: Account,
+        settings: AccountSettings,
+        extras: Bundle,
+        authority: String,
+        syncResult: SyncResult,
+        val provider: ContentProviderClient,
+        private val localAddressBook: LocalAddressBook
+): SyncManager(context, account, settings, extras, authority, syncResult, "addressBook") {
+
+    companion object {
+        private val MAX_MULTIGET = 10
+    }
+
+    private val readOnly = localAddressBook.getReadOnly()
+    private var numDiscarded = 0
+
+    private var hasVCard4 = false
+    private val groupMethod = settings.getGroupMethod()
+
+
+    init {
+        localCollection = localAddressBook
+    }
+
+    override fun notificationId() = Constants.NOTIFICATION_CONTACTS_SYNC
+
+    override fun getSyncErrorTitle() = context.getString(R.string.sync_error_contacts, account.name)!!
+
+
+    override fun prepare(): Boolean {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N && Build.VERSION.SDK_INT < Build.VERSION_CODES.O) {
+            // workaround for Android 7 which sets DIRTY flag when only meta-data is changed
+            val reallyDirty = localAddressBook.verifyDirty()
+            val deleted = localAddressBook.getDeleted().size
+            if (extras.containsKey(ContentResolver.SYNC_EXTRAS_UPLOAD) && reallyDirty == 0 && deleted == 0) {
+                Logger.log.info("This sync was called to up-sync dirty/deleted contacts, but no contacts have been changed")
+                return false
+            }
+        }
+
+        // set up Contacts Provider Settings
+        val values = ContentValues(2)
+        values.put(ContactsContract.Settings.SHOULD_SYNC, 1)
+        values.put(ContactsContract.Settings.UNGROUPED_VISIBLE, 1)
+        localAddressBook.updateSettings(values)
+
+        collectionURL = HttpUrl.parse(localAddressBook.getURL()) ?: return false
+        davCollection = DavAddressBook(httpClient.okHttpClient, collectionURL)
+
+        return true
+    }
+
+    override fun queryCapabilities() {
+        // prepare remote address book
+        davCollection.propfind(0, SupportedAddressData.NAME, GetCTag.NAME)
+        (davCollection.properties[SupportedAddressData.NAME] as SupportedAddressData?)?.let {
+            hasVCard4 = it.hasVCard4()
+        }
+        Logger.log.info("Server advertises VCard/4 support: $hasVCard4")
+
+        Logger.log.info("Contact group method: $groupMethod")
+        // in case of GROUP_VCARDs, treat groups as contacts in the local address book
+        localAddressBook.includeGroups = groupMethod == GroupMethod.GROUP_VCARDS
+    }
+
+    override fun processLocallyDeleted() {
+        if (readOnly) {
+            for (group in localAddressBook.getDeletedGroups()) {
+                Logger.log.warning("Restoring locally deleted group (read-only address book!)")
+                group.resetDeleted()
+                numDiscarded++
+            }
+
+            for (contact in localAddressBook.getDeletedContacts()) {
+                Logger.log.warning("Restoring locally deleted contact (read-only address book!)")
+                contact.resetDeleted()
+                numDiscarded++
+            }
+
+            if (numDiscarded > 0)
+                notifyDiscardedChange()
+        } else
+            // mirror deletions to remote collection (DELETE)
+            super.processLocallyDeleted()
+    }
+
+    override fun prepareDirty() {
+        // generate UID/file name for newly created contacts
+        super.prepareDirty()
+
+        if (readOnly) {
+            for (group in localAddressBook.getDirtyGroups()) {
+                Logger.log.warning("Resetting locally modified group to ETag=null (read-only address book!)")
+                group.clearDirty(null)
+                numDiscarded++
+            }
+
+            for (contact in localAddressBook.getDirtyContacts()) {
+                Logger.log.warning("Resetting locally modified contact to ETag=null (read-only address book!)")
+                contact.clearDirty(null)
+                numDiscarded++
+            }
+
+            if (numDiscarded > 0)
+                notifyDiscardedChange()
+
+        } else {
+            if (groupMethod == GroupMethod.CATEGORIES) {
+                /* groups memberships are represented as contact CATEGORIES */
+
+                // groups with DELETED=1: set all members to dirty, then remove group
+                for (group in localAddressBook.getDeletedGroups()) {
+                    Logger.log.fine("Finally removing group $group")
+                    // useless because Android deletes group memberships as soon as a group is set to DELETED:
+                    // group.markMembersDirty()
+                    group.delete()
+                }
+
+                // groups with DIRTY=1: mark all memberships as dirty, then clean DIRTY flag of group
+                for (group in localAddressBook.getDirtyGroups()) {
+                    Logger.log.fine("Marking members of modified group $group as dirty")
+                    group.markMembersDirty()
+                    group.clearDirty(null)
+                }
+            } else {
+                /* groups as separate VCards: there are group contacts and individual contacts */
+
+                // mark groups with changed members as dirty
+                val batch = BatchOperation(localAddressBook.provider!!)
+                for (contact in localAddressBook.getDirtyContacts())
+                    try {
+                        Logger.log.fine("Looking for changed group memberships of contact ${contact.fileName}")
+                        val cachedGroups = contact.getCachedGroupMemberships()
+                        val currentGroups = contact.getGroupMemberships()
+                        for (groupID in cachedGroups disjunct currentGroups) {
+                            Logger.log.fine("Marking group as dirty: $groupID")
+                            batch.enqueue(BatchOperation.Operation(
+                                    ContentProviderOperation.newUpdate(localAddressBook.syncAdapterURI(ContentUris.withAppendedId(Groups.CONTENT_URI, groupID)))
+                                    .withValue(Groups.DIRTY, 1)
+                                    .withYieldAllowed(true)
+                            ))
+                        }
+                    } catch(e: FileNotFoundException) {
+                    }
+                batch.commit()
+            }
+        }
+    }
+
+    private fun notifyDiscardedChange() {
+        val notification = NotificationCompat.Builder(context)
+                .setSmallIcon(R.drawable.ic_delete_light)
+                .setLargeIcon(App.getLauncherBitmap(context))
+                .setContentTitle(context.getString(R.string.sync_contacts_read_only_address_book))
+                .setContentText(context.resources.getQuantityString(R.plurals.sync_contacts_local_contact_changes_discarded, numDiscarded, numDiscarded))
+                .setSubText(account.name)
+                .setCategory(NotificationCompat.CATEGORY_ERROR)
+                .setPriority(NotificationCompat.PRIORITY_LOW)
+                .setLocalOnly(true)
+                .setAutoCancel(true)
+                .build()
+        NotificationManagerCompat.from(context).notify("discarded_${account.name}", 0, notification)
+    }
+
+    override fun prepareUpload(resource: LocalResource): RequestBody {
+        val contact: Contact
+        if (resource is LocalContact) {
+            contact = resource.contact!!
+
+            if (groupMethod == GroupMethod.CATEGORIES) {
+                // add groups as CATEGORIES
+                for (groupID in resource.getGroupMemberships()) {
+                    try {
+                        provider.query(
+                                localAddressBook.syncAdapterURI(ContentUris.withAppendedId(Groups.CONTENT_URI, groupID)),
+                                arrayOf(Groups.TITLE), null, null, null
+                        )?.use { cursor ->
+                            if (cursor.moveToNext()) {
+                                val title = cursor.getString(0)
+                                if (!title.isNullOrEmpty())
+                                    contact.categories.add(title)
+                            }
+                        }
+                    } catch(e: RemoteException) {
+                        throw ContactsStorageException("Couldn't find group for adding CATEGORIES", e)
+                    }
+                }
+            }
+        } else if (resource is LocalGroup)
+            contact = resource.contact!!
+        else
+            throw IllegalArgumentException("resource must be a LocalContact or a LocalGroup")
+
+        Logger.log.log(Level.FINE, "Preparing upload of VCard ${resource.fileName}", contact)
+
+        val os = ByteArrayOutputStream()
+        contact.write(if (hasVCard4) VCardVersion.V4_0 else VCardVersion.V3_0, groupMethod, os)
+
+        return RequestBody.create(
+                if (hasVCard4) DavAddressBook.MIME_VCARD4 else DavAddressBook.MIME_VCARD3_UTF8,
+                os.toByteArray()
+        )
+    }
+
+    override fun listRemote() {
+        val addressBook = davAddressBook()
+        currentDavResource = addressBook
+
+        // fetch list of remote VCards and build hash table to index file name
+        addressBook.propfind(1, ResourceType.NAME, GetETag.NAME)
+
+        remoteResources = HashMap<String, DavResource>(davCollection.members.size)
+        for (vCard in davCollection.members) {
+            // ignore member collections
+            val type = vCard.properties[ResourceType.NAME] as ResourceType?
+            if (type != null && type.types.contains(ResourceType.COLLECTION))
+                continue
+
+            val fileName = vCard.fileName()
+            Logger.log.fine("Found remote VCard: $fileName")
+            remoteResources[fileName] = vCard
+        }
+
+        currentDavResource = null
+    }
+
+    override fun downloadRemote() {
+        Logger.log.info("Downloading ${toDownload.size} contacts ($MAX_MULTIGET at once)")
+
+        // prepare downloader which may be used to download external resource like contact photos
+        val downloader = ResourceDownloader(collectionURL)
+
+        // download new/updated VCards from server
+        for (bunch in ListUtils.partition(toDownload.toList(), MAX_MULTIGET)) {
+            if (Thread.interrupted())
+                return
+
+            Logger.log.info("Downloading ${bunch.joinToString(", ")}")
+
+            if (bunch.size == 1) {
+                // only one contact, use GET
+                val remote = bunch.first()
+                currentDavResource = remote
+
+                val body = remote.get("text/vcard;version=4.0, text/vcard;charset=utf-8;q=0.8, text/vcard;q=0.5")
+
+                // CardDAV servers MUST return ETag on GET [https://tools.ietf.org/html/rfc6352#section-6.3.2.3]
+                val eTag = remote.properties[GetETag.NAME] as GetETag?
+                if (eTag == null || eTag.eTag.isNullOrEmpty())
+                    throw DavException("Received CardDAV GET response without ETag for ${remote.location}")
+
+                body.charStream().use { reader ->
+                    processVCard(remote.fileName(), eTag.eTag!!, reader, downloader)
+                }
+
+            } else {
+                // multiple contacts, use multi-get
+                val addressBook = davAddressBook()
+                currentDavResource = addressBook
+                addressBook.multiget(bunch.map { it.location }, hasVCard4)
+
+                // process multi-get results
+                for (remote in davCollection.members) {
+                    currentDavResource = remote
+
+                    val eTag = (remote.properties[GetETag.NAME] as GetETag?)?.eTag
+                            ?: throw DavException("Received multi-get response without ETag")
+
+                    val addressData = remote.properties[AddressData.NAME] as AddressData?
+                    val vCard = addressData?.vCard
+                            ?: throw DavException("Received multi-get response without address data")
+
+                    processVCard(remote.fileName(), eTag, StringReader(vCard), downloader)
+                }
+            }
+
+            currentDavResource = null
+        }
+    }
+
+    override fun postProcess() {
+        if (groupMethod == GroupMethod.CATEGORIES) {
+            /* VCard3 group handling: groups memberships are represented as contact CATEGORIES */
+
+            // remove empty groups
+            Logger.log.info("Removing empty groups")
+            localAddressBook.removeEmptyGroups()
+
+        } else {
+            /* VCard4 group handling: there are group contacts and individual contacts */
+            Logger.log.info("Assigning memberships of downloaded contact groups")
+            LocalGroup.applyPendingMemberships(localAddressBook)
+        }
+    }
+
+
+    // helpers
+
+    private fun davAddressBook() = davCollection as DavAddressBook
+
+    private fun processVCard(fileName: String, eTag: String, reader: Reader, downloader: Contact.Downloader) {
+        Logger.log.info("Processing CardDAV resource $fileName")
+        val contacts = Contact.fromReader(reader, downloader)
+        if (contacts.isEmpty()) {
+            Logger.log.warning("Received VCard without data, ignoring")
+            return
+        } else if (contacts.size > 1)
+            Logger.log.warning("Received multiple VCards, using first one")
+
+        val newData = contacts.first()
+
+        if (groupMethod == GroupMethod.CATEGORIES && newData.group) {
+            Logger.log.warning("Received group VCard although group method is CATEGORIES. Saving as regular contact")
+            newData.group = false
+        }
+
+        // update local contact, if it exists
+        var local = localResources[fileName]
+        currentLocalResource = local
+        if (local != null) {
+            Logger.log.log(Level.INFO, "Updating $fileName in local address book", newData)
+
+            if (local is LocalGroup && newData.group) {
+                // update group
+                local.eTag = eTag
+                local.updateFromServer(newData)
+                syncResult.stats.numUpdates++
+
+            } else if (local is LocalContact && !newData.group) {
+                // update contact
+                local.eTag = eTag
+                local.update(newData)
+                syncResult.stats.numUpdates++
+
+            } else {
+                // group has become an individual contact or vice versa
+                local.delete()
+                local = null
+            }
+        }
+
+        if (local == null) {
+            if (newData.group) {
+                Logger.log.log(Level.INFO, "Creating local group", newData)
+                val group = LocalGroup(localAddressBook, newData, fileName, eTag)
+                currentLocalResource = group
+                group.create()
+
+                local = group
+            } else {
+                Logger.log.log(Level.INFO, "Creating local contact", newData)
+                val contact = LocalContact(localAddressBook, newData, fileName, eTag)
+                currentLocalResource = contact
+                contact.create()
+
+                local = contact
+            }
+            syncResult.stats.numInserts++
+        }
+
+        if (groupMethod == GroupMethod.CATEGORIES && local is LocalContact) {
+            // VCard3: update group memberships from CATEGORIES
+            currentLocalResource = local
+
+            val batch = BatchOperation(provider)
+            Logger.log.log(Level.FINE, "Removing contact group memberships")
+            local.removeGroupMemberships(batch)
+
+            for (category in local.contact!!.categories) {
+                val groupID = localAddressBook.findOrCreateGroup(category)
+                Logger.log.log(Level.FINE, "Adding membership in group $category ($groupID)")
+                local.addToGroup(batch, groupID)
+            }
+
+            batch.commit()
+        }
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N && Build.VERSION.SDK_INT < Build.VERSION_CODES.O && local is LocalContact)
+            // workaround for Android 7 which sets DIRTY flag when only meta-data is changed
+            local.updateHashCode(null)
+
+        currentLocalResource = null
+    }
+
+
+    // downloader helper class
+
+    private inner class ResourceDownloader(
+            val baseUrl: HttpUrl
+    ): Contact.Downloader {
+
+        override fun download(url: String, accepts: String): ByteArray? {
+            val httpUrl = HttpUrl.parse(url)
+            if (httpUrl == null) {
+                Logger.log.log(Level.SEVERE, "Invalid external resource URL", url)
+                return null
+            }
+
+            val host = httpUrl.host()
+            if (host == null) {
+                Logger.log.log(Level.SEVERE, "External resource URL doesn't specify a host name", url)
+                return null
+            }
+
+            // authenticate only against a certain host, and only upon request
+            val username = settings.username()
+            val password = settings.password()
+            val builder = if (username != null && password != null)
+                    HttpClient.Builder(context, baseUrl.host(), username, password)
+                        else
+                    HttpClient.Builder(context)
+
+            // allow redirects
+            builder.followRedirects(true)
+
+            val client = builder.build()
+            try {
+                val response = client.okHttpClient.newCall(Request.Builder()
+                        .get()
+                        .url(httpUrl)
+                        .build()).execute()
+
+                if (response.isSuccessful)
+                    return response.body()?.bytes()
+                else
+                    Logger.log.warning("Couldn't download external resource")
+            } catch(e: IOException) {
+                Logger.log.log(Level.SEVERE, "Couldn't download external resource", e)
+            } finally {
+                client.close()
+            }
+            return null
+        }
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/syncadapter/NullAuthenticatorService.kt

@@ -0,0 +1,54 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.syncadapter
+
+import android.accounts.AbstractAccountAuthenticator
+import android.accounts.Account
+import android.accounts.AccountAuthenticatorResponse
+import android.accounts.AccountManager
+import android.app.Service
+import android.content.Context
+import android.content.Intent
+import android.os.Bundle
+import at.bitfire.davdroid.ui.AccountsActivity
+
+class NullAuthenticatorService: Service() {
+
+    private lateinit var accountAuthenticator: AccountAuthenticator
+
+    override fun onCreate() {
+        accountAuthenticator = AccountAuthenticator(this)
+    }
+
+    override fun onBind(intent: Intent?) =
+            accountAuthenticator.iBinder.takeIf { intent?.action == android.accounts.AccountManager.ACTION_AUTHENTICATOR_INTENT }
+
+
+    private class AccountAuthenticator(
+            val context: Context
+    ): AbstractAccountAuthenticator(context) {
+
+        override fun addAccount(response: AccountAuthenticatorResponse?, accountType: String?, authTokenType: String?, requiredFeatures: Array<String>?, options: Bundle?): Bundle {
+            val intent = Intent(context, AccountsActivity::class.java)
+            intent.putExtra(AccountManager.KEY_ACCOUNT_AUTHENTICATOR_RESPONSE, response)
+            val bundle = Bundle(1)
+            bundle.putParcelable(AccountManager.KEY_INTENT, intent)
+            return bundle
+        }
+
+        override fun editProperties(response: AccountAuthenticatorResponse?, accountType: String?) = null
+        override fun getAuthTokenLabel(p0: String?) = null
+        override fun confirmCredentials(p0: AccountAuthenticatorResponse?, p1: Account?, p2: Bundle?) = null
+        override fun updateCredentials(p0: AccountAuthenticatorResponse?, p1: Account?, p2: String?, p3: Bundle?) = null
+        override fun getAuthToken(p0: AccountAuthenticatorResponse?, p1: Account?, p2: String?, p3: Bundle?) = null
+        override fun hasFeatures(p0: AccountAuthenticatorResponse?, p1: Account?, p2: Array<out String>?) = null
+
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/syncadapter/SyncAdapterService.java

@@ -1,115 +0,0 @@
-/*
- * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.syncadapter;
-
-import android.accounts.Account;
-import android.app.Notification;
-import android.app.PendingIntent;
-import android.app.Service;
-import android.content.AbstractThreadedSyncAdapter;
-import android.content.ContentProviderClient;
-import android.content.Context;
-import android.content.Intent;
-import android.content.SyncResult;
-import android.net.ConnectivityManager;
-import android.net.NetworkInfo;
-import android.net.wifi.WifiInfo;
-import android.net.wifi.WifiManager;
-import android.os.Bundle;
-import android.os.IBinder;
-import android.support.annotation.NonNull;
-import android.support.annotation.Nullable;
-import android.support.v4.app.NotificationCompat;
-import android.support.v4.app.NotificationManagerCompat;
-
-import java.util.logging.Level;
-
-import at.bitfire.davdroid.AccountSettings;
-import at.bitfire.davdroid.App;
-import at.bitfire.davdroid.Constants;
-import at.bitfire.davdroid.R;
-import at.bitfire.davdroid.ui.PermissionsActivity;
-
-//import com.android.vending.billing.IInAppBillingService;
-
-public abstract class SyncAdapterService extends Service {
-
-    abstract protected AbstractThreadedSyncAdapter syncAdapter();
-
-    @Nullable
-    @Override
-    public IBinder onBind(Intent intent) {
-        return syncAdapter().getSyncAdapterBinder();
-    }
-
-
-    public static abstract class SyncAdapter extends AbstractThreadedSyncAdapter {
-
-        public SyncAdapter(Context context) {
-            super(context, false);
-        }
-
-        @Override
-        public void onPerformSync(Account account, Bundle extras, String authority, ContentProviderClient provider, SyncResult syncResult) {
-            App.log.log(Level.INFO, "Sync for " + authority + " has been initiated.", extras.keySet().toArray());
-
-            // required for dav4android (ServiceLoader)
-            Thread.currentThread().setContextClassLoader(getContext().getClassLoader());
-        }
-
-        @Override
-        public void onSecurityException(Account account, Bundle extras, String authority, SyncResult syncResult) {
-            App.log.log(Level.WARNING, "Security exception when opening content provider for " +  authority);
-            syncResult.databaseError = true;
-
-            Intent intent = new Intent(getContext(), PermissionsActivity.class);
-            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
-
-            Notification notify = new NotificationCompat.Builder(getContext())
-                    .setSmallIcon(R.drawable.ic_error_light)
-                    .setLargeIcon(App.getLauncherBitmap(getContext()))
-                    .setContentTitle(getContext().getString(R.string.sync_error_permissions))
-                    .setContentText(getContext().getString(R.string.sync_error_permissions_text))
-                    .setContentIntent(PendingIntent.getActivity(getContext(), 0, intent, PendingIntent.FLAG_UPDATE_CURRENT))
-                    .setCategory(NotificationCompat.CATEGORY_ERROR)
-                    .build();
-            NotificationManagerCompat nm = NotificationManagerCompat.from(getContext());
-            nm.notify(Constants.NOTIFICATION_PERMISSIONS, notify);
-        }
-
-        protected boolean checkSyncConditions(@NonNull AccountSettings settings) {
-            if (settings.getSyncWifiOnly()) {
-                ConnectivityManager cm = (ConnectivityManager)getContext().getSystemService(CONNECTIVITY_SERVICE);
-                NetworkInfo network = cm.getActiveNetworkInfo();
-                if (network == null) {
-                    App.log.info("No network available, stopping");
-                    return false;
-                }
-                if (network.getType() != ConnectivityManager.TYPE_WIFI || !network.isConnected()) {
-                    App.log.info("Not on connected WiFi, stopping");
-                    return false;
-                }
-
-                String onlySSID = settings.getSyncWifiOnlySSID();
-                if (onlySSID != null) {
-                    onlySSID = "\"" + onlySSID + "\"";
-                    WifiManager wifi = (WifiManager)getContext().getApplicationContext().getSystemService(WIFI_SERVICE);
-                    WifiInfo info = wifi.getConnectionInfo();
-                    if (info == null || !onlySSID.equals(info.getSSID())) {
-                        App.log.info("Connected to wrong WiFi network (" + info.getSSID() + ", required: " + onlySSID + "), ignoring");
-                        return false;
-                    }
-                }
-            }
-            return true;
-        }
-
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/syncadapter/SyncAdapterService.kt

@@ -0,0 +1,120 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.syncadapter
+
+import android.accounts.Account
+import android.app.PendingIntent
+import android.app.Service
+import android.content.*
+import android.net.ConnectivityManager
+import android.net.wifi.WifiManager
+import android.os.Bundle
+import android.support.v4.app.NotificationCompat
+import android.support.v4.app.NotificationManagerCompat
+import at.bitfire.davdroid.AccountSettings
+import at.bitfire.davdroid.App
+import at.bitfire.davdroid.Constants
+import at.bitfire.davdroid.R
+import at.bitfire.davdroid.log.Logger
+import at.bitfire.davdroid.settings.ISettings
+import at.bitfire.davdroid.settings.Settings
+import at.bitfire.davdroid.ui.PermissionsActivity
+import java.util.*
+import java.util.logging.Level
+
+abstract class SyncAdapterService: Service() {
+
+    companion object {
+        val runningSyncs = Collections.synchronizedSet(mutableSetOf<Pair<String, Account>>())
+    }
+
+    abstract protected fun syncAdapter(): AbstractThreadedSyncAdapter
+
+    override fun onBind(intent: Intent?) = syncAdapter().syncAdapterBinder!!
+
+
+    abstract class SyncAdapter(
+            context: Context
+    ): AbstractThreadedSyncAdapter(context, false) {
+
+        abstract fun sync(settings: ISettings, account: Account, extras: Bundle, authority: String, provider: ContentProviderClient, syncResult: SyncResult)
+
+        override fun onPerformSync(account: Account, extras: Bundle, authority: String, provider: ContentProviderClient, syncResult: SyncResult) {
+            Logger.log.log(Level.INFO, "$authority sync of $account has been initiated", extras.keySet().joinToString(", "))
+
+            // prevent multiple syncs of the same authority to be run for the same account
+            val currentSync = Pair(authority, account)
+            if (!runningSyncs.add(currentSync)) {
+                Logger.log.warning("There's already another $authority sync running for $account, aborting")
+                return
+            }
+
+            try {
+                // required for dav4android (ServiceLoader)
+                Thread.currentThread().contextClassLoader = context.classLoader
+
+                // load app settings
+                Settings.getInstance(context).use { settings ->
+                    if (settings == null) {
+                        syncResult.databaseError = true
+                        Logger.log.severe("Couldn't connect to Settings service, aborting sync")
+                        return
+                    }
+
+                    sync(settings, account, extras, authority, provider, syncResult)
+                }
+                Logger.log.info("Sync for $authority complete")
+            } finally {
+                runningSyncs -= currentSync
+            }
+        }
+
+        override fun onSecurityException(account: Account, extras: Bundle, authority: String, syncResult: SyncResult) {
+            Logger.log.log(Level.WARNING, "Security exception when opening content provider for $authority")
+            syncResult.databaseError = true
+
+            val intent = Intent(context, PermissionsActivity::class.java)
+            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
+
+            val notify = NotificationCompat.Builder(context)
+                    .setSmallIcon(R.drawable.ic_error_light)
+                    .setLargeIcon(App.getLauncherBitmap(context))
+                    .setContentTitle(context.getString(R.string.sync_error_permissions))
+                    .setContentText(context.getString(R.string.sync_error_permissions_text))
+                    .setContentIntent(PendingIntent.getActivity(context, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT))
+                    .setCategory(NotificationCompat.CATEGORY_ERROR)
+                    .build()
+            val nm = NotificationManagerCompat.from(context)
+            nm.notify(Constants.NOTIFICATION_PERMISSIONS, notify)
+        }
+
+        protected fun checkSyncConditions(settings: AccountSettings): Boolean {
+            if (settings.getSyncWifiOnly()) {
+                val connectivityManager = context.getSystemService(CONNECTIVITY_SERVICE) as ConnectivityManager
+                val network = connectivityManager.activeNetworkInfo
+                if (network == null || network.type != ConnectivityManager.TYPE_WIFI || !network.isConnected) {
+                    Logger.log.info("Not on connected WiFi, stopping")
+                    return false
+                }
+
+                settings.getSyncWifiOnlySSIDs()?.let { onlySSIDs ->
+                    val wifi = context.applicationContext.getSystemService(WIFI_SERVICE) as WifiManager
+                    val info = wifi.connectionInfo
+                    if (info == null || !onlySSIDs.contains(info.ssid.trim('"'))) {
+                        Logger.log.info("Connected to wrong WiFi network (${info.ssid}), ignoring")
+                        return false
+                    }
+                }
+            }
+            return true
+        }
+
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/syncadapter/SyncManager.java

@@ -1,484 +0,0 @@
-    /*
- * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-package at.bitfire.davdroid.syncadapter;
-
-import android.accounts.Account;
-import android.annotation.TargetApi;
-import android.app.PendingIntent;
-import android.content.ContentResolver;
-import android.content.Context;
-import android.content.Intent;
-import android.content.SyncResult;
-import android.net.Uri;
-import android.os.Bundle;
-import android.support.v4.app.NotificationManagerCompat;
-import android.support.v7.app.NotificationCompat;
-import android.text.TextUtils;
-
-import java.io.IOException;
-import java.util.Date;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.Map;
-import java.util.Set;
-import java.util.logging.Level;
-
-import at.bitfire.dav4android.DavResource;
-import at.bitfire.dav4android.exception.ConflictException;
-import at.bitfire.dav4android.exception.DavException;
-import at.bitfire.dav4android.exception.HttpException;
-import at.bitfire.dav4android.exception.PreconditionFailedException;
-import at.bitfire.dav4android.exception.ServiceUnavailableException;
-import at.bitfire.dav4android.exception.UnauthorizedException;
-import at.bitfire.dav4android.property.GetCTag;
-import at.bitfire.dav4android.property.GetETag;
-import at.bitfire.davdroid.AccountSettings;
-import at.bitfire.davdroid.App;
-import at.bitfire.davdroid.HttpClient;
-import at.bitfire.davdroid.InvalidAccountException;
-import at.bitfire.davdroid.R;
-import at.bitfire.davdroid.resource.LocalCollection;
-import at.bitfire.davdroid.resource.LocalResource;
-import at.bitfire.davdroid.ui.AccountSettingsActivity;
-import at.bitfire.davdroid.ui.DebugInfoActivity;
-import at.bitfire.ical4android.CalendarStorageException;
-import at.bitfire.vcard4android.ContactsStorageException;
-import okhttp3.HttpUrl;
-import okhttp3.OkHttpClient;
-import okhttp3.RequestBody;
-
-abstract public class SyncManager {
-
-    protected final int SYNC_PHASE_PREPARE = 0,
-                        SYNC_PHASE_QUERY_CAPABILITIES = 1,
-                        SYNC_PHASE_PROCESS_LOCALLY_DELETED = 2,
-                        SYNC_PHASE_PREPARE_DIRTY = 3,
-                        SYNC_PHASE_UPLOAD_DIRTY = 4,
-                        SYNC_PHASE_CHECK_SYNC_STATE = 5,
-                        SYNC_PHASE_LIST_LOCAL = 6,
-                        SYNC_PHASE_LIST_REMOTE = 7,
-                        SYNC_PHASE_COMPARE_LOCAL_REMOTE = 8,
-                        SYNC_PHASE_DOWNLOAD_REMOTE = 9,
-                        SYNC_PHASE_POST_PROCESSING = 10,
-                        SYNC_PHASE_SAVE_SYNC_STATE = 11;
-
-    protected final NotificationManagerCompat notificationManager;
-    protected final String uniqueCollectionId;
-
-    protected final Context context;
-    protected final Account account;
-    protected final Bundle extras;
-    protected final String authority;
-    protected final SyncResult syncResult;
-
-    protected final AccountSettings settings;
-    protected LocalCollection localCollection;
-
-    protected OkHttpClient httpClient;
-    protected HttpUrl collectionURL;
-    protected DavResource davCollection;
-
-
-    /** state information for debug info (local resource) */
-    protected LocalResource currentLocalResource;
-
-    /** state information for debug info (remote resource) */
-    protected DavResource currentDavResource;
-
-
-    /** remote CTag at the time of {@link #listRemote()} */
-    protected String remoteCTag = null;
-
-    /** sync-able resources in the local collection, as enumerated by {@link #listLocal()} */
-    protected Map<String, LocalResource> localResources;
-
-    /** sync-able resources in the remote collection, as enumerated by {@link #listRemote()} */
-    protected Map<String, DavResource> remoteResources;
-
-    /** resources which have changed on the server, as determined by {@link #compareLocalRemote()} */
-    protected Set<DavResource> toDownload;
-
-
-
-    public SyncManager(Context context, Account account, AccountSettings settings, Bundle extras, String authority, SyncResult syncResult, String uniqueCollectionId) throws InvalidAccountException {
-        this.context = context;
-        this.account = account;
-        this.settings = settings;
-        this.extras = extras;
-        this.authority = authority;
-        this.syncResult = syncResult;
-
-        // create HttpClient with given logger
-        httpClient = HttpClient.create(context, account);
-
-        // dismiss previous error notifications
-        this.uniqueCollectionId = uniqueCollectionId;
-        notificationManager = NotificationManagerCompat.from(context);
-        notificationManager.cancel(uniqueCollectionId, notificationId());
-    }
-
-    protected abstract int notificationId();
-    protected abstract String getSyncErrorTitle();
-
-    @TargetApi(21)
-    public void performSync() {
-        int syncPhase = SYNC_PHASE_PREPARE;
-        try {
-            App.log.info("Preparing synchronization");
-            if (!prepare()) {
-                App.log.info("No reason to synchronize, aborting");
-                return;
-            }
-
-            if (Thread.interrupted())
-                return;
-            syncPhase = SYNC_PHASE_QUERY_CAPABILITIES;
-            App.log.info("Querying capabilities");
-            queryCapabilities();
-
-            syncPhase = SYNC_PHASE_PROCESS_LOCALLY_DELETED;
-            App.log.info("Processing locally deleted entries");
-            processLocallyDeleted();
-
-            if (Thread.interrupted())
-                return;
-            syncPhase = SYNC_PHASE_PREPARE_DIRTY;
-            App.log.info("Locally preparing dirty entries");
-            prepareDirty();
-
-            syncPhase = SYNC_PHASE_UPLOAD_DIRTY;
-            App.log.info("Uploading dirty entries");
-            uploadDirty();
-
-            syncPhase = SYNC_PHASE_CHECK_SYNC_STATE;
-            App.log.info("Checking sync state");
-            if (checkSyncState()) {
-                syncPhase = SYNC_PHASE_LIST_LOCAL;
-                App.log.info("Listing local entries");
-                listLocal();
-
-                if (Thread.interrupted())
-                    return;
-                syncPhase = SYNC_PHASE_LIST_REMOTE;
-                App.log.info("Listing remote entries");
-                listRemote();
-
-                if (Thread.interrupted())
-                    return;
-                syncPhase = SYNC_PHASE_COMPARE_LOCAL_REMOTE;
-                App.log.info("Comparing local/remote entries");
-                compareLocalRemote();
-
-                syncPhase = SYNC_PHASE_DOWNLOAD_REMOTE;
-                App.log.info("Downloading remote entries");
-                downloadRemote();
-
-                syncPhase = SYNC_PHASE_POST_PROCESSING;
-                App.log.info("Post-processing");
-                postProcess();
-
-                syncPhase = SYNC_PHASE_SAVE_SYNC_STATE;
-                App.log.info("Saving sync state");
-                saveSyncState();
-            } else
-                App.log.info("Remote collection didn't change, skipping remote sync");
-
-        } catch(IOException|ServiceUnavailableException e) {
-            App.log.log(Level.WARNING, "I/O exception during sync, trying again later", e);
-            syncResult.stats.numIoExceptions++;
-
-            if (e instanceof ServiceUnavailableException) {
-                Date retryAfter = ((ServiceUnavailableException) e).retryAfter;
-                if (retryAfter != null) {
-                    // how many seconds to wait? getTime() returns ms, so divide by 1000
-                    syncResult.delayUntil = (retryAfter.getTime() - new Date().getTime()) / 1000;
-                }
-            }
-
-        } catch(Exception|OutOfMemoryError e) {
-            final int messageString;
-
-            if (e instanceof UnauthorizedException) {
-                App.log.log(Level.SEVERE, "Not authorized anymore", e);
-                messageString = R.string.sync_error_unauthorized;
-                syncResult.stats.numAuthExceptions++;
-            } else if (e instanceof HttpException || e instanceof DavException) {
-                App.log.log(Level.SEVERE, "HTTP/DAV Exception during sync", e);
-                messageString = R.string.sync_error_http_dav;
-                syncResult.stats.numParseExceptions++;
-            } else if (e instanceof CalendarStorageException || e instanceof ContactsStorageException) {
-                App.log.log(Level.SEVERE, "Couldn't access local storage", e);
-                messageString = R.string.sync_error_local_storage;
-                syncResult.databaseError = true;
-            } else {
-                App.log.log(Level.SEVERE, "Unknown sync error", e);
-                messageString = R.string.sync_error;
-                syncResult.stats.numParseExceptions++;
-            }
-
-            final Intent detailsIntent;
-            if (e instanceof UnauthorizedException) {
-                detailsIntent = new Intent(context, AccountSettingsActivity.class);
-                detailsIntent.putExtra(AccountSettingsActivity.EXTRA_ACCOUNT, account);
-            } else {
-                detailsIntent = new Intent(context, DebugInfoActivity.class);
-                detailsIntent.putExtra(DebugInfoActivity.KEY_THROWABLE, e);
-                detailsIntent.putExtra(DebugInfoActivity.KEY_ACCOUNT, account);
-                detailsIntent.putExtra(DebugInfoActivity.KEY_AUTHORITY, authority);
-                detailsIntent.putExtra(DebugInfoActivity.KEY_PHASE, syncPhase);
-                if (currentLocalResource != null)
-                    detailsIntent.putExtra(DebugInfoActivity.KEY_LOCAL_RESOURCE, currentLocalResource.toString());
-                if (currentDavResource != null)
-                    detailsIntent.putExtra(DebugInfoActivity.KEY_REMOTE_RESOURCE, currentDavResource.toString());
-            }
-
-            // to make the PendingIntent unique
-            detailsIntent.setData(Uri.parse("uri://" + getClass().getName() + "/" + uniqueCollectionId));
-
-            NotificationCompat.Builder builder = new NotificationCompat.Builder(context);
-            builder .setSmallIcon(R.drawable.ic_error_light)
-                    .setLargeIcon(App.getLauncherBitmap(context))
-                    .setContentTitle(getSyncErrorTitle())
-                    .setContentIntent(PendingIntent.getActivity(context, 0, detailsIntent, PendingIntent.FLAG_CANCEL_CURRENT))
-                    .setCategory(NotificationCompat.CATEGORY_ERROR);
-
-            try {
-                String[] phases = context.getResources().getStringArray(R.array.sync_error_phases);
-                String message = context.getString(messageString, phases[syncPhase]);
-                builder.setContentText(message);
-            } catch (IndexOutOfBoundsException ex) {
-                // should never happen
-            }
-
-            notificationManager.notify(uniqueCollectionId, notificationId(), builder.build());
-        }
-    }
-
-
-    /** Prepares synchronization (for instance, allocates necessary resources).
-     * @return whether actual synchronization is required / can be made. true = synchronization
-     *         shall be continued, false = synchronization can be skipped */
-    abstract protected boolean prepare() throws ContactsStorageException;
-
-    abstract protected void queryCapabilities() throws IOException, HttpException, DavException, CalendarStorageException, ContactsStorageException;
-
-    /**
-     * Process locally deleted entries (DELETE them on the server as well).
-     * Checks Thread.interrupted() before each request to allow quick sync cancellation.
-     */
-    protected void processLocallyDeleted() throws CalendarStorageException, ContactsStorageException {
-        // Remove locally deleted entries from server (if they have a name, i.e. if they were uploaded before),
-        // but only if they don't have changed on the server. Then finally remove them from the local address book.
-        LocalResource[] localList = localCollection.getDeleted();
-        for (final LocalResource local : localList) {
-            if (Thread.interrupted())
-                return;
-
-            currentLocalResource = local;
-
-            final String fileName = local.getFileName();
-            if (!TextUtils.isEmpty(fileName)) {
-                App.log.info(fileName + " has been deleted locally -> deleting from server");
-
-                final DavResource remote = new DavResource(httpClient, collectionURL.newBuilder().addPathSegment(fileName).build());
-                currentDavResource = remote;
-                try {
-                    remote.delete(local.getETag());
-                } catch (IOException|HttpException e) {
-                    App.log.warning("Couldn't delete " + fileName + " from server; ignoring (may be downloaded again)");
-                }
-            } else
-                App.log.info("Removing local record #" + local.getId() + " which has been deleted locally and was never uploaded");
-            local.delete();
-            syncResult.stats.numDeletes++;
-
-            currentLocalResource = null;
-            currentDavResource = null;
-        }
-    }
-
-    protected void prepareDirty() throws CalendarStorageException, ContactsStorageException {
-        // assign file names and UIDs to new contacts so that we can use the file name as an index
-        App.log.info("Looking for contacts/groups without file name");
-        for (final LocalResource local : localCollection.getWithoutFileName()) {
-            currentLocalResource = local;
-
-            App.log.fine("Found local record #" + local.getId() + " without file name; generating file name/UID if necessary");
-            local.prepareForUpload();
-
-            currentLocalResource = null;
-        }
-    }
-
-    abstract protected RequestBody prepareUpload(LocalResource resource) throws IOException, CalendarStorageException, ContactsStorageException;
-
-    /**
-     * Uploads dirty records to the server, using a PUT request for each record.
-     * Checks Thread.interrupted() before each request to allow quick sync cancellation.
-     */
-    protected void uploadDirty() throws IOException, HttpException, CalendarStorageException, ContactsStorageException {
-        // upload dirty contacts
-        for (final LocalResource local : localCollection.getDirty()) {
-            if (Thread.interrupted())
-                return;
-
-            currentLocalResource = local;
-            final String fileName = local.getFileName();
-
-            final DavResource remote = new DavResource(httpClient, collectionURL.newBuilder().addPathSegment(fileName).build());
-            currentDavResource = remote;
-
-            // generate entity to upload (VCard, iCal, whatever)
-            RequestBody body = prepareUpload(local);
-
-            try {
-                if (local.getETag() == null) {
-                    App.log.info("Uploading new record " + fileName);
-                    remote.put(body, null, true);
-                } else {
-                    App.log.info("Uploading locally modified record " + fileName);
-                    remote.put(body, local.getETag(), false);
-                }
-            } catch (ConflictException|PreconditionFailedException e) {
-                // we can't interact with the user to resolve the conflict, so we treat 409 like 412
-                App.log.log(Level.INFO, "Resource has been modified on the server before upload, ignoring", e);
-            }
-
-            String eTag = null;
-            GetETag newETag = (GetETag) remote.properties.get(GetETag.NAME);
-            if (newETag != null) {
-                eTag = newETag.eTag;
-                App.log.fine("Received new ETag=" + eTag + " after uploading");
-            } else
-                App.log.fine("Didn't receive new ETag after uploading, setting to null");
-
-            local.clearDirty(eTag);
-
-            currentLocalResource = null;
-            currentDavResource = null;
-        }
-    }
-
-    /**
-     * Checks the current sync state (e.g. CTag) and whether synchronization from remote is required.
-     * @return <ul>
-     *      <li><code>true</code>   if the remote collection has changed, i.e. synchronization from remote is required</li>
-     *      <li><code>false</code>  if the remote collection hasn't changed</li>
-     * </ul>
-     */
-    protected boolean checkSyncState() throws CalendarStorageException, ContactsStorageException {
-        // check CTag (ignore on manual sync)
-        GetCTag getCTag = (GetCTag)davCollection.properties.get(GetCTag.NAME);
-        if (getCTag != null)
-            remoteCTag = getCTag.cTag;
-
-        String localCTag = null;
-        if (extras.containsKey(ContentResolver.SYNC_EXTRAS_MANUAL))
-            App.log.info("Manual sync, ignoring CTag");
-        else
-            localCTag = localCollection.getCTag();
-
-        if (remoteCTag != null && remoteCTag.equals(localCTag)) {
-            App.log.info("Remote collection didn't change (CTag=" + remoteCTag + "), no need to query children");
-            return false;
-        } else
-            return true;
-    }
-
-    /**
-     * Lists all local resources which should be taken into account for synchronization into {@link #localResources}.
-     */
-    protected void listLocal() throws CalendarStorageException, ContactsStorageException {
-        // fetch list of local contacts and build hash table to index file name
-        LocalResource[] localList = localCollection.getAll();
-        localResources = new HashMap<>(localList.length);
-        for (LocalResource resource : localList) {
-            App.log.fine("Found local resource: " + resource.getFileName());
-            localResources.put(resource.getFileName(), resource);
-        }
-    }
-
-    /**
-     * Lists all members of the remote collection which should be taken into account for synchronization into {@link #remoteResources}.
-     */
-    abstract protected void listRemote() throws IOException, HttpException, DavException;
-
-    /**
-     * Compares {@link #localResources} and {@link #remoteResources} by file name and ETag:
-     * <ul>
-     *     <li>Local resources which are not available in the remote collection (anymore) will be removed.</li>
-     *     <li>Resources whose remote ETag has changed will be added into {@link #toDownload}</li>
-     * </ul>
-     */
-    protected void compareLocalRemote() throws IOException, HttpException, DavException, CalendarStorageException, ContactsStorageException {
-        /* check which contacts
-           1. are not present anymore remotely -> delete immediately on local side
-           2. updated remotely -> add to downloadNames
-           3. added remotely  -> add to downloadNames
-         */
-        toDownload = new HashSet<>();
-        for (String localName : localResources.keySet()) {
-            final DavResource remote = remoteResources.get(localName);
-            currentDavResource = remote;
-
-            if (remote == null) {
-                App.log.info(localName + " is not on server anymore, deleting");
-                final LocalResource local = localResources.get(localName);
-                currentLocalResource = local;
-                local.delete();
-                syncResult.stats.numDeletes++;
-            } else {
-                // contact is still on server, check whether it has been updated remotely
-                GetETag getETag = (GetETag)remote.properties.get(GetETag.NAME);
-                if (getETag == null || getETag.eTag == null)
-                    throw new DavException("Server didn't provide ETag");
-                String localETag = localResources.get(localName).getETag(),
-                        remoteETag = getETag.eTag;
-                if (remoteETag.equals(localETag))
-                    syncResult.stats.numSkippedEntries++;
-                else {
-                    App.log.info(localName + " has been changed on server (current ETag=" + remoteETag + ", last known ETag=" + localETag + ")");
-                    toDownload.add(remote);
-                }
-
-                // remote entry has been seen, remove from list
-                remoteResources.remove(localName);
-
-                currentDavResource = null;
-                currentLocalResource = null;
-            }
-        }
-
-        // add all unseen (= remotely added) remote contacts
-        if (!remoteResources.isEmpty()) {
-            App.log.info("New resources have been found on the server: " + TextUtils.join(", ", remoteResources.keySet()));
-            toDownload.addAll(remoteResources.values());
-        }
-    }
-
-    /**
-     * Downloads the remote resources in {@link #toDownload} and stores them locally.
-     * Must check Thread.interrupted() periodically to allow quick sync cancellation.
-     */
-    abstract protected void downloadRemote() throws IOException, HttpException, DavException, ContactsStorageException, CalendarStorageException;
-
-    /**
-     * For post-processing of entries, for instance assigning groups.
-     */
-    protected void postProcess() throws CalendarStorageException, ContactsStorageException {
-    }
-
-    protected void saveSyncState() throws CalendarStorageException, ContactsStorageException {
-        /* Save sync state (CTag). It doesn't matter if it has changed during the sync process
-           (for instance, because another client has uploaded changes), because this will simply
-           cause all remote entries to be listed at the next sync. */
-        App.log.info("Saving CTag=" + remoteCTag);
-        localCollection.setCTag(remoteCTag);
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/syncadapter/SyncManager.kt

@@ -0,0 +1,468 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+package at.bitfire.davdroid.syncadapter
+
+import android.accounts.Account
+import android.app.PendingIntent
+import android.content.ContentResolver
+import android.content.Context
+import android.content.Intent
+import android.content.SyncResult
+import android.net.Uri
+import android.os.Bundle
+import android.support.v4.app.NotificationManagerCompat
+import android.support.v7.app.NotificationCompat
+import at.bitfire.dav4android.DavResource
+import at.bitfire.dav4android.exception.*
+import at.bitfire.dav4android.property.GetCTag
+import at.bitfire.dav4android.property.GetETag
+import at.bitfire.davdroid.AccountSettings
+import at.bitfire.davdroid.App
+import at.bitfire.davdroid.HttpClient
+import at.bitfire.davdroid.R
+import at.bitfire.davdroid.log.Logger
+import at.bitfire.davdroid.resource.LocalCollection
+import at.bitfire.davdroid.resource.LocalResource
+import at.bitfire.davdroid.ui.AccountSettingsActivity
+import at.bitfire.davdroid.ui.DebugInfoActivity
+import at.bitfire.ical4android.CalendarStorageException
+import at.bitfire.vcard4android.ContactsStorageException
+import okhttp3.HttpUrl
+import okhttp3.RequestBody
+import java.io.Closeable
+import java.io.IOException
+import java.util.*
+import java.util.logging.Level
+
+abstract class SyncManager(
+        val context: Context,
+        val account: Account,
+        val settings: AccountSettings,
+        val extras: Bundle,
+        val authority: String,
+        val syncResult: SyncResult,
+        val uniqueCollectionId: String
+): Closeable {
+
+    val SYNC_PHASE_PREPARE = 0
+    val SYNC_PHASE_QUERY_CAPABILITIES = 1
+    val SYNC_PHASE_PROCESS_LOCALLY_DELETED = 2
+    val SYNC_PHASE_PREPARE_DIRTY = 3
+    val SYNC_PHASE_UPLOAD_DIRTY = 4
+    val SYNC_PHASE_CHECK_SYNC_STATE = 5
+    val SYNC_PHASE_LIST_LOCAL = 6
+    val SYNC_PHASE_LIST_REMOTE = 7
+    val SYNC_PHASE_COMPARE_LOCAL_REMOTE = 8
+    val SYNC_PHASE_DOWNLOAD_REMOTE = 9
+    val SYNC_PHASE_POST_PROCESSING = 10
+    val SYNC_PHASE_SAVE_SYNC_STATE = 11
+
+    protected val notificationManager = NotificationManagerCompat.from(context)!!
+
+    protected lateinit var localCollection: LocalCollection<*>
+
+    protected val httpClient = HttpClient.Builder(context, accountSettings = settings).build()
+    protected lateinit var collectionURL: HttpUrl
+    protected lateinit var davCollection: DavResource
+
+
+    /** state information for debug info (local resource) */
+    protected var currentLocalResource: LocalResource? = null
+
+    /** state information for debug info (remote resource) */
+    protected var currentDavResource: DavResource? = null
+
+
+    /** remote CTag at the time of {@link #listRemote()} */
+    protected var remoteCTag: String? = null
+
+    /** sync-able resources in the local collection, as enumerated by {@link #listLocal()} */
+    protected lateinit var localResources: MutableMap<String, LocalResource>
+
+    /** sync-able resources in the remote collection, as enumerated by {@link #listRemote()} */
+    protected lateinit var remoteResources: MutableMap<String, DavResource>
+
+    /** resources which have changed on the server, as determined by {@link #compareLocalRemote()} */
+    protected val toDownload = mutableSetOf<DavResource>()
+
+
+    companion object {
+        infix fun <T> Set<T>.disjunct(other: Set<T>) = (this - other) union (other - this)
+    }
+
+
+    protected abstract fun notificationId(): Int
+    protected abstract fun getSyncErrorTitle(): String
+
+    fun performSync() {
+        // dismiss previous error notifications
+        notificationManager.cancel(uniqueCollectionId, notificationId())
+
+        var syncPhase = SYNC_PHASE_PREPARE
+        try {
+            Logger.log.info("Preparing synchronization")
+            if (!prepare()) {
+                Logger.log.info("No reason to synchronize, aborting")
+                return
+            }
+
+            if (Thread.interrupted())
+                return
+            syncPhase = SYNC_PHASE_QUERY_CAPABILITIES
+            Logger.log.info("Querying capabilities")
+            queryCapabilities()
+
+            syncPhase = SYNC_PHASE_PROCESS_LOCALLY_DELETED
+            Logger.log.info("Processing locally deleted entries")
+            processLocallyDeleted()
+
+            if (Thread.interrupted())
+                return
+            syncPhase = SYNC_PHASE_PREPARE_DIRTY
+            Logger.log.info("Locally preparing dirty entries")
+            prepareDirty()
+
+            syncPhase = SYNC_PHASE_UPLOAD_DIRTY
+            Logger.log.info("Uploading dirty entries")
+            uploadDirty()
+
+            syncPhase = SYNC_PHASE_CHECK_SYNC_STATE
+            Logger.log.info("Checking sync state")
+            if (checkSyncState()) {
+                syncPhase = SYNC_PHASE_LIST_LOCAL
+                Logger.log.info("Listing local resources")
+                listLocal()
+
+                if (Thread.interrupted())
+                    return
+                syncPhase = SYNC_PHASE_LIST_REMOTE
+                Logger.log.info("Listing remote resources")
+                listRemote()
+
+                if (Thread.interrupted())
+                    return
+                syncPhase = SYNC_PHASE_COMPARE_LOCAL_REMOTE
+                Logger.log.info("Comparing local/remote entries")
+                compareLocalRemote()
+
+                syncPhase = SYNC_PHASE_DOWNLOAD_REMOTE
+                Logger.log.info("Downloading remote entries")
+                downloadRemote()
+
+                syncPhase = SYNC_PHASE_POST_PROCESSING
+                Logger.log.info("Post-processing")
+                postProcess()
+
+                syncPhase = SYNC_PHASE_SAVE_SYNC_STATE
+                Logger.log.info("Saving sync state")
+                saveSyncState()
+            } else
+                Logger.log.info("Remote collection didn't change, skipping remote sync")
+
+        } catch(e: IOException) {
+            Logger.log.log(Level.WARNING, "I/O exception during sync, trying again later", e)
+            syncResult.stats.numIoExceptions++
+        } catch(e: ServiceUnavailableException) {
+            Logger.log.log(Level.WARNING, "Got 503 Service unavailable, trying again later", e)
+            syncResult.stats.numIoExceptions++
+            e.retryAfter?.let { retryAfter ->
+                // how many seconds to wait? getTime() returns ms, so divide by 1000
+                syncResult.delayUntil = (retryAfter.time - Date().time) / 1000
+            }
+        } catch(e: Throwable) {
+            val messageString: Int
+
+            when (e) {
+                is UnauthorizedException -> {
+                    Logger.log.log(Level.SEVERE, "Not authorized anymore", e)
+                    messageString = R.string.sync_error_unauthorized
+                    syncResult.stats.numAuthExceptions++
+                }
+                is HttpException, is DavException -> {
+                    Logger.log.log(Level.SEVERE, "HTTP/DAV Exception during sync", e)
+                    messageString = R.string.sync_error_http_dav
+                    syncResult.stats.numParseExceptions++
+                }
+                is CalendarStorageException, is ContactsStorageException -> {
+                    Logger.log.log(Level.SEVERE, "Couldn't access local storage", e)
+                    messageString = R.string.sync_error_local_storage
+                    syncResult.databaseError = true
+                }
+                else -> {
+                    Logger.log.log(Level.SEVERE, "Unknown sync error", e)
+                    messageString = R.string.sync_error
+                    syncResult.stats.numParseExceptions++
+                }
+            }
+
+            val detailsIntent: Intent
+            if (e is UnauthorizedException) {
+                detailsIntent = Intent(context, AccountSettingsActivity::class.java)
+                detailsIntent.putExtra(AccountSettingsActivity.EXTRA_ACCOUNT, account)
+            } else {
+                detailsIntent = Intent(context, DebugInfoActivity::class.java)
+                detailsIntent.putExtra(DebugInfoActivity.KEY_THROWABLE, e)
+                detailsIntent.putExtra(DebugInfoActivity.KEY_ACCOUNT, account)
+                detailsIntent.putExtra(DebugInfoActivity.KEY_AUTHORITY, authority)
+                detailsIntent.putExtra(DebugInfoActivity.KEY_PHASE, syncPhase)
+                currentLocalResource?.let { detailsIntent.putExtra(DebugInfoActivity.KEY_LOCAL_RESOURCE, it.toString()) }
+                currentDavResource?.let { detailsIntent.putExtra(DebugInfoActivity.KEY_REMOTE_RESOURCE, it.toString()) }
+            }
+
+            // to make the PendingIntent unique
+            detailsIntent.data = Uri.parse("uri://${javaClass.name}/$uniqueCollectionId")
+
+            val builder = NotificationCompat.Builder(context)
+            builder .setSmallIcon(R.drawable.ic_error_light)
+                    .setLargeIcon(App.getLauncherBitmap(context))
+                    .setContentTitle(getSyncErrorTitle())
+                    .setContentIntent(PendingIntent.getActivity(context, 0, detailsIntent, PendingIntent.FLAG_CANCEL_CURRENT))
+                    .setCategory(NotificationCompat.CATEGORY_ERROR)
+
+            try {
+                val phases = context.resources.getStringArray(R.array.sync_error_phases)
+                val message = context.getString(messageString, phases[syncPhase])
+                builder.setContentText(message)
+            } catch (ex: IndexOutOfBoundsException) {
+                // should never happen
+            }
+
+            notificationManager.notify(uniqueCollectionId, notificationId(), builder.build())
+        }
+    }
+
+    override fun close() {
+        httpClient.close()
+    }
+
+
+    /** Prepares synchronization (for instance, allocates necessary resources).
+     * @return whether actual synchronization is required / can be made. true = synchronization
+     *         shall be continued, false = synchronization can be skipped */
+    abstract protected fun prepare(): Boolean
+
+    abstract protected fun queryCapabilities()
+
+    /**
+     * Process locally deleted entries (DELETE them on the server as well).
+     * Checks Thread.interrupted() before each request to allow quick sync cancellation.
+     */
+    protected open fun processLocallyDeleted() {
+        // Remove locally deleted entries from server (if they have a name, i.e. if they were uploaded before),
+        // but only if they don't have changed on the server. Then finally remove them from the local address book.
+        val localList = localCollection.getDeleted()
+        for (local in localList) {
+            if (Thread.interrupted())
+                return
+
+            currentLocalResource = local
+
+            val fileName = local.fileName
+            if (fileName != null) {
+                Logger.log.info("$fileName has been deleted locally -> deleting from server")
+
+                val remote = DavResource(httpClient.okHttpClient, collectionURL.newBuilder().addPathSegment(fileName).build())
+                currentDavResource = remote
+                try {
+                    remote.delete(local.eTag)
+                } catch (e: HttpException) {
+                    Logger.log.warning("Couldn't delete $fileName from server; ignoring (may be downloaded again)")
+                }
+            } else
+                Logger.log.info("Removing local record #${local.id} which has been deleted locally and was never uploaded")
+            local.delete()
+            syncResult.stats.numDeletes++
+
+            currentLocalResource = null
+            currentDavResource = null
+        }
+    }
+
+    protected open fun prepareDirty() {
+        // assign file names and UIDs to new contacts so that we can use the file name as an index
+        Logger.log.info("Looking for contacts/groups without file name")
+        for (local in localCollection.getWithoutFileName()) {
+            currentLocalResource = local
+
+            Logger.log.fine("Found local record #${local.id} without file name; generating file name/UID if necessary")
+            local.prepareForUpload()
+
+            currentLocalResource = null
+        }
+    }
+
+    abstract protected fun prepareUpload(resource: LocalResource): RequestBody
+
+    /**
+     * Uploads dirty records to the server, using a PUT request for each record.
+     * Checks Thread.interrupted() before each request to allow quick sync cancellation.
+     */
+    protected fun uploadDirty() {
+        // upload dirty contacts
+        for (local in localCollection.getDirty()) {
+            if (Thread.interrupted())
+                return
+
+            currentLocalResource = local
+            val fileName = local.fileName
+
+            val remote = DavResource(httpClient.okHttpClient, collectionURL.newBuilder().addPathSegment(fileName).build())
+            currentDavResource = remote
+
+            // generate entity to upload (VCard, iCal, whatever)
+            val body = prepareUpload(local)
+
+            try {
+                if (local.eTag == null) {
+                    Logger.log.info("Uploading new record $fileName")
+                    remote.put(body, null, true)
+                } else {
+                    Logger.log.info("Uploading locally modified record $fileName")
+                    remote.put(body, local.eTag, false)
+                }
+            } catch(e: ConflictException) {
+                // we can't interact with the user to resolve the conflict, so we treat 409 like 412
+                Logger.log.log(Level.INFO, "Edit conflict, ignoring", e)
+            } catch(e: PreconditionFailedException) {
+                Logger.log.log(Level.INFO, "Resource has been modified on the server before upload, ignoring", e)
+            }
+
+            val newETag = remote.properties[GetETag.NAME] as GetETag?
+            val eTag: String?
+            if (newETag != null) {
+                eTag = newETag.eTag
+                Logger.log.fine("Received new ETag=$eTag after uploading")
+            } else {
+                Logger.log.fine("Didn't receive new ETag after uploading, setting to null")
+                eTag = null
+            }
+
+            local.clearDirty(eTag)
+
+            currentLocalResource = null
+            currentDavResource = null
+        }
+    }
+
+    /**
+     * Checks the current sync state (e.g. CTag) and whether synchronization from remote is required.
+     * @return <ul>
+     *      <li><code>true</code>   if the remote collection has changed, i.e. synchronization from remote is required</li>
+     *      <li><code>false</code>  if the remote collection hasn't changed</li>
+     * </ul>
+     */
+    protected fun checkSyncState(): Boolean {
+        // check CTag (ignore on manual sync)
+        (davCollection.properties[GetCTag.NAME] as GetCTag?)?.let { remoteCTag = it.cTag }
+
+        val localCTag = if (extras.containsKey(ContentResolver.SYNC_EXTRAS_MANUAL)) {
+            Logger.log.info("Manual sync, ignoring CTag")
+            null
+        } else
+            localCollection.getCTag()
+
+        return if (remoteCTag != null && remoteCTag == localCTag) {
+            Logger.log.info("Remote collection didn't change (CTag=$remoteCTag), no need to query children")
+            false
+        } else
+            true
+    }
+
+    /**
+     * Lists all local resources which should be taken into account for synchronization into {@link #localResources}.
+     */
+    protected fun listLocal() {
+        // fetch list of local contacts and build hash table to index file name
+        val localList = localCollection.getAll()
+        val resources = HashMap<String, LocalResource>(localList.size)
+        for (resource in localList) {
+            Logger.log.fine("Found local resource: ${resource.fileName}")
+            resource.fileName?.let { resources[it] = resource }
+        }
+        localResources = resources
+        Logger.log.info("Found ${localResources.size} local resources")
+    }
+
+    /**
+     * Lists all members of the remote collection which should be taken into account for synchronization into {@link #remoteResources}.
+     */
+    abstract protected fun listRemote()
+
+    /**
+     * Compares {@link #localResources} and {@link #remoteResources} by file name and ETag:
+     * <ul>
+     *     <li>Local resources which are not available in the remote collection (anymore) will be removed.</li>
+     *     <li>Resources whose remote ETag has changed will be added into {@link #toDownload}</li>
+     * </ul>
+     */
+    protected fun compareLocalRemote() {
+        /* check which contacts
+           1. are not present anymore remotely -> delete immediately on local side
+           2. updated remotely -> add to downloadNames
+           3. added remotely  -> add to downloadNames
+         */
+        toDownload.clear()
+        for ((name,local) in localResources) {
+            val remote = remoteResources[name]
+            currentDavResource = remote
+
+            if (remote == null) {
+                Logger.log.info("$name is not on server anymore, deleting")
+                currentLocalResource = local
+                local.delete()
+                syncResult.stats.numDeletes++
+            } else {
+                // contact is still on server, check whether it has been updated remotely
+                val getETag = remote.properties[GetETag.NAME] as GetETag?
+                if (getETag == null || getETag.eTag == null)
+                    throw DavException("Server didn't provide ETag")
+                val localETag = local.eTag
+                val remoteETag = getETag.eTag
+                if (remoteETag == localETag) {
+                    Logger.log.fine("$name has not been changed on server (ETag still $remoteETag)")
+                    syncResult.stats.numSkippedEntries++
+                } else {
+                    Logger.log.info("$name has been changed on server (current ETag=$remoteETag, last known ETag=$localETag)")
+                    toDownload.add(remote)
+                }
+
+                // remote entry has been seen, remove from list
+                remoteResources.remove(name)
+
+                currentDavResource = null
+                currentLocalResource = null
+            }
+        }
+
+        // add all unseen (= remotely added) remote contacts
+        if (remoteResources.isNotEmpty()) {
+            Logger.log.info("New resources have been found on the server: ${remoteResources.keys.joinToString(", ")}")
+            toDownload.addAll(remoteResources.values)
+        }
+    }
+
+    /**
+     * Downloads the remote resources in {@link #toDownload} and stores them locally.
+     * Must check Thread.interrupted() periodically to allow quick sync cancellation.
+     */
+    abstract protected fun downloadRemote()
+
+    /**
+     * For post-processing of entries, for instance assigning groups.
+     */
+    protected open fun postProcess() {}
+
+    protected fun saveSyncState() {
+        /* Save sync state (CTag). It doesn't matter if it has changed during the sync process
+           (for instance, because another client has uploaded changes), because this will simply
+           cause all remote entries to be listed at the next sync. */
+        Logger.log.info("Saving CTag=$remoteCTag")
+        localCollection.setCTag(remoteCTag)
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/syncadapter/TasksSyncAdapterService.java

@@ -1,155 +0,0 @@
-/*
- * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-package at.bitfire.davdroid.syncadapter;
-
-import android.accounts.Account;
-import android.content.AbstractThreadedSyncAdapter;
-import android.content.ContentProviderClient;
-import android.content.ContentResolver;
-import android.content.ContentValues;
-import android.content.Context;
-import android.content.SyncResult;
-import android.database.Cursor;
-import android.database.DatabaseUtils;
-import android.database.sqlite.SQLiteDatabase;
-import android.database.sqlite.SQLiteOpenHelper;
-import android.os.Bundle;
-import android.support.annotation.NonNull;
-import android.support.annotation.Nullable;
-
-import org.dmfs.provider.tasks.TaskContract;
-
-import java.util.LinkedHashMap;
-import java.util.Map;
-import java.util.logging.Level;
-
-import at.bitfire.davdroid.AccountSettings;
-import at.bitfire.davdroid.App;
-import at.bitfire.davdroid.InvalidAccountException;
-import at.bitfire.davdroid.model.CollectionInfo;
-import at.bitfire.davdroid.model.ServiceDB;
-import at.bitfire.davdroid.model.ServiceDB.Collections;
-import at.bitfire.davdroid.model.ServiceDB.Services;
-import at.bitfire.davdroid.resource.LocalTaskList;
-import at.bitfire.ical4android.CalendarStorageException;
-import at.bitfire.ical4android.TaskProvider;
-import lombok.Cleanup;
-
-/**
- * Synchronization manager for CalDAV collections; handles tasks ({@code VTODO}).
- */
-public class TasksSyncAdapterService extends SyncAdapterService {
-
-    @Override
-    protected AbstractThreadedSyncAdapter syncAdapter() {
-        return new SyncAdapter(this);
-    }
-
-
-	private static class SyncAdapter extends SyncAdapterService.SyncAdapter {
-
-        public SyncAdapter(Context context) {
-            super(context);
-        }
-
-        @Override
-        public void onPerformSync(Account account, Bundle extras, String authority, ContentProviderClient providerClient, SyncResult syncResult) {
-            super.onPerformSync(account, extras, authority, providerClient, syncResult);
-
-            try {
-                @Cleanup TaskProvider provider = TaskProvider.acquire(getContext().getContentResolver(), TaskProvider.ProviderName.OpenTasks);
-                if (provider == null)
-                    throw new CalendarStorageException("Couldn't access OpenTasks provider");
-
-                AccountSettings settings = new AccountSettings(getContext(), account);
-                if (!extras.containsKey(ContentResolver.SYNC_EXTRAS_MANUAL) && !checkSyncConditions(settings))
-                    return;
-
-                updateLocalTaskLists(provider, account, settings);
-
-                for (LocalTaskList taskList : (LocalTaskList[])LocalTaskList.find(account, provider, LocalTaskList.Factory.INSTANCE, TaskContract.TaskLists.SYNC_ENABLED + "!=0", null)) {
-                    App.log.info("Synchronizing task list #" + taskList.getId() + " [" + taskList.getSyncId() + "]");
-                    TasksSyncManager syncManager = new TasksSyncManager(getContext(), account, settings, extras, authority, provider, syncResult, taskList);
-                    syncManager.performSync();
-                }
-            } catch (CalendarStorageException e) {
-                App.log.log(Level.SEVERE, "Couldn't enumerate local task lists", e);
-            } catch (InvalidAccountException e) {
-                App.log.log(Level.SEVERE, "Couldn't get account settings", e);
-            }
-
-            App.log.info("Task sync complete");
-        }
-
-        private void updateLocalTaskLists(TaskProvider provider, Account account, AccountSettings settings) throws CalendarStorageException {
-            SQLiteOpenHelper dbHelper = new ServiceDB.OpenHelper(getContext());
-            try {
-                // enumerate remote and local task lists
-                SQLiteDatabase db = dbHelper.getReadableDatabase();
-                Long service = getService(db, account);
-                Map<String, CollectionInfo> remote = remoteTaskLists(db, service);
-                LocalTaskList[] local = (LocalTaskList[])LocalTaskList.find(account, provider, LocalTaskList.Factory.INSTANCE, null, null);
-
-                boolean updateColors = settings.getManageCalendarColors();
-
-                // delete obsolete local task lists
-                for (LocalTaskList list : local) {
-                    String url = list.getSyncId();
-                    if (!remote.containsKey(url)) {
-                        App.log.fine("Deleting obsolete local task list" + url);
-                        list.delete();
-                    } else {
-                        // remote CollectionInfo found for this local collection, update data
-                        CollectionInfo info = remote.get(url);
-                        App.log.fine("Updating local task list " + url + " with " + info);
-                        list.update(info, updateColors);
-                        // we already have a local task list for this remote collection, don't take into consideration anymore
-                        remote.remove(url);
-                    }
-                }
-
-                // create new local task lists
-                for (String url : remote.keySet()) {
-                    CollectionInfo info = remote.get(url);
-                    App.log.info("Adding local task list " + info);
-                    LocalTaskList.create(account, provider, info);
-                }
-            } finally {
-                dbHelper.close();
-            }
-        }
-
-        @Nullable
-        Long getService(@NonNull SQLiteDatabase db, @NonNull Account account) {
-            @Cleanup Cursor c = db.query(Services._TABLE, new String[] { Services.ID },
-                    Services.ACCOUNT_NAME + "=? AND " + Services.SERVICE + "=?", new String[] { account.name, Services.SERVICE_CALDAV }, null, null, null);
-            if (c.moveToNext())
-                return c.getLong(0);
-            else
-                return null;
-        }
-
-        @NonNull
-        private Map<String, CollectionInfo> remoteTaskLists(@NonNull SQLiteDatabase db, Long service) {
-            Map<String, CollectionInfo> collections = new LinkedHashMap<>();
-            if (service != null) {
-                @Cleanup Cursor cursor = db.query(Collections._TABLE, null,
-                        Collections.SERVICE_ID + "=? AND " + Collections.SUPPORTS_VTODO + "!=0 AND " + Collections.SYNC,
-                        new String[] { String.valueOf(service) }, null, null, null);
-                while (cursor.moveToNext()) {
-                    ContentValues values = new ContentValues();
-                    DatabaseUtils.cursorRowToContentValues(cursor, values);
-                    CollectionInfo info = CollectionInfo.fromDB(values);
-                    collections.put(info.url, info);
-                }
-            }
-            return collections;
-        }
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/syncadapter/TasksSyncAdapterService.kt

@@ -0,0 +1,128 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+package at.bitfire.davdroid.syncadapter
+
+import android.accounts.Account
+import android.content.*
+import android.database.DatabaseUtils
+import android.os.Bundle
+import at.bitfire.davdroid.AccountSettings
+import at.bitfire.davdroid.log.Logger
+import at.bitfire.davdroid.model.CollectionInfo
+import at.bitfire.davdroid.model.ServiceDB
+import at.bitfire.davdroid.model.ServiceDB.Collections
+import at.bitfire.davdroid.model.ServiceDB.Services
+import at.bitfire.davdroid.resource.LocalTaskList
+import at.bitfire.davdroid.settings.ISettings
+import at.bitfire.ical4android.AndroidTaskList
+import at.bitfire.ical4android.TaskProvider
+import org.dmfs.provider.tasks.TaskContract
+import java.util.logging.Level
+
+/**
+ * Synchronization manager for CalDAV collections; handles tasks ({@code VTODO}).
+ */
+class TasksSyncAdapterService: SyncAdapterService() {
+
+    override fun syncAdapter() = SyncAdapter(this)
+
+
+	protected class SyncAdapter(
+            context: Context
+    ): SyncAdapterService.SyncAdapter(context) {
+
+        override fun sync(settings: ISettings, account: Account, extras: Bundle, authority: String, provider: ContentProviderClient, syncResult: SyncResult) {
+            try {
+                val taskProvider = TaskProvider.fromProviderClient(provider)
+                val settings = AccountSettings(context, settings, account)
+                /* don't run sync if
+                   - sync conditions (e.g. "sync only in WiFi") are not met AND
+                   - this is is an automatic sync (i.e. manual syncs are run regardless of sync conditions)
+                 */
+                if (!extras.containsKey(ContentResolver.SYNC_EXTRAS_MANUAL) && !checkSyncConditions(settings))
+                    return
+
+                updateLocalTaskLists(taskProvider, account, settings)
+
+                for (taskList in AndroidTaskList.find(account, taskProvider, LocalTaskList.Factory, "${TaskContract.TaskLists.SYNC_ENABLED}!=0", null)) {
+                    Logger.log.info("Synchronizing task list #${taskList.id} [${taskList.syncId}]")
+                    TasksSyncManager(context, account, settings, extras, authority, syncResult, taskProvider, taskList).use {
+                        it.performSync()
+                    }
+                }
+            } catch (e: Exception) {
+                Logger.log.log(Level.SEVERE, "Couldn't sync task lists", e)
+            }
+
+            Logger.log.info("Task sync complete")
+        }
+
+        private fun updateLocalTaskLists(provider: TaskProvider, account: Account, settings: AccountSettings) {
+            ServiceDB.OpenHelper(context).use { dbHelper ->
+                val db = dbHelper.readableDatabase
+
+                fun getService() =
+                        db.query(Services._TABLE, arrayOf(Services.ID),
+                                "${Services.ACCOUNT_NAME}=? AND ${Services.SERVICE}=?",
+                                arrayOf(account.name, Services.SERVICE_CALDAV), null, null, null)?.use { c ->
+                            if (c.moveToNext())
+                                c.getLong(0)
+                            else
+                                null
+                        }
+
+                fun remoteTaskLists(service: Long?): MutableMap<String, CollectionInfo> {
+                    val collections = mutableMapOf<String, CollectionInfo>()
+                    service?.let {
+                        db.query(Collections._TABLE, null,
+                                "${Collections.SERVICE_ID}=? AND ${Collections.SUPPORTS_VTODO}!=0 AND ${Collections.SYNC}",
+                                arrayOf(service.toString()), null, null, null)?.use { cursor ->
+                            while (cursor.moveToNext()) {
+                                val values = ContentValues(cursor.columnCount)
+                                DatabaseUtils.cursorRowToContentValues(cursor, values)
+                                val info = CollectionInfo(values)
+                                collections[info.url] = info
+                            }
+                        }
+                    }
+                    return collections
+                }
+
+                // enumerate remote and local task lists
+                val service = getService()
+                val remote = remoteTaskLists(service)
+
+                // delete/update local task lists
+                val updateColors = settings.getManageCalendarColors()
+
+                for (list in AndroidTaskList.find(account, provider, LocalTaskList.Factory, null, null))
+                    list.syncId?.let { url ->
+                        val info = remote[url]
+                        if (info == null) {
+                            Logger.log.fine("Deleting obsolete local task list $url")
+                            list.delete()
+                        } else {
+                            // remote CollectionInfo found for this local collection, update data
+                            Logger.log.log(Level.FINE, "Updating local task list $url", info)
+                            list.update(info, updateColors)
+                            // we already have a local task list for this remote collection, don't take into consideration anymore
+                            remote -= url
+                        }
+                    }
+
+                // create new local task lists
+                for ((_,info) in remote) {
+                    Logger.log.log(Level.INFO, "Adding local task list", info)
+                    LocalTaskList.create(account, provider, info)
+                }
+            }
+        }
+
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/syncadapter/TasksSyncManager.java

@@ -1,233 +0,0 @@
-/*
- * Copyright © 2013 – 2015 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.syncadapter;
-
-import android.accounts.Account;
-import android.content.Context;
-import android.content.SyncResult;
-import android.os.Bundle;
-
-import org.apache.commons.codec.Charsets;
-import org.apache.commons.lang3.StringUtils;
-
-import java.io.ByteArrayInputStream;
-import java.io.ByteArrayOutputStream;
-import java.io.IOException;
-import java.io.InputStream;
-import java.nio.charset.Charset;
-import java.util.HashMap;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.logging.Level;
-
-import at.bitfire.dav4android.DavCalendar;
-import at.bitfire.dav4android.DavResource;
-import at.bitfire.dav4android.exception.DavException;
-import at.bitfire.dav4android.exception.HttpException;
-import at.bitfire.dav4android.property.CalendarData;
-import at.bitfire.dav4android.property.GetCTag;
-import at.bitfire.dav4android.property.GetContentType;
-import at.bitfire.dav4android.property.GetETag;
-import at.bitfire.davdroid.AccountSettings;
-import at.bitfire.davdroid.App;
-import at.bitfire.davdroid.ArrayUtils;
-import at.bitfire.davdroid.Constants;
-import at.bitfire.davdroid.InvalidAccountException;
-import at.bitfire.davdroid.R;
-import at.bitfire.davdroid.resource.LocalResource;
-import at.bitfire.davdroid.resource.LocalTask;
-import at.bitfire.davdroid.resource.LocalTaskList;
-import at.bitfire.ical4android.CalendarStorageException;
-import at.bitfire.ical4android.InvalidCalendarException;
-import at.bitfire.ical4android.Task;
-import at.bitfire.ical4android.TaskProvider;
-import lombok.Cleanup;
-import okhttp3.HttpUrl;
-import okhttp3.MediaType;
-import okhttp3.RequestBody;
-import okhttp3.ResponseBody;
-
-public class TasksSyncManager extends SyncManager {
-
-    protected static final int MAX_MULTIGET = 30;
-
-    final protected TaskProvider provider;
-
-
-    public TasksSyncManager(Context context, Account account, AccountSettings settings, Bundle extras, String authority, TaskProvider provider, SyncResult result, LocalTaskList taskList) throws InvalidAccountException {
-        super(context, account, settings, extras, authority, result, "taskList/" + taskList.getId());
-        this.provider = provider;
-        localCollection = taskList;
-    }
-
-    @Override
-    protected int notificationId() {
-        return Constants.NOTIFICATION_TASK_SYNC;
-    }
-
-    @Override
-    protected String getSyncErrorTitle() {
-        return context.getString(R.string.sync_error_tasks, account.name);
-    }
-
-
-    @Override
-    protected boolean prepare() {
-        collectionURL = HttpUrl.parse(localTaskList().getSyncId());
-        davCollection = new DavCalendar(httpClient, collectionURL);
-        return true;
-    }
-
-    @Override
-    protected void queryCapabilities() throws DavException, IOException, HttpException {
-        davCollection.propfind(0, GetCTag.NAME);
-    }
-
-    @Override
-    protected RequestBody prepareUpload(LocalResource resource) throws IOException, CalendarStorageException {
-        LocalTask local = (LocalTask)resource;
-        App.log.log(Level.FINE, "Preparing upload of task " + local.getFileName(), local.getTask() );
-
-        ByteArrayOutputStream os = new ByteArrayOutputStream();
-        local.getTask().write(os);
-
-        return RequestBody.create(
-                DavCalendar.MIME_ICALENDAR,
-                os.toByteArray()
-        );
-    }
-
-    @Override
-    protected void listRemote() throws IOException, HttpException, DavException {
-        // fetch list of remote VTODOs and build hash table to index file name
-        final DavCalendar calendar = davCalendar();
-        currentDavResource = calendar;
-        calendar.calendarQuery("VTODO", null, null);
-
-        remoteResources = new HashMap<>(davCollection.members.size());
-        for (DavResource vCard : davCollection.members) {
-            String fileName = vCard.fileName();
-            App.log.fine("Found remote VTODO: " + fileName);
-            remoteResources.put(fileName, vCard);
-        }
-
-        currentDavResource = null;
-    }
-
-    @Override
-    protected void downloadRemote() throws IOException, HttpException, DavException, CalendarStorageException {
-        App.log.info("Downloading " + toDownload.size() + " tasks (" + MAX_MULTIGET + " at once)");
-
-        // download new/updated iCalendars from server
-        for (DavResource[] bunch : ArrayUtils.partition(toDownload.toArray(new DavResource[toDownload.size()]), MAX_MULTIGET)) {
-            if (Thread.interrupted())
-                return;
-
-            App.log.info("Downloading " + StringUtils.join(bunch, ", "));
-
-            if (bunch.length == 1) {
-                // only one contact, use GET
-                final DavResource remote = bunch[0];
-                currentDavResource = remote;
-
-                ResponseBody body = remote.get("text/calendar");
-
-                // CalDAV servers MUST return ETag on GET [https://tools.ietf.org/html/rfc4791#section-5.3.4]
-                GetETag eTag = (GetETag)remote.properties.get(GetETag.NAME);
-                if (eTag == null || StringUtils.isEmpty(eTag.eTag))
-                    throw new DavException("Received CalDAV GET response without ETag for " + remote.location);
-
-                Charset charset = Charsets.UTF_8;
-                MediaType contentType = body.contentType();
-                if (contentType != null)
-                    charset = contentType.charset(Charsets.UTF_8);
-
-                @Cleanup InputStream stream = body.byteStream();
-                processVTodo(remote.fileName(), eTag.eTag, stream, charset);
-
-            } else {
-                // multiple contacts, use multi-get
-                List<HttpUrl> urls = new LinkedList<>();
-                for (DavResource remote : bunch)
-                    urls.add(remote.location);
-
-                final DavCalendar calendar = davCalendar();
-                currentDavResource = calendar;
-                calendar.multiget(urls.toArray(new HttpUrl[urls.size()]));
-
-                // process multiget results
-                for (final DavResource remote : davCollection.members) {
-                    currentDavResource = remote;
-
-                    String eTag;
-                    GetETag getETag = (GetETag)remote.properties.get(GetETag.NAME);
-                    if (getETag != null)
-                        eTag = getETag.eTag;
-                    else
-                        throw new DavException("Received multi-get response without ETag");
-
-                    Charset charset = Charsets.UTF_8;
-                    GetContentType getContentType = (GetContentType)remote.properties.get(GetContentType.NAME);
-                    if (getContentType != null && getContentType.type != null) {
-                        MediaType type = MediaType.parse(getContentType.type);
-                        if (type != null)
-                            charset = type.charset(Charsets.UTF_8);
-                    }
-
-                    CalendarData calendarData = (CalendarData)remote.properties.get(CalendarData.NAME);
-                    if (calendarData == null || calendarData.iCalendar == null)
-                        throw new DavException("Received multi-get response without address data");
-
-                    @Cleanup InputStream stream = new ByteArrayInputStream(calendarData.iCalendar.getBytes());
-                    processVTodo(remote.fileName(), eTag, stream, charset);
-                }
-            }
-
-            currentDavResource = null;
-        }
-    }
-
-
-    // helpers
-
-    private LocalTaskList localTaskList() { return ((LocalTaskList)localCollection); }
-    private DavCalendar davCalendar() { return (DavCalendar)davCollection; }
-
-    private void processVTodo(String fileName, String eTag, InputStream stream, Charset charset) throws IOException, CalendarStorageException {
-        Task[] tasks;
-        try {
-            tasks = Task.fromStream(stream, charset);
-        } catch (InvalidCalendarException e) {
-            App.log.log(Level.SEVERE, "Received invalid iCalendar, ignoring", e);
-            return;
-        }
-
-        if (tasks.length == 1) {
-            Task newData = tasks[0];
-
-            // update local task, if it exists
-            LocalTask localTask = (LocalTask)localResources.get(fileName);
-            currentLocalResource = localTask;
-            if (localTask != null) {
-                App.log.info("Updating " + fileName + " in local tasklist");
-                localTask.setETag(eTag);
-                localTask.update(newData);
-                syncResult.stats.numUpdates++;
-            } else {
-                App.log.info("Adding " + fileName + " to local task list");
-                localTask = new LocalTask(localTaskList(), newData, fileName, eTag);
-                currentLocalResource = localTask;
-                localTask.add();
-                syncResult.stats.numInserts++;
-            }
-        } else
-            App.log.severe("Received VCALENDAR with not exactly one VTODO; ignoring " + fileName);
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/syncadapter/TasksSyncManager.kt

@@ -0,0 +1,192 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.syncadapter
+
+import android.accounts.Account
+import android.content.Context
+import android.content.SyncResult
+import android.os.Bundle
+import at.bitfire.dav4android.DavCalendar
+import at.bitfire.dav4android.DavResource
+import at.bitfire.dav4android.exception.DavException
+import at.bitfire.dav4android.property.CalendarData
+import at.bitfire.dav4android.property.GetCTag
+import at.bitfire.dav4android.property.GetETag
+import at.bitfire.davdroid.AccountSettings
+import at.bitfire.davdroid.Constants
+import at.bitfire.davdroid.R
+import at.bitfire.davdroid.log.Logger
+import at.bitfire.davdroid.resource.LocalResource
+import at.bitfire.davdroid.resource.LocalTask
+import at.bitfire.davdroid.resource.LocalTaskList
+import at.bitfire.ical4android.InvalidCalendarException
+import at.bitfire.ical4android.Task
+import at.bitfire.ical4android.TaskProvider
+import okhttp3.HttpUrl
+import okhttp3.RequestBody
+import org.apache.commons.collections4.ListUtils
+import java.io.ByteArrayOutputStream
+import java.io.Reader
+import java.io.StringReader
+import java.util.*
+import java.util.logging.Level
+
+class TasksSyncManager(
+        context: Context,
+        account: Account,
+        settings: AccountSettings,
+        extras: Bundle,
+        authority: String,
+        syncResult: SyncResult,
+        val provider: TaskProvider,
+        val localTaskList: LocalTaskList
+): SyncManager(context, account, settings, extras, authority, syncResult, "taskList/${localTaskList.id}") {
+
+    val MAX_MULTIGET = 30
+
+
+    init {
+        localCollection = localTaskList
+    }
+
+    override fun notificationId() = Constants.NOTIFICATION_TASK_SYNC
+
+    override fun getSyncErrorTitle() = context.getString(R.string.sync_error_tasks, account.name)!!
+
+
+    override fun prepare(): Boolean {
+        collectionURL = HttpUrl.parse(localTaskList.syncId ?: return false) ?: return false
+        davCollection = DavCalendar(httpClient.okHttpClient, collectionURL)
+        return true
+    }
+
+    override fun queryCapabilities() {
+        davCollection.propfind(0, GetCTag.NAME)
+    }
+
+    override fun prepareUpload(resource: LocalResource): RequestBody {
+        if (resource is LocalTask) {
+            val task = requireNotNull(resource.task)
+            Logger.log.log(Level.FINE, "Preparing upload of task ${resource.fileName}", task)
+
+            val os = ByteArrayOutputStream()
+            task.write(os)
+
+            return RequestBody.create(
+                    DavCalendar.MIME_ICALENDAR,
+                    os.toByteArray()
+            )
+        } else
+            throw IllegalArgumentException("resource must be a LocalTask")
+    }
+
+    override fun listRemote() {
+        // fetch list of remote VTODOs and build hash table to index file name
+        val calendar = davCalendar()
+        currentDavResource = calendar
+        calendar.calendarQuery("VTODO", null, null)
+
+        remoteResources = HashMap<String, DavResource>(davCollection.members.size)
+        for (vCard in davCollection.members) {
+            val fileName = vCard.fileName()
+            Logger.log.fine("Found remote VTODO: $fileName")
+            remoteResources[fileName] = vCard
+        }
+
+        currentDavResource = null
+    }
+
+    override fun downloadRemote() {
+        Logger.log.info("Downloading ${toDownload.size} tasks ($MAX_MULTIGET at once)")
+
+        // download new/updated iCalendars from server
+        for (bunch in ListUtils.partition(toDownload.toList(), MAX_MULTIGET)) {
+            if (Thread.interrupted())
+                return
+
+            Logger.log.info("Downloading ${bunch.joinToString(", ")}")
+
+            if (bunch.size == 1) {
+                // only one contact, use GET
+                val remote = bunch.first()
+                currentDavResource = remote
+
+                val body = remote.get("text/calendar")
+
+                // CalDAV servers MUST return ETag on GET [https://tools.ietf.org/html/rfc4791#section-5.3.4]
+                val eTag = remote.properties[GetETag.NAME] as GetETag?
+                if (eTag == null || eTag.eTag.isNullOrEmpty())
+                    throw DavException("Received CalDAV GET response without ETag for ${remote.location}")
+
+                body.charStream().use { reader ->
+                    processVTodo(remote.fileName(), eTag.eTag!!, reader)
+                }
+
+            } else {
+                // multiple contacts, use multi-get
+                val calendar = davCalendar()
+                currentDavResource = calendar
+                calendar.multiget(bunch.map { it.location })
+
+                // process multiget results
+                for (remote in davCollection.members) {
+                    currentDavResource = remote
+
+                    val eTag = (remote.properties[GetETag.NAME] as GetETag?)?.eTag
+                            ?: throw DavException("Received multi-get response without ETag")
+
+                    val calendarData = remote.properties[CalendarData.NAME] as CalendarData?
+                    val iCalendar = calendarData?.iCalendar
+                            ?: throw DavException("Received multi-get response without task data")
+
+                    processVTodo(remote.fileName(), eTag, StringReader(iCalendar))
+                }
+            }
+
+            currentDavResource = null
+        }
+    }
+
+
+    // helpers
+
+    private fun davCalendar() = davCollection as DavCalendar
+
+    private fun processVTodo(fileName: String, eTag: String, reader: Reader) {
+        val tasks: List<Task>
+        try {
+            tasks = Task.fromReader(reader)
+        } catch (e: InvalidCalendarException) {
+            Logger.log.log(Level.SEVERE, "Received invalid iCalendar, ignoring", e)
+            return
+        }
+
+        if (tasks.size == 1) {
+            val newData = tasks.first()
+
+            // update local task, if it exists
+            val localTask = localResources[fileName] as LocalTask?
+            currentLocalResource = localTask
+            if (localTask != null) {
+                Logger.log.info("Updating $fileName in local tasklist")
+                localTask.eTag = eTag
+                localTask.update(newData)
+                syncResult.stats.numUpdates++
+            } else {
+                Logger.log.info("Adding $fileName to local task list")
+                val newTask = LocalTask(localTaskList, newData, fileName, eTag)
+                currentLocalResource = newTask
+                newTask.add()
+                syncResult.stats.numInserts++
+            }
+        } else
+            Logger.log.severe("Received VCALENDAR with not exactly one VTODO; ignoring $fileName")
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/ui/AboutActivity.java

@@ -1,217 +0,0 @@
-/*
- * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.ui;
-
-import android.annotation.SuppressLint;
-import android.content.Context;
-import android.os.Bundle;
-import android.support.annotation.Nullable;
-import android.support.design.widget.TabLayout;
-import android.support.v4.app.Fragment;
-import android.support.v4.app.FragmentManager;
-import android.support.v4.app.FragmentPagerAdapter;
-import android.support.v4.app.LoaderManager;
-import android.support.v4.content.AsyncTaskLoader;
-import android.support.v4.content.Loader;
-import android.support.v4.view.ViewPager;
-import android.support.v7.app.AppCompatActivity;
-import android.support.v7.widget.Toolbar;
-import android.text.Html;
-import android.text.Spanned;
-import android.text.util.Linkify;
-import android.view.LayoutInflater;
-import android.view.View;
-import android.view.ViewGroup;
-import android.widget.TextView;
-
-import org.apache.commons.io.IOUtils;
-import org.apache.commons.lang3.time.DateFormatUtils;
-
-import java.io.IOException;
-import java.io.InputStream;
-import java.util.logging.Level;
-
-import at.bitfire.davdroid.App;
-import at.bitfire.davdroid.BuildConfig;
-import at.bitfire.davdroid.R;
-import ezvcard.Ezvcard;
-import lombok.Cleanup;
-import lombok.RequiredArgsConstructor;
-
-public class AboutActivity extends AppCompatActivity {
-
-    @Override
-    protected void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        setContentView(R.layout.activity_about);
-
-        setSupportActionBar((Toolbar)findViewById(R.id.toolbar));
-        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
-
-        ViewPager viewPager = (ViewPager)findViewById(R.id.viewpager);
-        viewPager.setAdapter(new TabsAdapter(getSupportFragmentManager()));
-
-        TabLayout tabLayout = (TabLayout)findViewById(R.id.tabs);
-        tabLayout.setupWithViewPager(viewPager);
-    }
-
-
-    @RequiredArgsConstructor
-    private static class ComponentInfo {
-        final String title, version, website, copyright;
-        final int licenseInfo;
-        final String licenseTextFile;
-    }
-
-    private final static ComponentInfo components[] = {
-            new ComponentInfo(
-                    "DAVdroid", BuildConfig.VERSION_NAME, "https://davdroid.bitfire.at",
-                    DateFormatUtils.format(BuildConfig.buildTime, "yyyy") + " Ricki Hirner, Bernhard Stockmann (bitfire web engineering)",
-                    R.string.about_license_info_no_warranty, "gpl-3.0-standalone.html"
-            ), new ComponentInfo(
-                    "AmbilWarna", null, "https://github.com/yukuku/ambilwarna",
-                    "Yuku", R.string.about_license_info_no_warranty, "apache2.html"
-            ), new ComponentInfo(
-                    "Apache Commons", null, "http://commons.apache.org/",
-                    "Apache Software Foundation", R.string.about_license_info_no_warranty, "apache2.html"
-            ), new ComponentInfo(
-                    "dnsjava", null, "http://dnsjava.org/",
-                    "Brian Wellington", R.string.about_license_info_no_warranty, "bsd.html"
-            ), new ComponentInfo(
-                    "ez-vcard", Ezvcard.VERSION, "https://github.com/mangstadt/ez-vcard",
-                    "Michael Angstadt", R.string.about_license_info_no_warranty, "bsd.html"
-            ), new ComponentInfo(
-                    "ical4j", "2.x", "https://ical4j.github.io/",
-                    "Ben Fortuna", R.string.about_license_info_no_warranty, "bsd-3clause.html"
-            ), new ComponentInfo(
-                    "OkHttp", null, "https://square.github.io/okhttp/",
-                    "Square, Inc.", R.string.about_license_info_no_warranty, "apache2.html"
-            ), new ComponentInfo(
-                    "Project Lombok", null, "https://projectlombok.org/",
-                    "The Project Lombok Authors", R.string.about_license_info_no_warranty, "mit.html"
-            )
-    };
-
-
-    private static class TabsAdapter extends FragmentPagerAdapter {
-        public TabsAdapter(FragmentManager fm) {
-            super(fm);
-        }
-
-        @Override
-        public int getCount() {
-            return components.length;
-        }
-
-        @Override
-        public CharSequence getPageTitle(int position) {
-            return components[position].title;
-        }
-
-        @Override
-        public Fragment getItem(int position) {
-            return ComponentFragment.instantiate(position);
-        }
-    }
-
-    public static class ComponentFragment extends Fragment implements LoaderManager.LoaderCallbacks<Spanned> {
-        private static final String
-                KEY_POSITION = "position",
-                KEY_FILE_NAME = "fileName";
-
-        public static ComponentFragment instantiate(int position) {
-            ComponentFragment frag = new ComponentFragment();
-            Bundle args = new Bundle(1);
-            args.putInt(KEY_POSITION, position);
-            frag.setArguments(args);
-            return frag;
-        }
-
-        @Nullable
-        @Override
-        @SuppressLint("SetTextI18n")
-        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
-            ComponentInfo info = components[getArguments().getInt(KEY_POSITION)];
-
-            View v = inflater.inflate(R.layout.about_component, container, false);
-
-            TextView tv = (TextView)v.findViewById(R.id.title);
-            tv.setText(info.title + (info.version != null ? (" " + info.version) : ""));
-
-            tv = (TextView)v.findViewById(R.id.website);
-            tv.setAutoLinkMask(Linkify.WEB_URLS);
-            tv.setText(info.website);
-
-            tv = (TextView)v.findViewById(R.id.copyright);
-            tv.setText("© " + info.copyright);
-
-            tv = (TextView)v.findViewById(R.id.license_info);
-            tv.setText(info.licenseInfo);
-
-            // load and format license text
-            Bundle args = new Bundle(1);
-            args.putString(KEY_FILE_NAME, info.licenseTextFile);
-            getLoaderManager().initLoader(0, args, this);
-
-            return v;
-        }
-
-        @Override
-        public Loader<Spanned> onCreateLoader(int id, Bundle args) {
-            return new LicenseLoader(getContext(), args.getString(KEY_FILE_NAME));
-        }
-
-        @Override
-        public void onLoadFinished(Loader<Spanned> loader, Spanned license) {
-            if (getView() != null) {
-                TextView tv = (TextView)getView().findViewById(R.id.license_text);
-                if (tv != null) {
-                    tv.setAutoLinkMask(Linkify.EMAIL_ADDRESSES | Linkify.WEB_URLS);
-                    tv.setText(license);
-                }
-            }
-        }
-
-        @Override
-        public void onLoaderReset(Loader<Spanned> loader) {
-        }
-    }
-
-    private static class LicenseLoader extends AsyncTaskLoader<Spanned> {
-        final String fileName;
-        Spanned content;
-
-        LicenseLoader(Context context, String fileName) {
-            super(context);
-            this.fileName = fileName;
-        }
-
-        @Override
-        protected void onStartLoading() {
-            if (content == null)
-                forceLoad();
-            else
-                deliverResult(content);
-        }
-
-        @Override
-        public Spanned loadInBackground() {
-            App.log.fine("Loading license file " + fileName);
-            try {
-                @Cleanup InputStream is = getContext().getResources().getAssets().open(fileName);
-                byte[] raw = IOUtils.toByteArray(is);
-                return content = Html.fromHtml(new String(raw));
-            } catch (IOException e) {
-                App.log.log(Level.SEVERE, "Couldn't read license file", e);
-                return null;
-            }
-        }
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/ui/AboutActivity.kt

@@ -0,0 +1,219 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.ui
+
+import android.annotation.SuppressLint
+import android.content.Context
+import android.os.Bundle
+import android.support.v4.app.Fragment
+import android.support.v4.app.FragmentManager
+import android.support.v4.app.FragmentPagerAdapter
+import android.support.v4.app.LoaderManager
+import android.support.v4.content.AsyncTaskLoader
+import android.support.v4.content.Loader
+import android.support.v7.app.AppCompatActivity
+import android.text.Html
+import android.text.Spanned
+import android.text.util.Linkify
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import at.bitfire.davdroid.BuildConfig
+import at.bitfire.davdroid.R
+import at.bitfire.davdroid.log.Logger
+import ezvcard.Ezvcard
+import kotlinx.android.synthetic.main.about_component.view.*
+import kotlinx.android.synthetic.main.activity_about.*
+import org.apache.commons.io.IOUtils
+import java.io.IOException
+import java.util.*
+import java.util.logging.Level
+
+class AboutActivity: AppCompatActivity() {
+
+    private class ComponentInfo(
+            val title: String?,
+            val version: String?,
+            val website: String,
+            val copyright: String,
+            val licenseInfo: Int?,
+            val licenseTextFile: String?
+    )
+
+    private lateinit var components: Array<ComponentInfo>
+
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+
+        components = arrayOf(
+            ComponentInfo(
+                    null, BuildConfig.VERSION_NAME, getString(R.string.homepage_url),
+                    "Ricki Hirner, Bernhard Stockmann (bitfire web engineering)",
+                    null, null
+            ), ComponentInfo(
+                    "AmbilWarna", null, "https://github.com/yukuku/ambilwarna",
+                    "Yuku", R.string.about_license_info_no_warranty, "apache2.html"
+            ), ComponentInfo(
+                    "Apache Commons", null, "http://commons.apache.org/",
+                    "Apache Software Foundation", R.string.about_license_info_no_warranty, "apache2.html"
+            ), ComponentInfo(
+                    "dnsjava", null, "http://dnsjava.org/",
+                    "Brian Wellington", R.string.about_license_info_no_warranty, "bsd.html"
+            ), ComponentInfo(
+                    "ez-vcard", Ezvcard.VERSION, "https://github.com/mangstadt/ez-vcard",
+                    "Michael Angstadt", R.string.about_license_info_no_warranty, "bsd.html"
+            ), ComponentInfo(
+                    "ical4j", "2.x", "https://ical4j.github.io/",
+                    "Ben Fortuna", R.string.about_license_info_no_warranty, "bsd-3clause.html"
+            ), ComponentInfo(
+                    "OkHttp", null, "https://square.github.io/okhttp/",
+                    "Square, Inc.", R.string.about_license_info_no_warranty, "apache2.html"
+            ), ComponentInfo(
+                    "Project Lombok", null, "https://projectlombok.org/",
+                    "The Project Lombok Authors", R.string.about_license_info_no_warranty, "mit.html"
+            )
+        )
+
+        setContentView(R.layout.activity_about)
+
+        setSupportActionBar(toolbar)
+        supportActionBar?.setDisplayHomeAsUpEnabled(true)
+
+        viewpager.adapter = TabsAdapter(supportFragmentManager)
+        tabs.setupWithViewPager(viewpager)
+    }
+
+
+    private inner class TabsAdapter(
+            fm: FragmentManager
+    ): FragmentPagerAdapter(fm) {
+
+        override fun getCount() = components.size
+
+        override fun getPageTitle(position: Int) =
+                components[position].title ?: getString(R.string.app_name)!!
+
+        override fun getItem(position: Int) = ComponentFragment.instantiate(position)
+    }
+
+
+    class ComponentFragment: Fragment(), LoaderManager.LoaderCallbacks<Spanned> {
+
+        companion object {
+            val KEY_POSITION = "position"
+            val KEY_FILE_NAME = "fileName"
+
+            fun instantiate(position: Int): ComponentFragment {
+                val frag = ComponentFragment()
+                val args = Bundle(1)
+                args.putInt(KEY_POSITION, position)
+                frag.arguments = args
+                return frag
+            }
+        }
+
+        private val licenseFragmentLoader = ServiceLoader.load(ILicenseFragment::class.java)!!.firstOrNull()
+
+
+        @SuppressLint("SetTextI18n")
+        override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
+            val info = (activity as AboutActivity).components[arguments.getInt(KEY_POSITION)]
+
+            val v = inflater.inflate(R.layout.about_component, container, false)
+
+            var title = info.title ?: getString(R.string.app_name)
+            info.version?.let { title += " ${info.version}" }
+            v.title.text = title
+
+            v.website.autoLinkMask = Linkify.WEB_URLS
+            v.website.text = info.website
+
+            v.copyright.text = "© ${info.copyright}"
+
+            if (info.licenseInfo == null && info.licenseTextFile == null) {
+                // No license text, so this must be the app's tab. Show the license fragment here, if available.
+                licenseFragmentLoader?.let { factory ->
+                    fragmentManager.beginTransaction()
+                            .add(R.id.license_fragment, factory.getFragment())
+                            .commit()
+                }
+                v.license_terms.visibility = View.GONE
+
+            } else {
+                // show license info
+                if (info.licenseInfo == null)
+                    v.license_info.visibility = View.GONE
+                else
+                    v.license_info.setText(info.licenseInfo)
+
+                // load and format license text
+                if (info.licenseTextFile == null) {
+                    v.license_header.visibility = View.GONE
+                    v.license_text.visibility = View.GONE
+                } else {
+                    val args = Bundle(1)
+                    args.putString(KEY_FILE_NAME, info.licenseTextFile)
+                    loaderManager.initLoader(0, args, this)
+                }
+            }
+
+
+            return v
+        }
+
+        override fun onCreateLoader(id: Int, args: Bundle) =
+                LicenseLoader(context, args.getString(KEY_FILE_NAME))
+
+        override fun onLoadFinished(loader: Loader<Spanned>, license: Spanned?) {
+            view?.let { v ->
+                v.license_text.autoLinkMask = Linkify.EMAIL_ADDRESSES or Linkify.WEB_URLS
+                v.license_text.text = license
+            }
+        }
+
+        override fun onLoaderReset(loader: Loader<Spanned>) {}
+    }
+
+    class LicenseLoader(
+            context: Context,
+            val fileName: String
+    ): AsyncTaskLoader<Spanned>(context) {
+
+        var content: Spanned? = null
+
+        override fun onStartLoading() {
+            if (content == null)
+                forceLoad()
+            else
+                deliverResult(content)
+        }
+
+        override fun loadInBackground(): Spanned? {
+            Logger.log.fine("Loading license file $fileName")
+            try {
+                context.resources.assets.open(fileName).use {
+                    content = Html.fromHtml(IOUtils.toString(it, Charsets.UTF_8))
+                    return content
+                }
+            } catch(e: IOException) {
+                Logger.log.log(Level.SEVERE, "Couldn't read license file", e)
+                return null
+            }
+        }
+    }
+
+
+    interface ILicenseFragment {
+
+        fun getFragment(): Fragment
+
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/ui/AccountActivity.java

@@ -1,688 +0,0 @@
-/*
- * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.ui;
-
-import android.accounts.Account;
-import android.accounts.AccountManager;
-import android.accounts.AccountManagerCallback;
-import android.accounts.AccountManagerFuture;
-import android.accounts.AuthenticatorException;
-import android.accounts.OperationCanceledException;
-import android.app.Dialog;
-import android.app.LoaderManager;
-import android.content.AsyncTaskLoader;
-import android.content.ComponentName;
-import android.content.ContentResolver;
-import android.content.ContentValues;
-import android.content.Context;
-import android.content.DialogInterface;
-import android.content.Intent;
-import android.content.Loader;
-import android.content.ServiceConnection;
-import android.content.SyncStatusObserver;
-import android.database.Cursor;
-import android.database.DatabaseUtils;
-import android.database.sqlite.SQLiteDatabase;
-import android.graphics.drawable.Drawable;
-import android.os.Build;
-import android.os.Bundle;
-import android.os.IBinder;
-import android.os.RemoteException;
-import android.provider.CalendarContract;
-import android.provider.ContactsContract;
-import android.support.annotation.NonNull;
-import android.support.design.widget.Snackbar;
-import android.support.v4.app.DialogFragment;
-import android.support.v7.app.AlertDialog;
-import android.support.v7.app.AppCompatActivity;
-import android.support.v7.widget.CardView;
-import android.support.v7.widget.Toolbar;
-import android.text.TextUtils;
-import android.view.LayoutInflater;
-import android.view.Menu;
-import android.view.MenuItem;
-import android.view.View;
-import android.view.ViewGroup;
-import android.widget.AbsListView;
-import android.widget.AdapterView;
-import android.widget.ArrayAdapter;
-import android.widget.CheckBox;
-import android.widget.EditText;
-import android.widget.ListView;
-import android.widget.PopupMenu;
-import android.widget.ProgressBar;
-import android.widget.RadioButton;
-import android.widget.TextView;
-
-import org.apache.commons.lang3.BooleanUtils;
-
-import java.io.IOException;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.logging.Level;
-
-import at.bitfire.cert4android.CustomCertManager;
-import at.bitfire.davdroid.App;
-import at.bitfire.davdroid.DavService;
-import at.bitfire.davdroid.R;
-import at.bitfire.davdroid.model.CollectionInfo;
-import at.bitfire.davdroid.model.ServiceDB;
-import at.bitfire.davdroid.model.ServiceDB.Collections;
-import at.bitfire.davdroid.model.ServiceDB.OpenHelper;
-import at.bitfire.davdroid.model.ServiceDB.Services;
-import at.bitfire.davdroid.resource.LocalAddressBook;
-import at.bitfire.davdroid.resource.LocalTaskList;
-import at.bitfire.ical4android.TaskProvider;
-import lombok.Cleanup;
-
-import static android.content.ContentResolver.SYNC_OBSERVER_TYPE_ACTIVE;
-
-public class AccountActivity extends AppCompatActivity implements Toolbar.OnMenuItemClickListener, PopupMenu.OnMenuItemClickListener, LoaderManager.LoaderCallbacks<AccountActivity.AccountInfo> {
-    public static final String EXTRA_ACCOUNT = "account";
-
-    private Account account;
-    private AccountInfo accountInfo;
-
-    ListView listCalDAV, listCardDAV;
-    Toolbar tbCardDAV, tbCalDAV;
-
-    @Override
-    protected void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-
-        account = getIntent().getParcelableExtra(EXTRA_ACCOUNT);
-        setTitle(account.name);
-
-        setContentView(R.layout.activity_account);
-
-        Drawable icMenu = Build.VERSION.SDK_INT >= 21 ? getDrawable(R.drawable.ic_menu_light) :
-                getResources().getDrawable(R.drawable.ic_menu_light);
-
-        // CardDAV toolbar
-        tbCardDAV = (Toolbar)findViewById(R.id.carddav_menu);
-        tbCardDAV.setOverflowIcon(icMenu);
-        tbCardDAV.inflateMenu(R.menu.carddav_actions);
-        tbCardDAV.setOnMenuItemClickListener(this);
-
-        // CalDAV toolbar
-        tbCalDAV = (Toolbar)findViewById(R.id.caldav_menu);
-        tbCalDAV.setOverflowIcon(icMenu);
-        tbCalDAV.inflateMenu(R.menu.caldav_actions);
-        tbCalDAV.setOnMenuItemClickListener(this);
-
-        // load CardDAV/CalDAV collections
-        getLoaderManager().initLoader(0, getIntent().getExtras(), this);
-    }
-
-    @Override
-    protected void onPause() {
-        super.onPause();
-        CustomCertManager certManager = ((App)getApplicationContext()).getCertManager();
-        if (certManager != null)
-            certManager.appInForeground = false;
-    }
-
-    @Override
-    protected void onResume() {
-        super.onResume();
-        CustomCertManager certManager = ((App)getApplicationContext()).getCertManager();
-        if (certManager != null)
-            certManager.appInForeground = true;
-    }
-
-    @Override
-    public boolean onCreateOptionsMenu(Menu menu) {
-        getMenuInflater().inflate(R.menu.activity_account, menu);
-        return true;
-    }
-
-    @Override
-    public boolean onPrepareOptionsMenu(Menu menu) {
-        MenuItem itemRename = menu.findItem(R.id.rename_account);
-        // renameAccount is available for API level 21+
-        itemRename.setVisible(Build.VERSION.SDK_INT >= 21);
-        return super.onPrepareOptionsMenu(menu);
-    }
-
-    @Override
-    public boolean onOptionsItemSelected(MenuItem item) {
-        switch (item.getItemId()) {
-            case R.id.sync_now:
-                requestSync();
-                break;
-            case R.id.settings:
-                Intent intent = new Intent(this, AccountSettingsActivity.class);
-                intent.putExtra(AccountSettingsActivity.EXTRA_ACCOUNT, account);
-                startActivity(intent);
-                break;
-            case R.id.rename_account:
-                RenameAccountFragment.newInstance(account).show(getSupportFragmentManager(), null);
-                break;
-            case R.id.delete_account:
-                new AlertDialog.Builder(AccountActivity.this)
-                        .setIcon(R.drawable.ic_error_dark)
-                        .setTitle(R.string.account_delete_confirmation_title)
-                        .setMessage(R.string.account_delete_confirmation_text)
-                        .setNegativeButton(android.R.string.no, null)
-                        .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
-                            @Override
-                            public void onClick(DialogInterface dialog, int which) {
-                                deleteAccount();
-                            }
-                        })
-                        .show();
-                break;
-            default:
-                return super.onOptionsItemSelected(item);
-        }
-        return true;
-    }
-
-    @Override
-    public boolean onMenuItemClick(MenuItem item) {
-        Intent intent;
-        switch (item.getItemId()) {
-            case R.id.refresh_address_books:
-                if (accountInfo != null && accountInfo.carddav != null) {
-                    intent = new Intent(this, DavService.class);
-                    intent.setAction(DavService.ACTION_REFRESH_COLLECTIONS);
-                    intent.putExtra(DavService.EXTRA_DAV_SERVICE_ID, accountInfo.carddav.id);
-                    startService(intent);
-                }
-                break;
-            case R.id.create_address_book:
-                intent = new Intent(this, CreateAddressBookActivity.class);
-                intent.putExtra(CreateAddressBookActivity.EXTRA_ACCOUNT, account);
-                startActivity(intent);
-                break;
-            case R.id.refresh_calendars:
-                if (accountInfo != null && accountInfo.caldav != null) {
-                    intent = new Intent(this, DavService.class);
-                    intent.setAction(DavService.ACTION_REFRESH_COLLECTIONS);
-                    intent.putExtra(DavService.EXTRA_DAV_SERVICE_ID, accountInfo.caldav.id);
-                    startService(intent);
-                }
-                break;
-            case R.id.create_calendar:
-                intent = new Intent(this, CreateCalendarActivity.class);
-                intent.putExtra(CreateCalendarActivity.EXTRA_ACCOUNT, account);
-                startActivity(intent);
-                break;
-        }
-        return false;
-    }
-
-
-    private AdapterView.OnItemClickListener onItemClickListener = new AdapterView.OnItemClickListener() {
-        @Override
-        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
-            final ListView list = (ListView)parent;
-            final ArrayAdapter<CollectionInfo> adapter = (ArrayAdapter)list.getAdapter();
-            final CollectionInfo info = adapter.getItem(position);
-
-            boolean nowChecked = !info.selected;
-
-            if (list.getChoiceMode() == AbsListView.CHOICE_MODE_SINGLE)
-                // clear all other checked items
-                for (int i = adapter.getCount()-1; i >= 0; i--)
-                    adapter.getItem(i).selected = false;
-
-            OpenHelper dbHelper = new OpenHelper(AccountActivity.this);
-            try {
-                SQLiteDatabase db = dbHelper.getWritableDatabase();
-                db.beginTransactionNonExclusive();
-
-                if (list.getChoiceMode() == AbsListView.CHOICE_MODE_SINGLE) {
-                    // disable all other collections
-                    ContentValues values = new ContentValues(1);
-                    values.put(Collections.SYNC, 0);
-                    db.update(Collections._TABLE, values, Collections.SERVICE_ID + "=?", new String[] { String.valueOf(info.serviceID) });
-                }
-
-                ContentValues values = new ContentValues(1);
-                values.put(Collections.SYNC, nowChecked ? 1 : 0);
-                db.update(Collections._TABLE, values, Collections.ID + "=?", new String[] { String.valueOf(info.id) });
-
-                db.setTransactionSuccessful();
-                db.endTransaction();
-
-                info.selected = nowChecked;
-                adapter.notifyDataSetChanged();
-            } finally {
-                dbHelper.close();
-            }
-        }
-    };
-
-    private AdapterView.OnItemLongClickListener onItemLongClickListener = new AdapterView.OnItemLongClickListener() {
-        @Override
-        public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
-            final ListView list = (ListView)parent;
-            final ArrayAdapter<CollectionInfo> adapter = (ArrayAdapter)list.getAdapter();
-            final CollectionInfo info = adapter.getItem(position);
-
-            PopupMenu popup = new PopupMenu(AccountActivity.this, view);
-            popup.inflate(R.menu.account_collection_operations);
-            popup.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
-                @Override
-                public boolean onMenuItemClick(MenuItem item) {
-                    switch (item.getItemId()) {
-                        case R.id.delete_collection:
-                            DeleteCollectionFragment.ConfirmDeleteCollectionFragment.newInstance(account, info).show(getSupportFragmentManager(), null);
-                            break;
-                    }
-                    return true;
-                }
-            });
-            popup.show();
-
-            // long click was handled
-            return true;
-        }
-    };
-
-
-    /* LOADERS AND LOADED DATA */
-
-    protected static class AccountInfo {
-        ServiceInfo carddav, caldav;
-
-        public static class ServiceInfo {
-            long id;
-            boolean refreshing;
-
-            boolean hasHomeSets;
-            List<CollectionInfo> collections;
-        }
-    }
-
-    @Override
-    public Loader<AccountInfo> onCreateLoader(int id, Bundle args) {
-        return new AccountLoader(this, account);
-    }
-
-    public void reload() {
-        getLoaderManager().restartLoader(0, getIntent().getExtras(), this);
-    }
-
-    @Override
-    public void onLoadFinished(Loader<AccountInfo> loader, final AccountInfo info) {
-        accountInfo = info;
-
-        CardView card = (CardView)findViewById(R.id.carddav);
-        if (info.carddav != null) {
-            ProgressBar progress = (ProgressBar)findViewById(R.id.carddav_refreshing);
-            progress.setVisibility(info.carddav.refreshing ? View.VISIBLE : View.GONE);
-
-            listCardDAV = (ListView)findViewById(R.id.address_books);
-            listCardDAV.setEnabled(!info.carddav.refreshing);
-            listCardDAV.setAlpha(info.carddav.refreshing ? 0.5f : 1);
-
-            tbCardDAV.getMenu().findItem(R.id.create_address_book).setEnabled(info.carddav.hasHomeSets);
-
-            AddressBookAdapter adapter = new AddressBookAdapter(this);
-            adapter.addAll(info.carddav.collections);
-            listCardDAV.setAdapter(adapter);
-            listCardDAV.setOnItemClickListener(onItemClickListener);
-            listCardDAV.setOnItemLongClickListener(onItemLongClickListener);
-        } else
-            card.setVisibility(View.GONE);
-
-        card = (CardView)findViewById(R.id.caldav);
-        if (info.caldav != null) {
-            ProgressBar progress = (ProgressBar)findViewById(R.id.caldav_refreshing);
-            progress.setVisibility(info.caldav.refreshing ? View.VISIBLE : View.GONE);
-
-            listCalDAV = (ListView)findViewById(R.id.calendars);
-            listCalDAV.setEnabled(!info.caldav.refreshing);
-            listCalDAV.setAlpha(info.caldav.refreshing ? 0.5f : 1);
-
-            tbCalDAV.getMenu().findItem(R.id.create_calendar).setEnabled(info.caldav.hasHomeSets);
-
-            final CalendarAdapter adapter = new CalendarAdapter(this);
-            adapter.addAll(info.caldav.collections);
-            listCalDAV.setAdapter(adapter);
-            listCalDAV.setOnItemClickListener(onItemClickListener);
-            listCalDAV.setOnItemLongClickListener(onItemLongClickListener);
-        } else
-            card.setVisibility(View.GONE);
-    }
-
-    @Override
-    public void onLoaderReset(Loader<AccountInfo> loader) {
-        if (listCardDAV != null)
-            listCardDAV.setAdapter(null);
-
-        if (listCalDAV != null)
-            listCalDAV.setAdapter(null);
-    }
-
-
-    private static class AccountLoader extends AsyncTaskLoader<AccountInfo> implements DavService.RefreshingStatusListener, ServiceConnection, SyncStatusObserver {
-        private final Account account;
-        private DavService.InfoBinder davService;
-        private Object syncStatusListener;
-
-        public AccountLoader(Context context, Account account) {
-            super(context);
-            this.account = account;
-        }
-
-        @Override
-        protected void onStartLoading() {
-            syncStatusListener = ContentResolver.addStatusChangeListener(SYNC_OBSERVER_TYPE_ACTIVE, this);
-
-            getContext().bindService(new Intent(getContext(), DavService.class), this, Context.BIND_AUTO_CREATE);
-        }
-
-        @Override
-        protected void onStopLoading() {
-            davService.removeRefreshingStatusListener(this);
-            getContext().unbindService(this);
-
-            if (syncStatusListener != null)
-                ContentResolver.removeStatusChangeListener(syncStatusListener);
-        }
-
-        @Override
-        public void onServiceConnected(ComponentName name, IBinder service) {
-            davService = (DavService.InfoBinder)service;
-            davService.addRefreshingStatusListener(this, false);
-
-            forceLoad();
-        }
-
-        @Override
-        public void onServiceDisconnected(ComponentName name) {
-            davService = null;
-        }
-
-        @Override
-        public void onDavRefreshStatusChanged(long id, boolean refreshing) {
-            forceLoad();
-        }
-
-        @Override
-        public void onStatusChanged(int which) {
-            forceLoad();
-        }
-
-        @Override
-        public AccountInfo loadInBackground() {
-            AccountInfo info = new AccountInfo();
-
-            @Cleanup OpenHelper dbHelper = new OpenHelper(getContext());
-            SQLiteDatabase db = dbHelper.getReadableDatabase();
-
-            @Cleanup Cursor cursor = db.query(
-                    Services._TABLE,
-                    new String[] { Services.ID, Services.SERVICE },
-                    Services.ACCOUNT_NAME + "=?", new String[] { account.name },
-                    null, null, null);
-
-            while (cursor.moveToNext()) {
-                long id = cursor.getLong(0);
-                String service = cursor.getString(1);
-                if (Services.SERVICE_CARDDAV.equals(service)) {
-                    info.carddav = new AccountInfo.ServiceInfo();
-                    info.carddav.id = id;
-                    info.carddav.refreshing = (davService != null && davService.isRefreshing(id)) || ContentResolver.isSyncActive(account, ContactsContract.AUTHORITY);
-                    info.carddav.hasHomeSets = hasHomeSets(db, id);
-                    info.carddav.collections = readCollections(db, id);
-
-                } else if (Services.SERVICE_CALDAV.equals(service)) {
-                    info.caldav = new AccountInfo.ServiceInfo();
-                    info.caldav.id = id;
-                    info.caldav.refreshing = (davService != null && davService.isRefreshing(id)) ||
-                            ContentResolver.isSyncActive(account, CalendarContract.AUTHORITY) ||
-                            ContentResolver.isSyncActive(account, TaskProvider.ProviderName.OpenTasks.authority);
-                    info.caldav.hasHomeSets = hasHomeSets(db, id);
-                    info.caldav.collections = readCollections(db, id);
-                }
-            }
-            return info;
-        }
-
-        private boolean hasHomeSets(@NonNull SQLiteDatabase db, long service) {
-            @Cleanup Cursor cursor = db.query(ServiceDB.HomeSets._TABLE, null, ServiceDB.HomeSets.SERVICE_ID + "=?",
-                    new String[] { String.valueOf(service) }, null, null, null);
-            return cursor.getCount() > 0;
-        }
-
-        private List<CollectionInfo> readCollections(@NonNull SQLiteDatabase db, long service) {
-            List<CollectionInfo> collections = new LinkedList<>();
-            @Cleanup Cursor cursor = db.query(Collections._TABLE, null, Collections.SERVICE_ID + "=?",
-                    new String[] { String.valueOf(service) }, null, null, Collections.SUPPORTS_VEVENT + " DESC," + Collections.DISPLAY_NAME);
-            while (cursor.moveToNext()) {
-                ContentValues values = new ContentValues();
-                DatabaseUtils.cursorRowToContentValues(cursor, values);
-                collections.add(CollectionInfo.fromDB(values));
-            }
-            return collections;
-        }
-
-    }
-
-
-    /* LIST ADAPTERS */
-
-    public static class AddressBookAdapter extends ArrayAdapter<CollectionInfo> {
-        public AddressBookAdapter(Context context) {
-            super(context, R.layout.account_carddav_item);
-        }
-
-        @Override
-        public View getView(int position, View v, ViewGroup parent) {
-            if (v == null)
-                v = LayoutInflater.from(getContext()).inflate(R.layout.account_carddav_item, parent, false);
-
-            final CollectionInfo info = getItem(position);
-
-            RadioButton checked = (RadioButton)v.findViewById(R.id.checked);
-            checked.setChecked(info.selected);
-
-            TextView tv = (TextView)v.findViewById(R.id.title);
-            tv.setText(TextUtils.isEmpty(info.displayName) ? info.url : info.displayName);
-
-            tv = (TextView)v.findViewById(R.id.description);
-            if (TextUtils.isEmpty(info.description))
-                tv.setVisibility(View.GONE);
-            else {
-                tv.setVisibility(View.VISIBLE);
-                tv.setText(info.description);
-            }
-
-            tv = (TextView)v.findViewById(R.id.read_only);
-            tv.setVisibility(info.readOnly ? View.VISIBLE : View.GONE);
-
-            return v;
-        }
-    }
-
-    public static class CalendarAdapter extends ArrayAdapter<CollectionInfo> {
-        public CalendarAdapter(Context context) {
-            super(context, R.layout.account_caldav_item);
-        }
-
-        @Override
-        public View getView(final int position, View v, ViewGroup parent) {
-            if (v == null)
-                v = LayoutInflater.from(getContext()).inflate(R.layout.account_caldav_item, parent, false);
-
-            final CollectionInfo info = getItem(position);
-
-            CheckBox checked = (CheckBox)v.findViewById(R.id.checked);
-            checked.setChecked(info.selected);
-
-            View vColor = v.findViewById(R.id.color);
-            if (info.color != null) {
-                vColor.setVisibility(View.VISIBLE);
-                vColor.setBackgroundColor(info.color);
-            } else
-                vColor.setVisibility(View.GONE);
-
-            TextView tv = (TextView)v.findViewById(R.id.title);
-            tv.setText(TextUtils.isEmpty(info.displayName) ? info.url : info.displayName);
-
-            tv = (TextView)v.findViewById(R.id.description);
-            if (TextUtils.isEmpty(info.description))
-                tv.setVisibility(View.GONE);
-            else {
-                tv.setVisibility(View.VISIBLE);
-                tv.setText(info.description);
-            }
-
-            tv = (TextView)v.findViewById(R.id.read_only);
-            tv.setVisibility(info.readOnly ? View.VISIBLE : View.GONE);
-
-            tv = (TextView)v.findViewById(R.id.events);
-            tv.setVisibility(BooleanUtils.isTrue(info.supportsVEVENT) ? View.VISIBLE : View.GONE);
-
-            tv = (TextView)v.findViewById(R.id.tasks);
-            tv.setVisibility(BooleanUtils.isTrue(info.supportsVTODO) ? View.VISIBLE : View.GONE);
-
-            return v;
-        }
-    }
-
-
-    /* DIALOG FRAGMENTS */
-
-    public static class RenameAccountFragment extends DialogFragment {
-
-        private final static String ARG_ACCOUNT = "account";
-
-        static RenameAccountFragment newInstance(@NonNull Account account) {
-            RenameAccountFragment fragment = new RenameAccountFragment();
-            Bundle args = new Bundle(1);
-            args.putParcelable(ARG_ACCOUNT, account);
-            fragment.setArguments(args);
-            return fragment;
-        }
-
-        @Override
-        public Dialog onCreateDialog(Bundle savedInstanceState) {
-            final Account oldAccount = getArguments().getParcelable(ARG_ACCOUNT);
-
-            final EditText editText = new EditText(getContext());
-            editText.setText(oldAccount.name);
-
-            return new AlertDialog.Builder(getContext())
-                    .setTitle(R.string.account_rename)
-                    .setMessage(R.string.account_rename_new_name)
-                    .setView(editText)
-                    .setPositiveButton(R.string.account_rename_rename, new DialogInterface.OnClickListener() {
-                        @Override
-                        public void onClick(DialogInterface dialog, int which) {
-                            final String newName = editText.getText().toString();
-
-                            if (newName.equals(oldAccount.name))
-                                return;
-
-                            final AccountManager accountManager = AccountManager.get(getContext());
-                            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP)
-                                accountManager.renameAccount(oldAccount, newName,
-                                        new AccountManagerCallback<Account>() {
-                                            @Override
-                                            public void run(AccountManagerFuture<Account> future) {
-                                                App.log.info("Updating account name references");
-
-                                                // cancel running synchronization
-                                                ContentResolver.cancelSync(oldAccount, null);
-
-                                                // update account name references in database
-                                                @Cleanup OpenHelper dbHelper = new OpenHelper(getContext());
-                                                ServiceDB.onRenameAccount(dbHelper.getWritableDatabase(), oldAccount.name, newName);
-
-                                                // update account_name of local contacts
-                                                try {
-                                                    LocalAddressBook.onRenameAccount(getContext().getContentResolver(), oldAccount.name, newName);
-                                                } catch(RemoteException e) {
-                                                    App.log.log(Level.SEVERE, "Couldn't propagate new account name to contacts provider");
-                                                }
-
-                                                // calendar provider doesn't allow changing account_name of Events
-
-                                                // update account_name of local tasks
-                                                try {
-                                                    LocalTaskList.onRenameAccount(getContext().getContentResolver(), oldAccount.name, newName);
-                                                } catch(RemoteException e) {
-                                                    App.log.log(Level.SEVERE, "Couldn't propagate new account name to tasks provider");
-                                                }
-
-                                                // synchronize again
-                                                requestSync(new Account(newName, oldAccount.type));
-                                            }
-                                        }, null
-                                );
-                            getActivity().finish();
-                        }
-                    })
-                    .setNegativeButton(android.R.string.cancel, new DialogInterface.OnClickListener() {
-                        @Override
-                        public void onClick(DialogInterface dialog, int which) {
-                        }
-                    })
-                    .create();
-        }
-    }
-
-
-    /* USER ACTIONS */
-
-    private void deleteAccount() {
-        AccountManager accountManager = AccountManager.get(this);
-
-        if (Build.VERSION.SDK_INT >= 22)
-            accountManager.removeAccount(account, this, new AccountManagerCallback<Bundle>() {
-                @Override
-                public void run(AccountManagerFuture<Bundle> future) {
-                    try {
-                        if (future.getResult().getBoolean(AccountManager.KEY_BOOLEAN_RESULT))
-                            finish();
-                    } catch(OperationCanceledException|IOException|AuthenticatorException e) {
-                        App.log.log(Level.SEVERE, "Couldn't remove account", e);
-                    }
-                }
-            }, null);
-        else
-            accountManager.removeAccount(account, new AccountManagerCallback<Boolean>() {
-                @Override
-                public void run(AccountManagerFuture<Boolean> future) {
-                    try {
-                        if (future.getResult())
-                            finish();
-                    } catch (OperationCanceledException|IOException|AuthenticatorException e) {
-                        App.log.log(Level.SEVERE, "Couldn't remove account", e);
-                    }
-                }
-            }, null);
-    }
-
-    protected static void requestSync(Account account) {
-        String authorities[] = {
-                ContactsContract.AUTHORITY,
-                CalendarContract.AUTHORITY,
-                TaskProvider.ProviderName.OpenTasks.authority
-        };
-
-        for (String authority : authorities) {
-            Bundle extras = new Bundle();
-            extras.putBoolean(ContentResolver.SYNC_EXTRAS_MANUAL, true);        // manual sync
-            extras.putBoolean(ContentResolver.SYNC_EXTRAS_EXPEDITED, true);     // run immediately (don't queue)
-            ContentResolver.requestSync(account, authority, extras);
-        }
-    }
-
-    private void requestSync() {
-        requestSync(account);
-        Snackbar.make(findViewById(R.id.parent), R.string.account_synchronizing_now, Snackbar.LENGTH_LONG).show();
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/ui/AccountActivity.kt

@@ -0,0 +1,688 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.ui
+
+import android.Manifest
+import android.accounts.Account
+import android.accounts.AccountManager
+import android.app.Dialog
+import android.app.LoaderManager
+import android.content.*
+import android.content.pm.PackageManager
+import android.database.DatabaseUtils
+import android.database.sqlite.SQLiteDatabase
+import android.net.Uri
+import android.os.Build
+import android.os.Bundle
+import android.os.IBinder
+import android.provider.CalendarContract
+import android.provider.ContactsContract
+import android.support.design.widget.Snackbar
+import android.support.v4.app.ActivityCompat
+import android.support.v4.app.DialogFragment
+import android.support.v4.content.ContextCompat
+import android.support.v7.app.AlertDialog
+import android.support.v7.app.AppCompatActivity
+import android.support.v7.widget.Toolbar
+import android.view.*
+import android.widget.*
+import at.bitfire.davdroid.DavService
+import at.bitfire.davdroid.R
+import at.bitfire.davdroid.log.Logger
+import at.bitfire.davdroid.model.CollectionInfo
+import at.bitfire.davdroid.model.ServiceDB
+import at.bitfire.davdroid.model.ServiceDB.*
+import at.bitfire.davdroid.model.ServiceDB.Collections
+import at.bitfire.davdroid.resource.LocalAddressBook
+import at.bitfire.davdroid.resource.LocalTaskList
+import at.bitfire.ical4android.TaskProvider
+import at.bitfire.vcard4android.ContactsStorageException
+import kotlinx.android.synthetic.main.account_caldav_item.view.*
+import kotlinx.android.synthetic.main.activity_account.*
+import java.util.*
+import java.util.logging.Level
+
+class AccountActivity: AppCompatActivity(), Toolbar.OnMenuItemClickListener, PopupMenu.OnMenuItemClickListener, LoaderManager.LoaderCallbacks<AccountActivity.AccountInfo> {
+
+    companion object {
+        @JvmField val EXTRA_ACCOUNT = "account"
+
+        private fun requestSync(context: Context, account: Account) {
+            val authorities = arrayOf(
+                    context.getString(R.string.address_books_authority),
+                    CalendarContract.AUTHORITY,
+                    TaskProvider.ProviderName.OpenTasks.authority
+            )
+
+            for (authority in authorities) {
+                val extras = Bundle(2)
+                extras.putBoolean(ContentResolver.SYNC_EXTRAS_MANUAL, true)        // manual sync
+                extras.putBoolean(ContentResolver.SYNC_EXTRAS_EXPEDITED, true)     // run immediately (don't queue)
+                ContentResolver.requestSync(account, authority, extras)
+            }
+        }
+
+    }
+
+    lateinit var account: Account
+    private var accountInfo: AccountInfo? = null
+
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+
+        account = intent.getParcelableExtra(EXTRA_ACCOUNT)
+        title = account.name
+
+        setContentView(R.layout.activity_account)
+
+        val icMenu = if (Build.VERSION.SDK_INT >= 21)
+            getDrawable(R.drawable.ic_menu_light)
+        else
+            resources.getDrawable(R.drawable.ic_menu_light)
+
+        // CardDAV toolbar
+        carddav_menu.overflowIcon = icMenu
+        carddav_menu.inflateMenu(R.menu.carddav_actions)
+        carddav_menu.setOnMenuItemClickListener(this)
+
+        // CalDAV toolbar
+        caldav_menu.overflowIcon = icMenu
+        caldav_menu.inflateMenu(R.menu.caldav_actions)
+        caldav_menu.setOnMenuItemClickListener(this)
+
+        // Webcal toolbar
+        webcal_menu.overflowIcon = icMenu
+        webcal_menu.inflateMenu(R.menu.webcal_actions)
+        webcal_menu.setOnMenuItemClickListener(this)
+
+        // load CardDAV/CalDAV collections
+        loaderManager.initLoader(0, null, this)
+    }
+
+    override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>, grantResults: IntArray) {
+        if (grantResults.any { it == PackageManager.PERMISSION_GRANTED })
+            // we've got additional permissions; try to load everything again
+            reload()
+    }
+
+    override fun onCreateOptionsMenu(menu: Menu): Boolean {
+        menuInflater.inflate(R.menu.activity_account, menu)
+        return true
+    }
+
+    override fun onPrepareOptionsMenu(menu: Menu): Boolean {
+        val itemRename = menu.findItem(R.id.rename_account)
+        // renameAccount is available for API level 21+
+        itemRename.isVisible = Build.VERSION.SDK_INT >= 21
+        return super.onPrepareOptionsMenu(menu)
+    }
+
+    override fun onOptionsItemSelected(item: MenuItem): Boolean {
+        when (item.itemId) {
+            R.id.sync_now ->
+                requestSync()
+            R.id.settings -> {
+                val intent = Intent(this, AccountSettingsActivity::class.java)
+                intent.putExtra(AccountSettingsActivity.EXTRA_ACCOUNT, account)
+                startActivity(intent)
+            }
+            R.id.rename_account ->
+                RenameAccountFragment.newInstance(account).show(supportFragmentManager, null)
+            R.id.delete_account -> {
+                AlertDialog.Builder(this)
+                        .setIcon(R.drawable.ic_error_dark)
+                        .setTitle(R.string.account_delete_confirmation_title)
+                        .setMessage(R.string.account_delete_confirmation_text)
+                        .setNegativeButton(android.R.string.no, null)
+                        .setPositiveButton(android.R.string.yes, { _, _ ->
+                            deleteAccount()
+                        })
+                        .show()
+            }
+            else ->
+                return super.onOptionsItemSelected(item)
+        }
+        return true
+    }
+
+    override fun onMenuItemClick(item: MenuItem): Boolean {
+        when (item.itemId) {
+            R.id.refresh_address_books ->
+                accountInfo?.carddav?.let { carddav ->
+                    val intent = Intent(this, DavService::class.java)
+                    intent.action = DavService.ACTION_REFRESH_COLLECTIONS
+                    intent.putExtra(DavService.EXTRA_DAV_SERVICE_ID, carddav.id)
+                    startService(intent)
+                }
+            R.id.create_address_book -> {
+                val intent = Intent(this, CreateAddressBookActivity::class.java)
+                intent.putExtra(CreateAddressBookActivity.EXTRA_ACCOUNT, account)
+                startActivity(intent)
+            }
+            R.id.refresh_calendars ->
+                accountInfo?.caldav?.let { caldav ->
+                    val intent = Intent(this, DavService::class.java)
+                    intent.action = DavService.ACTION_REFRESH_COLLECTIONS
+                    intent.putExtra(DavService.EXTRA_DAV_SERVICE_ID, caldav.id)
+                    startService(intent)
+                }
+            R.id.create_calendar -> {
+                val intent = Intent(this, CreateCalendarActivity::class.java)
+                intent.putExtra(CreateCalendarActivity.EXTRA_ACCOUNT, account)
+                startActivity(intent)
+            }
+        }
+        return false
+    }
+
+
+    private val onItemClickListener = AdapterView.OnItemClickListener { parent, view, position, _ ->
+        if (!view.isEnabled)
+            return@OnItemClickListener
+
+        val list = parent as ListView
+        val adapter = list.adapter as ArrayAdapter<CollectionInfo>
+        val info = adapter.getItem(position)
+        val nowChecked = !info.selected
+
+        OpenHelper(this@AccountActivity).use { dbHelper ->
+            val db = dbHelper.writableDatabase
+            db.beginTransactionNonExclusive()
+
+            val values = ContentValues(1)
+            values.put(Collections.SYNC, if (nowChecked) 1 else 0)
+            db.update(Collections._TABLE, values, "${Collections.ID}=?", arrayOf(info.id.toString()))
+
+            db.setTransactionSuccessful()
+            db.endTransaction()
+        }
+
+        info.selected = nowChecked
+        adapter.notifyDataSetChanged()
+
+        if (nowChecked && info.type == CollectionInfo.Type.ADDRESS_BOOK && info.readOnly)
+            Snackbar.make(parent, R.string.account_read_only_address_book_selected, Snackbar.LENGTH_LONG).show()
+    }
+
+    private val onItemLongClickListener = AdapterView.OnItemLongClickListener { parent, view, position, _ ->
+        val list = parent as ListView
+        val adapter = list.adapter as ArrayAdapter<CollectionInfo>
+        val info = adapter.getItem(position)
+
+        val popup = PopupMenu(this@AccountActivity, view)
+        popup.inflate(R.menu.account_collection_operations)
+        popup.setOnMenuItemClickListener({ item ->
+            when (item.itemId) {
+                R.id.delete_collection ->
+                    DeleteCollectionFragment.ConfirmDeleteCollectionFragment.newInstance(account, info).show(getSupportFragmentManager(), null);
+            }
+            true
+        })
+        popup.show()
+
+        // long click was handled
+        true
+    }
+
+    private val webcalOnItemClickListener = AdapterView.OnItemClickListener { parent, _, position, _ ->
+        val info = parent.getItemAtPosition(position) as CollectionInfo
+        var uri = Uri.parse(info.source)
+
+        val nowChecked = !info.selected
+        if (nowChecked) {
+            // subscribe to Webcal feed
+            when {
+                uri.scheme.equals("http", true) -> uri = uri.buildUpon().scheme("webcal").build()
+                uri.scheme.equals("https", true) -> uri = uri.buildUpon().scheme("webcals").build()
+            }
+
+            val intent = Intent(Intent.ACTION_VIEW, uri)
+            if (packageManager.resolveActivity(intent, 0) != null)
+                startActivity(intent)
+            else {
+                val snack = Snackbar.make(parent, R.string.account_no_webcal_handler_found, Snackbar.LENGTH_LONG)
+
+                val installIntent = Intent(Intent.ACTION_VIEW, Uri.parse("market://details?id=at.bitfire.icsdroid"))
+                if (packageManager.resolveActivity(installIntent, 0) != null)
+                    snack.setAction(R.string.account_install_icsdroid, {
+                        startActivity(installIntent)
+                    })
+
+                snack.show()
+            }
+        } else {
+            // unsubscribe from Webcal feed
+            if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_CALENDAR) == PackageManager.PERMISSION_GRANTED)
+                contentResolver.acquireContentProviderClient(CalendarContract.AUTHORITY)?.let { provider ->
+                    try {
+                        provider.delete(CalendarContract.Calendars.CONTENT_URI, "${CalendarContract.Calendars.NAME}=?", arrayOf(info.source))
+                        reload()
+                    } finally {
+                        provider.release()
+                    }
+                }
+        }
+    }
+
+
+    /* LOADERS AND LOADED DATA */
+
+    class AccountInfo {
+        var carddav: ServiceInfo? = null
+        var caldav: ServiceInfo? = null
+
+        class ServiceInfo {
+            var id: Long? = null
+            var refreshing = false
+
+            var hasHomeSets = false
+            var collections = listOf<CollectionInfo>()
+        }
+    }
+
+    override fun onCreateLoader(id: Int, args: Bundle?) =
+            AccountLoader(this, account)
+
+    fun reload() {
+        loaderManager.restartLoader(0, null, this)
+    }
+
+    override fun onLoadFinished(loader: Loader<AccountInfo>, info: AccountInfo?) {
+        accountInfo = info
+
+        carddav.visibility = info?.carddav?.let { carddav ->
+            carddav_refreshing.visibility = if (carddav.refreshing) View.VISIBLE else View.GONE
+
+            address_books.isEnabled = !carddav.refreshing
+            address_books.alpha = if (carddav.refreshing) 0.5f else 1f
+
+            carddav_menu.menu.findItem(R.id.create_address_book).isEnabled = carddav.hasHomeSets
+
+            val adapter = AddressBookAdapter(this)
+            adapter.addAll(carddav.collections)
+            address_books.adapter = adapter
+            address_books.onItemClickListener = onItemClickListener
+            address_books.onItemLongClickListener = onItemLongClickListener
+
+            View.VISIBLE
+        } ?: View.GONE
+
+        caldav.visibility = info?.caldav?.let { caldav ->
+            caldav_refreshing.visibility = if (caldav.refreshing) View.VISIBLE else View.GONE
+
+            calendars.isEnabled = !caldav.refreshing
+            calendars.alpha = if (caldav.refreshing) 0.5f else 1f
+
+            caldav_menu.menu.findItem(R.id.create_calendar).isEnabled = caldav.hasHomeSets
+
+            val adapter = CalendarAdapter(this)
+            adapter.addAll(caldav.collections.filter { it.type == CollectionInfo.Type.CALENDAR })
+            calendars.adapter = adapter
+            calendars.onItemClickListener = onItemClickListener
+            calendars.onItemLongClickListener = onItemLongClickListener
+
+            View.VISIBLE
+        } ?: View.GONE
+
+        webcal.visibility = info?.caldav?.let {
+            val collections = it.collections.filter { it.type == CollectionInfo.Type.WEBCAL }
+
+            val adapter = CalendarAdapter(this)
+            adapter.addAll(collections)
+            webcals.adapter = adapter
+            webcals.onItemClickListener = webcalOnItemClickListener
+
+            if (collections.isNotEmpty())
+                View.VISIBLE
+            else
+                View.GONE
+        } ?: View.GONE
+    }
+
+    override fun onLoaderReset(loader: Loader<AccountInfo>) {
+        address_books?.adapter = null
+        calendars?.adapter = null
+    }
+
+
+    class AccountLoader(
+            val activity: AccountActivity,
+            val account: Account
+    ): AsyncTaskLoader<AccountInfo>(activity), DavService.RefreshingStatusListener, ServiceConnection, SyncStatusObserver {
+
+        private var davService: DavService.InfoBinder? = null
+        private lateinit var syncStatusListener: Any
+
+        override fun onStartLoading() {
+            syncStatusListener = ContentResolver.addStatusChangeListener(ContentResolver.SYNC_OBSERVER_TYPE_ACTIVE, this)
+            context.bindService(Intent(context, DavService::class.java), this, Context.BIND_AUTO_CREATE)
+        }
+
+        override fun onStopLoading() {
+            davService?.removeRefreshingStatusListener(this)
+            context.unbindService(this)
+            ContentResolver.removeStatusChangeListener(syncStatusListener)
+        }
+
+        override fun onServiceConnected(name: ComponentName, service: IBinder) {
+            davService = service as DavService.InfoBinder
+            service.addRefreshingStatusListener(this, false)
+
+            forceLoad()
+        }
+
+        override fun onServiceDisconnected(name: ComponentName) {
+            davService = null
+        }
+
+        override fun onDavRefreshStatusChanged(id: Long, refreshing: Boolean) =
+                forceLoad()
+
+        override fun onStatusChanged(which: Int) =
+                forceLoad()
+
+        override fun loadInBackground(): AccountInfo {
+            val info = AccountInfo()
+
+            OpenHelper(context).use { dbHelper ->
+                val db = dbHelper.readableDatabase
+                db.query(
+                        Services._TABLE,
+                        arrayOf(Services.ID, Services.SERVICE),
+                        "${Services.ACCOUNT_NAME}=?", arrayOf(account.name),
+                        null, null, null).use { cursor ->
+                    while (cursor.moveToNext()) {
+                        val id = cursor.getLong(0)
+                        when (cursor.getString(1)) {
+                            Services.SERVICE_CARDDAV -> {
+                                val carddav = AccountInfo.ServiceInfo()
+                                info.carddav = carddav
+                                carddav.id = id
+                                carddav.refreshing =
+                                        davService?.isRefreshing(id) ?: false ||
+                                        ContentResolver.isSyncActive(account, context.getString(R.string.address_books_authority))
+
+                                val accountManager = AccountManager.get(context)
+                                for (addrBookAccount in accountManager.getAccountsByType(context.getString(R.string.account_type_address_book))) {
+                                    val addressBook = LocalAddressBook(context, addrBookAccount, null)
+                                    try {
+                                        if (account == addressBook.getMainAccount())
+                                            carddav.refreshing = carddav.refreshing || ContentResolver.isSyncActive(addrBookAccount, ContactsContract.AUTHORITY)
+                                    } catch(e: ContactsStorageException) {
+                                    }
+                                }
+
+                                carddav.hasHomeSets = hasHomeSets(db, id)
+                                carddav.collections = readCollections(db, id)
+                            }
+                            Services.SERVICE_CALDAV -> {
+                                val caldav = AccountInfo.ServiceInfo()
+                                info.caldav = caldav
+                                caldav.id = id
+                                caldav.refreshing =
+                                        davService?.isRefreshing(id) ?: false ||
+                                        ContentResolver.isSyncActive(account, CalendarContract.AUTHORITY) ||
+                                        ContentResolver.isSyncActive(account, TaskProvider.ProviderName.OpenTasks.authority)
+                                caldav.hasHomeSets = hasHomeSets(db, id)
+                                caldav.collections = readCollections(db, id)
+                            }
+                        }
+                    }
+                }
+
+            }
+            return info
+        }
+
+        private fun hasHomeSets(db: SQLiteDatabase, service: Long): Boolean {
+            db.query(ServiceDB.HomeSets._TABLE, null, "${ServiceDB.HomeSets.SERVICE_ID}=?",
+                    arrayOf(service.toString()), null, null, null)?.use { cursor ->
+                return cursor.count > 0
+            }
+            return false
+        }
+
+        private fun readCollections(db: SQLiteDatabase, service: Long): List<CollectionInfo>  {
+            val collections = LinkedList<CollectionInfo>()
+            db.query(Collections._TABLE, null, Collections.SERVICE_ID + "=?", arrayOf(service.toString()),
+                    null, null, "${Collections.SUPPORTS_VEVENT} DESC,${Collections.DISPLAY_NAME}").use { cursor ->
+                while (cursor.moveToNext()) {
+                    val values = ContentValues(cursor.columnCount)
+                    DatabaseUtils.cursorRowToContentValues(cursor, values)
+                    collections.add(CollectionInfo(values))
+                }
+            }
+
+            // Webcal: check whether calendar is already subscribed by ICSdroid
+            // (or any other app that stores the URL in Calendars.NAME)
+            val webcalCollections = collections.filter { it.type == CollectionInfo.Type.WEBCAL }
+            if (webcalCollections.isNotEmpty()) {
+                if (ContextCompat.checkSelfPermission(context, Manifest.permission.READ_CALENDAR) == PackageManager.PERMISSION_GRANTED)
+                    context.contentResolver.acquireContentProviderClient(CalendarContract.AUTHORITY)?.let { provider ->
+                        try {
+                            for (info in webcalCollections) {
+                                provider.query(CalendarContract.Calendars.CONTENT_URI, null,
+                                        "${CalendarContract.Calendars.NAME}=?", arrayOf(info.source), null)?.use { cursor ->
+                                    if (cursor.moveToNext())
+                                        info.selected = true
+                                }
+                            }
+                        } finally {
+                            provider.release()
+                        }
+                    }
+                else
+                    ActivityCompat.requestPermissions(activity, arrayOf(Manifest.permission.READ_CALENDAR), 0)
+            }
+
+            return collections
+        }
+
+    }
+
+
+    /* LIST ADAPTERS */
+
+    class AddressBookAdapter(
+            context: Context
+    ): ArrayAdapter<CollectionInfo>(context, R.layout.account_carddav_item) {
+        override fun getView(position: Int, v: View?, parent: ViewGroup?): View {
+            val v = v ?: LayoutInflater.from(context).inflate(R.layout.account_carddav_item, parent, false)
+            val info = getItem(position)
+
+            val checked: CheckBox = v.findViewById(R.id.checked)
+            checked.isChecked = info.selected
+
+            var tv: TextView = v.findViewById(R.id.title)
+            tv.text = if (!info.displayName.isNullOrBlank()) info.displayName else info.url
+
+            tv = v.findViewById(R.id.description)
+            if (info.description.isNullOrBlank())
+                tv.visibility = View.GONE
+            else {
+                tv.visibility = View.VISIBLE
+                tv.text = info.description
+            }
+
+            v.findViewById<ImageView>(R.id.read_only).visibility =
+                    if (info.readOnly) View.VISIBLE else View.GONE
+
+            return v
+        }
+    }
+
+    class CalendarAdapter(
+            context: Context
+    ): ArrayAdapter<CollectionInfo>(context, R.layout.account_caldav_item) {
+        override fun getView(position: Int, v: View?, parent: ViewGroup?): View {
+            val v = v ?: LayoutInflater.from(context).inflate(R.layout.account_caldav_item, parent, false)
+            val info = getItem(position)
+
+            val enabled = info.selected || info.supportsVEVENT || info.supportsVTODO
+            v.isEnabled = enabled
+            v.checked.isEnabled = enabled
+
+            val checked: CheckBox = v.findViewById(R.id.checked)
+            checked.isChecked = info.selected
+
+            val vColor: View = v.findViewById(R.id.color)
+            vColor.visibility = info.color?.let {
+                vColor.setBackgroundColor(it)
+                View.VISIBLE
+            } ?: View.GONE
+
+            var tv: TextView = v.findViewById(R.id.title)
+            tv.text = if (!info.displayName.isNullOrBlank()) info.displayName else info.url
+
+            tv = v.findViewById(R.id.description)
+            if (info.description.isNullOrBlank())
+                tv.visibility = View.GONE
+            else {
+                tv.visibility = View.VISIBLE
+                tv.text = info.description
+            }
+
+            v.findViewById<ImageView>(R.id.read_only).visibility =
+                    if (info.readOnly) View.VISIBLE else View.GONE
+
+            v.findViewById<ImageView>(R.id.events).visibility =
+                    if (info.supportsVEVENT) View.VISIBLE else View.GONE
+
+            v.findViewById<ImageView>(R.id.tasks).visibility =
+                    if (info.supportsVTODO) View.VISIBLE else View.GONE
+
+            return v
+        }
+    }
+
+
+    /* DIALOG FRAGMENTS */
+
+    class RenameAccountFragment: DialogFragment() {
+
+        companion object {
+
+            val ARG_ACCOUNT = "account"
+
+            fun newInstance(account: Account): RenameAccountFragment {
+                val fragment = RenameAccountFragment()
+                val args = Bundle(1)
+                args.putParcelable(ARG_ACCOUNT, account)
+                fragment.arguments = args
+                return fragment
+            }
+
+        }
+
+        override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
+            val oldAccount: Account = arguments.getParcelable(ARG_ACCOUNT)
+
+            val editText = EditText(activity)
+            editText.setText(oldAccount.name)
+
+            return AlertDialog.Builder(activity)
+                    .setTitle(R.string.account_rename)
+                    .setMessage(R.string.account_rename_new_name)
+                    .setView(editText)
+                    .setPositiveButton(R.string.account_rename_rename, DialogInterface.OnClickListener { dialog, which ->
+                        val newName = editText.text.toString()
+
+                        if (newName == oldAccount.name)
+                            return@OnClickListener
+
+                        val accountManager = AccountManager.get(activity)
+                        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP)
+                            accountManager.renameAccount(oldAccount, newName, { _ ->
+                                Logger.log.info("Updating account name references")
+
+                                // cancel maybe running synchronization
+                                ContentResolver.cancelSync(oldAccount, null)
+                                for (addrBookAccount in accountManager.getAccountsByType(getString(R.string.account_type_address_book)))
+                                    ContentResolver.cancelSync(addrBookAccount, null)
+
+                                // update account name references in database
+                                OpenHelper(activity).use { dbHelper ->
+                                    ServiceDB.onRenameAccount(dbHelper.getWritableDatabase(), oldAccount.name, newName)
+                                }
+
+                                // update main account of address book accounts
+                                try {
+                                    for (addrBookAccount in accountManager.getAccountsByType(getString(R.string.account_type_address_book))) {
+                                        val provider = activity.contentResolver.acquireContentProviderClient(ContactsContract.AUTHORITY)
+                                        try {
+                                            if (provider != null) {
+                                                val addressBook = LocalAddressBook(activity, addrBookAccount, provider)
+                                                if (oldAccount == addressBook.getMainAccount())
+                                                    addressBook.setMainAccount(Account(newName, oldAccount.type))
+                                            }
+                                        } finally {
+                                            if (Build.VERSION.SDK_INT >= 24)
+                                                provider?.close()
+                                            else
+                                                provider?.release()
+                                        }
+
+                                    }
+                                } catch(e: ContactsStorageException) {
+                                    Logger.log.log(Level.SEVERE, "Couldn't update address book accounts", e)
+                                }
+
+                                // calendar provider doesn't allow changing account_name of Events
+                                // (all events will have to be downloaded again)
+
+                                // update account_name of local tasks
+                                try {
+                                    LocalTaskList.onRenameAccount(activity.contentResolver, oldAccount.name, newName)
+                                } catch(e: Exception) {
+                                    Logger.log.log(Level.SEVERE, "Couldn't propagate new account name to tasks provider", e)
+                                }
+
+                                // synchronize again
+                                requestSync(activity, Account(newName, oldAccount.type))
+                            }, null)
+                        activity.finish()
+                    })
+                    .setNegativeButton(android.R.string.cancel, { _, _ -> })
+                    .create()
+        }
+    }
+
+
+    /* USER ACTIONS */
+
+    private fun deleteAccount() {
+        val accountManager = AccountManager.get(this)
+
+        if (Build.VERSION.SDK_INT >= 22)
+            accountManager.removeAccount(account, this, { future ->
+                try {
+                    if (future.result.getBoolean(AccountManager.KEY_BOOLEAN_RESULT))
+                        finish()
+                } catch(e: Exception) {
+                    Logger.log.log(Level.SEVERE, "Couldn't remove account", e)
+                }
+            }, null)
+        else
+            accountManager.removeAccount(account, { future ->
+                try {
+                    if (future.result)
+                        finish()
+                } catch (e: Exception) {
+                    Logger.log.log(Level.SEVERE, "Couldn't remove account", e)
+                }
+            }, null)
+    }
+
+    private fun requestSync() {
+        requestSync(this, account)
+        Snackbar.make(findViewById(R.id.parent), R.string.account_synchronizing_now, Snackbar.LENGTH_LONG).show()
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/ui/AccountListFragment.java

@@ -1,135 +0,0 @@
-/*
- * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.ui;
-
-import android.accounts.Account;
-import android.accounts.AccountManager;
-import android.accounts.OnAccountsUpdateListener;
-import android.annotation.SuppressLint;
-import android.content.Context;
-import android.content.Intent;
-import android.os.Bundle;
-import android.support.v4.app.ListFragment;
-import android.support.v4.app.LoaderManager;
-import android.support.v4.content.AsyncTaskLoader;
-import android.support.v4.content.Loader;
-import android.view.LayoutInflater;
-import android.view.View;
-import android.view.ViewGroup;
-import android.widget.AbsListView;
-import android.widget.AdapterView;
-import android.widget.ArrayAdapter;
-import android.widget.ListView;
-import android.widget.TextView;
-
-import at.bitfire.davdroid.AccountsChangedReceiver;
-import at.bitfire.davdroid.Constants;
-import at.bitfire.davdroid.R;
-
-public class AccountListFragment extends ListFragment implements LoaderManager.LoaderCallbacks<Account[]>, AdapterView.OnItemClickListener {
-
-    @Override
-    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
-        setListAdapter(new AccountListAdapter(getContext()));
-
-        return inflater.inflate(R.layout.account_list, container, false);
-    }
-
-    @Override
-    public void onViewCreated(View view, Bundle savedInstanceState) {
-        super.onViewCreated(view, savedInstanceState);
-        getLoaderManager().initLoader(0, getArguments(), this);
-
-        ListView list = getListView();
-        list.setOnItemClickListener(this);
-        list.setChoiceMode(AbsListView.CHOICE_MODE_SINGLE);
-    }
-
-    @Override
-    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
-        Account account = (Account)getListAdapter().getItem(position);
-
-        Intent intent = new Intent(getContext(), AccountActivity.class);
-        intent.putExtra(AccountActivity.EXTRA_ACCOUNT, account);
-        startActivity(intent);
-    }
-
-
-    // loader
-
-    @Override
-    public Loader<Account[]> onCreateLoader(int id, Bundle args) {
-        return new AccountLoader(getContext());
-    }
-
-    @Override
-    public void onLoadFinished(Loader<Account[]> loader, Account[] accounts) {
-        AccountListAdapter adapter = (AccountListAdapter)getListAdapter();
-        adapter.clear();
-        adapter.addAll(accounts);
-    }
-
-    @Override
-    public void onLoaderReset(Loader<Account[]> loader) {
-        ((AccountListAdapter)getListAdapter()).clear();
-    }
-
-    private static class AccountLoader extends AsyncTaskLoader<Account[]> implements OnAccountsUpdateListener {
-        private final AccountManager accountManager;
-
-        public AccountLoader(Context context) {
-            super(context);
-            accountManager = AccountManager.get(context);
-        }
-
-        @Override
-        protected void onStartLoading() {
-            AccountsChangedReceiver.registerListener(this, true);
-        }
-
-        @Override
-        protected void onStopLoading() {
-            AccountsChangedReceiver.unregisterListener(this);
-        }
-
-        @Override
-        public void onAccountsUpdated(Account[] accounts) {
-            forceLoad();
-        }
-
-        @Override
-        @SuppressLint("MissingPermission")
-        public Account[] loadInBackground() {
-            return accountManager.getAccountsByType(Constants.ACCOUNT_TYPE);
-        }
-    }
-
-
-    // list adapter
-
-    static class AccountListAdapter extends ArrayAdapter<Account> {
-        public AccountListAdapter(Context context) {
-            super(context, R.layout.account_list_item);
-        }
-
-        @Override
-        public View getView(int position, View v, ViewGroup parent) {
-            if (v == null)
-                v = LayoutInflater.from(getContext()).inflate(R.layout.account_list_item, parent, false);
-
-            Account account = getItem(position);
-
-            TextView tv = (TextView)v.findViewById(R.id.account_name);
-            tv.setText(account.name);
-
-            return v;
-        }
-    }
-
-}

app/src/main/java/at/bitfire/davdroid/ui/AccountListFragment.kt

@@ -0,0 +1,103 @@
+/*
+ * Copyright © Ricki Hirner (bitfire web engineering).
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the GNU Public License v3.0
+ * which accompanies this distribution, and is available at
+ * http://www.gnu.org/licenses/gpl.html
+ */
+
+package at.bitfire.davdroid.ui
+
+import android.accounts.Account
+import android.accounts.AccountManager
+import android.accounts.OnAccountsUpdateListener
+import android.app.ListFragment
+import android.app.LoaderManager
+import android.content.AsyncTaskLoader
+import android.content.Context
+import android.content.Intent
+import android.content.Loader
+import android.os.Bundle
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.AbsListView
+import android.widget.AdapterView
+import android.widget.ArrayAdapter
+import at.bitfire.davdroid.AccountsChangedReceiver
+import at.bitfire.davdroid.R
+import kotlinx.android.synthetic.main.account_list_item.view.*
+
+class AccountListFragment: ListFragment(), LoaderManager.LoaderCallbacks<Array<Account>> {
+
+    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
+        listAdapter = AccountListAdapter(activity)
+
+        return inflater.inflate(R.layout.account_list, container, false)
+    }
+
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        super.onViewCreated(view, savedInstanceState)
+        loaderManager.initLoader(0, arguments, this)
+
+        listView.choiceMode = AbsListView.CHOICE_MODE_SINGLE
+        listView.onItemClickListener = AdapterView.OnItemClickListener { _, _, position, _ ->
+            val account = listAdapter.getItem(position) as Account
+            val intent = Intent(activity, AccountActivity::class.java)
+            intent.putExtra(AccountActivity.EXTRA_ACCOUNT, account)
+            startActivity(intent)
+        }
+    }
+
+
+    // loader
+
+    override fun onCreateLoader(id: Int, args: Bundle?) =
+            AccountLoader(activity)
+
+    override fun onLoadFinished(loader: Loader<Array<Account>>, accounts: Array<Account>) {
+        val adapter = listAdapter as AccountListAdapter
+        adapter.clear()
+        adapter.addAll(*accounts)
+    }
+
+    override fun onLoaderReset(loader: Loader<Array<Account>>) {
+        (listAdapter as AccountListAdapter).clear()
+    }
+
+    class AccountLoader(
+            context: Context
+    ): AsyncTaskLoader<Array<Account>>(context), OnAccountsUpdateListener {
+
+        override fun onStartLoading() =
+                AccountsChangedReceiver.registerListener(this, true)
+
+        override fun onStopLoading() =
+                AccountsChangedReceiver.unregisterListener(this)
+
+        override fun onAccountsUpdated(accounts: Array<Account>?) =
+                forceLoad()
+
+        override fun loadInBackground(): Array<Account> =
+            AccountManager.get(context).getAccountsByType(context.getString(R.string.account_type))
+
+    }
+
+
+    // list adapter
+
+    class AccountListAdapter(
+            context: Context
+    ): ArrayAdapter<Account>(context, R.layout.account_list_item) {
+
+        override fun getView(position: Int, v: View?, parent: ViewGroup?): View {
+            val account = getItem(position)
+
+            val v = v ?: LayoutInflater.from(context).inflate(R.layout.account_list_item, parent, false)
+            v.account_name.text = account.name
+
+            return v
+        }
+    }
+
+}

app/src/main/java/at/bitfire/davdroid/ui/AccountSettingsActivity.java

@@ -1,319 +0,0 @@
-/*
- * Copyright © 2013 – 2016 Ricki Hirner (bitfire web engineering).
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the GNU Public License v3.0
- * which accompanies this distribution, and is available at
- * http://www.gnu.org/licenses/gpl.html
- */
-
-package at.bitfire.davdroid.ui;
-
-import android.accounts.Account;
-import android.content.ContentResolver;
-import android.content.Context;
-import android.content.Intent;
-import android.content.SyncStatusObserver;
-import android.os.Bundle;
-import android.provider.CalendarContract;
-import android.provider.ContactsContract;
-import android.support.v4.app.LoaderManager;
-import android.support.v4.app.NavUtils;
-import android.support.v4.content.AsyncTaskLoader;
-import android.support.v4.content.Loader;
-import android.support.v7.app.AppCompatActivity;
-import android.support.v7.preference.EditTextPreference;
-import android.support.v7.preference.ListPreference;
-import android.support.v7.preference.Preference;
-import android.support.v7.preference.PreferenceFragmentCompat;
-import android.support.v7.preference.SwitchPreferenceCompat;
-import android.text.TextUtils;
-import android.view.MenuItem;
-
-import at.bitfire.davdroid.AccountSettings;
-import at.bitfire.davdroid.InvalidAccountException;
-import at.bitfire.davdroid.R;
-import at.bitfire.ical4android.TaskProvider;
-import at.bitfire.vcard4android.GroupMethod;
-
-public class AccountSettingsActivity extends AppCompatActivity {
-    public final static String EXTRA_ACCOUNT = "account";
-
-    private Account account;
-
-    @Override
-    protected void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-
-        account = getIntent().getParcelableExtra(EXTRA_ACCOUNT);
-        setTitle(getString(R.string.settings_title, account.name));
-
-        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
-
-        if (savedInstanceState == null)
-            getSupportFragmentManager().beginTransaction()
-                    .replace(android.R.id.content, AccountSettingsFragment.instantiate(this, AccountSettingsFragment.class.getName(), getIntent().getExtras()))
-                    .commit();
-    }
-
-    @Override
-    public boolean onOptionsItemSelected(MenuItem item) {
-        if (item.getItemId() == android.R.id.home) {
-            Intent intent = new Intent(this, AccountActivity.class);
-            intent.putExtra(AccountActivity.EXTRA_ACCOUNT, account);
-            NavUtils.navigateUpTo(this, intent);
-            return true;
-        } else
-            return false;
-    }
-
-
-    public static class AccountSettingsFragment extends PreferenceFragmentCompat implements LoaderManager.LoaderCallbacks<AccountSettings> {
-        Account account;
-
-        @Override
-        public void onCreate(Bundle savedInstanceState) {
-            super.onCreate(savedInstanceState);
-
-            account = getArguments().getParcelable(EXTRA_ACCOUNT);
-
-            getLoaderManager().initLoader(0, getArguments(), this);
-        }
-
-        @Override
-        public void onCreatePreferences(Bundle bundle, String s) {
-            addPreferencesFromResource(R.xml.settings_account);
-        }
-
-        @Override
-        public Loader<AccountSettings> onCreateLoader(int id, Bundle args) {
-            return new AccountSettingsLoader(getContext(), (Account)args.getParcelable(EXTRA_ACCOUNT));
-        }
-
-        @Override
-        public void onLoadFinished(Loader<AccountSettings> loader, final AccountSettings settings) {
-            if (settings == null) {
-                getActivity().finish();
-                return;
-            }
-
-            // category: authentication
-            final EditTextPreference prefUserName = (EditTextPreference)findPreference("username");
-            prefUserName.setSummary(settings.username());
-            prefUserName.setText(settings.username());
-            prefUserName.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
-                @Override
-                public boolean onPreferenceChange(Preference preference, Object newValue) {
-                    settings.username((String)newValue);
-                    getLoaderManager().restartLoader(0, getArguments(), AccountSettingsFragment.this);
-                    return false;
-                }
-            });
-
-            final EditTextPreference prefPassword = (EditTextPreference)findPreference("password");
-            prefPassword.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
-                @Override
-                public boolean onPreferenceChange(Preference preference, Object newValue) {
-                    settings.password((String)newValue);
-                    getLoaderManager().restartLoader(0, getArguments(), AccountSettingsFragment.this);
-                    return false;
-                }
-            });
-
-            // category: synchronization
-            final ListPreference prefSyncContacts = (ListPreference)findPreference("sync_interval_contacts");
-            final Long syncIntervalContacts = settings.getSyncInterval(ContactsContract.AUTHORITY);
-            if (syncIntervalContacts != null) {
-                prefSyncContacts.setValue(syncIntervalContacts.toString());
-                if (syncIntervalContacts == AccountSettings.SYNC_INTERVAL_MANUALLY)
-                    prefSyncContacts.setSummary(R.string.settings_sync_summary_manually);
-                else
-                    prefSyncContacts.setSummary(getString(R.string.settings_sync_summary_periodically, syncIntervalContacts / 60));
-                prefSyncContacts.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
-                    @Override
-                    public boolean onPreferenceChange(Preference preference, Object newValue) {
-                        settings.setSyncInterval(ContactsContract.AUTHORITY, Long.parseLong((String)newValue));
-                        return false;
-                    }
-                });
-            } else {
-                prefSyncContacts.setEnabled(false);
-                prefSyncContacts.setSummary(R.string.settings_sync_summary_not_available);
-            }
-
-            final ListPreference prefSyncCalendars = (ListPreference)findPreference("sync_interval_calendars");
-            final Long syncIntervalCalendars = settings.getSyncInterval(CalendarContract.AUTHORITY);
-            if (syncIntervalCalendars != null) {
-                prefSyncCalendars.setValue(syncIntervalCalendars.toString());
-                if (syncIntervalCalendars == AccountSettings.SYNC_INTERVAL_MANUALLY)
-                    prefSyncCalendars.setSummary(R.string.settings_sync_summary_manually);
-                else
-                    prefSyncCalendars.setSummary(getString(R.string.settings_sync_summary_periodically, syncIntervalCalendars / 60));
-                prefSyncCalendars.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
-                    @Override
-                    public boolean onPreferenceChange(Preference preference, Object newValue) {
-                        settings.setSyncInterval(CalendarContract.AUTHORITY, Long.parseLong((String)newValue));
-                        return false;
-                    }
-                });
-            } else {
-                prefSyncCalendars.setEnabled(false);
-                prefSyncCalendars.setSummary(R.string.settings_sync_summary_not_available);
-            }
-
-            final ListPreference prefSyncTasks = (ListPreference)findPreference("sync_interval_tasks");
-            final Long syncIntervalTasks = settings.getSyncInterval(TaskProvider.ProviderName.OpenTasks.authority);
-            if (syncIntervalTasks != null) {
-                prefSyncTasks.setValue(syncIntervalTasks.toString());
-                if (syncIntervalTasks == AccountSettings.SYNC_INTERVAL_MANUALLY)
-                    prefSyncTasks.setSummary(R.string.settings_sync_summary_manually);
-                else
-                    prefSyncTasks.setSummary(getString(R.string.settings_sync_summary_periodically, syncIntervalTasks / 60));
-                prefSyncTasks.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
-                    @Override
-                    public boolean onPreferenceChange(Preference preference, Object newValue) {
-                        settings.setSyncInterval(TaskProvider.ProviderName.OpenTasks.authority, Long.parseLong((String)newValue));
-                        return false;
-                    }
-                });
-            } else {
-                prefSyncTasks.setEnabled(false);
-                prefSyncTasks.setSummary(R.string.settings_sync_summary_not_available);
-            }
-
-            final SwitchPreferenceCompat prefWifiOnly = (SwitchPreferenceCompat)findPreference("sync_wifi_only");
-            prefWifiOnly.setChecked(settings.getSyncWifiOnly());
-            prefWifiOnly.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
-                @Override
-                public boolean onPreferenceChange(Preference preference, Object wifiOnly) {
-                    settings.setSyncWiFiOnly((Boolean)wifiOnly);
-                    getLoaderManager().restartLoader(0, getArguments(), AccountSettingsFragment.this);
-                    return false;
-                }
-            });
-
-            final EditTextPreference prefWifiOnlySSID = (EditTextPreference)findPreference("sync_wifi_only_ssid");
-            final String onlySSID = settings.getSyncWifiOnlySSID();
-            prefWifiOnlySSID.setText(onlySSID);
-            if (onlySSID != null)
-                prefWifiOnlySSID.setSummary(getString(R.string.settings_sync_wifi_only_ssid_on, onlySSID));
-            else
-                prefWifiOnlySSID.setSummary(R.string.settings_sync_wifi_only_ssid_off);
-            prefWifiOnlySSID.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
-                @Override
-                public boolean onPreferenceChange(Preference preference, Object newValue) {
-                    String ssid = (String)newValue;
-                    settings.setSyncWifiOnlySSID(!TextUtils.isEmpty(ssid) ? ssid : null);
-                    getLoaderManager().restartLoader(0, getArguments(), AccountSettingsFragment.this);
-                    return false;
-                }
-            });
-
-            // category: CardDAV
-            final ListPreference prefGroupMethod = (ListPreference)findPreference("contact_group_method");
-            if (syncIntervalContacts != null) {
-                prefGroupMethod.setValue(settings.getGroupMethod().name());
-                prefGroupMethod.setSummary(prefGroupMethod.getEntry());
-                prefGroupMethod.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
-                    @Override
-                    public boolean onPreferenceChange(Preference preference, Object o) {
-                        String name = (String)o;
-                        settings.setGroupMethod(GroupMethod.valueOf(name));
-                        getLoaderManager().restartLoader(0, getArguments(), AccountSettingsFragment.this);
-                        return false;
-                    }
-                });
-            } else
-                prefGroupMethod.setEnabled(false);
-
-            // category: CalDAV
-            final EditTextPreference prefTimeRangePastDays = (EditTextPreference)findPreference("time_range_past_days");
-            if (syncIntervalCalendars != null) {
-                Integer pastDays = settings.getTimeRangePastDays();
-                if (pastDays != null) {
-                    prefTimeRangePastDays.setText(pastDays.toString());
-                    prefTimeRangePastDays.setSummary(getResources().getQuantityString(R.plurals.settings_sync_time_range_past_days, pastDays, pastDays));
-                } else {
-                    prefTimeRangePastDays.setText(null);
-                    prefTimeRangePastDays.setSummary(R.string.settings_sync_time_range_past_none);
-                }
-                prefTimeRangePastDays.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
-                    @Override
-                    public boolean onPreferenceChange(Preference preference, Object newValue) {
-                        int days;
-                        try {
-                            days = Integer.parseInt((String)newValue);
-                        } catch(NumberFormatException ignored) {
-                            days = -1;
-                        }
-                        settings.setTimeRangePastDays(days < 0 ? null : days);
-                        getLoaderManager().restartLoader(0, getArguments(), AccountSettingsFragment.this);
-                        return false;
-                    }
-                });
-            } else
-                prefTimeRangePastDays.setEnabled(false);
-
-            final SwitchPreferenceCompat prefManageColors = (SwitchPreferenceCompat)findPreference("manage_calendar_colors");
-            if (syncIntervalCalendars != null || syncIntervalTasks != null) {
-                prefManageColors.setChecked(settings.getManageCalendarColors());
-                prefManageColors.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
-                    @Override
-                    public boolean onPreferenceChange(Preference preference, Object newValue) {
-                        settings.setManageCalendarColors((Boolean)newValue);
-                        getLoaderManager().restartLoader(0, getArguments(), AccountSettingsFragment.this);
-                        return false;
-                    }
-                });
-            } else
-                prefManageColors.setEnabled(false);
-
-        }
-
-        @Override
-        public void onLoaderReset(Loader<AccountSettings> loader) {
-        }
-
-    }
-
-
-    private static class AccountSettingsLoader extends AsyncTaskLoader<AccountSettings> implements SyncStatusObserver {
-
-        final Account account;
-        Object listenerHandle;
-
-        public AccountSettingsLoader(Context context, Account account) {
-            super(context);
-            this.account = account;
-        }
-
-        @Override
-        protected void onStartLoading() {
-            forceLoad();
-
-            listenerHandle = ContentResolver.addStatusChangeListener(ContentResolver.SYNC_OBSERVER_TYPE_SETTINGS, this);
-        }
-
-        @Override
-        protected void onStopLoading() {
-            ContentResolver.removeStatusChangeListener(listenerHandle);
-        }
-
-        @Override
-        public AccountSettings loadInBackground() {
-            AccountSettings settings;
-            try {
-                settings = new AccountSettings(getContext(), account);
-            } catch(InvalidAccountException e) {
-                return null;
-            }
-            return settings;
-        }
-
-        @Override
-        public void onStatusChanged(int which) {
-            forceLoad();
-        }
-
-    }
-
-}