Update gradle plugin

* scan unrequested responses for useful auto-detection information
* cert4android: Kotlin

.gitlab-ci.yml

@@ -0,0 +1,20 @@
+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
+
+cache:
+  paths:
+     - .gradle/
+
+test:
+  script:
+    - ./gradlew check mergeAndroidReports
+  artifacts:
+    paths:
+      - app/build/outputs/lint-results-debug.html
+      - app/build/reports
+      - build/reports

.gitmodules

@@ -1,13 +1,12 @@
 [submodule "dav4android"]
 	path = dav4android
-	url = https://gitlab.com/bitfireAT/dav4android.git
+	url = ../dav4android.git
 [submodule "ical4android"]
 	path = ical4android
-	url = https://gitlab.com/bitfireAT/ical4android.git
+	url = ../ical4android.git
 [submodule "vcard4android"]
 	path = vcard4android
-	url = https://gitlab.com/bitfireAT/vcard4android.git
-[submodule "MemorizingTrustManager"]
-	path = MemorizingTrustManager
-	url = https://github.com/ge0rg/MemorizingTrustManager
-	ignore = dirty
+	url = ../vcard4android.git
+[submodule "cert4android"]
+	path = cert4android
+	url = ../cert4android.git

README.md

@@ -1,4 +1,7 @@
 
+[![build status](https://gitlab.com/bitfireAT/davdroid/badges/master/build.svg)](https://gitlab.com/bitfireAT/davdroid/commits/master)
+
+
 DAVdroid
 ========
 
@@ -7,18 +10,21 @@ 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 /
+[davdroid-announce](https://davdroid.bitfire.at/download/newsletter/) mailing list
 
 Help and discussion: [DAVdroid forums](https://davdroid.bitfire.at/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:
 
+* [cert4android](https://gitlab.com/bitfireAT/cert4android) – custom certificate management
 * [dav4android](https://gitlab.com/bitfireAT/dav4android) – WebDAV/CalDav/CardDAV framework
 * [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
 ==========================
@@ -28,7 +34,5 @@ Those libraries are used by DAVdroid (alphabetically):
 * [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)
-* [MemorizingTrustManager](https://github.com/ge0rg/MemorizingTrustManager) – [MIT License](https://raw.githubusercontent.com/ge0rg/MemorizingTrustManager/master/LICENSE.txt)
 * [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)
-* [SLF4J](http://www.slf4j.org/) – [MIT License](http://www.slf4j.org/license.html)

app/build.gradle

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013 – 2016 Ricki Hirner (bitfire web engineering).
+ * Copyright (c) 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
@@ -9,25 +9,71 @@
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 23
-    buildToolsVersion "23.0.3"
+    compileSdkVersion 26
+    buildToolsVersion '26.0.0'
 
     defaultConfig {
         applicationId "at.bitfire.davdroid"
-        minSdkVersion 14
-        targetSdkVersion 23
-
-        versionCode 109
+        resValue "string", "packageID", applicationId
 
+        versionCode 152
         buildConfigField "long", "buildTime", System.currentTimeMillis() + "L"
+
+        minSdkVersion 15
+        targetSdkVersion 25
+
+        buildConfigField "boolean", "customCerts", "false"
+        buildConfigField "at.bitfire.vcard4android.GroupMethod", "settingContactGroupMethod", "null"
     }
 
     productFlavors {
         standard {
-            versionName "1.2"
+            versionName "1.6.2"
+            buildConfigField "boolean", "customCerts", "true"
         }
+
         gplay {
-            versionName "1.2-gplay"
+            versionName "1.6.2-gplay"
+            buildConfigField "boolean", "customCerts", "true"
+        }
+        icloud {
+            applicationId "at.bitfire.cloudsync"
+            resValue "string", "packageID", applicationId
+
+            versionName "1.6.2-cloud"
+            buildConfigField "at.bitfire.vcard4android.GroupMethod", "settingContactGroupMethod", "at.bitfire.vcard4android.GroupMethod.GROUP_VCARDS"
+        }
+        soldupe {
+            applicationId "com.soldupe.cloudsync"
+            resValue "string", "packageID", applicationId
+            minSdkVersion 21
+
+            versionName "1.6.2-soldupe"
+            buildConfigField "boolean", "customCerts", "true"
+            buildConfigField "at.bitfire.vcard4android.GroupMethod", "settingContactGroupMethod", "at.bitfire.vcard4android.GroupMethod.CATEGORIES"
+        }
+    }
+
+    sourceSets {
+        standard.java.srcDirs = [ "src/davdroid/java" ]
+        standard.res.srcDirs = [ "src/davdroid/res" ]
+        gplay.java.srcDirs = [ "src/gplay/java", "src/davdroid/java" ]
+        gplay.res.srcDirs = [ "src/gplay/res", "src/davdroid/res" ]
+
+    }
+
+    signingConfigs {
+        bitfire {
+            storeFile file("${System.env.HOME}/Entwicklung/GooglePlay/bitfire.jks")
+            storePassword '***REMOVED***'
+            keyAlias 'bitfire'
+            keyPassword '***REMOVED***'
+        }
+        soldupe {
+            storeFile file("${System.env.HOME}/Entwicklung/GooglePlay/soldupe.jks")
+            storePassword 'hei8eePh'
+            keyAlias 'soldupe'
+            keyPassword 'ocaip6oZ'
         }
     }
 
@@ -38,6 +84,9 @@ android {
         release {
             minifyEnabled true
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
+
+            signingConfig signingConfigs.bitfire
+            productFlavors.soldupe.signingConfig signingConfigs.soldupe
         }
     }
 
@@ -48,9 +97,8 @@ android {
         disable 'IconColors'
         disable 'IconLauncherShape'
         disable 'IconMissingDensityFolder'
-        disable 'ImpliedQuantity'
-        disable 'MissingTranslation'
-        disable 'MissingQuantity'
+        disable 'ImpliedQuantity', 'MissingQuantity'
+        disable 'MissingTranslation', 'ExtraTranslation'	// translations from Transifex are not always up to date
         disable 'Recycle'           // doesn't understand Lombok's @Cleanup
         disable 'RtlEnabled'
         disable 'RtlHardcoded'
@@ -61,28 +109,43 @@ android {
         exclude 'META-INF/LICENSE.txt'
         exclude 'META-INF/NOTICE.txt'
     }
+
+    defaultConfig {
+        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+    }
 }
 
 dependencies {
+    compile project(':cert4android')
     compile project(':dav4android')
     compile project(':ical4android')
     compile project(':vcard4android')
+    compile project(':market_licensing')
 
-    compile 'com.android.support:appcompat-v7:23.+'
-    compile 'com.android.support:cardview-v7:23.+'
-    compile 'com.android.support:design:23.+'
-    compile 'com.android.support:preference-v14:23.+'
+    compile 'com.android.support:appcompat-v7:26.+'
+    compile 'com.android.support:cardview-v7:26.+'
+    compile 'com.android.support:design:26.+'
+    compile 'com.android.support:preference-v14:26.+'
 
     compile 'com.github.yukuku:ambilwarna:2.0.1'
-    compile project(':MemorizingTrustManager')
 
-    compile 'dnsjava:dnsjava:2.1.7'
-    compile 'org.apache.commons:commons-lang3:3.4'
+    compile 'com.squareup.okhttp3:logging-interceptor:3.8.1'
+    compile 'commons-io:commons-io:2.5'
+    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:1.16.8'
+    provided 'org.projectlombok:lombok:1.16.16'
 
     // for tests
+    androidTestCompile('com.android.support.test:runner:+') {
+        exclude group: 'com.android.support', module: 'support-annotations'
+    }
+    androidTestCompile('com.android.support.test:rules:+') {
+        exclude group: 'com.android.support', module: 'support-annotations'
+    }
+    androidTestCompile 'junit:junit:4.12'
+    androidTestCompile 'com.squareup.okhttp3:mockwebserver:3.8.1'
+
     testCompile 'junit:junit:4.12'
-    testCompile 'com.squareup.okhttp3:mockwebserver:3.3.1'
-    androidTestCompile 'com.squareup.okhttp3:mockwebserver:3.3.1'
+    testCompile 'com.squareup.okhttp3:mockwebserver:3.8.1'
 }

app/proguard-rules.txt

@@ -1,9 +1,9 @@
 
 # ProGuard usage for DAVdroid:
-# 	shrinking		yes (main reason for using ProGuard)
-# 	optimization		yes
-# 	obfuscation		no (DAVdroid is open-source)
-# 	preverification		no
+#       shrinking        yes (main reason for using ProGuard)
+#       optimization     yes
+#       obfuscation      no (DAVdroid is open-source)
+#       preverification  no
 
 -dontobfuscate
 
@@ -13,29 +13,26 @@
 -dontpreverify
 
 # 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 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)
+-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 groovy.**                       # Groovy-based ContentBuilder not used
 -dontwarn org.codehaus.groovy.**
--dontwarn org.apache.commons.logging.**		# Commons logging is not available
--dontwarn net.fortuna.ical4j.model.**		# ignore warnings from Groovy dependency
--keep class net.fortuna.ical4j.model.** { *; }	# keep all model classes (properties/factories, created at runtime)
+-dontwarn net.fortuna.ical4j.model.**     # ignore warnings from Groovy dependency
+-keep class net.fortuna.ical4j.** { *; }  # keep all model classes (properties/factories, created at runtime)
 
 # okhttp
--dontwarn java.nio.file.**		# not available on Android
--dontwarn org.codehaus.mojo.animal_sniffer.IgnoreJRERequirement
-
-# MemorizingTrustManager
--dontwarn de.duenndns.ssl.MemorizingTrustManager
+-dontwarn okio.**
+-dontwarn javax.annotation.Nullable
+-dontwarn javax.annotation.ParametersAreNonnullByDefault
 
 # dnsjava
--dontwarn sun.net.spi.nameservice.**		# not available on Android
+-dontwarn sun.net.spi.nameservice.**   # not available on Android
 
 # DAVdroid + libs
--keep class at.bitfire.** { *; }	# all DAVdroid code is required
+-keep class at.bitfire.** { *; }       # all DAVdroid code is required

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

@@ -9,33 +9,43 @@
 package at.bitfire.davdroid;
 
 import android.os.Build;
-import android.test.InstrumentationTestCase;
+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 de.duenndns.ssl.MemorizingTrustManager;
+import at.bitfire.cert4android.CustomCertManager;
 import okhttp3.mockwebserver.MockWebServer;
 
-public class SSLSocketFactoryCompatTest extends InstrumentationTestCase {
+import static android.support.test.InstrumentationRegistry.getTargetContext;
+import static junit.framework.TestCase.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+public class SSLSocketFactoryCompatTest {
 
     SSLSocketFactoryCompat factory;
     MockWebServer server = new MockWebServer();
 
-    @Override
-    protected void setUp() throws Exception {
-        factory = new SSLSocketFactoryCompat(new MemorizingTrustManager(getInstrumentation().getTargetContext().getApplicationContext()));
+    @Before
+    public void startServer() throws Exception {
+        factory = new SSLSocketFactoryCompat(new CustomCertManager(getTargetContext().getApplicationContext(), true));
         server.start();
     }
 
-    @Override
-    protected void tearDown() throws Exception {
+    @After
+    public void stopServer() throws Exception {
         server.shutdown();
     }
 
 
+    @Test
     public void testUpgradeTLS() throws IOException {
         Socket s = factory.createSocket(server.getHostName(), server.getPort());
         assertTrue(s instanceof SSLSocket);

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

@@ -9,8 +9,10 @@
 package at.bitfire.davdroid.model;
 
 import android.content.ContentValues;
+import android.support.test.runner.AndroidJUnit4;
 
-import junit.framework.TestCase;
+import org.junit.Test;
+import org.junit.runner.RunWith;
 
 import java.io.IOException;
 
@@ -23,10 +25,16 @@ import at.bitfire.davdroid.model.ServiceDB.Collections;
 import okhttp3.mockwebserver.MockResponse;
 import okhttp3.mockwebserver.MockWebServer;
 
-public class CollectionInfoTest extends TestCase {
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+
+public class CollectionInfoTest {
 
     MockWebServer server = new MockWebServer();
 
+    @Test
     public void testFromDavResource() throws IOException, HttpException, DavException {
         // r/w address book
         server.enqueue(new MockResponse()
@@ -42,7 +50,7 @@ public class CollectionInfoTest extends TestCase {
                         "</response>" +
                         "</multistatus>"));
 
-        DavResource dav = new DavResource(HttpClient.create(), server.url("/"));
+        DavResource dav = new DavResource(HttpClient.create(null), server.url("/"));
         dav.propfind(0, ResourceType.NAME);
         CollectionInfo info = CollectionInfo.fromDavResource(dav);
         assertEquals(CollectionInfo.Type.ADDRESS_BOOK, info.type);
@@ -66,7 +74,7 @@ public class CollectionInfoTest extends TestCase {
                         "</response>" +
                         "</multistatus>"));
 
-        dav = new DavResource(HttpClient.create(), server.url("/"));
+        dav = new DavResource(HttpClient.create(null), server.url("/"));
         dav.propfind(0, ResourceType.NAME);
         info = CollectionInfo.fromDavResource(dav);
         assertEquals(CollectionInfo.Type.CALENDAR, info.type);
@@ -79,6 +87,7 @@ public class CollectionInfoTest extends TestCase {
         assertTrue(info.supportsVTODO);
     }
 
+    @Test
     public void testFromDB() {
         ContentValues values = new ContentValues();
         values.put(Collections.ID, 1);

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

@@ -8,8 +8,14 @@
 
 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;
 
@@ -29,7 +35,13 @@ import okhttp3.mockwebserver.MockResponse;
 import okhttp3.mockwebserver.MockWebServer;
 import okhttp3.mockwebserver.RecordedRequest;
 
-public class DavResourceFinderTest extends InstrumentationTestCase {
+import static android.support.test.InstrumentationRegistry.getTargetContext;
+import static junit.framework.TestCase.assertFalse;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+
+public class DavResourceFinderTest {
 
     MockWebServer server = new MockWebServer();
 
@@ -48,24 +60,24 @@ public class DavResourceFinderTest extends InstrumentationTestCase {
             SUBPATH_ADDRESSBOOK_HOMESET = "/addressbooks",
             SUBPATH_ADDRESSBOOK = "/addressbooks/private-contacts";
 
-    @Override
-    protected void setUp() throws Exception {
+    @Before
+    public void initServerAndClient() throws Exception {
         server.setDispatcher(new TestDispatcher());
         server.start();
 
-        credentials = new LoginCredentials(URI.create("/"), "mock", "12345", true);
-        finder = new DavResourceFinder(getInstrumentation().getContext(), credentials);
+        credentials = new LoginCredentials(URI.create("/"), "mock", "12345");
+        finder = new DavResourceFinder(getTargetContext(), credentials);
 
-        client = HttpClient.create();
-        client = HttpClient.addAuthentication(client, credentials.userName, credentials.password, credentials.authPreemptive);
+        client = HttpClient.create(null);
+        client = HttpClient.addAuthentication(client, credentials.userName, credentials.password);
     }
 
-    @Override
-    protected void tearDown() throws Exception {
+    @After
+    public void stopServer() throws Exception {
         server.shutdown();
     }
 
-
+    @Test
     public void testRememberIfAddressBookOrHomeset() throws IOException, HttpException, DavException {
         ServiceInfo info;
 
@@ -91,6 +103,7 @@ public class DavResourceFinderTest extends InstrumentationTestCase {
         assertEquals(0, info.homeSets.size());
     }
 
+    @Test
     public void testProvidesService() throws IOException {
         assertFalse(finder.providesService(server.url(PATH_NO_DAV), DavResourceFinder.Service.CALDAV));
         assertFalse(finder.providesService(server.url(PATH_NO_DAV), DavResourceFinder.Service.CARDDAV));
@@ -105,6 +118,7 @@ public class DavResourceFinderTest extends InstrumentationTestCase {
         assertTrue(finder.providesService(server.url(PATH_CALDAV_AND_CARDDAV), DavResourceFinder.Service.CARDDAV));
     }
 
+    @Test
     public void testGetCurrentUserPrincipal() throws IOException, HttpException, DavException {
         assertNull(finder.getCurrentUserPrincipal(server.url(PATH_NO_DAV), DavResourceFinder.Service.CALDAV));
         assertNull(finder.getCurrentUserPrincipal(server.url(PATH_NO_DAV), DavResourceFinder.Service.CARDDAV));
@@ -129,8 +143,11 @@ public class DavResourceFinderTest extends InstrumentationTestCase {
 
         @Override
         public MockResponse dispatch(RecordedRequest rq) throws InterruptedException {
-            if (!checkAuth(rq))
-                return new MockResponse().setResponseCode(401);
+            if (!checkAuth(rq)) {
+                MockResponse authenticate = new MockResponse().setResponseCode(401);
+                authenticate.setHeader("WWW-Authenticate", "Basic realm=\"test\"");
+                return authenticate;
+            }
 
             String path = rq.getPath();
 

app/src/davdroid/java/at/bitfire/davdroid/ui/DefaultAccountsDrawerHandler.java

@@ -0,0 +1,50 @@
+package at.bitfire.davdroid.ui;
+
+import android.app.Activity;
+import android.content.Intent;
+import android.net.Uri;
+import android.support.annotation.NonNull;
+import android.view.MenuItem;
+
+import at.bitfire.davdroid.App;
+import at.bitfire.davdroid.BuildConfig;
+import at.bitfire.davdroid.Constants;
+import at.bitfire.davdroid.R;
+
+public class DefaultAccountsDrawerHandler implements IAccountsDrawerHandler {
+
+    @Override
+    public boolean onNavigationItemSelected(@NonNull Activity activity, MenuItem item) {
+        switch (item.getItemId()) {
+            case R.id.nav_about:
+                activity.startActivity(new Intent(activity, AboutActivity.class));
+                break;
+            case R.id.nav_app_settings:
+                activity.startActivity(new Intent(activity, AppSettingsActivity.class));
+                break;
+            case R.id.nav_twitter:
+                activity.startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse("https://twitter.com/davdroidapp")));
+                break;
+            case R.id.nav_website:
+                activity.startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse(activity.getString(R.string.homepage_url))));
+                break;
+            case R.id.nav_faq:
+                activity.startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse(activity.getString(R.string.navigation_drawer_faq_url))));
+                break;
+            case R.id.nav_forums:
+                activity.startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse(activity.getString(R.string.homepage_url))
+                        .buildUpon().appendEncodedPath("forums/").build()));
+                break;
+            case R.id.nav_donate:
+                if (BuildConfig.FLAVOR != App.FLAVOR_GOOGLE_PLAY)
+                    activity.startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse(activity.getString(R.string.homepage_url))
+                            .buildUpon().appendEncodedPath("donate/").build()));
+                break;
+	    default:
+                return false;
+        }
+
+        return true;
+    }
+
+}

app/src/davdroid/java/at/bitfire/davdroid/ui/setup/DefaultLoginCredentialsFragment.java

@@ -8,14 +8,16 @@
 
 package at.bitfire.davdroid.ui.setup;
 
+import android.app.Activity;
+import android.content.Intent;
 import android.net.Uri;
 import android.os.Bundle;
+import android.support.annotation.Nullable;
 import android.support.v4.app.Fragment;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.Button;
-import android.widget.CheckBox;
 import android.widget.CompoundButton;
 import android.widget.EditText;
 import android.widget.LinearLayout;
@@ -32,7 +34,7 @@ import at.bitfire.dav4android.Constants;
 import at.bitfire.davdroid.R;
 import at.bitfire.davdroid.ui.widget.EditPassword;
 
-public class LoginCredentialsFragment extends Fragment implements CompoundButton.OnCheckedChangeListener {
+public class DefaultLoginCredentialsFragment extends Fragment implements CompoundButton.OnCheckedChangeListener {
 
     RadioButton radioUseEmail;
     LinearLayout emailDetails;
@@ -43,9 +45,9 @@ public class LoginCredentialsFragment extends Fragment implements CompoundButton
     LinearLayout urlDetails;
     EditText editBaseURL, editUserName;
     EditPassword editUrlPassword;
-    CheckBox checkPreemptiveAuth;
 
 
+    @Nullable
     @Override
     public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
         View v = inflater.inflate(R.layout.login_credentials_fragment, container, false);
@@ -60,13 +62,35 @@ public class LoginCredentialsFragment extends Fragment implements CompoundButton
         editBaseURL = (EditText)v.findViewById(R.id.base_url);
         editUserName = (EditText)v.findViewById(R.id.user_name);
         editUrlPassword = (EditPassword)v.findViewById(R.id.url_password);
-        checkPreemptiveAuth = (CheckBox)v.findViewById(R.id.preemptive_auth);
 
         radioUseEmail.setOnCheckedChangeListener(this);
         radioUseURL.setOnCheckedChangeListener(this);
 
-        if (savedInstanceState == null)
-            radioUseEmail.setChecked(true);
+        if (savedInstanceState == null) {
+            // first call
+
+            Activity activity = getActivity();
+            Intent intent = (activity != null) ? activity.getIntent() : null;
+            if (intent != null) {
+                // we've got initial login data
+                String  url = intent.getStringExtra(LoginActivity.EXTRA_URL),
+                        username = intent.getStringExtra(LoginActivity.EXTRA_USERNAME),
+                        password = intent.getStringExtra(LoginActivity.EXTRA_PASSWORD);
+
+                if (url != null) {
+                    radioUseURL.setChecked(true);
+                    editBaseURL.setText(url);
+                    editUserName.setText(username);
+                    editUrlPassword.setText(password);
+                } else {
+                    radioUseEmail.setChecked(true);
+                    editEmailAddress.setText(username);
+                    editEmailPassword.setText(password);
+                }
+
+            } else
+                radioUseEmail.setChecked(true);
+        }
 
         final Button login = (Button)v.findViewById(R.id.login);
         login.setOnClickListener(new View.OnClickListener() {
@@ -114,7 +138,7 @@ public class LoginCredentialsFragment extends Fragment implements CompoundButton
                 valid = false;
             }
 
-            return valid ? new LoginCredentials(uri, email, password, true) : null;
+            return valid ? new LoginCredentials(uri, email, password) : null;
 
         } else if (radioUseURL.isChecked()) {
             URI uri = null;
@@ -159,10 +183,20 @@ public class LoginCredentialsFragment extends Fragment implements CompoundButton
                 valid = false;
             }
 
-            return valid ? new LoginCredentials(uri, userName, password, checkPreemptiveAuth.isChecked()) : null;
+            return valid ? new LoginCredentials(uri, userName, password) : null;
         }
 
         return null;
     }
 
+
+    public static class Factory implements ILoginCredentialsFragment {
+
+        @Override
+        public Fragment getFragment() {
+            return new DefaultLoginCredentialsFragment();
+        }
+
+    }
+
 }

app/src/davdroid/res/layout/login_credentials_fragment.xml

@@ -94,13 +94,6 @@
                     android:layout_height="wrap_content"
                     android:hint="@string/login_password"/>
 
-                <CheckBox
-                    android:id="@+id/preemptive_auth"
-                    android:layout_width="wrap_content"
-                    android:layout_height="wrap_content"
-                    android:text="@string/login_auth_preemptive"
-                    android:checked="true"/>
-
             </LinearLayout>
 
         </RadioGroup>

app/src/davdroid/res/values-ca/strings.xml

@@ -14,9 +14,9 @@
   <!--AddAccountActivity-->
   <string name="login_type_email">Entra amb una adreça de correu electrònic</string>
   <string name="login_type_url">Entra amb una URL i un nom d\'usuari</string>
-  <string name="login_auth_preemptive">Autentificació preferent (recomanat però incompatible amb l\'autentificació Digest)</string>
   <!--AccountSettingsActivity-->
   <!--collection management-->
   <!--ExceptionInfoFragment-->
   <!--sync errors and DebugInfoActivity-->
+  <!--cert4android-->
 </resources>

app/src/davdroid/res/values-cs/strings.xml

@@ -7,6 +7,9 @@
   <string name="please_wait">Chvíli strpení ...</string>
   <string name="send">Odeslat</string>
   <!--startup dialogs-->
+  <string name="startup_battery_optimization">Optimalizace využití baterie</string>
+  <string name="startup_battery_optimization_message">Android může po několika dnech vypnout/prodloužit interval synchronizování DAVdroid. Chcete-li tomuto zabránit, vypněte optimalizaci baterie.</string>
+  <string name="startup_battery_optimization_disable">Vypnout pro DAVdroid</string>
   <string name="startup_dont_show_again">Již nezobrazovat</string>
   <string name="startup_development_version">DAVdroid preview vydání</string>
   <string name="startup_development_version_message">Toto je vývojová verze aplikace DAVdroid. Mějte na paměti, že vše nemusí správně fungovat. Budeme rádi za konstruktivní zpětnou vazbu, která pomůže vylepšit DAVdroid.</string>
@@ -53,14 +56,19 @@
   <string name="app_settings_reset_hints">Resetovat nápovědu</string>
   <string name="app_settings_reset_hints_summary">Znovu povolí vypnuté texty nápovědy</string>
   <string name="app_settings_reset_hints_success">Budou zobrazovány všechny texty nápovědy</string>
+  <string name="app_settings_connection">Připojení</string>
+  <string name="app_settings_override_proxy">Přepsat proxy nastavení</string>
+  <string name="app_settings_override_proxy_on">Použít vlastní proxy nastavení</string>
+  <string name="app_settings_override_proxy_off">Použít výchozí systémová proxy nastavení</string>
+  <string name="app_settings_override_proxy_host">HTTP proxy hostname</string>
+  <string name="app_settings_override_proxy_port">HTTP proxy port</string>
   <string name="app_settings_security">Zabezpečení</string>
-  <string name="app_settings_reset_trusted_certificates">Resetovat důvěryhodné certifikáty</string>
-  <string name="app_settings_reset_trusted_certificates_summary">Zapomene všechny dříve akceptované certifikáty</string>
-  <plurals name="app_settings_reset_trusted_certificates_success">
-    <item quantity="one">Znedůvěryhodněn jeden certifikát</item>
-    <item quantity="few">Znedůvěryhodněny %d certifikáty</item>
-    <item quantity="other">Znedůvěryhodněno %d certifikátů</item>
-  </plurals>
+  <string name="app_settings_distrust_system_certs">Nedůvěřovat systémovým certifikátům</string>
+  <string name="app_settings_distrust_system_certs_on">Systémovým a uživatelem přidaným CA nebude důvěřováno</string>
+  <string name="app_settings_distrust_system_certs_off">Systémovým a uživatelem přidaným CA bude důvěřováno (doporučeno)</string>
+  <string name="app_settings_reset_certificates">Resetovat (ne)důvěryhodné certifikáty</string>
+  <string name="app_settings_reset_certificates_summary">Resetovat důvěryhodnost všech vlastních certifikátů</string>
+  <string name="app_settings_reset_certificates_success">Všechny vlastní certifikáty byly resetovány</string>
   <string name="app_settings_debug">Ladění</string>
   <string name="app_settings_log_to_external_storage">Logovat do externího souboru</string>
   <string name="app_settings_log_to_external_storage_on">Logování do externího úložiště (pokud dostupné)</string>
@@ -71,6 +79,9 @@
   <string name="account_synchronize_now">Synchronizovat nyní</string>
   <string name="account_synchronizing_now">Probíhá synchronizace</string>
   <string name="account_settings">Nastavení účtu</string>
+  <string name="account_rename">Přejmenovat účet</string>
+  <string name="account_rename_new_name">Neuložená místní data mohou být vynechána. Po přejmenování je vyžadována nová synchronizace. Nové jméno účtu:</string>
+  <string name="account_rename_rename">Přejmenovat</string>
   <string name="account_delete">Smazat účet</string>
   <string name="account_delete_confirmation_title">Opravdu smazat účet?</string>
   <string name="account_delete_confirmation_text">Všechny místní kopie adresáře, kalendářů a úkolů budou smazány.</string>
@@ -102,7 +113,6 @@
   <string name="login_user_name">Uživatelské jméno</string>
   <string name="login_user_name_required">Vyžadováno uživatelské jméno</string>
   <string name="login_base_url">Základní URL</string>
-  <string name="login_auth_preemptive">Preemptivní ověření (doporučeno, ale není kompatibilní s Digest ověřením)</string>
   <string name="login_login">Login</string>
   <string name="login_back">Zpět</string>
   <string name="login_create_account">Vytvořit účet</string>
@@ -123,9 +133,6 @@
   <string name="settings_password">Heslo</string>
   <string name="settings_password_summary">Aktualizovat heslo dle svého serveru.</string>
   <string name="settings_enter_password">Vložit své heslo:</string>
-  <string name="settings_preemptive">Preemptivní ověření</string>
-  <string name="settings_preemptive_on">Přihlašovací údaje jsou zasílány s každým požadavkem (doporučeno)</string>
-  <string name="settings_preemptive_off">Přihlašovací údaje jsou zasílány po vyžádání serverem</string>
   <string name="settings_sync">Synchronizace</string>
   <string name="settings_sync_interval_contacts">Interval synchronizace kontaktů</string>
   <string name="settings_sync_summary_manually">Pouze manuálně</string>
@@ -170,9 +177,6 @@
     <item>Skupiny jsou oddělené soubory VCard</item>
     <item>Skupiny jsou kategorie na kontakt</item>
   </string-array>
-  <string name="settings_rfc6868_for_vcards">Použít RFC6868 pro VCard</string>
-  <string name="settings_rfc6868_for_vcards_on">Uvozovky lze použít v hodnotách parametrů</string>
-  <string name="settings_rfc6868_for_vcards_off">Uvozovky nelze použít v hodnotách parametrů</string>
   <string name="settings_caldav">CalDAV</string>
   <string name="settings_sync_time_range_past">Časový limit pro staré události</string>
   <string name="settings_sync_time_range_past_none">Synchronizovat všechny události</string>
@@ -185,9 +189,6 @@
   <string name="settings_manage_calendar_colors">Spravovat barvy kalendářů</string>
   <string name="settings_manage_calendar_colors_on">Barvy kalendářů spravuje DAVdroid</string>
   <string name="settings_manage_calendar_colors_off">Barvy kalendářů nespravuje DAVdroid</string>
-  <string name="settings_version_update">Aktualizace verze DAVdroid</string>
-  <string name="settings_version_update_settings_updated">Vnitřní nastavení byla aktualizována.</string>
-  <string name="settings_version_update_install_hint">Při problémech odinstalujte a znovu nainstalujte DAVdroid.</string>
   <!--collection management-->
   <string name="create_addressbook">Vytvořit adresář</string>
   <string name="create_addressbook_display_name_hint">Můj adresář</string>
@@ -239,4 +240,7 @@
     <item>ukládání stavu synchronizace</item>
   </string-array>
   <string name="sync_error_unauthorized">Chybné uživatelské jméno/heslo</string>
+  <!--cert4android-->
+  <string name="certificate_notification_connection_security">DAVdroid: Zabezpečení připojení</string>
+  <string name="trust_certificate_unknown_certificate_found">DAVdroid nalezl neznámý certifikát. Chcete mu důvěřovat?</string>
 </resources>

app/src/davdroid/res/values-da/strings.xml

@@ -2,11 +2,16 @@
 <resources xmlns:tools="http://schemas.android.com/tools">
   <!--common strings-->
   <string name="app_name">DAVdroid</string>
+  <string name="account_title_address_book">DAVdroid Addressebog</string>
+  <string name="address_books_authority_title">Adressebøger</string>
   <string name="help">Hjælp</string>
   <string name="manage_accounts">Administrer konti</string>
-  <string name="please_wait">Vent venligst -</string>
+  <string name="please_wait">Vent venligst ...</string>
   <string name="send">Send</string>
   <!--startup dialogs-->
+  <string name="startup_battery_optimization">Batterioptimering</string>
+  <string name="startup_battery_optimization_message">Android kan deaktivere/reducere DAVDroid synkronisering efter et par dage. For at undgå dette, slå batterioptimering fra.</string>
+  <string name="startup_battery_optimization_disable">Deaktiver DAVdroid</string>
   <string name="startup_dont_show_again">Vis ikke igen</string>
   <string name="startup_development_version">DAVdroid Preview</string>
   <string name="startup_development_version_message">Dette er udviklingsversionen af DAVdroid. Bemærk, at nogle ting måske ikke fungerer, som man forventer. Giv os gerne konstruktiv kritik for at forbedre DAVdroid.</string>
@@ -44,6 +49,8 @@
   <string name="navigation_drawer_forums">Community</string>
   <string name="navigation_drawer_donate">Donation</string>
   <string name="account_list_empty">Velkommen til DAVdroid!\n\nDu kan nu tilføje en CaDAV/CardDAV-konto.</string>
+  <string name="accounts_global_sync_disabled">Automatisk synkronisering på tværs af systemet er deaktiveret</string>
+  <string name="accounts_global_sync_enable">Aktiver</string>
   <!--DavService-->
   <string name="dav_service_refresh_failed">Registrering af tjeneste kunne ikke foretages</string>
   <string name="dav_service_refresh_couldnt_refresh">Kunne opdatere liste over sæt</string>
@@ -53,13 +60,19 @@
   <string name="app_settings_reset_hints">Nulstil vejledende popups</string>
   <string name="app_settings_reset_hints_summary">Genaktiverer hjælp, som er blevet lukket tidligere</string>
   <string name="app_settings_reset_hints_success">Al vejledning vil blive vist igen</string>
+  <string name="app_settings_connection">Forbindelse</string>
+  <string name="app_settings_override_proxy">Tilsidesæt proxyindstillinger</string>
+  <string name="app_settings_override_proxy_on">Brug brugerdefinerede proxyindstillinger</string>
+  <string name="app_settings_override_proxy_off">Brug systemstandard proxyindstillinger</string>
+  <string name="app_settings_override_proxy_host">HTTP proxy værtsnavn</string>
+  <string name="app_settings_override_proxy_port">HTTP proxy port</string>
   <string name="app_settings_security">Sikkerhed</string>
-  <string name="app_settings_reset_trusted_certificates">Nulstil verificerede certifikater</string>
-  <string name="app_settings_reset_trusted_certificates_summary">Glemmer alle certifikater, der er blevet godkendt tidligere</string>
-  <plurals name="app_settings_reset_trusted_certificates_success">
-    <item quantity="one">Ikke-accepteret certifikat</item>
-    <item quantity="other">%d kke-accepterede certifikater</item>
-  </plurals>
+  <string name="app_settings_distrust_system_certs">Stol ikke på systemcertifikater</string>
+  <string name="app_settings_distrust_system_certs_on">System og brugertilføjede CA\'er vil ikke blive betroet</string>
+  <string name="app_settings_distrust_system_certs_off">System og brugertilføjede CA\'er vil blive betroet (anbefalet)</string>
+  <string name="app_settings_reset_certificates">Nulstil (ikke-)betroede certifikater</string>
+  <string name="app_settings_reset_certificates_summary">Nulstiller tilliden til brugerdefinerede certifikater</string>
+  <string name="app_settings_reset_certificates_success">Alle brugerdefinerede certifikater er blevet rydet</string>
   <string name="app_settings_debug">Debugging</string>
   <string name="app_settings_log_to_external_storage">Log til ekstern fil</string>
   <string name="app_settings_log_to_external_storage_on">Logger til eksternt lager (hvis muligt)</string>
@@ -70,6 +83,9 @@
   <string name="account_synchronize_now">Synkroniser nu</string>
   <string name="account_synchronizing_now">Synkroniserer nu</string>
   <string name="account_settings">Opsætning af konti</string>
+  <string name="account_rename">Omdøb konto</string>
+  <string name="account_rename_new_name">Lokaldata der ikke er gemt kan gå tabt. Eftersynkronisering er krævet efter omdøbning. Nyt kontonavn: </string>
+  <string name="account_rename_rename">Omdøb</string>
   <string name="account_delete">Slet konto</string>
   <string name="account_delete_confirmation_title">Ønsker du at slette konto?</string>
   <string name="account_delete_confirmation_text">Alle lokale kopier af addessebøger, kalendere og opgavelister vil blive slettet.</string>
@@ -101,7 +117,6 @@
   <string name="login_user_name">Brugernavn</string>
   <string name="login_user_name_required">Brugernavn påkrævet</string>
   <string name="login_base_url">Basis-URL</string>
-  <string name="login_auth_preemptive">Forhåndsgodkendelse (preemptive authentication - anbefalet, men ikke kompatiblelt med Digest auth)</string>
   <string name="login_login">Login</string>
   <string name="login_back">Tilbage</string>
   <string name="login_create_account">Opret konto</string>
@@ -122,9 +137,6 @@
   <string name="settings_password">Adgangskode</string>
   <string name="settings_password_summary">Opdater adgangskoden, så den svarer til din server.</string>
   <string name="settings_enter_password">Indtast adgangskode:</string>
-  <string name="settings_preemptive">Forhåndsgodkendelse</string>
-  <string name="settings_preemptive_on">Loginoplysninger sendes ved hver anmodning (anbefalet)</string>
-  <string name="settings_preemptive_off">Loginoplysninger sendes efter server anmoder om dem</string>
   <string name="settings_sync">Synkronisering</string>
   <string name="settings_sync_interval_contacts">Synkroniseringsinterval for kontakter</string>
   <string name="settings_sync_summary_manually">Kun manuelt</string>
@@ -169,9 +181,6 @@
     <item>Grupper er særskilte VCards</item>
     <item>Grupper er kategorier pr. kontakt</item>
   </string-array>
-  <string name="settings_rfc6868_for_vcards">Anvend RFC6868 for VCards</string>
-  <string name="settings_rfc6868_for_vcards_on">Dobbelte citationstegn kan bruges til at sætte parametre</string>
-  <string name="settings_rfc6868_for_vcards_off">Dobbelte citationstegn kan ikke bruges til at sætte parametre</string>
   <string name="settings_caldav">CalDAV</string>
   <string name="settings_sync_time_range_past">Tidsafgrænsning for tidligere begivenheder</string>
   <string name="settings_sync_time_range_past_none">Alle begivenheder vil blive synkroniseret</string>
@@ -183,9 +192,6 @@
   <string name="settings_manage_calendar_colors">Administrer farver for kalender</string>
   <string name="settings_manage_calendar_colors_on">Kalenderfarver administreres af DAVdroid</string>
   <string name="settings_manage_calendar_colors_off">Kalenderfarver sættes ikke fra DAVdroid</string>
-  <string name="settings_version_update">Versionsopdatering af DAVdroid</string>
-  <string name="settings_version_update_settings_updated">Interne indstillinger er blevet opdateret.</string>
-  <string name="settings_version_update_install_hint">Problemer? Afinstaller DAVdroid og geninstaller.</string>
   <!--collection management-->
   <string name="create_addressbook">Opret adressebog</string>
   <string name="create_addressbook_display_name_hint">Min adressebog</string>
@@ -237,4 +243,7 @@
     <item>gemmer synkroniseringsstatus</item>
   </string-array>
   <string name="sync_error_unauthorized">Fejl i brugernavn/adgangskode</string>
+  <!--cert4android-->
+  <string name="certificate_notification_connection_security">DAVdroid: Forbindelsessikkerhed</string>
+  <string name="trust_certificate_unknown_certificate_found">DAVdroid er stødt på et ukendt certifikat. Vil du stole på det? </string>
 </resources>

app/src/davdroid/res/values-es/strings.xml

@@ -7,6 +7,9 @@
   <string name="please_wait">Por favor, espere...</string>
   <string name="send">Enviar</string>
   <!--startup dialogs-->
+  <string name="startup_battery_optimization">Optimización de batería</string>
+  <string name="startup_battery_optimization_message">Android puede desactivar/reducir la sincronización de DAVdroid después de unos días. Para prevenir esto, desactiva la optimización.</string>
+  <string name="startup_battery_optimization_disable">Apagar para DAVdroid</string>
   <string name="startup_dont_show_again">No mostrar de nuevo</string>
   <string name="startup_development_version">Versión candidata final de DAVdroid</string>
   <string name="startup_development_version_message">Esta es una versión de desarrollo de DAVdroid. Tenga presente que puede que no todo funcione como espera. Por favor, denos una retroalimentación constructiva para mejorar DAVdroid.</string>
@@ -43,7 +46,7 @@
   <string name="navigation_drawer_faq">Preguntas frequentes</string>
   <string name="navigation_drawer_forums">Comunidad</string>
   <string name="navigation_drawer_donate">Donar</string>
-  <string name="account_list_empty">Bienvenido a DAVdroid!\n\nAhora puede añadir una cuenta CalDAV/CardDAV.</string>
+  <string name="account_list_empty">Bienvenido a DAVdroid!\n\nAhora puedes añadir una cuenta CalDAV/CardDAV.</string>
   <!--DavService-->
   <string name="dav_service_refresh_failed">Falló la detección del servicio</string>
   <string name="dav_service_refresh_couldnt_refresh">No se pudo refrescar lista de colección</string>
@@ -51,15 +54,21 @@
   <string name="app_settings">Ajustes</string>
   <string name="app_settings_user_interface">Interfaz de usuario</string>
   <string name="app_settings_reset_hints">Restablecer advertencias</string>
-  <string name="app_settings_reset_hints_summary">Habilita las advertencias que han sido cesadas con anterioridad</string>
-  <string name="app_settings_reset_hints_success">Todas las advertencias serán mostradas de nuevo</string>
+  <string name="app_settings_reset_hints_summary">Habilita las advertencias que han sido rechazadas con anterioridad</string>
+  <string name="app_settings_reset_hints_success">Todas las advertencias se mostrarán nuevamente</string>
+  <string name="app_settings_connection">Conexión</string>
+  <string name="app_settings_override_proxy">Anular ajustes del proxy</string>
+  <string name="app_settings_override_proxy_on">Usar ajustes personalizados del proxy</string>
+  <string name="app_settings_override_proxy_off">Usar ajustes del proxy predefinidos por el sistema</string>
+  <string name="app_settings_override_proxy_host">Nombre del host del proxy HTTP</string>
+  <string name="app_settings_override_proxy_port">Puerto del proxy HTTP</string>
   <string name="app_settings_security">Seguridad</string>
-  <string name="app_settings_reset_trusted_certificates">Restablecer certificados de confianza</string>
-  <string name="app_settings_reset_trusted_certificates_summary">Olvidar todos los certificados aceptados previamente</string>
-  <plurals name="app_settings_reset_trusted_certificates_success">
-    <item quantity="one">Retirada la confianza de un certificado</item>
-    <item quantity="other">Retirada la confianza de %d certificados</item>
-  </plurals>
+  <string name="app_settings_distrust_system_certs">Invalidar los certificados del sistema</string>
+  <string name="app_settings_distrust_system_certs_on">Los CA del sistema y los añadidos por el usuario no serán válidos</string>
+  <string name="app_settings_distrust_system_certs_off">Los CA del sistema y los añadidos por el usuario serán usados y de confianza (recomendado)</string>
+  <string name="app_settings_reset_certificates">Reiniciar certificados (in)validados</string>
+  <string name="app_settings_reset_certificates_summary">Reinicia la validez de todos los certificados particulares</string>
+  <string name="app_settings_reset_certificates_success">Todos los certificados particulares han sido limpiados</string>
   <string name="app_settings_debug">Depuración</string>
   <string name="app_settings_log_to_external_storage">Registrar en fichero externo</string>
   <string name="app_settings_log_to_external_storage_on">Registro en almacenamiento externo (si está disponible)</string>
@@ -70,9 +79,12 @@
   <string name="account_synchronize_now">Sincronizar ahora</string>
   <string name="account_synchronizing_now">Sincronizando...</string>
   <string name="account_settings">Ajustes de cuenta</string>
+  <string name="account_rename">Renombrar cuenta</string>
+  <string name="account_rename_new_name">Información local no guardada puede ser desechada. Se requiere resincronizar después de renombrar. Nuevo nombre de cuenta:</string>
+  <string name="account_rename_rename">Renombrar</string>
   <string name="account_delete">Eliminar cuenta</string>
-  <string name="account_delete_confirmation_title">¿Seguro que desea eliminar la cuenta?</string>
-  <string name="account_delete_confirmation_text">Todas las copias locales de sus contactos, calendarios y tareas serán eliminadas.</string>
+  <string name="account_delete_confirmation_title">¿Seguro que deseas eliminar la cuenta?</string>
+  <string name="account_delete_confirmation_text">Todas las copias locales de tus contactos, calendarios y tareas serán eliminadas.</string>
   <string name="account_refresh_address_book_list">Refrescar contactos</string>
   <string name="account_create_new_address_book">Crear nueva lista de contactos</string>
   <string name="account_refresh_calendar_list">Refrescar calendario</string>
@@ -80,13 +92,13 @@
   <!--PermissionsActivity-->
   <string name="permissions_title">Permisos de DAVdroid</string>
   <string name="permissions_calendar">Permisos de calendario</string>
-  <string name="permissions_calendar_details">Para sincronizar eventos CalDAV con sus calendarios locales, DAVdroid necesita acceder a los mismos.</string>
+  <string name="permissions_calendar_details">Para sincronizar eventos CalDAV con tus calendarios locales, DAVdroid necesita acceder a los mismos.</string>
   <string name="permissions_calendar_request">Solicitar permisos sobre calendario</string>
   <string name="permissions_contacts">Permisos de contactos</string>
-  <string name="permissions_contacts_details">Para sincronizar libretas de contactos CadDAV con sus contactos locales, DAVdroid necesita acceder a los mismos.</string>
+  <string name="permissions_contacts_details">Para sincronizar libretas de contactos CadDAV con tus contactos locales, DAVdroid necesita acceder a los mismos.</string>
   <string name="permissions_contacts_request">Solicitar permisos sobre contactos</string>
   <string name="permissions_opentasks">Permisos de OpenTasks</string>
-  <string name="permissions_opentasks_details">Para sincronizar listas de tareas CalDAV con sus listas de tareas locales, DAVdroid necesita acceder a OpenTasks.</string>
+  <string name="permissions_opentasks_details">Para sincronizar listas de tareas CalDAV con tus listas de tareas locales, DAVdroid necesita acceder a OpenTasks.</string>
   <string name="permissions_opentasks_request">Solicitar permisos sobre OpenTasks</string>
   <!--AddAccountActivity-->
   <string name="login_title">Añadir cuenta</string>
@@ -101,17 +113,17 @@
   <string name="login_user_name">Nombre de usuario</string>
   <string name="login_user_name_required">Nombre de usuario requerido</string>
   <string name="login_base_url">URL base</string>
-  <string name="login_auth_preemptive">Autenticación preferente (recomendado, pero incompatible con Digest auth)</string>
   <string name="login_login">Registrar</string>
   <string name="login_back">Volver</string>
   <string name="login_create_account">Crear cuenta</string>
   <string name="login_account_name">Nombre de cuenta</string>
-  <string name="login_account_name_info">Use su dirección de correo como nombre de su cuenta puesto que Android usará el nombre de la cuenta como campo de \"organizador\" en los eventos que cree. No puede tener dos cuentas con el mismo nombre.</string>
+  <string name="login_account_name_info">Usa tu dirección de correo como nombre de cuenta puesto que Android usará el nombre de la cuenta como campo de \"organizador\" en los eventos que cree. No puedes tener dos cuentas con el mismo nombre.</string>
+  <string name="login_account_contact_group_method">Método de contacto de grupo:</string>
   <string name="login_account_name_required">Nombre de cuenta requerido</string>
   <string name="login_account_not_created">La cuenta no pudo ser creada</string>
   <string name="login_configuration_detection">Detectar configuración</string>
-  <string name="login_querying_server">Por favor espere, consultando al servidor...</string>
-  <string name="login_no_caldav_carddav">No se pudo encontrar servicio CalDAV o CardDAV.</string>
+  <string name="login_querying_server">Por favor espera, consultando al servidor...</string>
+  <string name="login_no_caldav_carddav">No se pudo encontrar el servicio CalDAV o CardDAV.</string>
   <string name="login_view_logs">Ver registros</string>
   <!--AccountSettingsActivity-->
   <string name="settings_title">Ajustes: %s</string>
@@ -121,9 +133,6 @@
   <string name="settings_password">Contraseña</string>
   <string name="settings_password_summary">Actualiza la contraseña de acuerdo a tu servidor.</string>
   <string name="settings_enter_password">Introduce tu contraseña:</string>
-  <string name="settings_preemptive">Autenticación preferente</string>
-  <string name="settings_preemptive_on">Las credenciales se envían en cada petición (recomendado)</string>
-  <string name="settings_preemptive_off">Las credenciales se envían después de que el servidor las pida</string>
   <string name="settings_sync">Sincronización</string>
   <string name="settings_sync_interval_contacts">Intervalo de sincronización de contactos</string>
   <string name="settings_sync_summary_manually">Solo manualmente</string>
@@ -153,11 +162,21 @@
   </string-array>
   <string name="settings_sync_wifi_only">Sincronizar sólo sobre WiFi</string>
   <string name="settings_sync_wifi_only_on">La sincronización está restringida a conexiones WiFi</string>
-  <string name="settings_sync_wifi_only_off">Tipo de conexión no tomada en consideración</string>
+  <string name="settings_sync_wifi_only_off">Tipo de conexión no tenido en cuenta</string>
   <string name="settings_sync_wifi_only_ssid">Restricción WiFi SSID</string>
   <string name="settings_sync_wifi_only_ssid_on">Sólo se sincronizará sobre %s</string>
   <string name="settings_sync_wifi_only_ssid_off">Todas las conexiones WiFi pueden ser usadas</string>
-  <string name="settings_sync_wifi_only_ssid_message">Introduzca el nombre de una red WiFi (SSID) para restringir la sincronización a esta red, o deje el campo en blanco para usar todas las conexiones WiFi.</string>
+  <string name="settings_sync_wifi_only_ssid_message">Introduce el nombre de una red WiFi (SSID) para restringir la sincronización a esta red, o deja el campo en blanco para usar todas las conexiones WiFi.</string>
+  <string name="settings_carddav">CardDAV</string>
+  <string name="settings_contact_group_method">Método de contacto de grupo</string>
+  <string-array name="settings_contact_group_method_values">
+    <item>GROUP_VCARDS</item>
+    <item>CATEGORIES</item>
+  </string-array>
+  <string-array name="settings_contact_group_method_entries">
+    <item>Los groups tienen VCards separadas</item>
+    <item>Los groups tienen una categoría por contacto</item>
+  </string-array>
   <string name="settings_caldav">CalDAV</string>
   <string name="settings_sync_time_range_past">Límite de tiempo de eventos pasados</string>
   <string name="settings_sync_time_range_past_none">Todos los eventos serán sincronizados</string>
@@ -165,13 +184,10 @@
     <item quantity="one">Los eventos anteriores a un día serán ignorados</item>
     <item quantity="other">Los eventos anteriores a %d días serán ignorados</item>
   </plurals>
-  <string name="settings_sync_time_range_past_message">Los eventos anteriores a este número de días serán ignorados (puede ser 0). Deje en blanco el campo para sincronizar todos los eventos.</string>
+  <string name="settings_sync_time_range_past_message">Los eventos anteriores a este número de días serán ignorados (puede ser 0). Deja en blanco el campo para sincronizar todos los eventos.</string>
   <string name="settings_manage_calendar_colors">Colores de calendario</string>
   <string name="settings_manage_calendar_colors_on">Los colores de los calendarios son administrados por DAVdroid</string>
   <string name="settings_manage_calendar_colors_off">Los colores de los calendarios no son establecidos por DAVdroid</string>
-  <string name="settings_version_update">Actualización de la versión de Android</string>
-  <string name="settings_version_update_settings_updated">Los ajustes internos han sido actualizados.</string>
-  <string name="settings_version_update_install_hint">¿Problemas? Desinstala y vuelve a instalar DAVdroid.</string>
   <!--collection management-->
   <string name="create_addressbook">Crear nueva lista de contactos</string>
   <string name="create_addressbook_display_name_hint">Agendas</string>
@@ -190,7 +206,7 @@
   <string name="create_collection_home_set">Establecer localización:</string>
   <string name="create_collection_create">Crear</string>
   <string name="delete_collection">Eliminar colección</string>
-  <string name="delete_collection_confirm_title">¿Está seguro/a?</string>
+  <string name="delete_collection_confirm_title">¿Estás seguro/a?</string>
   <string name="delete_collection_confirm_warning">Esta colección (%s) y toda su información será eliminada del servidor.</string>
   <string name="delete_collection_deleting_collection">Eliminando colección</string>
   <!--ExceptionInfoFragment-->
@@ -208,5 +224,22 @@
   <string name="sync_error">Error al %s</string>
   <string name="sync_error_http_dav">Error de servidor al %s</string>
   <string name="sync_error_local_storage">Error de base de datos al %s</string>
+  <string-array name="sync_error_phases">
+    <item>preparando sincronización</item>
+    <item>buscando capacidades</item>
+    <item>procesando entradas borradas localmente</item>
+    <item>preparando entradas creadas/modificadas</item>
+    <item>cargando entradas creadas/modificadas</item>
+    <item>comprobando estado de sincronización</item>
+    <item>enumerando entradas locales</item>
+    <item>enumerando entradas remotas</item>
+    <item>comparando entradas locales/remotas</item>
+    <item>descargando entradas remotas</item>
+    <item>post-procesando</item>
+    <item>guardando estado de sincronización</item>
+  </string-array>
   <string name="sync_error_unauthorized">Nombre de usuario/contraseña erróneo</string>
+  <!--cert4android-->
+  <string name="certificate_notification_connection_security">DAVdroid: Seguridad de conexión</string>
+  <string name="trust_certificate_unknown_certificate_found">DAVdroid ha encontrado un certificado desconocido. ¿Quieres que sea válido?</string>
 </resources>

app/src/davdroid/res/values-fr/strings.xml

@@ -2,11 +2,16 @@
 <resources xmlns:tools="http://schemas.android.com/tools">
   <!--common strings-->
   <string name="app_name">DAVdroid</string>
+  <string name="account_title_address_book">Carnet d\'adresses DAVdroid</string>
+  <string name="address_books_authority_title">Carnets d\'adresses</string>
   <string name="help">Aide</string>
   <string name="manage_accounts">Gestion des comptes</string>
   <string name="please_wait">SVP attendez ...</string>
   <string name="send">Envoyer</string>
   <!--startup dialogs-->
+  <string name="startup_battery_optimization">Optimisation de la batterie</string>
+  <string name="startup_battery_optimization_message">Android peut désactiver/réduire la synchronisation de DAVdroid après quelques jours. Pour éviter cela, désactivez l\'optimisation de la batterie.</string>
+  <string name="startup_battery_optimization_disable">Désactiver pour DAVdroid</string>
   <string name="startup_dont_show_again">Ne plus afficher</string>
   <string name="startup_development_version">Pré-version de DAVdroid</string>
   <string name="startup_development_version_message">Il s\'agit d\'une version de développement de DAVdroid. Il se peut que les choses ne fonctionnent pas comme prévu. S’il vous plaît faites-nous un retour pour améliorer DAVdroid.</string>
@@ -17,7 +22,7 @@
   <string name="startup_donate_later">Plus tard</string>
   <string name="startup_google_play_accounts_removed">Erreur information Play Store DRM</string>
   <string name="startup_google_play_accounts_removed_message">Dans certaines conditions, Play Store DRM peut provoquer la disparition de tous les comptes DAVdroid après un redémarrage ou après la mise à niveau de DAVdroid. Si vous êtes concerné par ce problème (et seulement alors), s\'il vous plaît installer \"DAVdroid JB Solution\" du Play Store.</string>
-  <string name="startup_google_play_accounts_removed_more_info">Plus d\'information</string>
+  <string name="startup_google_play_accounts_removed_more_info">Plus d\'informations</string>
   <string name="startup_opentasks_not_installed">OpenTasks n\'est pas installé</string>
   <string name="startup_opentasks_not_installed_message">L\'application OpenTasks n\'est pas disponible, donc DAVdroid ne pourra pas synchroniser des listes de tâches.</string>
   <string name="startup_opentasks_reinstall_davdroid">Après l\'installation OpenTasks, vous devez RE-INSTALLER DAVdroid et ajoutez vos comptes à nouveau (bug Android).</string>
@@ -34,6 +39,7 @@
   <!--AccountsActivity-->
   <string name="navigation_drawer_open">Ouvrir le tiroir de navigation</string>
   <string name="navigation_drawer_close">Fermer le tiroir de navigation</string>
+  <string name="navigation_drawer_subtitle">Adaptateur de synchronisation CalDAV/CardDAV</string>
   <string name="navigation_drawer_about">A propos / Licence</string>
   <string name="navigation_drawer_settings">Paramètres</string>
   <string name="navigation_drawer_news_updates">Actualité &amp; mise à jour</string>
@@ -43,6 +49,8 @@
   <string name="navigation_drawer_forums">Communauté</string>
   <string name="navigation_drawer_donate">Faire un don</string>
   <string name="account_list_empty">Bienvenue sur DAVdroid!\n\nVous pouvez maintenant ajouter un compte CalDAV/CardDAV.</string>
+  <string name="accounts_global_sync_disabled">La synchronisation automatique globale est désactivée</string>
+  <string name="accounts_global_sync_enable">Activer</string>
   <!--DavService-->
   <string name="dav_service_refresh_failed">La détection du service a échoué</string>
   <string name="dav_service_refresh_couldnt_refresh">Impossible d\'actualiser la liste de collection</string>
@@ -50,15 +58,21 @@
   <string name="app_settings">Paramètres</string>
   <string name="app_settings_user_interface">Interface utilisateur</string>
   <string name="app_settings_reset_hints">Réinitialiser les astuces</string>
-  <string name="app_settings_reset_hints_summary">Réactiver les astuces qui ont été vu précédemment</string>
+  <string name="app_settings_reset_hints_summary">Réactiver les astuces qui ont été vues précédemment</string>
   <string name="app_settings_reset_hints_success">Toutes les astuces seront affichés à nouveau</string>
+  <string name="app_settings_connection">Connexion</string>
+  <string name="app_settings_override_proxy">Ignorer les paramètres proxy</string>
+  <string name="app_settings_override_proxy_on">Utiliser des paramètres proxy personnalisés</string>
+  <string name="app_settings_override_proxy_off">Utiliser les paramètres proxy du système</string>
+  <string name="app_settings_override_proxy_host">Nom de l\'hôte du proxy HTTP</string>
+  <string name="app_settings_override_proxy_port">Port du proxy HTTP</string>
   <string name="app_settings_security">Sécurité</string>
-  <string name="app_settings_reset_trusted_certificates">Réinitialiser les certificats de confiance</string>
-  <string name="app_settings_reset_trusted_certificates_summary">Oublier tous les certificats qui ont été acceptés précédemment</string>
-  <plurals name="app_settings_reset_trusted_certificates_success">
-    <item quantity="one">Un certificat douteux</item>
-    <item quantity="other">%d certificats douteux</item>
-  </plurals>
+  <string name="app_settings_distrust_system_certs">Révoquer les certificats du système</string>
+  <string name="app_settings_distrust_system_certs_on">Les certificats du système et ceux ajoutés par l\'utilisateur ne seront pas  dignes de confiance</string>
+  <string name="app_settings_distrust_system_certs_off">Les certificats du système et ceux ajoutés par l\'utilisateur seront dignes de confiance (recommandé)</string>
+  <string name="app_settings_reset_certificates">Réinitialiser les certificats de (non)confiance</string>
+  <string name="app_settings_reset_certificates_summary">Réinitialiser la confiance de tous les certificats personnalisés</string>
+  <string name="app_settings_reset_certificates_success">Tous les certificats personnalisés ont été effacés</string>
   <string name="app_settings_debug">Débogage</string>
   <string name="app_settings_log_to_external_storage">Journaliser dans un fichier externe</string>
   <string name="app_settings_log_to_external_storage_on">Journaliser sur le stockage externe (si disponible)</string>
@@ -69,11 +83,14 @@
   <string name="account_synchronize_now">Synchroniser maintenant</string>
   <string name="account_synchronizing_now">Synchronisation en cours</string>
   <string name="account_settings">Paramètres du compte</string>
+  <string name="account_rename">Renommer le compte</string>
+  <string name="account_rename_new_name">Les données locales non enregistrées pourraient être perdues. Une re-synchronisation est nécessaire après avoir renommé le compte. Nouveau nom du compte : </string>
+  <string name="account_rename_rename">Renommer</string>
   <string name="account_delete">Supprimer le compte</string>
   <string name="account_delete_confirmation_title">Voulez-vous vraiment supprimer le compte?</string>
   <string name="account_delete_confirmation_text">Toutes les copies locales des carnets d\'adresses, des calendriers et des listes de tâches seront supprimées.</string>
-  <string name="account_refresh_address_book_list">Actualiser le carnet d\'adresse</string>
-  <string name="account_create_new_address_book">Créer un nouveau carnet d\'adresse</string>
+  <string name="account_refresh_address_book_list">Actualiser le carnet d\'adresses</string>
+  <string name="account_create_new_address_book">Créer un nouveau carnet d\'adresses</string>
   <string name="account_refresh_calendar_list">Actualiser le calendrier</string>
   <string name="account_create_new_calendar">Créer un nouveau calendrier</string>
   <!--PermissionsActivity-->
@@ -88,10 +105,11 @@
   <string name="permissions_opentasks_details">Pour synchroniser les tâches de CalDAV avec vos listes de tâches locales, DAVdroid a besoin d\'accéder à OpenTasks.</string>
   <string name="permissions_opentasks_request">Demande d\'autorisations d\'accéder à OpenTasks</string>
   <!--AddAccountActivity-->
+  <string name="login_help_url">https://davdroid.bitfire.at/configuration/?pk_campaign=davdroid-app</string>
   <string name="login_title">Ajouter un compte</string>
   <string name="login_type_email">Connexion avec une adresse email</string>
   <string name="login_email_address">Adresse mail</string>
-  <string name="login_email_address_error">Une adresse e-mail valide est requis</string>
+  <string name="login_email_address_error">Une adresse e-mail valide est requise</string>
   <string name="login_password">Mot de passe</string>
   <string name="login_password_required">Mot de passe requis</string>
   <string name="login_type_url">Connexion avec une URL et un nom d\'utilisateur</string>
@@ -100,12 +118,12 @@
   <string name="login_user_name">Nom d\'utilisateur</string>
   <string name="login_user_name_required">Nom d\'utilisateur requis</string>
   <string name="login_base_url">URL de base</string>
-  <string name="login_auth_preemptive">Authentification préventive (recommandé, mais incompatible avec l\'authentification Digest)</string>
   <string name="login_login">Se connecter</string>
   <string name="login_back">Retour</string>
   <string name="login_create_account">Créer un compte</string>
   <string name="login_account_name">Nom du compte</string>
   <string name="login_account_name_info">Utilisez votre adresse e-mail comme nom de compte car Android utilisera ce nom en tant que champ ORGANISATEUR pour les événements que vous créerez. Vous ne pouvez pas avoir deux comptes avec le même nom.</string>
+  <string name="login_account_contact_group_method">Méthode pour les contacts de type groupe :</string>
   <string name="login_account_name_required">Nom du compte requis</string>
   <string name="login_account_not_created">Le compte n\'a pas pu être créé</string>
   <string name="login_configuration_detection">Détection de la configuration</string>
@@ -120,16 +138,13 @@
   <string name="settings_password">Mot de passe</string>
   <string name="settings_password_summary">Mettre à jour le mot de passe </string>
   <string name="settings_enter_password">Saisissez votre mot de passe :</string>
-  <string name="settings_preemptive">Authentification préventive</string>
-  <string name="settings_preemptive_on">Le nom d\'utilisateur et le mot de passe sont envoyés avec chaque requête (recommandé)</string>
-  <string name="settings_preemptive_off">Le nom d\'utilisateur et le mot de passe sont envoyés à la demande du serveur.</string>
   <string name="settings_sync">Synchronisation</string>
-  <string name="settings_sync_interval_contacts">Interval de synchronisation des carnets d\'adresses</string>
+  <string name="settings_sync_interval_contacts">Intervalle de synchronisation des carnets d\'adresses</string>
   <string name="settings_sync_summary_manually">Manuellement</string>
   <string name="settings_sync_summary_periodically" tools:ignore="PluralsCandidate">Toutes les %d minutes et immédiatement après un changement local</string>
   <string name="settings_sync_summary_not_available">Indisponible</string>
-  <string name="settings_sync_interval_calendars">Interval de synchronisation des agendas</string>
-  <string name="settings_sync_interval_tasks">Interval de synchronisation des tâches</string>
+  <string name="settings_sync_interval_calendars">Intervalle de synchronisation des agendas</string>
+  <string name="settings_sync_interval_tasks">Intervalle de synchronisation des tâches</string>
   <string-array name="settings_sync_interval_seconds">
     <item>-1</item>
     <item>300</item>
@@ -158,13 +173,15 @@
   <string name="settings_sync_wifi_only_ssid_off">Toutes les connexions WiFi peuvent être utilisées</string>
   <string name="settings_sync_wifi_only_ssid_message">Entrez le nom d\'un réseau WiFi (SSID) pour restreindre la synchronisation à ce réseau, ou laisser vide pour autoriser toutes les connexions WiFi.</string>
   <string name="settings_carddav">CardDAV</string>
+  <string name="settings_contact_group_method">Méthode pour les contacts de type groupe</string>
   <string-array name="settings_contact_group_method_values">
     <item>GROUP_VCARDS</item>
     <item>CATEGORIES</item>
   </string-array>
-  <string name="settings_rfc6868_for_vcards">Utiliser RFC6868 pour VCards</string>
-  <string name="settings_rfc6868_for_vcards_on">Les guillemets doubles peuvent être utilisés dans les valeurs de paramètre</string>
-  <string name="settings_rfc6868_for_vcards_off">Les guillemets doubles ne peuvent pas être utilisés dans les valeurs de paramètre</string>
+  <string-array name="settings_contact_group_method_entries">
+    <item>Les groupes sont des VCards indépendantes</item>
+    <item>Les groupes sont des catégories pour chacun des contacts</item>
+  </string-array>
   <string name="settings_caldav">CalDAV</string>
   <string name="settings_sync_time_range_past">Limite des événements passés</string>
   <string name="settings_sync_time_range_past_none">Tous les événements seront synchronisés</string>
@@ -176,9 +193,6 @@
   <string name="settings_manage_calendar_colors">Choisir couleur du calendrier</string>
   <string name="settings_manage_calendar_colors_on">Les couleurs de calendrier sont gérées par DAVdroid</string>
   <string name="settings_manage_calendar_colors_off">Les couleurs de calendrier ne sont pas gérées par DAVdroid</string>
-  <string name="settings_version_update">Mise à jour de la version de DAVdroid</string>
-  <string name="settings_version_update_settings_updated">Les paramètres internes ont été mis à jour.</string>
-  <string name="settings_version_update_install_hint">Un problème? Désinstaller DAVdroid, puis réinstaller.</string>
   <!--collection management-->
   <string name="create_addressbook">Créer un carnet d\'adresses</string>
   <string name="create_addressbook_display_name_hint">Mon carnet d\'adresses</string>
@@ -215,5 +229,22 @@
   <string name="sync_error">Erreur durant %s</string>
   <string name="sync_error_http_dav">Erreur de serveur durant %s</string>
   <string name="sync_error_local_storage">Erreur de base de donnée durant %s</string>
+  <string-array name="sync_error_phases">
+    <item>prépare la synchronisation</item>
+    <item>demande les autorisations</item>
+    <item>procède à la suppression des entrées locales</item>
+    <item>prépare les entrées créées/modifiées</item>
+    <item>envoi les entrées créées/modifiées</item>
+    <item>vérifie l\'état de la synchronisation</item>
+    <item>liste les entrées locales</item>
+    <item>liste les entrées distantes</item>
+    <item>compare les entrées locales/distantes</item>
+    <item>télécharge les entrées distantes</item>
+    <item>post-traitement</item>
+    <item>enregistre l\'état de la synchronisation</item>
+  </string-array>
   <string name="sync_error_unauthorized">Nom d\'utilisateur ou mot de passe erroné</string>
+  <!--cert4android-->
+  <string name="certificate_notification_connection_security">DAVdroid : Sécurité de la connexion</string>
+  <string name="trust_certificate_unknown_certificate_found">DAVdroid a rencontré un certificat inconnu. Voulez-vous lui faire confiance?</string>
 </resources>

app/src/davdroid/res/values-hu/strings.xml

@@ -2,11 +2,16 @@
 <resources xmlns:tools="http://schemas.android.com/tools">
   <!--common strings-->
   <string name="app_name">DAVdroid</string>
+  <string name="account_title_address_book">DAVdroid címjegyzék</string>
+  <string name="address_books_authority_title">Címjegyzékek</string>
   <string name="help">Súgó</string>
   <string name="manage_accounts">Fiókok kezelése</string>
   <string name="please_wait">Kérjük, várjon ...</string>
   <string name="send">Küldés</string>
   <!--startup dialogs-->
+  <string name="startup_battery_optimization">Akkumulátoroptimalizálás </string>
+  <string name="startup_battery_optimization_message">Az operációs rendszer a DAVdroid szinkronizálást pár nap után leállíthatja vagy visszafoghatja.  Ennek elkerülésére kapcsolja ki az akkumulátoroptimalizálást.</string>
+  <string name="startup_battery_optimization_disable">Kikapcsolás a DAVdroid kapcsán</string>
   <string name="startup_dont_show_again">Ne jelenjen meg többet</string>
   <string name="startup_development_version">DAVdroid előzetes kiadás</string>
   <string name="startup_development_version_message">Ez a DAVdroid egy fejlesztői verziója.  Elképzelhető, hogy nem minden működik úgy, ahogyan kellene.  Ha így lenne, kérjük küldjön a tapasztaltakról visszajelzést.</string>
@@ -44,6 +49,8 @@
   <string name="navigation_drawer_forums">Közösség</string>
   <string name="navigation_drawer_donate">Támogatás</string>
   <string name="account_list_empty">Üdvözöljük a DAVdroid felhasználók között!\n\nMost már felvehet CalDAV/CardDav fiókokat.</string>
+  <string name="accounts_global_sync_disabled">A rendszerszintű automatikus szinkronizálás ki van kapcsolva</string>
+  <string name="accounts_global_sync_enable">Bekapcsolás</string>
   <!--DavService-->
   <string name="dav_service_refresh_failed">Szolgáltatások felderítése nem sikerült</string>
   <string name="dav_service_refresh_couldnt_refresh">Gyűjteménylista frissítése nem sikerült</string>
@@ -53,13 +60,19 @@
   <string name="app_settings_reset_hints">Tippek visszaállítása</string>
   <string name="app_settings_reset_hints_summary">Újra jelenjen meg az összes tipp</string>
   <string name="app_settings_reset_hints_success">Az összes tipp újra meg fog jelenni</string>
+  <string name="app_settings_connection">Kapcsolat</string>
+  <string name="app_settings_override_proxy">Proxybeállítások felülírása</string>
+  <string name="app_settings_override_proxy_on">Egyedi proxybeállítások</string>
+  <string name="app_settings_override_proxy_off">Az alapértelmezett proxybeállítás használata</string>
+  <string name="app_settings_override_proxy_host">HTTP proxyállomás neve</string>
+  <string name="app_settings_override_proxy_port">HTTP proxy port</string>
   <string name="app_settings_security">Biztonság</string>
-  <string name="app_settings_reset_trusted_certificates">A tanúsítványtár visszaállítása</string>
-  <string name="app_settings_reset_trusted_certificates_summary">Az összes korábban megbízhatónak kiválasztott tanúsítvány törlése</string>
-  <plurals name="app_settings_reset_trusted_certificates_success">
-    <item quantity="one">Egy tanúsítvány megbízhatósága törölve</item>
-    <item quantity="other">%d tanúsítvány megbízhatósága törölve</item>
-  </plurals>
+  <string name="app_settings_distrust_system_certs">A rendszertanúsítványok elfogadása</string>
+  <string name="app_settings_distrust_system_certs_on">A rendszer által kezelt, előre vagy felhasználó által telepített tanúsítványok figyelmen kívül lesznek hagyva</string>
+  <string name="app_settings_distrust_system_certs_off">A rendszer által kezelt, előre vagy felhasználó által telepített tanúsítványok megbízhatóak (javasolt)</string>
+  <string name="app_settings_reset_certificates">A tanúsítványok megbízhatóságának törlésére</string>
+  <string name="app_settings_reset_certificates_summary">A tanúsítványok megbízhatóságával kapcsolatos beállítások törlésére</string>
+  <string name="app_settings_reset_certificates_success">A tanúsítványok megbízhatóságával kapcsolatos beállítások törölve</string>
   <string name="app_settings_debug">Hibakeresés</string>
   <string name="app_settings_log_to_external_storage">Naplózás fájlba</string>
   <string name="app_settings_log_to_external_storage_on">Naplózás külső tárhelyre (ha elérhető)</string>
@@ -70,6 +83,9 @@
   <string name="account_synchronize_now">Szinkronizálás most</string>
   <string name="account_synchronizing_now">Szinkronizálás</string>
   <string name="account_settings">Fiókbeállítások</string>
+  <string name="account_rename">Fiók átnevezése</string>
+  <string name="account_rename_new_name">Az elmentetlen helyben tárolt adatok elvesznek.  Az átnevezés után szinkronizálásra lesz szükség.  Új fióknév:</string>
+  <string name="account_rename_rename">Átnevez</string>
   <string name="account_delete">Fiók törlése</string>
   <string name="account_delete_confirmation_title">Valóban törölni akarja a fiókot?</string>
   <string name="account_delete_confirmation_text">Az összes címjegyzék, naptár és feladatlista helyi példányai törölve lesznek.</string>
@@ -101,7 +117,6 @@
   <string name="login_user_name">Felhasználónév</string>
   <string name="login_user_name_required">A felhasználónév megadása feltétlenül szükséges</string>
   <string name="login_base_url">URL-törzs</string>
-  <string name="login_auth_preemptive">Preemptív authentikáció (ajánlott, de Digest authentikációval nem működik)</string>
   <string name="login_login">Bejelentkezés</string>
   <string name="login_back">Vissza</string>
   <string name="login_create_account">Fiók létrehozása</string>
@@ -122,9 +137,6 @@
   <string name="settings_password">Jelszó</string>
   <string name="settings_password_summary">Adja meg a szerveren érvényes új jelszót.</string>
   <string name="settings_enter_password">Adja meg a jelszót:</string>
-  <string name="settings_preemptive">Preemptív authentikáció</string>
-  <string name="settings_preemptive_on">A hitelesítő adatok elküldése minden kérésnél (ajánlott)</string>
-  <string name="settings_preemptive_off">A hitelesítő adatok elküldése, csak ha a szerver azt igényli</string>
   <string name="settings_sync">Szinkronizálás</string>
   <string name="settings_sync_interval_contacts">Névjegyszinkronizálás sűrűsége</string>
   <string name="settings_sync_summary_manually">Manuális</string>
@@ -161,13 +173,14 @@
   <string name="settings_sync_wifi_only_ssid_message">Adja meg a WIFI hálózat nevét (SSID) a szinkronizálás egy hálózatra való korlátozához, vagy hagyja üresen, ha nem akar ilyen szűkítést.</string>
   <string name="settings_carddav">CardDAV</string>
   <string name="settings_contact_group_method">A csoportok kezelésének módja</string>
+  <string-array name="settings_contact_group_method_values">
+    <item>GROUP_VCARDS</item>
+    <item>CATEGORIES</item>
+  </string-array>
   <string-array name="settings_contact_group_method_entries">
     <item>Minden csoport egy különálló VCard</item>
     <item>A csoportok a kapcsolatonkéni kategóriák</item>
   </string-array>
-  <string name="settings_rfc6868_for_vcards">RFC6868 szabványnak megfelelő VCards használata</string>
-  <string name="settings_rfc6868_for_vcards_on">A paraméterértékek tartalmazhatnak idézőjelet</string>
-  <string name="settings_rfc6868_for_vcards_off">A paraméterértékek nem tartalmazhatnak idézőjelet</string>
   <string name="settings_caldav">CalDAV</string>
   <string name="settings_sync_time_range_past">Múltbéli események időkorlátja</string>
   <string name="settings_sync_time_range_past_none">Minden esemény szinkronizálása</string>
@@ -179,9 +192,6 @@
   <string name="settings_manage_calendar_colors">Naptárszínek kezelése</string>
   <string name="settings_manage_calendar_colors_on">A naptárszíneket a DAVdroid kezeli</string>
   <string name="settings_manage_calendar_colors_off">A naptárszíneket nem a DAVdroid kezeli</string>
-  <string name="settings_version_update">DAVdroid frissítése</string>
-  <string name="settings_version_update_settings_updated">A belső beállítások frissítve lettek.</string>
-  <string name="settings_version_update_install_hint">Probléma?  Próbálja meg törölni majd újratelepíteni a DAVdroid-ot.</string>
   <!--collection management-->
   <string name="create_addressbook">Címjegyzék létrehozása</string>
   <string name="create_addressbook_display_name_hint">Új címjegyzék</string>
@@ -233,4 +243,7 @@
     <item>szinkronizációs állapot mentése</item>
   </string-array>
   <string name="sync_error_unauthorized">A felhasználónév vagy jelszó hibás</string>
+  <!--cert4android-->
+  <string name="certificate_notification_connection_security">DAVdroid: kapcsolatbiztonság</string>
+  <string name="trust_certificate_unknown_certificate_found">Egy eddig ismeretlen tanúsítvány érkezett.  Megbízhatónak kívánja elfogadni?</string>
 </resources>

app/src/davdroid/res/values-it/strings.xml

@@ -0,0 +1,249 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<resources xmlns:tools="http://schemas.android.com/tools">
+  <!--common strings-->
+  <string name="app_name">DAVdroid</string>
+  <string name="account_title_address_book">Rubrica degli indirizzi DAVdroid</string>
+  <string name="address_books_authority_title">Rubriche degli indirizzi</string>
+  <string name="help">Aiuto</string>
+  <string name="manage_accounts">Gestione account</string>
+  <string name="please_wait">Attendere prego …</string>
+  <string name="send">Invia</string>
+  <!--startup dialogs-->
+  <string name="startup_battery_optimization">Ottimizazione della batteria</string>
+  <string name="startup_battery_optimization_message">Android può ridurre o disabilitare la sincronizzazione di DAVdroid dopo alcuni giorni. Per prevenire questo comportamento disabilita l\'ottimizzazione della batteria</string>
+  <string name="startup_battery_optimization_disable">Disabilita per DAVdroid</string>
+  <string name="startup_dont_show_again">Non mostrare più</string>
+  <string name="startup_development_version">Versione di sviluppo di DAVdroid</string>
+  <string name="startup_development_version_message">Questa è una versione di sviluppo di DAVdroid. Attenzione perché potrebbe avere malfunzionamenti. Inviateci consigli utili per migliorarlo.</string>
+  <string name="startup_development_version_give_feedback">Invia un rapporto</string>
+  <string name="startup_donate">Informazioni sull\'Open-Source</string>
+  <string name="startup_donate_message">Siamo soddisfatti del tuo uso di DAVdroid, programma Open-Source (GPLv3). Poiché lo sviluppo è un\'iniziativa complessa che comporta molte ore di lavoro ti invitiamo a fare una donazione.</string>
+  <string name="startup_donate_now">Mostra pagina donazioni</string>
+  <string name="startup_donate_later">Più tardi</string>
+  <string name="startup_google_play_accounts_removed">Informazioni sul bug del DRM di Play Store</string>
+  <string name="startup_google_play_accounts_removed_message">In alcune condizioni il DRM di Play Store può causare la perdita di tutti gli account DAVdroid dopo un riavvio o dopo un aggiornamento di DAVdroid. Se verificate questo problema installate successivamente \"DAVdroid JB Workaround\" da Play Store.</string>
+  <string name="startup_google_play_accounts_removed_more_info">Maggiori informazioni</string>
+  <string name="startup_opentasks_not_installed">OpenTasks non installata</string>
+  <string name="startup_opentasks_not_installed_message">L\'applicazione OpenTasks non è installata: di conseguenza DAVdroid non potrà sincronizzare l\'elenco delle attività.</string>
+  <string name="startup_opentasks_reinstall_davdroid">Dopo l\'installazione di OpenTasks è necessario INSTALLARE NUOVAMENTE DAVdroid e aggiungere ancora gli account (per un bug di Android).</string>
+  <string name="startup_opentasks_not_installed_install">Installa OpenTasks</string>
+  <!--AboutActivity-->
+  <string name="about_license_terms">Termini di licenza</string>
+  <string name="about_license_info_no_warranty">Il programma è distribuito SENZA ALCUNA GARANZIA. È software libero e può essere redistribuito sotto alcune condizioni.</string>
+  <!--global settings-->
+  <string name="logging_davdroid_file_logging">Invio del log di DAVdroid su file</string>
+  <string name="logging_to_external_storage">Log su dispositivo esterno: %s</string>
+  <string name="logging_to_external_storage_warning">Cancellare prima possibile i file di log!</string>
+  <string name="logging_couldnt_create_file">Non riesco a creare il file di log esterno: %s</string>
+  <string name="logging_no_external_storage">Dispositivo esterno non disponibile</string>
+  <!--AccountsActivity-->
+  <string name="navigation_drawer_open">Apri barra di navigazione</string>
+  <string name="navigation_drawer_close">Chiudi barra di navigazione</string>
+  <string name="navigation_drawer_subtitle">CalDAV/CardDAV adattatore di sincronizzazione</string>
+  <string name="navigation_drawer_about">Informazioni / Licenza</string>
+  <string name="navigation_drawer_settings">Impostazioni</string>
+  <string name="navigation_drawer_news_updates">Notizie &amp; aggiornamenti</string>
+  <string name="navigation_drawer_external_links">Link esterni</string>
+  <string name="navigation_drawer_website">Sito web</string>
+  <string name="navigation_drawer_faq">Domande Frequenti</string>
+  <string name="navigation_drawer_forums">Comunità</string>
+  <string name="navigation_drawer_donate">Donazione</string>
+  <string name="account_list_empty">Benvenuto a DAVdroid!\n\nÈ ora possibile aggiungere account CalDAV/CardDAV.</string>
+  <string name="accounts_global_sync_disabled">La sincronizzazione automatica dell\'intero sistema è disabilitata</string>
+  <string name="accounts_global_sync_enable">Attiva</string>
+  <!--DavService-->
+  <string name="dav_service_refresh_failed">Fallita l\'individuazione dei servizi</string>
+  <string name="dav_service_refresh_couldnt_refresh">Impossibile aggiornare la lista delle raccolte</string>
+  <!--AppSettingsActivity-->
+  <string name="app_settings">Impostazioni</string>
+  <string name="app_settings_user_interface">Interfaccia utente</string>
+  <string name="app_settings_reset_hints">Reimposta i suggerimenti</string>
+  <string name="app_settings_reset_hints_summary">Riabilita i suggerimenti precedentemente disabilitati</string>
+  <string name="app_settings_reset_hints_success">I suggerimenti verranno mostrati</string>
+  <string name="app_settings_connection">Connessione</string>
+  <string name="app_settings_override_proxy">Non rispettare la impostazioni del proxy</string>
+  <string name="app_settings_override_proxy_on">Impostazioni personalizzate del proxy</string>
+  <string name="app_settings_override_proxy_off">Usa le impostazioni di sistema del proxy</string>
+  <string name="app_settings_override_proxy_host">Nome host del proxy HTTP</string>
+  <string name="app_settings_override_proxy_port">Porta del proxy HTTP</string>
+  <string name="app_settings_security">Sicurezza</string>
+  <string name="app_settings_distrust_system_certs">Non ti fidare dei certificati di sistema</string>
+  <string name="app_settings_distrust_system_certs_on">Le CA di sistema e quelle aggiunte dall\'utente non sono affidabili</string>
+  <string name="app_settings_distrust_system_certs_off">Le CA di sistema e quelle aggiunte dall\'utente sono affidabili (raccomandato)</string>
+  <string name="app_settings_reset_certificates">Reimposta la fiducia in tutti i certificati</string>
+  <string name="app_settings_reset_certificates_summary">Reimposta la fiducia nei certificati aggiunti</string>
+  <string name="app_settings_reset_certificates_success">Sono stati cancellati tutti i certificati aggiunti</string>
+  <string name="app_settings_debug">Debug</string>
+  <string name="app_settings_log_to_external_storage">Log su file esterno</string>
+  <string name="app_settings_log_to_external_storage_on">Log su dispositivo esterno (se disponibile)</string>
+  <string name="app_settings_log_to_external_storage_off">Log su file esterno disabilitato</string>
+  <string name="app_settings_show_debug_info">Mostra informazioni di debug</string>
+  <string name="app_settings_show_debug_info_details">Mostra e condividi i dettagli del programma e della configurazione</string>
+  <!--AccountActivity-->
+  <string name="account_synchronize_now">Sincronizza adesso</string>
+  <string name="account_synchronizing_now">Sincronizzazione in corso</string>
+  <string name="account_settings">Impostazioni account</string>
+  <string name="account_rename">Rinomina account</string>
+  <string name="account_rename_new_name">I dati locali non salvati potrebbero essere rimossi. È necessario effettuare la risincronizzazione dopo la rinomina. Nuovo nome dell\'account:</string>
+  <string name="account_rename_rename">Rinomina</string>
+  <string name="account_delete">Elimina account</string>
+  <string name="account_delete_confirmation_title">Cancellare l\'account?</string>
+  <string name="account_delete_confirmation_text">Tutte le copie locali delle rubriche, dei calendari e degli elenchi attività verranno eliminate.</string>
+  <string name="account_refresh_address_book_list">Aggiorna elenco degli indirizzari</string>
+  <string name="account_create_new_address_book">Crea un nuovo indirizzario</string>
+  <string name="account_refresh_calendar_list">Aggiorna lista calendari</string>
+  <string name="account_create_new_calendar">Crea nuovo calendario</string>
+  <!--PermissionsActivity-->
+  <string name="permissions_title">Permessi DAVdroid</string>
+  <string name="permissions_calendar">Permessi calendario</string>
+  <string name="permissions_calendar_details">Per sincronizzare gli eventi CalDAV con i calendari locali DAVdroid deve avere l\'accesso ai tuoi calendari.</string>
+  <string name="permissions_calendar_request">Richiesta autorizzazione al calendario</string>
+  <string name="permissions_contacts">Permessi Contatti</string>
+  <string name="permissions_contacts_details">Per sincronizzare l\'indirizzario CardDAV con i contatti locali DAVdroid deve avere l\'accesso ai tuoi contatti.</string>
+  <string name="permissions_contacts_request">Richiesta autorizzazione ai contatti</string>
+  <string name="permissions_opentasks">Permessi OpenTasks</string>
+  <string name="permissions_opentasks_details">Per sincronizzazione l\'elenco attività di CalDAV con l\'elenco locale DAVdroid deve avere l\'accesso  ad OpenTasks.</string>
+  <string name="permissions_opentasks_request">Richiesta autorizzazione ad OpenTasks</string>
+  <!--AddAccountActivity-->
+  <string name="login_title">Aggiungi account</string>
+  <string name="login_type_email">Accedi con indirizzo email</string>
+  <string name="login_email_address">Indirizzo email</string>
+  <string name="login_email_address_error">È necessario un indirizzo email valido</string>
+  <string name="login_password">Password</string>
+  <string name="login_password_required">Password richiesta</string>
+  <string name="login_type_url">Accedi con URL e nome utente</string>
+  <string name="login_url_must_be_http_or_https">L\'URL deve iniziare con http(s)://</string>
+  <string name="login_url_host_name_required">Nome host richiesto</string>
+  <string name="login_user_name">Nome utente</string>
+  <string name="login_user_name_required">Nome utente richiesto</string>
+  <string name="login_base_url">Base URL</string>
+  <string name="login_login">Login</string>
+  <string name="login_back">Indietro</string>
+  <string name="login_create_account">Crea account</string>
+  <string name="login_account_name">Nome account</string>
+  <string name="login_account_name_info">Inserisci il tuo indirizzo email come nome dell\'account in quanto Android userà il nome dell\'account nel campo ORGANIZER degli eventi creati. Non è possibile avere due account con nome uguale.</string>
+  <string name="login_account_contact_group_method">Metodo del contact group:</string>
+  <string name="login_account_name_required">Richiesto il nome dell\'account</string>
+  <string name="login_account_not_created">L\'account non può essere creato</string>
+  <string name="login_configuration_detection">Rilevazione configurazione</string>
+  <string name="login_querying_server">Attendere, invio richiesta al server...</string>
+  <string name="login_no_caldav_carddav">Impossibile trovare servizi CalDAV o CardDAV.</string>
+  <string name="login_view_logs">Vedi i log</string>
+  <!--AccountSettingsActivity-->
+  <string name="settings_title">Impostazioni: %s</string>
+  <string name="settings_authentication">Autenticazione</string>
+  <string name="settings_username">Nome utente</string>
+  <string name="settings_enter_username">Inserisci nome utente:</string>
+  <string name="settings_password">Password</string>
+  <string name="settings_password_summary">Aggiorna la password come sul tuo server.</string>
+  <string name="settings_enter_password">Inserisci la tua password:</string>
+  <string name="settings_sync">Sincronizzazione</string>
+  <string name="settings_sync_interval_contacts">Intervallo sincr. Contatti</string>
+  <string name="settings_sync_summary_manually">Solo manualmente</string>
+  <string name="settings_sync_summary_periodically" tools:ignore="PluralsCandidate">Ogni %d minuti e a seguito di ogni cambiamento locale</string>
+  <string name="settings_sync_summary_not_available">Non disponile</string>
+  <string name="settings_sync_interval_calendars">Intervallo sincr. calendari</string>
+  <string name="settings_sync_interval_tasks">Intervallo sincr. attività</string>
+  <string-array name="settings_sync_interval_seconds">
+    <item>-1</item>
+    <item>300</item>
+    <item>600</item>
+    <item>900</item>
+    <item>3600</item>
+    <item>7200</item>
+    <item>14400</item>
+    <item>86400</item>
+  </string-array>
+  <string-array name="settings_sync_interval_names">
+    <item>Solo manualmente</item>
+    <item>Ogni 5 minuti</item>
+    <item>Ogni 10 minuti</item>
+    <item>Ogni 15 minuti</item>
+    <item>Ogni ora</item>
+    <item>Ogni 2 ore</item>
+    <item>Ogni 4 ore</item>
+    <item>Una volta al giorno</item>
+  </string-array>
+  <string name="settings_sync_wifi_only">Sincr. solo tramite WiFi</string>
+  <string name="settings_sync_wifi_only_on">La sincronizzazione è limitata alle connessioni WiFi</string>
+  <string name="settings_sync_wifi_only_off">Il tipo di connessione non è preso in considerazione</string>
+  <string name="settings_sync_wifi_only_ssid">Restrizione sul SSID del WiFi</string>
+  <string name="settings_sync_wifi_only_ssid_on">La sincronizzazione avverrà solo con %s</string>
+  <string name="settings_sync_wifi_only_ssid_off">Verranno usate tutte le connessioni WiFi</string>
+  <string name="settings_sync_wifi_only_ssid_message">Inserisci il nome di una rete WiFi (SSID) per limitare la sincronizzazione solo con questa rete o lasciare in bianco per usare tutte le connessioni WiFi.</string>
+  <string name="settings_carddav">CardDAV</string>
+  <string name="settings_contact_group_method">Organizzazione dei gruppi di contatto</string>
+  <string-array name="settings_contact_group_method_values">
+    <item>GROUP_VCARDS</item>
+    <item>CATEGORIES</item>
+  </string-array>
+  <string-array name="settings_contact_group_method_entries">
+    <item>I gruppi sono VCards separate</item>
+    <item>I gruppi sono categorie per ogni contatto</item>
+  </string-array>
+  <string name="settings_caldav">CalDAV</string>
+  <string name="settings_sync_time_range_past">Limite di tempo per gli eventi trascorsi</string>
+  <string name="settings_sync_time_range_past_none">Verranno sincronizzati tutti gli eventi</string>
+  <plurals name="settings_sync_time_range_past_days">
+    <item quantity="one">Eventi più vecchi di un giorno saranno ignorati</item>
+    <item quantity="other">Eventi più vecchi di %d giorni saranno ignorati</item>
+  </plurals>
+  <string name="settings_sync_time_range_past_message">Eventi più vecchi di questo numero di giorni verranno ignorati(può anche essere 0). Lasciare in bianco per sincronizzare tutti gli eventi.</string>
+  <string name="settings_manage_calendar_colors">Cambia il colore del calendario</string>
+  <string name="settings_manage_calendar_colors_on">I colori dei calendari sono gestiti da DAVdroid</string>
+  <string name="settings_manage_calendar_colors_off">I colori dei calendari non sono gestiti da DAVdroid</string>
+  <!--collection management-->
+  <string name="create_addressbook">Crea indirizzario</string>
+  <string name="create_addressbook_display_name_hint">Il mio indirizzario</string>
+  <string name="create_calendar">Crea raccolta CalDAV</string>
+  <string name="create_calendar_display_name_hint">Mio calendario</string>
+  <string name="create_calendar_time_zone">Fuso orario:</string>
+  <string name="create_calendar_type">Tipo di raccolta:</string>
+  <string name="create_calendar_type_only_events">Calendario (solo eventi)</string>
+  <string name="create_calendar_type_only_tasks">Elenco attività (solo attività)</string>
+  <string name="create_calendar_type_events_and_tasks">Combinato (eventi e attività)</string>
+  <string name="create_collection_color">Imposta colore della raccolta</string>
+  <string name="create_collection_creating">Crea una raccolta</string>
+  <string name="create_collection_display_name">Mostra il nome (titolo) di questa raccolta:</string>
+  <string name="create_collection_display_name_required">Il titolo è richiesto</string>
+  <string name="create_collection_description">Descrizione (opzionale):</string>
+  <string name="create_collection_home_set">Imposta la home:</string>
+  <string name="create_collection_create">Crea</string>
+  <string name="delete_collection">Elimina raccolta</string>
+  <string name="delete_collection_confirm_title">Sei sicuro?</string>
+  <string name="delete_collection_confirm_warning">Questa raccolta (%s) e tutti i suoi dati saranno rimossi dal server.</string>
+  <string name="delete_collection_deleting_collection">Cancellazione della raccolta</string>
+  <!--ExceptionInfoFragment-->
+  <string name="exception">Si è verificato un errore.</string>
+  <string name="exception_httpexception">Si è verificato un errore HTTP.</string>
+  <string name="exception_ioexception">Si è verificato un errore di I/O.</string>
+  <string name="exception_show_details">Mostra dettagli</string>
+  <!--sync errors and DebugInfoActivity-->
+  <string name="debug_info_title">Informazioni di debug</string>
+  <string name="sync_error_permissions">Autorizzazioni DAVdroid</string>
+  <string name="sync_error_permissions_text">Autorizzazioni addizionali richieste</string>
+  <string name="sync_error_calendar">Sincronizzazione del calendario fallita (%s)</string>
+  <string name="sync_error_contacts">Sincronizzazione dell\'indirizzario fallita (%s)</string>
+  <string name="sync_error_tasks">Sincronizzazione delle attività fallita (%s)</string>
+  <string name="sync_error">Errore nel %s</string>
+  <string name="sync_error_http_dav">Errore del server nel %s</string>
+  <string name="sync_error_local_storage">Errore del database nel %s</string>
+  <string-array name="sync_error_phases">
+    <item>inizio sincronizzazione</item>
+    <item>controllo caratteristiche del server</item>
+    <item>elaborazione voci cancellate in locale</item>
+    <item>elaborazione voci create o modificate</item>
+    <item>invio voci create o modificate</item>
+    <item>controllo stato della sincronizzazione</item>
+    <item>elenco voci locali</item>
+    <item>elenco voci remote</item>
+    <item>confronto voci locali e remote</item>
+    <item>download voci remote</item>
+    <item>post-processing</item>
+    <item>salvataggio stato della sincronizzazione</item>
+  </string-array>
+  <string name="sync_error_unauthorized">Nome utente o password errati</string>
+  <!--cert4android-->
+  <string name="certificate_notification_connection_security">DAVdroid: sicurezza della connessione</string>
+  <string name="trust_certificate_unknown_certificate_found">DAVdroid ha trovato un certificato sconosciuto. Ritenerlo affidabile?</string>
+</resources>

app/src/davdroid/res/values-ja/strings.xml

@@ -2,11 +2,17 @@
 <resources xmlns:tools="http://schemas.android.com/tools">
   <!--common strings-->
   <string name="app_name">DAVdroid</string>
+  <string name="account_title_address_book">DAVdroid アドレス帳</string>
+  <string name="address_books_authority_title">アドレス帳</string>
   <string name="help">ヘルプ</string>
   <string name="manage_accounts">アカウントの管理</string>
   <string name="please_wait">しばらくお待ちください …</string>
   <string name="send">送信</string>
+  <string name="homepage_url">https://davdroid.bitfire.at/?pk_campaign=davdroid-app</string>
   <!--startup dialogs-->
+  <string name="startup_battery_optimization">バッテリー最適化</string>
+  <string name="startup_battery_optimization_message">Android は数日後に DAVdroid の同期を無効にする/減らすことがあります。これを防止するには、バッテリー最適化をオフにしてください。</string>
+  <string name="startup_battery_optimization_disable">DAVdroid 用にオフにする</string>
   <string name="startup_dont_show_again">次回から表示しない</string>
   <string name="startup_development_version">DAVdroid プレビュー リリース</string>
   <string name="startup_development_version_message">これは DAVdroid の開発版です。期待した通りに動作しない可能性があることにご注意ください。私たちが DAVdroid を改善するために、建設的なフィードバックをお願いします。</string>
@@ -41,9 +47,12 @@
   <string name="navigation_drawer_external_links">外部リンク</string>
   <string name="navigation_drawer_website">Web サイト</string>
   <string name="navigation_drawer_faq">FAQ</string>
+  <string name="navigation_drawer_faq_url">https://davdroid.bitfire.at/faq/?pk_campaign=davdroid-app</string>
   <string name="navigation_drawer_forums">コミュニティ</string>
   <string name="navigation_drawer_donate">寄付</string>
   <string name="account_list_empty">DAVdroid にようこそ!\n\nCalDAV/CardDAV アカウントを追加できるようになりました。</string>
+  <string name="accounts_global_sync_disabled">システム全体の自動同期が無効です</string>
+  <string name="accounts_global_sync_enable">有効</string>
   <!--DavService-->
   <string name="dav_service_refresh_failed">サービスの検出に失敗しました</string>
   <string name="dav_service_refresh_couldnt_refresh">コレクション リストを更新できません</string>
@@ -53,12 +62,19 @@
   <string name="app_settings_reset_hints">ヒントをリセット</string>
   <string name="app_settings_reset_hints_summary">以前非表示にしたヒントを、再度有効にします</string>
   <string name="app_settings_reset_hints_success">すべてのヒントが再度表示されます</string>
+  <string name="app_settings_connection">接続</string>
+  <string name="app_settings_override_proxy">プロキシ設定を上書き</string>
+  <string name="app_settings_override_proxy_on">カスタムのプロキシ設定を使用する</string>
+  <string name="app_settings_override_proxy_off">システムデフォルトのプロキシ設定を使用する</string>
+  <string name="app_settings_override_proxy_host">HTTP プロキシのホスト名</string>
+  <string name="app_settings_override_proxy_port">HTTP プロキシのポート</string>
   <string name="app_settings_security">セキュリティ</string>
-  <string name="app_settings_reset_trusted_certificates">信頼済証明書をリセット</string>
-  <string name="app_settings_reset_trusted_certificates_summary">以前承認されたすべての証明書を忘れます</string>
-  <plurals name="app_settings_reset_trusted_certificates_success">
-    <item quantity="other">%d 証明書の信頼を解除しました</item>
-  </plurals>
+  <string name="app_settings_distrust_system_certs">システム証明書の信頼を解除</string>
+  <string name="app_settings_distrust_system_certs_on">システムとユーザーが追加したCAを信頼しない</string>
+  <string name="app_settings_distrust_system_certs_off">システムとユーザーが追加したCAを信頼する (推奨)</string>
+  <string name="app_settings_reset_certificates">(未)信頼済証明書をリセット</string>
+  <string name="app_settings_reset_certificates_summary">すべてのカスタム証明書の信頼をリセット</string>
+  <string name="app_settings_reset_certificates_success">すべてのカスタム証明書をクリアしました</string>
   <string name="app_settings_debug">デバッグ</string>
   <string name="app_settings_log_to_external_storage">外部ファイルにログ出力</string>
   <string name="app_settings_log_to_external_storage_on">(可能な場合) 外部ストレージにログ出力します</string>
@@ -69,6 +85,9 @@
   <string name="account_synchronize_now">今すぐ同期</string>
   <string name="account_synchronizing_now">同期中</string>
   <string name="account_settings">アカウント設定</string>
+  <string name="account_rename">アカウントの名前を変更</string>
+  <string name="account_rename_new_name">未保存のローカルデータが破棄されることがあります。 名前の変更後に再同期が必要です。 新しいアカウント名:</string>
+  <string name="account_rename_rename">名前を変更</string>
   <string name="account_delete">アカウントを削除</string>
   <string name="account_delete_confirmation_title">アカウントを削除してもよろしいですか?</string>
   <string name="account_delete_confirmation_text">アドレス帳、カレンダー、タスクリストのローカルコピーがすべて削除されます。</string>
@@ -88,6 +107,7 @@
   <string name="permissions_opentasks_details">ローカルのタスクリストと CalDAV タスクを同期するため、DAVdroid が OpenTasks にアクセスする必要があります。</string>
   <string name="permissions_opentasks_request">OpenTasks アクセス許可の要求</string>
   <!--AddAccountActivity-->
+  <string name="login_help_url">https://davdroid.bitfire.at/configuration/?pk_campaign=davdroid-app</string>
   <string name="login_title">アカウントを追加</string>
   <string name="login_type_email">メールアドレスでログイン</string>
   <string name="login_email_address">メールアドレス</string>
@@ -100,7 +120,6 @@
   <string name="login_user_name">ユーザー名</string>
   <string name="login_user_name_required">ユーザー名が必要です</string>
   <string name="login_base_url">ベース URL</string>
-  <string name="login_auth_preemptive">プリエンプティブ認証 (推奨ですが、ダイジェスト認証と互換性がありません)</string>
   <string name="login_login">ログイン</string>
   <string name="login_back">戻る</string>
   <string name="login_create_account">アカウントを作成</string>
@@ -121,9 +140,6 @@
   <string name="settings_password">パスワード</string>
   <string name="settings_password_summary">ご利用のサーバーに従ってパスワードを更新します。</string>
   <string name="settings_enter_password">パスワードを入力:</string>
-  <string name="settings_preemptive">プリエンプティブ認証</string>
-  <string name="settings_preemptive_on">すべてのリクエストで資格情報を送信します (推奨)</string>
-  <string name="settings_preemptive_off">サーバーが要求した後、資格情報を送信します</string>
   <string name="settings_sync">同期</string>
   <string name="settings_sync_interval_contacts">連絡先同期間隔</string>
   <string name="settings_sync_summary_manually">手動のみ</string>
@@ -131,16 +147,6 @@
   <string name="settings_sync_summary_not_available">利用不可</string>
   <string name="settings_sync_interval_calendars">カレンダー同期間隔</string>
   <string name="settings_sync_interval_tasks">タスク同期間隔</string>
-  <string-array name="settings_sync_interval_seconds">
-    <item>-1</item>
-    <item>300</item>
-    <item>600</item>
-    <item>900</item>
-    <item>3600</item>
-    <item>7200</item>
-    <item>14400</item>
-    <item>86400</item>
-  </string-array>
   <string-array name="settings_sync_interval_names">
     <item>手動のみ</item>
     <item>5 分ごと</item>
@@ -160,17 +166,10 @@
   <string name="settings_sync_wifi_only_ssid_message">このネットワークで同期を制限する WiFi ネットワーク (SSID) の名前を入力してください。すべての WiFi 接続は空白のままにします。</string>
   <string name="settings_carddav">CardDAV</string>
   <string name="settings_contact_group_method">連絡先グループ方法</string>
-  <string-array name="settings_contact_group_method_values">
-    <item>GROUP_VCARDS</item>
-    <item>CATEGORIES</item>
-  </string-array>
   <string-array name="settings_contact_group_method_entries">
     <item>グループは個別の VCards</item>
     <item>グループは連絡先カテゴリーごと</item>
   </string-array>
-  <string name="settings_rfc6868_for_vcards">RFC6868 の VCards を使用する</string>
-  <string name="settings_rfc6868_for_vcards_on">二重引用符を、パラメーター値に使用することができます</string>
-  <string name="settings_rfc6868_for_vcards_off">二重引用符を、パラメーター値に使用することができません</string>
   <string name="settings_caldav">CalDAV</string>
   <string name="settings_sync_time_range_past">過去イベントの時間限度</string>
   <string name="settings_sync_time_range_past_none">すべてのイベントが同期されます</string>
@@ -181,9 +180,6 @@
   <string name="settings_manage_calendar_colors">カレンダーの色を管理</string>
   <string name="settings_manage_calendar_colors_on">カレンダーの色は DAVdroid が管理します</string>
   <string name="settings_manage_calendar_colors_off">カレンダーの色を DAVdroid が設定しません</string>
-  <string name="settings_version_update">DAVdroid バージョンの更新</string>
-  <string name="settings_version_update_settings_updated">内部設定が更新されました。</string>
-  <string name="settings_version_update_install_hint">問題がありますか? DAVdroid をアンインストールして、再度インストールしてください。</string>
   <!--collection management-->
   <string name="create_addressbook">アドレス帳を作成</string>
   <string name="create_addressbook_display_name_hint">マイ アドレス帳</string>
@@ -235,4 +231,7 @@
     <item>同期の状態を保存中</item>
   </string-array>
   <string name="sync_error_unauthorized">ユーザー名/パスワードが間違っています</string>
+  <!--cert4android-->
+  <string name="certificate_notification_connection_security">DAVdroid: 接続セキュリティ</string>
+  <string name="trust_certificate_unknown_certificate_found">DAVdroidは、未知の証明書を検出しました。それを信頼しますか?</string>
 </resources>

app/src/davdroid/res/values-nl/strings.xml

@@ -2,11 +2,17 @@
 <resources xmlns:tools="http://schemas.android.com/tools">
   <!--common strings-->
   <string name="app_name">DAVdroid</string>
+  <string name="account_title_address_book">DAVdroid Adresboek</string>
+  <string name="address_books_authority_title">Adresboeken</string>
   <string name="help">Help</string>
   <string name="manage_accounts">Beheer accounts</string>
   <string name="please_wait">Een moment geduld...</string>
   <string name="send">Verzenden</string>
+  <string name="homepage_url">https://davdroid.bitfire.at/?pk_campaign=davdroid-app</string>
   <!--startup dialogs-->
+  <string name="startup_battery_optimization">Batterij optimalisatie</string>
+  <string name="startup_battery_optimization_message">Android kan mogelijk de DAVdroid synchronisatie stoppen na een paar dagen. Om dit te voorkomen zet u de batterij optimalisatie uit.</string>
+  <string name="startup_battery_optimization_disable">DAVdroid afsluiten</string>
   <string name="startup_dont_show_again">Niet opnieuw weergeven</string>
   <string name="startup_development_version">DAVdroid voorlopige versie</string>
   <string name="startup_development_version_message">Dit is een ontwikkelversie van DAVdroid. Het kan zijn dat dingen niet werken zoals verwacht. Geef ons constructieve feedback om DAVdroid te verbeteren.</string>
@@ -41,9 +47,12 @@
   <string name="navigation_drawer_external_links">Externe links</string>
   <string name="navigation_drawer_website">Website</string>
   <string name="navigation_drawer_faq">FAQ</string>
+  <string name="navigation_drawer_faq_url">https://davdroid.bitfire.at/faq/?pk_campaign=davdroid-app</string>
   <string name="navigation_drawer_forums">Community</string>
   <string name="navigation_drawer_donate">Doneren</string>
   <string name="account_list_empty">Welkom bij DAVdroid!\n\nJe kunt nu een CalDAV/CardDAv account toevoegen.</string>
+  <string name="accounts_global_sync_disabled">Systeembrede automatische synchronisatie is uitgeschakeld</string>
+  <string name="accounts_global_sync_enable">Inschakelen</string>
   <!--DavService-->
   <string name="dav_service_refresh_failed">Service herkenning is mislukt</string>
   <string name="dav_service_refresh_couldnt_refresh">Kon de collectie lijst niet vernieuwen</string>
@@ -53,13 +62,19 @@
   <string name="app_settings_reset_hints">Hints resetten </string>
   <string name="app_settings_reset_hints_summary">Hints die al gezien zijn opnieuw weergeven</string>
   <string name="app_settings_reset_hints_success">Alle hints worden opnieuw weergegeven</string>
+  <string name="app_settings_connection">Verbinding</string>
+  <string name="app_settings_override_proxy">Proxy instellingen overschrijven</string>
+  <string name="app_settings_override_proxy_on">Eigen proxy instellingen gebruiken</string>
+  <string name="app_settings_override_proxy_off">Systeem proxy instellingen gebruiken</string>
+  <string name="app_settings_override_proxy_host">HTTP proxy beheerder naam</string>
+  <string name="app_settings_override_proxy_port">HTTP proxy poort</string>
   <string name="app_settings_security">Beveiliging</string>
-  <string name="app_settings_reset_trusted_certificates">Vertrouwde certificaten resetten</string>
-  <string name="app_settings_reset_trusted_certificates_summary">Vergeet alle eerder geaccepteerde certificaten</string>
-  <plurals name="app_settings_reset_trusted_certificates_success">
-    <item quantity="one">Onbetrouwbaar certificaat</item>
-    <item quantity="other">Onbetrouwbaar %d certificaten</item>
-  </plurals>
+  <string name="app_settings_distrust_system_certs">Systeem certificaten niet vertrouwen</string>
+  <string name="app_settings_distrust_system_certs_on">Systeem en CAs van toegevoegde gebruiker wordt niet vertrouwd</string>
+  <string name="app_settings_distrust_system_certs_off">Systeem en CAs van toegevoegde gebruiker wordt vertrouwd (aanbevolen)</string>
+  <string name="app_settings_reset_certificates">Resetten (niet) vertrouwde certificaten</string>
+  <string name="app_settings_reset_certificates_summary">Resetten alle bewerkte certificaten</string>
+  <string name="app_settings_reset_certificates_success">Alle bewerkte certificaten zijn vrijgemaakt</string>
   <string name="app_settings_debug">Debuggen</string>
   <string name="app_settings_log_to_external_storage">Log naar extern bestand</string>
   <string name="app_settings_log_to_external_storage_on">Loggen naar externe opslag (wanneer beschikbaar)</string>
@@ -70,6 +85,9 @@
   <string name="account_synchronize_now">Synchroniseer nu</string>
   <string name="account_synchronizing_now">Aan het synchronizeren...</string>
   <string name="account_settings">Account instellingen</string>
+  <string name="account_rename">Account hernoemen</string>
+  <string name="account_rename_new_name">Niet opgeslagen lokale informatie mag verloren gaan. Synchronisatie is noodzakelijk na hernoemen. Nieuw account naam:</string>
+  <string name="account_rename_rename">Hernoemen</string>
   <string name="account_delete">Account verwijderen</string>
   <string name="account_delete_confirmation_title">Account echt verwijderen?</string>
   <string name="account_delete_confirmation_text">Alle lokale kopieën van adresboeken, agenda\'s en taken worden verwijderd.</string>
@@ -89,6 +107,7 @@
   <string name="permissions_opentasks_details">Om CalDAV taken te synchroniseren met uw local takenlijst dient DAVdroid toegang te hebben tot OpenTasks</string>
   <string name="permissions_opentasks_request">OpenTasks rechten verkrijgen</string>
   <!--AddAccountActivity-->
+  <string name="login_help_url">https://davdroid.bitfire.at/configuration/?pk_campaign=davdroid-app</string>
   <string name="login_title">Account toevoegen</string>
   <string name="login_type_email">Inloggen met e-mailadres</string>
   <string name="login_email_address">Email adres</string>
@@ -101,12 +120,12 @@
   <string name="login_user_name">Gebruikersnaam</string>
   <string name="login_user_name_required">Gebruikersnaam vereist</string>
   <string name="login_base_url">Basis URL</string>
-  <string name="login_auth_preemptive">Preëmptieve authenticatie (aanbevolen, maar werkt niet met Digest-auth)</string>
   <string name="login_login">Login</string>
   <string name="login_back">Terug</string>
   <string name="login_create_account">Maak een account</string>
   <string name="login_account_name">Accountnaam</string>
   <string name="login_account_name_info">Gebruik je email adres als account naam want Android zal je account naam gebruiken als ORGANIZER veld voor gemaakte afspraken. Je kunt geen 2 accounts met dezelfde naam hebben,</string>
+  <string name="login_account_contact_group_method">Contact groep methode:</string>
   <string name="login_account_name_required">Accountnaam vereist</string>
   <string name="login_account_not_created">Account kon niet gemaakt worden.</string>
   <string name="login_configuration_detection">Configuratie detectie</string>
@@ -121,9 +140,6 @@
   <string name="settings_password">Wachtwoord</string>
   <string name="settings_password_summary">Gebruik het zelfde wachtwoord als op de server.</string>
   <string name="settings_enter_password">Wachtwoord invoeren:</string>
-  <string name="settings_preemptive">Preëmptieve authenticatie</string>
-  <string name="settings_preemptive_on">Credentials worden met elk verzoek verzonden (aanbevolen)</string>
-  <string name="settings_preemptive_off">Credentials worden alleen op aanvraag verzonden</string>
   <string name="settings_sync">Synchronisatie</string>
   <string name="settings_sync_interval_contacts">Contacten verversen</string>
   <string name="settings_sync_summary_manually">Alleen handmatig</string>
@@ -158,6 +174,16 @@
   <string name="settings_sync_wifi_only_ssid_on">Zal alleen synchroniseren over %s</string>
   <string name="settings_sync_wifi_only_ssid_off">Alle WiFI verbindingen mogen worden gebruikt</string>
   <string name="settings_sync_wifi_only_ssid_message">Type de naam van het WiFi netwerk (SSID) om synchronisatie tot dit netwerk te beperken. Leeg laten voor sync over alle netwerken.</string>
+  <string name="settings_carddav">CardDAV</string>
+  <string name="settings_contact_group_method">Contact groep methode</string>
+  <string-array name="settings_contact_group_method_values">
+    <item>GROUP_VCARDS</item>
+    <item>CATEGORIES</item>
+  </string-array>
+  <string-array name="settings_contact_group_method_entries">
+    <item>Groepen zijn apparte VCards</item>
+    <item>Groepen zijn per-contact categories</item>
+  </string-array>
   <string name="settings_caldav">CalDAV</string>
   <string name="settings_sync_time_range_past">Tijdslimiet verleden afspraken</string>
   <string name="settings_sync_time_range_past_none">Alle afspraken worden gesynchronizeerd</string>
@@ -169,9 +195,6 @@
   <string name="settings_manage_calendar_colors">Agenda kleuren beheren</string>
   <string name="settings_manage_calendar_colors_on">Agenda kleuren worden door DAVdroid beheerd.</string>
   <string name="settings_manage_calendar_colors_off">Agenda kleuren worden niet door DAVdroid ingesteld</string>
-  <string name="settings_version_update">DAVdroid versie update</string>
-  <string name="settings_version_update_settings_updated">Interne instellingen zijn bijgewerkt.</string>
-  <string name="settings_version_update_install_hint">Problemen? Deïnstalleer DAVdroid, daarna herinstalleren.</string>
   <!--collection management-->
   <string name="create_addressbook">Maak adresboek</string>
   <string name="create_addressbook_display_name_hint">Mijn adresboek</string>
@@ -208,5 +231,22 @@
   <string name="sync_error">Fout tijdens %s</string>
   <string name="sync_error_http_dav">Serverfout tijdens %s</string>
   <string name="sync_error_local_storage">Database fout tijdens %s</string>
+  <string-array name="sync_error_phases">
+    <item>synchronisatie voorbereiden</item>
+    <item>querying mogelijkheden</item>
+    <item>verwerken van lokaal verwijderde data</item>
+    <item>voorberteiding maken/wijzigen data</item>
+    <item>uploaden maken/bewerken data</item>
+    <item>controleren syngronisatie voortgang</item>
+    <item>lijst lokale data</item>
+    <item>lijst remote data</item>
+    <item>vergelijken lokale/remote data</item>
+    <item>downloaden remote data</item>
+    <item>nabewerking</item>
+    <item>opslaan sync voortgang</item>
+  </string-array>
   <string name="sync_error_unauthorized">Gebruikersnaam/wachtwoord onjuist</string>
+  <!--cert4android-->
+  <string name="certificate_notification_connection_security">DAVdroid: Verbinding beveiliging</string>
+  <string name="trust_certificate_unknown_certificate_found">Davdroid is benaderd door een onbekend certificaat. Vertrouwd u dit?</string>
 </resources>

app/src/davdroid/res/values-pl/strings.xml

@@ -2,18 +2,26 @@
 <resources xmlns:tools="http://schemas.android.com/tools">
   <!--common strings-->
   <string name="app_name">DAVdroid</string>
+  <string name="account_title_address_book">Książka adresowa DAVdroid</string>
+  <string name="address_books_authority_title">Książka adresowa</string>
   <string name="help">Pomoc</string>
   <string name="manage_accounts">Zadządzaj kontami</string>
   <string name="please_wait">Proszę czekać</string>
   <string name="send">Wyślij</string>
   <!--startup dialogs-->
+  <string name="startup_battery_optimization">Optymalizacja baterii</string>
+  <string name="startup_battery_optimization_message">Android może wyłączyć/zmniejszyć synchronizacje DAVdroid po kilku dniach. Aby temu zapobiec należy wyłączyć optymalizację baterii.</string>
+  <string name="startup_battery_optimization_disable">Wyłącz dla DAVdroid</string>
   <string name="startup_dont_show_again">Nie pokazuj ponownie</string>
   <string name="startup_development_version">DAVdroid Preview Release</string>
+  <string name="startup_development_version_message">Jest to wersja rozwojowa DAVdroid. Należy pamiętać, że rzeczy mogą nie działać zgodnie z oczekiwaniami. Prosimy o konstruktywny informacje zwrotne, aby ulepszyć DAVdroid.</string>
   <string name="startup_development_version_give_feedback">Przekaż opinię</string>
   <string name="startup_donate">Informacje Open-Source</string>
+  <string name="startup_donate_message">Jesteśmy szczęśliwi, że używasz DAVdroid, który jest oprogramowaniem open-source (GPLv3). Ponieważ rozwijanie DAVdroid jest ciężką pracą i zajęło nam tysiące godzin pracy, prosimy o rozważenie darowizny.</string>
   <string name="startup_donate_now">Pokaż stronę darowizny</string>
   <string name="startup_donate_later">Może później</string>
   <string name="startup_google_play_accounts_removed">Informacje o błędzie DRM Sklepu Play</string>
+  <string name="startup_google_play_accounts_removed_message">Pod pewnymi warunkami, DRM Sklepu Play może powodować, że wszystkie konta DAVdroid mogą zostać usunięte po uruchomieniu lub po uaktualnieniu DAVdroid. Jeśli jesteś dotknięty tym problemem (i tylko wtedy) należy zainstalować \"DAVdroid JB Obejście\" ze Sklepu Play.</string>
   <string name="startup_google_play_accounts_removed_more_info">Więcej informacji</string>
   <string name="startup_opentasks_not_installed">OpenTasks nie jest zainstalowany</string>
   <string name="startup_opentasks_not_installed_message">Aplikacja Open Tasks nie jest dostępna, więc DAVdroid nie będzie mógł synchronizować listy zadań. </string>
@@ -21,6 +29,7 @@
   <string name="startup_opentasks_not_installed_install">Zainstaluj OpenTasks</string>
   <!--AboutActivity-->
   <string name="about_license_terms">Warunki licencji</string>
+  <string name="about_license_info_no_warranty">Ten program jest ABSOLUTNIE BEZ GWARANCJI. To jest wolne oprogramowanie i mile widziane jest dalsze rozpowszechnianie go pod pewnymi warunkami.</string>
   <!--global settings-->
   <string name="logging_davdroid_file_logging">Plik logów DAVdroid</string>
   <string name="logging_to_external_storage">Logowanie do zewnątrznej pamięci: %s</string>
@@ -33,31 +42,53 @@
   <string name="navigation_drawer_subtitle">Adapter synchronizacji CalDAV/CardDAV</string>
   <string name="navigation_drawer_about">O DAVdroid / Licencja</string>
   <string name="navigation_drawer_settings">Ustawienia</string>
-  <string name="navigation_drawer_news_updates">Nowości &amp; aktualizacje
-</string>
+  <string name="navigation_drawer_news_updates">Nowości &amp; aktualizacje</string>
   <string name="navigation_drawer_external_links">Zewnętrzne odnośniki</string>
   <string name="navigation_drawer_website">Strona WWW</string>
   <string name="navigation_drawer_faq">FQA</string>
   <string name="navigation_drawer_forums">Społeczność</string>
   <string name="navigation_drawer_donate">Dotacja</string>
+  <string name="account_list_empty">Witamy w DAVdroid!\n\nMożesz teraz dodać konto CalDAV/CardDAV.</string>
+  <string name="accounts_global_sync_disabled">Automatyczna synchronizacja dla całego systemu jest wyłączona</string>
+  <string name="accounts_global_sync_enable">Włącz</string>
   <!--DavService-->
   <string name="dav_service_refresh_failed">Wykrycie serwisu nie powiodło się</string>
   <string name="dav_service_refresh_couldnt_refresh">Nie można odświeżyć listy kolekcji</string>
   <!--AppSettingsActivity-->
   <string name="app_settings">Ustawienia</string>
-  <string name="app_settings_user_interface">
-Interfejs użytkownika</string>
+  <string name="app_settings_user_interface">Interfejs użytkownika</string>
   <string name="app_settings_reset_hints">Zresetuj podpowiedzi</string>
+  <string name="app_settings_reset_hints_summary">Ponownie włącz wskazówki, które zostały usunięte wcześniej</string>
+  <string name="app_settings_reset_hints_success">Wszystkie wskazówki pojawią się ponownie</string>
+  <string name="app_settings_connection">Łączność</string>
+  <string name="app_settings_override_proxy">Nadpisz ustawienia proxy</string>
+  <string name="app_settings_override_proxy_on">Użyj niestandardowych ustawień proxy </string>
+  <string name="app_settings_override_proxy_off">Użyj systemowych ustawień proxy</string>
+  <string name="app_settings_override_proxy_host">Nazwa hosta HTTP proxy</string>
+  <string name="app_settings_override_proxy_port">Port HTTP proxy</string>
   <string name="app_settings_security">Bezpieczeństwo</string>
+  <string name="app_settings_distrust_system_certs">Usuń certyfikaty systemowe</string>
+  <string name="app_settings_distrust_system_certs_on">CA systemowe i użytkownika nie zostaną dodane</string>
+  <string name="app_settings_distrust_system_certs_off">CA systemowe i użytkownika zostaną dodane (zalecane)</string>
+  <string name="app_settings_reset_certificates">Zresetuj (nie)zaufane certyfikaty</string>
+  <string name="app_settings_reset_certificates_summary">Zresetuj wszystkie niestandardowe certyfikaty.</string>
+  <string name="app_settings_reset_certificates_success">Wszystkie niestandardowe certyfikaty zostały wyczyszczone</string>
   <string name="app_settings_debug">Debugowanie</string>
   <string name="app_settings_log_to_external_storage">Loguj to zewnętrznego pliku</string>
+  <string name="app_settings_log_to_external_storage_on">Logowanie do zewnętrznej pamięci (jeśli jest dostępna)</string>
+  <string name="app_settings_log_to_external_storage_off">Logowanie do zewnętrznego pliku jest niedostępne</string>
   <string name="app_settings_show_debug_info">Pokaż informacje do debug\'owania</string>
+  <string name="app_settings_show_debug_info_details">Przeglądaj/udostępnij oprogramowanie i szczegóły konfiguracji </string>
   <!--AccountActivity-->
   <string name="account_synchronize_now">Synchronizuj teraz</string>
   <string name="account_synchronizing_now">Synchronizcja w toku</string>
   <string name="account_settings">Ustawienia konta</string>
+  <string name="account_rename">Zmień nazwę konta</string>
+  <string name="account_rename_new_name">Niezapisane dane lokalne mogą zostać usunięte. Ponowna synchronizacja jest wymagana po zmianie nazwy. Nowa nazwa konta:</string>
+  <string name="account_rename_rename">Zmień nazwę</string>
   <string name="account_delete">Usuń konto</string>
   <string name="account_delete_confirmation_title">Naprawdę chcesz usunąć konto?</string>
+  <string name="account_delete_confirmation_text">Wszystkie lokalne kopie książek adresowych, kalendarzy i list zadań zostaną usunięte.</string>
   <string name="account_refresh_address_book_list">Odśwież list książek adresowych</string>
   <string name="account_create_new_address_book">Stwórz nową książkę adresową</string>
   <string name="account_refresh_calendar_list">Odśwież liste kalendarzy</string>
@@ -65,10 +96,13 @@ Interfejs użytkownika</string>
   <!--PermissionsActivity-->
   <string name="permissions_title">Uprawnienia DAVdroid</string>
   <string name="permissions_calendar">Uprawnienia kalendarza</string>
+  <string name="permissions_calendar_details">Aby synchronizować wydarzenia CalDav z lokalnymi kalendarzami, DAVdroid potrzebuje dostępu do twoich kalendarzy.</string>
   <string name="permissions_calendar_request">Zezwól na uprawnienia kalendarza</string>
   <string name="permissions_contacts">Uprawnienia kontaktów</string>
+  <string name="permissions_contacts_details">Aby synchronizować książki adresowe CardDAV z lokalnymi kontaktami, DAVdroid potrzebuje dostępu do twoich kontaktów.</string>
   <string name="permissions_contacts_request">Zezwól na uprawnienia kontaktów</string>
   <string name="permissions_opentasks">Uprawnienia OpenTasks</string>
+  <string name="permissions_opentasks_details">Aby synchronizować zadania CalDav z lokalnymi listami zadań, DAVdroid potrzebuje dostępu do OpenTasks.</string>
   <string name="permissions_opentasks_request">Zezwól na uprawnienia OpenTasks</string>
   <!--AddAccountActivity-->
   <string name="login_title">Dodaj konto</string>
@@ -78,20 +112,22 @@ Interfejs użytkownika</string>
   <string name="login_password">Hasło</string>
   <string name="login_password_required">Wymagane hasło</string>
   <string name="login_type_url">Logowanie za pomocą adresu URL i nazwy użytkownika</string>
+  <string name="login_url_must_be_http_or_https">URL musi zaczynać się z http(s)://</string>
   <string name="login_url_host_name_required">Wymagana nazwa hosta</string>
   <string name="login_user_name">Nazwa użytkownika</string>
   <string name="login_user_name_required">Wymagana nazwa użtkonika</string>
   <string name="login_base_url">Podstawowy URL</string>
-  <string name="login_auth_preemptive">Autoryzacja prewencyjna (zalecana, ale niezgodna z autoryzacją Digest)</string>
   <string name="login_login">Zaloguj</string>
   <string name="login_back">Wróć</string>
   <string name="login_create_account">Stwórz konto</string>
   <string name="login_account_name">Nazwa konta</string>
   <string name="login_account_name_info">Użyj swojego adresu e-mail jako nazwy konta, ponieważ Android będzie używał nazwy konta jako pola ORGANIZATOR dla wydarzeń, które stworzysz. Nie możesz posiadać dwóch kont o takiej samej nazwie.</string>
+  <string name="login_account_contact_group_method">Metoda grupowania kontaktów:</string>
   <string name="login_account_name_required">Wymagana nazwa konta</string>
   <string name="login_account_not_created">Konto nie mogło zostać stworzone</string>
   <string name="login_configuration_detection">Wykrywanie konfiguracji</string>
   <string name="login_querying_server">Proszę czekać, odpytywanie serwera...</string>
+  <string name="login_no_caldav_carddav">Nie można znaleźć usługi CalDAV lub CardDAV.</string>
   <string name="login_view_logs">Pokaż logi</string>
   <!--AccountSettingsActivity-->
   <string name="settings_title">Ustawienia: %s</string>
@@ -101,9 +137,6 @@ Interfejs użytkownika</string>
   <string name="settings_password">Hasło</string>
   <string name="settings_password_summary">Zaktualizuj hasło zgodnie z serwerem.</string>
   <string name="settings_enter_password">Wpisz hasło:</string>
-  <string name="settings_preemptive">Autoryzacja prewencyjna</string>
-  <string name="settings_preemptive_on">Listy uwierzytelniające są wysyłane przy każdym zapytaniu (zalecane)</string>
-  <string name="settings_preemptive_off">Listy uwierzytelniające są wysyłane po zapytaniu serwera o nie</string>
   <string name="settings_sync">Synchronizacja</string>
   <string name="settings_sync_interval_contacts">Okres synchronizacji kontktów</string>
   <string name="settings_sync_summary_manually">Tylko ręcznie</string>
@@ -131,19 +164,32 @@ Interfejs użytkownika</string>
     <item>Co 4 godziny</item>
     <item>Raz dziennie</item>
   </string-array>
+  <string name="settings_sync_wifi_only">Synchronizuj tylko przez WiFi</string>
+  <string name="settings_sync_wifi_only_on">Synchronizacja jest ograniczony do połączeń WiFi</string>
+  <string name="settings_sync_wifi_only_off">Rodzaj połączenia nie jest brany pod uwagę</string>
+  <string name="settings_sync_wifi_only_ssid">Organicznie WiFi SSID</string>
+  <string name="settings_sync_wifi_only_ssid_on">Będzie synchronizować tylko przez %s.</string>
+  <string name="settings_sync_wifi_only_ssid_off">Wszystkie połączenia WiFi mogą zostać wykorzystane</string>
+  <string name="settings_sync_wifi_only_ssid_message">Wprowadź nazwę sieci WiFi (SSID), aby ograniczyć synchronizację do tej sieci lub pozostaw puste dla wszystkich połączeń WiFi.</string>
   <string name="settings_carddav">CardDAV</string>
   <string name="settings_contact_group_method">Metoda grupowania kontaktów</string>
   <string-array name="settings_contact_group_method_values">
     <item>GROUP_VCARDS</item>
     <item>CATEGORIES</item>
   </string-array>
-  <string name="settings_rfc6868_for_vcards">Użyj RFC6868 dla VCards</string>
   <string name="settings_caldav">CalDAV</string>
+  <string name="settings_sync_time_range_past">Limit czasowy przeszłych wydarzeń</string>
+  <string name="settings_sync_time_range_past_none">Wszystkie wydarzenia zostaną synchronizowane</string>
+  <plurals name="settings_sync_time_range_past_days">
+    <item quantity="one">Wydarzenia starsze niż jeden dzień zostaną zignorowane.</item>
+    <item quantity="few">Wydarzenia starsze niż %d dni zostaną zignorowane.</item>
+    <item quantity="many">Wydarzenia starsze niż %d dni zostaną zignorowane.</item>
+    <item quantity="other">Wydarzenia starsze niż %d dni zostaną zignorowane.</item>
+  </plurals>
+  <string name="settings_sync_time_range_past_message">Wydarzenia, które są starsze niż podana liczba dni zostaną zignorowane (może być 0). Zostaw puste, aby synchronizować wszystkie wydarzenia.</string>
   <string name="settings_manage_calendar_colors">Zarządzaj kolorami kalendarza</string>
   <string name="settings_manage_calendar_colors_on">Kolory kalendarza są zarządzane przez DAVdroid</string>
   <string name="settings_manage_calendar_colors_off">Kolory kalendarze nie są ustawiane przez DAVdroid</string>
-  <string name="settings_version_update">Aktualizacji wersji DAVdroid</string>
-  <string name="settings_version_update_install_hint">Problemy? Odinstaluj DAVdroid i zainstaluj ponownie.</string>
   <!--collection management-->
   <string name="create_addressbook">Stwórz książkę adresową</string>
   <string name="create_addressbook_display_name_hint">Moja książka adresowa</string>
@@ -180,5 +226,22 @@ Interfejs użytkownika</string>
   <string name="sync_error">Błąd podczas %s</string>
   <string name="sync_error_http_dav">Błąd servera podczas %s</string>
   <string name="sync_error_local_storage">Bład bazy danych podczas %s</string>
+  <string-array name="sync_error_phases">
+    <item>przygotowanie synchronizacji</item>
+    <item>odpytywanie możliwości</item>
+    <item>przetwarzanie lokalnie usuniętych wpisów</item>
+    <item>przygotowanie stworzonych/zmodyfikowanych wpisów</item>
+    <item>wysyłanie stworzonych/zmodyfikowanych wpisów</item>
+    <item>sprawdzanie stanu synchronizacji</item>
+    <item>listowanie lokalnych wpisów</item>
+    <item>listowanie zdalnych wpisów</item>
+    <item>porównywanie lokalnych/zdalnych wpisów</item>
+    <item>pobieranie zdalnych wpisów</item>
+    <item>przetwarzanie końcowe</item>
+    <item>zapisywanie stanu synchronizacji</item>
+  </string-array>
   <string name="sync_error_unauthorized">Błędna nazwa użytkownika lub hasło</string>
+  <!--cert4android-->
+  <string name="certificate_notification_connection_security">DAVdroid: Bezpieczeństwo połączenia</string>
+  <string name="trust_certificate_unknown_certificate_found">DAVdroid napotkał nieznany certyfikat. Czy chcesz go dodać?</string>
 </resources>

app/src/davdroid/res/values-pt-rBR/strings.xml

@@ -2,11 +2,16 @@
 <resources xmlns:tools="http://schemas.android.com/tools">
   <!--common strings-->
   <string name="app_name">DAVdroid</string>
+  <string name="account_title_address_book">Livro de endereços DAVdroid</string>
+  <string name="address_books_authority_title">Livros de endereços</string>
   <string name="help">Ajuda</string>
   <string name="manage_accounts">Gerenciar contas</string>
   <string name="please_wait">Por favor, aguarde...</string>
   <string name="send">Enviar</string>
   <!--startup dialogs-->
+  <string name="startup_battery_optimization">Otimização da bateria</string>
+  <string name="startup_battery_optimization_message">O Android pode desativar/reduzir a sincronização do DAVdroid depois de alguns dias. Para evitar isso, desligue a otimização da bateria.</string>
+  <string name="startup_battery_optimization_disable">Desligar para o DAVdroid</string>
   <string name="startup_dont_show_again">Não mostrar novamente</string>
   <string name="startup_development_version">Versão prévia do DAVdroid</string>
   <string name="startup_development_version_message">Esta é uma versão de desenvolvimento do DAVdroid. Lembre-se de que as coisas podem não funcionar como esperado. Por favor, envie sugestões e comentários construtivos para melhorar o DAVdroid.</string>
@@ -44,6 +49,8 @@
   <string name="navigation_drawer_forums">Comunidade</string>
   <string name="navigation_drawer_donate">Doações</string>
   <string name="account_list_empty">Bem-vindo ao DAVdroid!\n\nVocê pode adicionar uma conta CalDAV/CardDAV agora.</string>
+  <string name="accounts_global_sync_disabled">A sincronização automática pelo sistema está desativada</string>
+  <string name="accounts_global_sync_enable">Ativar</string>
   <!--DavService-->
   <string name="dav_service_refresh_failed">Falha na detecção do serviço</string>
   <string name="dav_service_refresh_couldnt_refresh">Não foi possível atualizar a lista da coleção</string>
@@ -53,23 +60,32 @@
   <string name="app_settings_reset_hints">Restaurar sugestões</string>
   <string name="app_settings_reset_hints_summary">Restaura as sugestões que foram descartadas anteriormente</string>
   <string name="app_settings_reset_hints_success">Todas as sugestões serão exibidas novamente</string>
+  <string name="app_settings_connection">Conexão</string>
+  <string name="app_settings_override_proxy">Substituir as configurações de proxy</string>
+  <string name="app_settings_override_proxy_on">Usar configurações de proxy personalizadas</string>
+  <string name="app_settings_override_proxy_off">Usar configurações de proxy padrão do sistema</string>
+  <string name="app_settings_override_proxy_host">Nome do servidor proxy HTTP</string>
+  <string name="app_settings_override_proxy_port">Porta do proxy HTTP</string>
   <string name="app_settings_security">Segurança</string>
-  <string name="app_settings_reset_trusted_certificates">Restaurar certificados confiáveis</string>
-  <string name="app_settings_reset_trusted_certificates_summary">Esquece de todos os certificados que foram aceitos anteriormente</string>
-  <plurals name="app_settings_reset_trusted_certificates_success">
-    <item quantity="one">Retirada a confiança de um certificado</item>
-    <item quantity="other">Retirada a confiança de %d certificados</item>
-  </plurals>
+  <string name="app_settings_distrust_system_certs">Desconfiar dos certificados de sistema</string>
+  <string name="app_settings_distrust_system_certs_on">ACs adicionadas pelo usuário e pelo sistema não serão confiáveis</string>
+  <string name="app_settings_distrust_system_certs_off">ACs adicionadas pelo usuário e pelo sistema serão confiáveis (recomendado)</string>
+  <string name="app_settings_reset_certificates">Restaurar certificados não-confiáveis</string>
+  <string name="app_settings_reset_certificates_summary">Restaura a confiança de todos os certificados personalizados</string>
+  <string name="app_settings_reset_certificates_success">Todos os certificados personalizados foram restaurados</string>
   <string name="app_settings_debug">Depuração</string>
   <string name="app_settings_log_to_external_storage">Registrar em arquivo externo</string>
   <string name="app_settings_log_to_external_storage_on">Registrando no armazenamento externo (se disponível)</string>
   <string name="app_settings_log_to_external_storage_off">O registro em arquivo externo está desativado</string>
   <string name="app_settings_show_debug_info">Mostrar informações de depuração</string>
-  <string name="app_settings_show_debug_info_details">Exibir/compartilhar o software e os detalhes da configuração</string>
+  <string name="app_settings_show_debug_info_details">Exibe/compartilha o software e os detalhes da configuração</string>
   <!--AccountActivity-->
   <string name="account_synchronize_now">Sincronizar agora</string>
   <string name="account_synchronizing_now">Sincronizando</string>
   <string name="account_settings">Configurações da conta</string>
+  <string name="account_rename">Renomear conta</string>
+  <string name="account_rename_new_name">Dados locais que não foram salvos podem ser descartados. É necessário efetuar uma nova sincronização após renomear. Novo nome da conta:</string>
+  <string name="account_rename_rename">Renomear</string>
   <string name="account_delete">Excluir conta</string>
   <string name="account_delete_confirmation_title">Deseja excluir a conta?</string>
   <string name="account_delete_confirmation_text">Todas as cópias locais dos livros de endereços, calendários e listas de tarefas serão excluídas.</string>
@@ -101,7 +117,6 @@
   <string name="login_user_name">Usuário</string>
   <string name="login_user_name_required">É necessário um nome de usuário</string>
   <string name="login_base_url">URL base</string>
-  <string name="login_auth_preemptive">Autenticação preferencial (recomendado, mas incompatível com autenticação Digest)</string>
   <string name="login_login">Autenticar</string>
   <string name="login_back">Voltar</string>
   <string name="login_create_account">Criar conta</string>
@@ -122,9 +137,6 @@
   <string name="settings_password">Senha</string>
   <string name="settings_password_summary">Atualize a senha de acordo com seu servidor</string>
   <string name="settings_enter_password">Digite sua senha:</string>
-  <string name="settings_preemptive">Autenticação preferencial</string>
-  <string name="settings_preemptive_on">Credenciais enviadas a cada requisição (recomendado)</string>
-  <string name="settings_preemptive_off">Credenciais enviadas após a requisição do servidor</string>
   <string name="settings_sync">Sincronização</string>
   <string name="settings_sync_interval_contacts">Intervalo sinc. de contatos</string>
   <string name="settings_sync_summary_manually">Apenas manualmente</string>
@@ -169,9 +181,6 @@
     <item>Grupos são VCards separados</item>
     <item>Grupos são categorias por contato</item>
   </string-array>
-  <string name="settings_rfc6868_for_vcards">Usar RFC6868 para VCards</string>
-  <string name="settings_rfc6868_for_vcards_on">Aspas podem ser utilizadas nos valores dos parâmetros</string>
-  <string name="settings_rfc6868_for_vcards_off">Aspas não podem ser utilizadas nos valores dos parâmetros</string>
   <string name="settings_caldav">CalDAV</string>
   <string name="settings_sync_time_range_past">Limite de tempo para eventos passados</string>
   <string name="settings_sync_time_range_past_none">Todos os eventos serão sincronizados</string>
@@ -183,9 +192,6 @@
   <string name="settings_manage_calendar_colors">Gerenciar cores dos calendários</string>
   <string name="settings_manage_calendar_colors_on">Cores dos calendários definidas pelo DAVdroid</string>
   <string name="settings_manage_calendar_colors_off">Cores dos calendários não definidas pelo DAVdroid</string>
-  <string name="settings_version_update">Atualização da versão do DAVdroid</string>
-  <string name="settings_version_update_settings_updated">As configurações internas foram atualizadas.</string>
-  <string name="settings_version_update_install_hint">Problemas? Desinstale o DAVdroid e instale novamente.</string>
   <!--collection management-->
   <string name="create_addressbook">Criar livro de endereços</string>
   <string name="create_addressbook_display_name_hint">Meu livro de endereços</string>
@@ -237,4 +243,7 @@
     <item>salvando o estado da sincronização</item>
   </string-array>
   <string name="sync_error_unauthorized">Usuário/senha incorreto</string>
+  <!--cert4android-->
+  <string name="certificate_notification_connection_security">DAVdroid: Segurança da conexão</string>
+  <string name="trust_certificate_unknown_certificate_found">O DAVdroid encontrou um certificado desconhecido. Deseja torná-lo confiável?</string>
 </resources>

app/src/davdroid/res/values-pt/strings.xml

@@ -14,7 +14,6 @@
   <!--AddAccountActivity-->
   <string name="login_type_email">Login com seu enderço de email</string>
   <string name="login_type_url">Login com URL e nome do usuário</string>
-  <string name="login_auth_preemptive">Autenticação preferida (recomendado, mas incompatível com Digest)</string>
   <!--AccountSettingsActivity-->
   <string name="settings_authentication">Autenticação</string>
   <string name="settings_username">Nome de usuário</string>
@@ -22,9 +21,6 @@
   <string name="settings_password">Senha</string>
   <string name="settings_password_summary">Atualize sua denha de acordo com a do seu servidor.</string>
   <string name="settings_enter_password">Informe sua senha:</string>
-  <string name="settings_preemptive">Pre-emptive authentication</string>
-  <string name="settings_preemptive_on">Credenciais são enviadas com cadas requisição (recomendado)</string>
-  <string name="settings_preemptive_off">Credenciais são enviadas apos o servidor requisitar</string>
   <string name="settings_sync">Sincronização</string>
   <string name="settings_sync_interval_contacts">Intervalo de sincronização dos contatos</string>
   <string name="settings_sync_summary_manually">Manualmente apenas</string>
@@ -54,4 +50,5 @@
   <!--collection management-->
   <!--ExceptionInfoFragment-->
   <!--sync errors and DebugInfoActivity-->
+  <!--cert4android-->
 </resources>

app/src/davdroid/res/values-ru/strings.xml

@@ -0,0 +1,243 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<resources xmlns:tools="http://schemas.android.com/tools">
+  <!--common strings-->
+  <string name="app_name">DAVdroid</string>
+  <string name="help">Помощь</string>
+  <string name="manage_accounts">Управление аккаунтами</string>
+  <string name="please_wait">Пожалуйста подождите...</string>
+  <string name="send">Отправить</string>
+  <!--startup dialogs-->
+  <string name="startup_battery_optimization">Оптимизация батареи</string>
+  <string name="startup_battery_optimization_message">Андроид может отключить/уменьшить синхронизацию DAVdroid через несколько дней. Чтобы этого не произошло, выключите оптимизацию батареи.</string>
+  <string name="startup_battery_optimization_disable">Отключить для DAVdroid</string>
+  <string name="startup_dont_show_again">Больше не показывать</string>
+  <string name="startup_development_version">DAVdroid Предварительный Релиз</string>
+  <string name="startup_development_version_message">Это разрабатываемая версия DAVdroid. Она может не работать как Вы ожидаете. Пожалуйста, присылайте нам конструктивные отзывы, чтобы улучшить DAVdroid.</string>
+  <string name="startup_development_version_give_feedback">Оставить отзыв</string>
+  <string name="startup_donate">Open-Source информация</string>
+  <string name="startup_donate_message">Мы рады, что вы используете DAVdroid, который является программным обеспечением с открытым исходным кодом (GPLv3). Разработка DAVdroid является сложной задачей, потребовавшей от нас тысяч рабочих часов. Пожалуйста, рассмотрите возможность поддержать проект.</string>
+  <string name="startup_donate_now">Поддержать проект</string>
+  <string name="startup_donate_later">Возможно, позже</string>
+  <string name="startup_google_play_accounts_removed">Информация об ошибке в Play Store DRM</string>
+  <string name="startup_google_play_accounts_removed_message">При определённых условиях Play Store DRM может стать причиной потери всех DAVdroid аккаунтов после перезагрузки устройства или после обновления DAVdroid. Если Вы столкнулись с этой проблемой (и только в этом случае), установите \"DAVdroid JB Workaround\" из Play Store.</string>
+  <string name="startup_google_play_accounts_removed_more_info">Дополнительно</string>
+  <string name="startup_opentasks_not_installed">OpenTasks не установлен</string>
+  <string name="startup_opentasks_not_installed_message">OpenTasks недоступен, DAVdroid не сможет синхронизировать список задач</string>
+  <string name="startup_opentasks_reinstall_davdroid">После установки OpenTasks необходимо ПЕРЕУСТАНОВИТЬ DAVdroid и добавить Ваши аккаунты ещё раз (ошибка Android).</string>
+  <string name="startup_opentasks_not_installed_install">Установить OpenTasks</string>
+  <!--AboutActivity-->
+  <string name="about_license_terms">Лицензионное соглашение</string>
+  <string name="about_license_info_no_warranty">Эта программа поставляется АБСОЛЮТНО БЕЗ КАКИХ-ЛИБО ГАРАНТИЙ. Это свободная программа, и вы приглашаетесь повторно распространять ее при определенных условиях.</string>
+  <!--global settings-->
+  <string name="logging_davdroid_file_logging">Файл логов DAVdroid</string>
+  <string name="logging_to_external_storage">Сохранение логов во внешнем хранилище: %s</string>
+  <string name="logging_to_external_storage_warning">Удалять логи насколько возможно быстро!</string>
+  <string name="logging_couldnt_create_file">Не удалось создать внешний лог файл: %s</string>
+  <string name="logging_no_external_storage">Внешнее хранилище не найдено</string>
+  <!--AccountsActivity-->
+  <string name="navigation_drawer_open">Открыть панель навигации</string>
+  <string name="navigation_drawer_close">Закрыть панель навигации</string>
+  <string name="navigation_drawer_subtitle">Адаптер синхронизации CalDAV/CardDAV</string>
+  <string name="navigation_drawer_about">О программе / Лицензия</string>
+  <string name="navigation_drawer_settings">Настройки</string>
+  <string name="navigation_drawer_news_updates">Новости и обновления</string>
+  <string name="navigation_drawer_external_links">Внешние ссылки</string>
+  <string name="navigation_drawer_website">Веб сайт</string>
+  <string name="navigation_drawer_faq">ЧАВО</string>
+  <string name="navigation_drawer_forums">Сообщество</string>
+  <string name="navigation_drawer_donate">Пожертвовать</string>
+  <string name="account_list_empty">Вас приветствует DAVdroid\n\nМожете добавить CalDAV/CardDAV аккаунт сейчас.</string>
+  <!--DavService-->
+  <string name="dav_service_refresh_failed">Не удалось обнаружить сервисы</string>
+  <string name="dav_service_refresh_couldnt_refresh">Невозможно обновить список коллекций</string>
+  <!--AppSettingsActivity-->
+  <string name="app_settings">Настройки</string>
+  <string name="app_settings_user_interface">Интерфейс пользователя</string>
+  <string name="app_settings_reset_hints">Включить подсказки</string>
+  <string name="app_settings_reset_hints_summary">Включить подсказки, которые были отключены ранее</string>
+  <string name="app_settings_reset_hints_success">Все подсказки будут показаны снова</string>
+  <string name="app_settings_connection">Соединение</string>
+  <string name="app_settings_override_proxy">Переопределить настройки прокси-сервера</string>
+  <string name="app_settings_override_proxy_on">Использовать пользовательские настройки прокси-сервера</string>
+  <string name="app_settings_override_proxy_off">Использовать системные настройки прокси-сервера</string>
+  <string name="app_settings_override_proxy_host">Имя хоста HTTP прокси-сервера</string>
+  <string name="app_settings_override_proxy_port">Порт HTTP прокси-сервера</string>
+  <string name="app_settings_security">Безопасность</string>
+  <string name="app_settings_distrust_system_certs">Не доверять системным сертификатам</string>
+  <string name="app_settings_distrust_system_certs_on">Не доверять системным и добавленным пользователем CA</string>
+  <string name="app_settings_distrust_system_certs_off">Доверять системным и добавленным пользователем CA (рекомендуется)</string>
+  <string name="app_settings_reset_certificates">Сброс (не)доверенных сертификатов</string>
+  <string name="app_settings_reset_certificates_summary">Отменить доверие ко всем пользовательским сертификатам</string>
+  <string name="app_settings_reset_certificates_success">Все пользовательские сертификаты были очищены</string>
+  <string name="app_settings_debug">Отладка</string>
+  <string name="app_settings_log_to_external_storage">Сохранять лог во внешний файл</string>
+  <string name="app_settings_log_to_external_storage_on">Сохранение логов во внешнем хранилище (если доступно)</string>
+  <string name="app_settings_log_to_external_storage_off">Сохранение логов во внешний файл отключено</string>
+  <string name="app_settings_show_debug_info">Отладочная информация</string>
+  <string name="app_settings_show_debug_info_details">Просмотреть/поделиться программой и настройками</string>
+  <!--AccountActivity-->
+  <string name="account_synchronize_now">Синхронизировать</string>
+  <string name="account_synchronizing_now">Синхронизация</string>
+  <string name="account_settings">Настройки аккаунта</string>
+  <string name="account_rename">Переименовать аккаунт</string>
+  <string name="account_rename_new_name">Несохранённые локальные данные могут быть потеряны. Требуется выполнить синхронизацию после переименования. Новое имя аккаунта:</string>
+  <string name="account_rename_rename">Переименовать</string>
+  <string name="account_delete">Удалить аккаунт</string>
+  <string name="account_delete_confirmation_title">Вы действительно хотите удалить аккаунт?</string>
+  <string name="account_delete_confirmation_text">Все локальные копии контактов, календарей и задач будут удалены.</string>
+  <string name="account_refresh_address_book_list">Обновить список адресных книг</string>
+  <string name="account_create_new_address_book">Создать новую адресную книгу</string>
+  <string name="account_refresh_calendar_list">Обновить календарь</string>
+  <string name="account_create_new_calendar">Создать новый календарь</string>
+  <!--PermissionsActivity-->
+  <string name="permissions_title">Разрешения DAVdroid</string>
+  <string name="permissions_calendar">Разрешения для календаря</string>
+  <string name="permissions_calendar_details">Для синхронизации CalDAV событий с Вашими локальными календарями DAVdroid должен иметь доступ к Вашим календарям.</string>
+  <string name="permissions_calendar_request">Запрос разрешений для календаря</string>
+  <string name="permissions_contacts">Разрешения для контактов</string>
+  <string name="permissions_contacts_details">Для синхронизации CardDAV адресных книг с Вашими локальными контактами DAVdroid должен иметь доступ к Вашим контактам.</string>
+  <string name="permissions_contacts_request">Запрос разрешений для контактов</string>
+  <string name="permissions_opentasks">Разрешения OpenTasks</string>
+  <string name="permissions_opentasks_details">Для синхронизации CalDAV задач с Вашими локальными списками задач DAVdroid должен иметь доступ к OpenTasks.</string>
+  <string name="permissions_opentasks_request">Запрос разрешений для OpenTasks</string>
+  <!--AddAccountActivity-->
+  <string name="login_title">Добавить аккаунт</string>
+  <string name="login_type_email">Вход по адресу электронной почты</string>
+  <string name="login_email_address">Адрес электронной почты</string>
+  <string name="login_email_address_error">Требуется действующий адрес электронной почты</string>
+  <string name="login_password">Пароль</string>
+  <string name="login_password_required">Требуется пароль</string>
+  <string name="login_type_url">Вход через URL и имя пользователя</string>
+  <string name="login_url_must_be_http_or_https">URL должен начинаться с http(s)://</string>
+  <string name="login_url_host_name_required">Требуется имя хоста</string>
+  <string name="login_user_name">Имя</string>
+  <string name="login_user_name_required">Требуется имя</string>
+  <string name="login_base_url">Базовый URL</string>
+  <string name="login_login">Логин</string>
+  <string name="login_back">Назад</string>
+  <string name="login_create_account">Создать аккаунт</string>
+  <string name="login_account_name">Имя аккаунта</string>
+  <string name="login_account_name_info">Используйте Ваш адрес адрес электронной почты в качестве имени аккаунта, так как Android будет использовать имя аккаунта в поле ORGANIZER для событий, которые Вы создаёте. Вы не можете иметь два аккаунта с одинаковыми именами.</string>
+  <string name="login_account_contact_group_method">Метод группировки контактов:</string>
+  <string name="login_account_name_required">Требуется имя аккаунта</string>
+  <string name="login_account_not_created">Аккаунт не может быть создан</string>
+  <string name="login_configuration_detection">Обнаружение конфигурации</string>
+  <string name="login_querying_server">Пожалуйста, подождите, выполняется запрос к серверу...</string>
+  <string name="login_no_caldav_carddav">Не найдены CalDAV или CardDAV сервисы.</string>
+  <string name="login_view_logs">Просмотр логов</string>
+  <!--AccountSettingsActivity-->
+  <string name="settings_title">Настройки: %s</string>
+  <string name="settings_authentication">Аутентификация</string>
+  <string name="settings_username">Имя</string>
+  <string name="settings_enter_username">Введите имя пользователя:</string>
+  <string name="settings_password">Пароль</string>
+  <string name="settings_password_summary">Обновить пароль в соответствии с вашим сервером.</string>
+  <string name="settings_enter_password">Введите свой пароль:</string>
+  <string name="settings_sync">Синхронизация</string>
+  <string name="settings_sync_interval_contacts">Интервал синхронизации контактов</string>
+  <string name="settings_sync_summary_manually">Вручную</string>
+  <string name="settings_sync_summary_periodically" tools:ignore="PluralsCandidate">Каждые %d минут и немедленно при локальных изменениях</string>
+  <string name="settings_sync_summary_not_available">Недоступно</string>
+  <string name="settings_sync_interval_calendars">Интервал синхронизации календарей</string>
+  <string name="settings_sync_interval_tasks">Интервал синхронизации задач</string>
+  <string-array name="settings_sync_interval_seconds">
+    <item>-1</item>
+    <item>300</item>
+    <item>600</item>
+    <item>900</item>
+    <item>3600</item>
+    <item>7200</item>
+    <item>14400</item>
+    <item>86400</item>
+  </string-array>
+  <string-array name="settings_sync_interval_names">
+    <item>Вручную</item>
+    <item>Каждые 5 минут</item>
+    <item>Каждые 10 минут</item>
+    <item>Каждые 15 минут</item>
+    <item>Каждый час</item>
+    <item>Каждые 2 часа</item>
+    <item>Каждые 4 часа</item>
+    <item>Раз в сутки</item>
+  </string-array>
+  <string name="settings_sync_wifi_only">Синхронизировать только через WiFi</string>
+  <string name="settings_sync_wifi_only_on">Разрешить синхронизацию только через WiFi</string>
+  <string name="settings_sync_wifi_only_off">Не учитывать тип соединения</string>
+  <string name="settings_sync_wifi_only_ssid">Разрешённые WiFi SSID</string>
+  <string name="settings_sync_wifi_only_ssid_on">Синхронизировать только через %s</string>
+  <string name="settings_sync_wifi_only_ssid_off">Могут использоваться все WiFi подключения</string>
+  <string name="settings_sync_wifi_only_ssid_message">Укажите имя WiFi сети (SSID), чтобы разрешить синхронизацию только через эту сеть. Или оставьте пустым для синхронизации через любые WiFi соединения.</string>
+  <string name="settings_carddav">CardDAV</string>
+  <string name="settings_contact_group_method">Метод группировки контактов</string>
+  <string-array name="settings_contact_group_method_entries">
+    <item>Группы как отдельные vCards</item>
+    <item>Группы как категории внутри контакта</item>
+  </string-array>
+  <string name="settings_caldav">CalDAV</string>
+  <string name="settings_sync_time_range_past">Интервал синхронизации</string>
+  <string name="settings_sync_time_range_past_none">Все события будут синхронизированы</string>
+  <plurals name="settings_sync_time_range_past_days">
+    <item quantity="one">События старше одного дня будут игнорироваться</item>
+    <item quantity="few">События старше %d дней будут игнорироваться</item>
+    <item quantity="many">События старше %d дней будут игнорироваться</item>
+    <item quantity="other">События старше %d дней будут игнорироваться</item>
+  </plurals>
+  <string name="settings_sync_time_range_past_message">События старше указанного количества дней будут игнорироваться (может быть 0). Оставьте пустым для синхронизации всех событий.</string>
+  <string name="settings_manage_calendar_colors">Управление цветами календаря</string>
+  <string name="settings_manage_calendar_colors_on">Цвета календаря управляются DAVdroid</string>
+  <string name="settings_manage_calendar_colors_off">Цвета календаря не управляются DAVdroid</string>
+  <!--collection management-->
+  <string name="create_addressbook">Создать адресную книгу</string>
+  <string name="create_addressbook_display_name_hint">Моя Адресная книга</string>
+  <string name="create_calendar">Создать CalDAV коллекцию</string>
+  <string name="create_calendar_display_name_hint">Мой Календарь</string>
+  <string name="create_calendar_time_zone">Часовой пояс:</string>
+  <string name="create_calendar_type">Тип коллекции:</string>
+  <string name="create_calendar_type_only_events">Календарь (только события)</string>
+  <string name="create_calendar_type_only_tasks">Список задач (только задачи)</string>
+  <string name="create_calendar_type_events_and_tasks">Совмещённый (события и задачи)</string>
+  <string name="create_collection_color">Установить цвет коллекции</string>
+  <string name="create_collection_creating">Создание коллекции</string>
+  <string name="create_collection_display_name">Отображаемое имя (название) этой коллекции:</string>
+  <string name="create_collection_display_name_required">Требуется название</string>
+  <string name="create_collection_description">Описание (необязательно):</string>
+  <string name="create_collection_home_set">Главная папка:</string>
+  <string name="create_collection_create">Создать</string>
+  <string name="delete_collection">Удалить коллекцию</string>
+  <string name="delete_collection_confirm_title">Вы уверены?</string>
+  <string name="delete_collection_confirm_warning">Коллекция (%s) и все её данные будут удалены с сервера.</string>
+  <string name="delete_collection_deleting_collection">Удаление коллекции</string>
+  <!--ExceptionInfoFragment-->
+  <string name="exception">Произошла ошибка.</string>
+  <string name="exception_httpexception">Произошла ошибка HTTP</string>
+  <string name="exception_ioexception">Произошла ошибка ввода/вывода.</string>
+  <string name="exception_show_details">Подробнее</string>
+  <!--sync errors and DebugInfoActivity-->
+  <string name="debug_info_title">Отладочная информация</string>
+  <string name="sync_error_permissions">Разрешения DAVdroid</string>
+  <string name="sync_error_permissions_text">Требуются дополнительные разрешения</string>
+  <string name="sync_error_calendar">Ошибка при синхронизации Календаря (%s)</string>
+  <string name="sync_error_contacts">Ошибка при синхронизации Контактов (%s)</string>
+  <string name="sync_error_tasks">Ошибка при синхронизации Задачи (%s)</string>
+  <string name="sync_error">Ошибка %s</string>
+  <string name="sync_error_http_dav">Ошибка сервера %s</string>
+  <string name="sync_error_local_storage">Ошибка базы данных %s</string>
+  <string-array name="sync_error_phases">
+    <item>подготовка синхронизации</item>
+    <item>запрос поддерживаемых возможностей</item>
+    <item>обработка локально удалённых записей</item>
+    <item>подготовка созданных/изменённых записей</item>
+    <item>загрузка созданных/изменённых записей</item>
+    <item>проверка статуса синхронизации</item>
+    <item>просмотр локальных записей</item>
+    <item>просмотр серверных записей</item>
+    <item>сравнение локальных/серверных записей</item>
+    <item>загрузка серверных записей</item>
+    <item>пост-обработка</item>
+    <item>сохранение статуса синхронизации</item>
+  </string-array>
+  <string name="sync_error_unauthorized">Имя пользователя/пароль неверные</string>
+  <!--cert4android-->
+  <string name="certificate_notification_connection_security">DAVdroid: Безопасность подключения</string>
+  <string name="trust_certificate_unknown_certificate_found">DAVdroid обнаружил неизвестный сертификат. Вы хотите доверять ему?</string>
+</resources>

app/src/davdroid/res/values-sr/strings.xml

@@ -2,11 +2,16 @@
 <resources xmlns:tools="http://schemas.android.com/tools">
   <!--common strings-->
   <string name="app_name">ДАВдроид</string>
+  <string name="account_title_address_book">ДАВдроид адресар</string>
+  <string name="address_books_authority_title">Адресари</string>
   <string name="help">Помоћ</string>
   <string name="manage_accounts">Управљај налозима</string>
   <string name="please_wait">Сачекајте…</string>
   <string name="send">Пошаљи</string>
   <!--startup dialogs-->
+  <string name="startup_battery_optimization">Оптимизација батерије</string>
+  <string name="startup_battery_optimization_message">Андроид може да искључи/умањи синхронизацију ДАВдроида након неколико дана. Да бисте спречили ово, искључите оптимизацију батерије.</string>
+  <string name="startup_battery_optimization_disable">Искључи за ДАВдроид</string>
   <string name="startup_dont_show_again">Не приказуј поново</string>
   <string name="startup_development_version">ДАВдроид прелиминарно издање</string>
   <string name="startup_development_version_message">Ово је развојно издање ДАВдроида. Имајте на уму да можда неће радити очекивано. Замољавамо вас за конструктивне повратне информације како бисмо га побољшали.</string>
@@ -44,6 +49,8 @@
   <string name="navigation_drawer_forums">Заједница</string>
   <string name="navigation_drawer_donate">Донирај</string>
   <string name="account_list_empty">Добро дошли у ДАВдроид!\n\nМожете сада да додате КалДАВ/КардДАВ налог.</string>
+  <string name="accounts_global_sync_disabled">Синхронизација је системски искључена</string>
+  <string name="accounts_global_sync_enable">Укључи</string>
   <!--DavService-->
   <string name="dav_service_refresh_failed">Откривање услуге није успело</string>
   <string name="dav_service_refresh_couldnt_refresh">Не могох да освежим списак збирки</string>
@@ -53,14 +60,19 @@
   <string name="app_settings_reset_hints">Ресетуј савете</string>
   <string name="app_settings_reset_hints_summary">Поновно приказивање претходно одбачених савета</string>
   <string name="app_settings_reset_hints_success">Сви савети ће поново бити приказани</string>
+  <string name="app_settings_connection">Повезивање</string>
+  <string name="app_settings_override_proxy">Надјачај поставке проксија</string>
+  <string name="app_settings_override_proxy_on">Користи прилагођене поставке проксија</string>
+  <string name="app_settings_override_proxy_off">Користи системски подразумеване поставке проксија</string>
+  <string name="app_settings_override_proxy_host">ХТТП прокси домаћин</string>
+  <string name="app_settings_override_proxy_port">ХТТП прокси порт</string>
   <string name="app_settings_security">Безбедност</string>
-  <string name="app_settings_reset_trusted_certificates">Ресетуј поуздане сертификате</string>
-  <string name="app_settings_reset_trusted_certificates_summary">Заборављање претходно прихваћених сертификата</string>
-  <plurals name="app_settings_reset_trusted_certificates_success">
-    <item quantity="one">Посумњано у један сертификат</item>
-    <item quantity="few">Посумњано у %d сертификата</item>
-    <item quantity="other">Посумњано у %d сертификата</item>
-  </plurals>
+  <string name="app_settings_distrust_system_certs">Посумњај у системске сертификате</string>
+  <string name="app_settings_distrust_system_certs_on">Системски и кориснички додати сертификати неће бити поуздани</string>
+  <string name="app_settings_distrust_system_certs_off">Системски и кориснички додати сертификати ће бити поуздани (препоручљиво)</string>
+  <string name="app_settings_reset_certificates">Ресетуј (не)поуздане сертификате</string>
+  <string name="app_settings_reset_certificates_summary">Ресетуј поуздање свих прилагођених сертификата</string>
+  <string name="app_settings_reset_certificates_success">Сви прилагођени сертификати су уклоњени</string>
   <string name="app_settings_debug">Тражење грешака</string>
   <string name="app_settings_log_to_external_storage">Уписуј у спољашњи фајл</string>
   <string name="app_settings_log_to_external_storage_on">Уписивање евиденције у спољашње складиште (ако је доступно)</string>
@@ -71,6 +83,9 @@
   <string name="account_synchronize_now">Синхронизуј одмах</string>
   <string name="account_synchronizing_now">Синхронизујем</string>
   <string name="account_settings">Поставке налога</string>
+  <string name="account_rename">Преименуј налог</string>
+  <string name="account_rename_new_name">Несачувани локални подаци могу бити изгубљни. Потребна је ресинхронизација након преименовања. Нови назив налога:</string>
+  <string name="account_rename_rename">Преименуј</string>
   <string name="account_delete">Обриши налог</string>
   <string name="account_delete_confirmation_title">Заиста обрисати налог?</string>
   <string name="account_delete_confirmation_text">Све локалне копије адресара, календара и листи задатака ће бити обрисане.</string>
@@ -102,7 +117,6 @@
   <string name="login_user_name">Корисничко име</string>
   <string name="login_user_name_required">Корисничко име је обавезно</string>
   <string name="login_base_url">Корени УРЛ</string>
-  <string name="login_auth_preemptive">Превентивна аутентификација (препоручено, али некомпатибилно са Дигест аутентификацијом)</string>
   <string name="login_login">Пријава</string>
   <string name="login_back">Назад</string>
   <string name="login_create_account">Направи налог</string>
@@ -123,9 +137,6 @@
   <string name="settings_password">Лозинка</string>
   <string name="settings_password_summary">Ажурирајте лозинку за ваш сервер.</string>
   <string name="settings_enter_password">Унесите лозинку:</string>
-  <string name="settings_preemptive">Превентивна аутентификација</string>
-  <string name="settings_preemptive_on">Слање акредитива са сваким захтевом (препоручено)</string>
-  <string name="settings_preemptive_off">Слање акредитива по захтеву сервера</string>
   <string name="settings_sync">Синхронизација</string>
   <string name="settings_sync_interval_contacts">Интервал синх. контаката</string>
   <string name="settings_sync_summary_manually">Само ручно</string>
@@ -170,9 +181,6 @@
     <item>Групе су одвојене В-карте</item>
     <item>Групе су категорије по контакту</item>
   </string-array>
-  <string name="settings_rfc6868_for_vcards">Користи РФЦ6868 за В-карте</string>
-  <string name="settings_rfc6868_for_vcards_on">Двоструки наводници могу да се користе у вредностима параметара</string>
-  <string name="settings_rfc6868_for_vcards_off">Двоструки наводници не могу да се користе у вредностима параметара</string>
   <string name="settings_caldav">КалДАВ</string>
   <string name="settings_sync_time_range_past">Ограничење догађаја у прошлости</string>
   <string name="settings_sync_time_range_past_none">Сви догађаји се синхронизују</string>
@@ -185,9 +193,6 @@
   <string name="settings_manage_calendar_colors">Управљај бојама календара</string>
   <string name="settings_manage_calendar_colors_on">Бојама календара управља ДАВдроид</string>
   <string name="settings_manage_calendar_colors_off">Боје календара није поставио ДАВдроид</string>
-  <string name="settings_version_update">Надоградња ДАВдроид издања</string>
-  <string name="settings_version_update_settings_updated">Унутрашње поставке су ажуриране.</string>
-  <string name="settings_version_update_install_hint">Проблеми? Уклоните ДАВдроид па га поново инсталирајте.</string>
   <!--collection management-->
   <string name="create_addressbook">Направи адресар</string>
   <string name="create_addressbook_display_name_hint">Мој адресар</string>
@@ -239,4 +244,7 @@
     <item>уписујем стање синхронизације</item>
   </string-array>
   <string name="sync_error_unauthorized">Корисничко име или лозинка погрешни</string>
+  <!--cert4android-->
+  <string name="certificate_notification_connection_security">ДАВдроид: Безбедност везе</string>
+  <string name="trust_certificate_unknown_certificate_found">ДАВдроид је наишао на непознат сертификат. Желите ли да се поуздате у њега?</string>
 </resources>

app/src/davdroid/res/values-tr-rTR/strings.xml

@@ -54,11 +54,6 @@
   <string name="app_settings_reset_hints_summary">Daha önceden azat edilen ipuçlarını yeniden etkinleştirir</string>
   <string name="app_settings_reset_hints_success">Tüm ipuçları artık gösterilecek</string>
   <string name="app_settings_security">Güvenlik</string>
-  <string name="app_settings_reset_trusted_certificates">Güvenilen sertifikaları sıfırla</string>
-  <string name="app_settings_reset_trusted_certificates_summary">Daha önceden kabul edilmiş tüm sertifikaları unutur</string>
-  <plurals name="app_settings_reset_trusted_certificates_success">
-    <item quantity="other">Güvenilmeyen %d sertifikaları</item>
-  </plurals>
   <string name="app_settings_debug">Hata ayıklama</string>
   <string name="app_settings_log_to_external_storage">Harici dosyaya jurnalle</string>
   <string name="app_settings_log_to_external_storage_on">Harici depolamaya jurnalleniyor (eğer uygunsa)</string>
@@ -101,7 +96,6 @@
   <string name="login_user_name">Kullanıcı adı</string>
   <string name="login_user_name_required">Kullanıcı adı zorunludur</string>
   <string name="login_base_url">Baz URL</string>
-  <string name="login_auth_preemptive">Önleyici doğrulama (tavsiye edilir, fakat Digest doğrulama ile uyumsuz)</string>
   <string name="login_login">Giriş</string>
   <string name="login_back">Geri</string>
   <string name="login_create_account">Hesap yarat</string>
@@ -121,9 +115,6 @@
   <string name="settings_password">Parola</string>
   <string name="settings_password_summary">Parolayı sunucunuza göre güncelleyin.</string>
   <string name="settings_enter_password">Parola girin:</string>
-  <string name="settings_preemptive">Önleyici doğrulama</string>
-  <string name="settings_preemptive_on">Giriş bilgileri her istek ile gönderilir (tavsiye edilir)</string>
-  <string name="settings_preemptive_off">Giriş bilgileri sunucu istedikten sonra gönderilir</string>
   <string name="settings_sync">Senkronizasyon</string>
   <string name="settings_sync_interval_contacts">Kişiler senk. aralığı</string>
   <string name="settings_sync_summary_manually">Sadece elle</string>
@@ -168,9 +159,6 @@
   <string name="settings_manage_calendar_colors">Takvim renklerini yönet</string>
   <string name="settings_manage_calendar_colors_on">Takvim renkleri DAVdroid tarafından yönetilmekte</string>
   <string name="settings_manage_calendar_colors_off">Takvim renkleri DAVdroid tarafından ayarlanmadı</string>
-  <string name="settings_version_update">DAVdroid sürüm güncellemesi</string>
-  <string name="settings_version_update_settings_updated">Dahili ayarlar güncellendi.</string>
-  <string name="settings_version_update_install_hint">Sorunlar mı var? DAVdroid\'i kaldırıp, yeniden kurun.</string>
   <!--collection management-->
   <string name="create_addressbook">Rehber yarat</string>
   <string name="create_addressbook_display_name_hint">Benim Rehberim</string>
@@ -209,4 +197,5 @@
   <string name="sync_error_http_dav">%s yaparken sunucu hatası</string>
   <string name="sync_error_local_storage">%s yaparken veritabanı hatası</string>
   <string name="sync_error_unauthorized">Kullanıcı adı/parola yanlış</string>
+  <!--cert4android-->
 </resources>

app/src/davdroid/res/values-uk/strings.xml

@@ -0,0 +1,246 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<resources xmlns:tools="http://schemas.android.com/tools">
+  <!--common strings-->
+  <string name="app_name">DAVdroid</string>
+  <string name="account_title_address_book">Адресна книга DAVdroid</string>
+  <string name="address_books_authority_title">Адресні книги</string>
+  <string name="help">Допомога</string>
+  <string name="manage_accounts">Керування обліковими записами</string>
+  <string name="please_wait">Будь ласка, зачекайте...</string>
+  <string name="send">Відправити</string>
+  <!--startup dialogs-->
+  <string name="startup_battery_optimization">Оптимізація енергоспоживання</string>
+  <string name="startup_battery_optimization_message">Android може вимкнути, чи призупинити синхронізацію DAVdroid через деякий час. Аби запобігти цьому, вимкніть оптимізацію енергоспоживання для додатку.</string>
+  <string name="startup_battery_optimization_disable">Вимкнути для DAVdroid</string>
+  <string name="startup_dont_show_again">Не показувати знову</string>
+  <string name="startup_development_version">DAVdroid попередній випуск</string>
+  <string name="startup_development_version_message">Це версія DAVdroid для розробників. Майте на увазі, дещо може працювати не так, як заплановано. Будь ласка, залиште конструктивний відгук для поліпшення DAVdroid.</string>
+  <string name="startup_development_version_give_feedback">Залишити відгук</string>
+  <string name="startup_donate">Інформація Open-Source</string>
+  <string name="startup_donate_message">Ми раді, що Ви використовуєте DAVdroid, який є програмним засобом з відкритим джерельним кодом (GPLv3). Розробка DAVdroid є досить складним завданням і потребує від нас тисячі годин роботи. Будь ласка, розгляньте можливість підтримати проект.</string>
+  <string name="startup_donate_now">Показати сторінку пожертви</string>
+  <string name="startup_donate_later">Можливо пізніше</string>
+  <string name="startup_google_play_accounts_removed">Інформація про ваду в Play Store DRM</string>
+  <string name="startup_google_play_accounts_removed_message">При деяких обставинах Play Store DRM може стати причиною втрати всіх облікових записів DAVdroid після перезавантаження пристрою чи оновлення DAVdroid. Якщо ви зіткнулися із цим (і лише у цьому випадку), будь ласка, встановіть \"DAVdroid JB Workaround\" з Play Store.</string>
+  <string name="startup_google_play_accounts_removed_more_info">Детальніше</string>
+  <string name="startup_opentasks_not_installed">OpenTasks не встановлено</string>
+  <string name="startup_opentasks_not_installed_message">Додаток OpenTasks не встановлено, ото ж DAVdroid не зможе синхронізувати завдання.</string>
+  <string name="startup_opentasks_reinstall_davdroid">Після встановлення OpenTasks, необхідно перевстановити DAVdroid та додати облікові записи знову (Вада системи Android).</string>
+  <string name="startup_opentasks_not_installed_install">Встановити OpenTasks</string>
+  <!--AboutActivity-->
+  <string name="about_license_terms">Умови ліцензії</string>
+  <string name="about_license_info_no_warranty">Цей програмний засіб постачається АБСОЛЮТНО БЕЗ БУДЬ-ЯКИХ ГАРАНТІЙ. Це вільне програмне забезпечення, і ви можете поширювати її, за деякими умовами.</string>
+  <!--global settings-->
+  <string name="logging_davdroid_file_logging">Файл звітування DAVdroid</string>
+  <string name="logging_to_external_storage">Звітування до зовнішнього сховища: %s</string>
+  <string name="logging_to_external_storage_warning">Вилучіть звіт якомога швидше!</string>
+  <string name="logging_couldnt_create_file">Не вдалося створити файл зовнішнього звіту: %s</string>
+  <string name="logging_no_external_storage">Не знайдено зовнішнього сховища</string>
+  <!--AccountsActivity-->
+  <string name="navigation_drawer_open">Відкрити панель навігації</string>
+  <string name="navigation_drawer_close">Закрити панель навігації</string>
+  <string name="navigation_drawer_subtitle">Адаптер синхронізації CalDAV/CardDAV</string>
+  <string name="navigation_drawer_about">Про / Ліцензія</string>
+  <string name="navigation_drawer_settings">Налаштування</string>
+  <string name="navigation_drawer_news_updates">Новини та оновлення</string>
+  <string name="navigation_drawer_external_links">Зовнішні посилання</string>
+  <string name="navigation_drawer_website">Веб сайт</string>
+  <string name="navigation_drawer_faq">Питання/Відповіді</string>
+  <string name="navigation_drawer_forums">Спільнота</string>
+  <string name="navigation_drawer_donate">Підтримка</string>
+  <string name="account_list_empty">Вітаємо у DAVdroid!\n\nТепер можете додавати облікові записи CalDAV/CardDAV.</string>
+  <string name="accounts_global_sync_disabled">Автоматичну синхронізацію вимкнено зі сторони системи</string>
+  <string name="accounts_global_sync_enable">Увімкнути</string>
+  <!--DavService-->
+  <string name="dav_service_refresh_failed">Не вдалося виявити сервіси</string>
+  <string name="dav_service_refresh_couldnt_refresh">Не вдалося оновити перелік колекції</string>
+  <!--AppSettingsActivity-->
+  <string name="app_settings">Налаштування</string>
+  <string name="app_settings_user_interface">Інтерфейс користувача</string>
+  <string name="app_settings_reset_hints">Скинути підказки</string>
+  <string name="app_settings_reset_hints_summary">Включення підказок, які раніше були вимкнуті</string>
+  <string name="app_settings_reset_hints_success">Всі підказки будуть показані знову</string>
+  <string name="app_settings_connection">З\'єднання</string>
+  <string name="app_settings_override_proxy">Перевизначити налаштування проксі</string>
+  <string name="app_settings_override_proxy_on">Власні налаштування проксі</string>
+  <string name="app_settings_override_proxy_off">Типові системні налаштування проксі</string>
+  <string name="app_settings_override_proxy_host">Ім\'я хосту HTTP проксі</string>
+  <string name="app_settings_override_proxy_port">Порт HTTP проксі</string>
+  <string name="app_settings_security">Безпека</string>
+  <string name="app_settings_distrust_system_certs">Не довіряти системним сертифікатам</string>
+  <string name="app_settings_distrust_system_certs_on">Не довіряти системним та доданим користувачем сертифікатам</string>
+  <string name="app_settings_distrust_system_certs_off">Довіряти системним та доданим користувачем сертифікатам (рекомендується)</string>
+  <string name="app_settings_reset_certificates">Скидання (не)довірених сертифікатів</string>
+  <string name="app_settings_reset_certificates_summary">Скинути довіру до всіх призначених користувачу сертифікатів</string>
+  <string name="app_settings_reset_certificates_success">Всі сертифікати, що призначені користувачу очищено</string>
+  <string name="app_settings_debug">Зневадження</string>
+  <string name="app_settings_log_to_external_storage">Звіт до зовнішнього файлу</string>
+  <string name="app_settings_log_to_external_storage_on">Звітування до зовнішнього файлу (якщо доступно)</string>
+  <string name="app_settings_log_to_external_storage_off">Звітування у зовнішній файл вимкнено</string>
+  <string name="app_settings_show_debug_info">Показати інформацію зневадження</string>
+  <string name="app_settings_show_debug_info_details">Переглянути/поділитися програмним засобом та деталями конфігурації</string>
+  <!--AccountActivity-->
+  <string name="account_synchronize_now">Синхронізувати зараз</string>
+  <string name="account_synchronizing_now">Синхронізація</string>
+  <string name="account_settings">Налаштування облікового запису</string>
+  <string name="account_rename">Перейменувати обліковий запис</string>
+  <string name="account_rename_new_name">Незбережені локальні дані можуть бути втрачені. Необхідно виконати синхронізацію після перейменування. Нова назва облікового запису:</string>
+  <string name="account_rename_rename">Перейменувати</string>
+  <string name="account_delete">Видалити запис</string>
+  <string name="account_delete_confirmation_title">Дійсно видалити обліковий запис?</string>
+  <string name="account_delete_confirmation_text">Всі локальні копії адресних книг, календарів та завдань будуть вилучені.</string>
+  <string name="account_refresh_address_book_list">Оновити перелік адресних книг</string>
+  <string name="account_create_new_address_book">Створити нову адресну книгу</string>
+  <string name="account_refresh_calendar_list">Оновити перелік каленарів</string>
+  <string name="account_create_new_calendar">Створити новий календар</string>
+  <!--PermissionsActivity-->
+  <string name="permissions_title">Дозволи DAVdroid</string>
+  <string name="permissions_calendar">Дозволи календаря</string>
+  <string name="permissions_calendar_details">Для синхронізації CalDAV подій з локальним календарем необхідний дозвіл до Ваших календарів.</string>
+  <string name="permissions_calendar_request">Запит дозволів календаря</string>
+  <string name="permissions_contacts">Дозволи контактів</string>
+  <string name="permissions_contacts_details">Для синхронізації адресної книги CalDAV з локальними контактами необхідний дозвіл до Ваших контактів.</string>
+  <string name="permissions_contacts_request">Запит дозволів контактів</string>
+  <string name="permissions_opentasks">Дозволи OpenTasks</string>
+  <string name="permissions_opentasks_details">Для синхронізації CalDAV завдань з локальним списком завдань необхідний дозвіл до OpenTasks.</string>
+  <string name="permissions_opentasks_request">Запит дозволів OpenTasks</string>
+  <!--AddAccountActivity-->
+  <string name="login_title">Додати запис</string>
+  <string name="login_type_email">Увійти за допомогою електронної пошти</string>
+  <string name="login_email_address">Адреса пошти</string>
+  <string name="login_email_address_error">Потребує валідну електронну адресу</string>
+  <string name="login_password">Пароль</string>
+  <string name="login_password_required">Потребує пароль</string>
+  <string name="login_type_url">Увійти за допомогою URL та імені користувача</string>
+  <string name="login_url_must_be_http_or_https">URL адреса повинна починатися з http(s)://</string>
+  <string name="login_url_host_name_required">Потребує назву хосту</string>
+  <string name="login_user_name">Ім\'я користувача</string>
+  <string name="login_user_name_required">Потребує ім\'я користувача</string>
+  <string name="login_base_url">Базовий URL</string>
+  <string name="login_login">Увійти</string>
+  <string name="login_back">Назад</string>
+  <string name="login_create_account">Створити запис</string>
+  <string name="login_account_name">Назва запису</string>
+  <string name="login_account_name_info">Використовуйте вашу електронну адресу як ім\'я облікового запису, так як Android буде використовувати ім\'я облікового запису в полі ORGANIZER для подій, які ви створюватимете. Ви не можете мати два облікових записи з однаковими іменами.</string>
+  <string name="login_account_contact_group_method">Метод групування контактів:</string>
+  <string name="login_account_name_required">Потребує назви облікового запису</string>
+  <string name="login_account_not_created">Обліковий запис не може бути створений</string>
+  <string name="login_configuration_detection">Виявлення конфігурації</string>
+  <string name="login_querying_server">Будь ласка, зачекайте, запит до серверу...</string>
+  <string name="login_no_caldav_carddav">Не вдалося знайти  CalDAV чи CardDAV сервіс.</string>
+  <string name="login_view_logs">Переглянути звіти</string>
+  <!--AccountSettingsActivity-->
+  <string name="settings_title">Налаштування: %s</string>
+  <string name="settings_authentication">Автентифікація</string>
+  <string name="settings_username">Ім\'я користувача</string>
+  <string name="settings_enter_username">Введіть ім\'я користувача:</string>
+  <string name="settings_password">Пароль</string>
+  <string name="settings_password_summary">Оновити пароль, згідно налаштувань Вашого сервера.</string>
+  <string name="settings_enter_password">Введіть Ваш пароль:</string>
+  <string name="settings_sync">Синхронізація</string>
+  <string name="settings_sync_interval_contacts">Інтервал синхронізації контактів</string>
+  <string name="settings_sync_summary_manually">Лише вручну</string>
+  <string name="settings_sync_summary_periodically" tools:ignore="PluralsCandidate">Кожних %d хвилин, а також негайно при внесенні локальних змін</string>
+  <string name="settings_sync_summary_not_available">Не доступно</string>
+  <string name="settings_sync_interval_calendars">Інтервал синхронізації календарів</string>
+  <string name="settings_sync_interval_tasks">Інтервал синхронізації завдань</string>
+  <string-array name="settings_sync_interval_seconds">
+    <item>-1</item>
+    <item>300</item>
+    <item>600</item>
+    <item>900</item>
+    <item>3600</item>
+    <item>7200</item>
+    <item>14400</item>
+    <item>86400</item>
+  </string-array>
+  <string-array name="settings_sync_interval_names">
+    <item>Лише вручну</item>
+    <item>Кожних 5 хвилин</item>
+    <item>Кожних 10 хвилин</item>
+    <item>Кожних 15 хвилин</item>
+    <item>Щогодини</item>
+    <item>Кожних 2 години</item>
+    <item>Кожних 4 години</item>
+    <item>Раз на добу</item>
+  </string-array>
+  <string name="settings_sync_wifi_only">Синхронізувати лише через Wi-Fi</string>
+  <string name="settings_sync_wifi_only_on">Виконувати синхронізацію лише через Wi-Fi</string>
+  <string name="settings_sync_wifi_only_off">Не враховувати тип з\'єднання</string>
+  <string name="settings_sync_wifi_only_ssid">Обмеження WiFi SSID</string>
+  <string name="settings_sync_wifi_only_ssid_on">Синхронізувати лише через %s</string>
+  <string name="settings_sync_wifi_only_ssid_off">Може використовуватись всі Wi-Fi з\'єднання</string>
+  <string name="settings_sync_wifi_only_ssid_message">Вкажіть назву Wi-Fi мережі (SSID), аби дозволити синхронізацію лише через неї. Або залиште пустим, для синхронізації через будь-які Wi-Fi мережі.</string>
+  <string name="settings_carddav">CardDAV</string>
+  <string name="settings_contact_group_method">Метод групування контактів</string>
+  <string-array name="settings_contact_group_method_entries">
+    <item>Групи як окремі VCard</item>
+    <item>Групи як категорії в середині контактів</item>
+  </string-array>
+  <string name="settings_caldav">CalDAV</string>
+  <string name="settings_sync_time_range_past">Інтервал синхронізації</string>
+  <string name="settings_sync_time_range_past_none">Всі події будуть синхронізовані</string>
+  <plurals name="settings_sync_time_range_past_days">
+    <item quantity="one">Події старші одного дня будуть проігноровані</item>
+    <item quantity="few">Події старші %d днів будуть проігноровані</item>
+    <item quantity="other">Події старші %d днів будуть проігноровані</item>
+  </plurals>
+  <string name="settings_sync_time_range_past_message">Події старші вказаного часу будуть проігноровані (може бути 0). Залиште порожнім, аби синхронізувати всі події.</string>
+  <string name="settings_manage_calendar_colors">Керування кольорами календаря</string>
+  <string name="settings_manage_calendar_colors_on">Кольори календаря керуються DAVdroid</string>
+  <string name="settings_manage_calendar_colors_off">Кольори календаря не керуються DAVdroid</string>
+  <!--collection management-->
+  <string name="create_addressbook">Створити адресну книгу</string>
+  <string name="create_addressbook_display_name_hint">Моя адресна книга</string>
+  <string name="create_calendar">Створити CalDAV колекцію</string>
+  <string name="create_calendar_display_name_hint">Мій календар</string>
+  <string name="create_calendar_time_zone">Часова зона:</string>
+  <string name="create_calendar_type">Тип колекції:</string>
+  <string name="create_calendar_type_only_events">Календар (лише події)</string>
+  <string name="create_calendar_type_only_tasks">Список завдань (лише завдання)</string>
+  <string name="create_calendar_type_events_and_tasks">Об\'єднаний (події та завдання)</string>
+  <string name="create_collection_color">Встановити колір колекції</string>
+  <string name="create_collection_creating">Створення колекції</string>
+  <string name="create_collection_display_name">Ім\'я, що показуватиметься (назва ) для колекції</string>
+  <string name="create_collection_display_name_required">Потребує назву</string>
+  <string name="create_collection_description">Опис (за бажанням):</string>
+  <string name="create_collection_home_set">Головна тека:</string>
+  <string name="create_collection_create">Створити</string>
+  <string name="delete_collection">Видалити колекцію</string>
+  <string name="delete_collection_confirm_title">Ви впевнені?</string>
+  <string name="delete_collection_confirm_warning">Колекція (%s) та всі пов\'язані данні будуть вилучені з даного серверу.</string>
+  <string name="delete_collection_deleting_collection">Видалення колекції</string>
+  <!--ExceptionInfoFragment-->
+  <string name="exception">Трапилась помилка.</string>
+  <string name="exception_httpexception">Трапилась помилка HTTP.</string>
+  <string name="exception_ioexception">Трапилась помилка I/O.</string>
+  <string name="exception_show_details">Показати подробиці</string>
+  <!--sync errors and DebugInfoActivity-->
+  <string name="debug_info_title">Інформація зневадження</string>
+  <string name="sync_error_permissions">Дозволи DAVdroid</string>
+  <string name="sync_error_permissions_text">Потребує додаткові дозволи</string>
+  <string name="sync_error_calendar">Помилка синхронізації календаря (%s)</string>
+  <string name="sync_error_contacts">Помилка синхронізації адресної книги (%s)</string>
+  <string name="sync_error_tasks">Помилка синхронізації завдань (%s)</string>
+  <string name="sync_error">Помилка під час %s</string>
+  <string name="sync_error_http_dav">Помилка серверу під час %s</string>
+  <string name="sync_error_local_storage">Помилка серверу під час %s</string>
+  <string-array name="sync_error_phases">
+    <item>підготовка синхронізації</item>
+    <item>опитування можливостей</item>
+    <item>обробка локально вилучених записів</item>
+    <item>підготовка створених/змінених записів</item>
+    <item>вивантаження створених/змінених записів</item>
+    <item>перевірка стану синхронізації</item>
+    <item>перелік локальних записів</item>
+    <item>перелік віддалених записів</item>
+    <item>порівняння локальних/віддалених записів</item>
+    <item>завантаження віддалених записів</item>
+    <item>після обробка</item>
+    <item>збереження стану синхронізації</item>
+  </string-array>
+  <string name="sync_error_unauthorized">Невірне ім\'я користувача чи пароль</string>
+  <!--cert4android-->
+  <string name="certificate_notification_connection_security">DAVdroid: Безпека з\'єднання</string>
+  <string name="trust_certificate_unknown_certificate_found">DAVdroid зіткнувся з невідомим сертифікатом. Чи довіряти йому?</string>
+</resources>

app/src/davdroid/res/values-zh-rCN/strings.xml

@@ -2,11 +2,17 @@
 <resources xmlns:tools="http://schemas.android.com/tools">
   <!--common strings-->
   <string name="app_name">DAVdroid</string>
+  <string name="account_title_address_book">DAVdroid 通讯录</string>
+  <string name="address_books_authority_title">通讯录</string>
   <string name="help">帮助</string>
   <string name="manage_accounts">管理账户</string>
   <string name="please_wait">请稍等...</string>
   <string name="send">发送</string>
+  <string name="homepage_url">https://davdroid.bitfire.at/?pk_campaign=davdroid-app</string>
   <!--startup dialogs-->
+  <string name="startup_battery_optimization">电池优化</string>
+  <string name="startup_battery_optimization_message">系统可能会在几天后减少或停用 DAVdroid 同步。为了避免这一情况，请禁用对 DAVdroid 的电池优化。</string>
+  <string name="startup_battery_optimization_disable">禁用电池优化</string>
   <string name="startup_dont_show_again">不再显示</string>
   <string name="startup_development_version">DAVdroid 预览版</string>
   <string name="startup_development_version_message">这是 DAVdroid 的开发版本，部分功能可能无法正常工作。请您提出建设性反馈，帮助我们完善 DAVdroid。</string>
@@ -16,7 +22,7 @@
   <string name="startup_donate_now">显示捐助页面</string>
   <string name="startup_donate_later">稍后提示</string>
   <string name="startup_google_play_accounts_removed">Play 商店 DRM 问题提醒</string>
-  <string name="startup_google_play_accounts_removed_message">在部分情况下，Play 商店的 DRM 可能会导致所有 DAVdroid 账户在设备重启或升级 DAVdroid 后消失。如果你遇到了该问题（并且只有这一问题），请从 Play 商店安装“DAVdroid JB Workaround”。</string>
+  <string name="startup_google_play_accounts_removed_message">在某些情况下，Play 商店的 DRM 可能会导致所有 DAVdroid 账户在设备重启或升级 DAVdroid 后消失。如果你遇到了该问题，请从 Play 商店安装“DAVdroid JB Workaround”，否则请不要安装修复程序。</string>
   <string name="startup_google_play_accounts_removed_more_info">更多信息</string>
   <string name="startup_opentasks_not_installed">OpenTasks 未安装</string>
   <string name="startup_opentasks_not_installed_message">未安装 OpenTasks 应用，故 DAVdroid 无法同步任务列表。</string>
@@ -38,12 +44,15 @@
   <string name="navigation_drawer_about">关于 / 许可</string>
   <string name="navigation_drawer_settings">设置</string>
   <string name="navigation_drawer_news_updates">最新消息</string>
-  <string name="navigation_drawer_external_links">外部网站</string>
+  <string name="navigation_drawer_external_links">外部链接</string>
   <string name="navigation_drawer_website">应用网站</string>
   <string name="navigation_drawer_faq">常见问题</string>
+  <string name="navigation_drawer_faq_url">https://davdroid.bitfire.at/faq/?pk_campaign=davdroid-app</string>
   <string name="navigation_drawer_forums">社区</string>
   <string name="navigation_drawer_donate">捐助</string>
   <string name="account_list_empty">欢迎使用 DAVdroid！\n\n现在你可以增加 CalDAV/CardDAV 账户。</string>
+  <string name="accounts_global_sync_disabled">系统全局自动同步已禁用</string>
+  <string name="accounts_global_sync_enable">启用</string>
   <!--DavService-->
   <string name="dav_service_refresh_failed">服务配置检测失败</string>
   <string name="dav_service_refresh_couldnt_refresh">无法刷新集合列表</string>
@@ -53,12 +62,19 @@
   <string name="app_settings_reset_hints">重设提示</string>
   <string name="app_settings_reset_hints_summary">重新显示之前忽略过的提示</string>
   <string name="app_settings_reset_hints_success">所有提示将会再次显示</string>
+  <string name="app_settings_connection">连接</string>
+  <string name="app_settings_override_proxy">覆盖代理设置</string>
+  <string name="app_settings_override_proxy_on">使用自定义代理设置</string>
+  <string name="app_settings_override_proxy_off">使用系统默认代理设置</string>
+  <string name="app_settings_override_proxy_host">HTTP 代理主机名</string>
+  <string name="app_settings_override_proxy_port">HTTP 代理端口</string>
   <string name="app_settings_security">安全</string>
-  <string name="app_settings_reset_trusted_certificates">重设受信任证书</string>
-  <string name="app_settings_reset_trusted_certificates_summary">取消信任所有之前接受的证书</string>
-  <plurals name="app_settings_reset_trusted_certificates_success">
-    <item quantity="other">已删除 %d 个证书</item>
-  </plurals>
+  <string name="app_settings_distrust_system_certs">不信任系统证书</string>
+  <string name="app_settings_distrust_system_certs_on">系统和用户增加的发布者不会被信任</string>
+  <string name="app_settings_distrust_system_certs_off">系统和用户增加的发布者会被信任（推荐）</string>
+  <string name="app_settings_reset_certificates">重设证书信任状态</string>
+  <string name="app_settings_reset_certificates_summary">重设所有自定义证书的信任状态</string>
+  <string name="app_settings_reset_certificates_success">所有自定义证书已清除</string>
   <string name="app_settings_debug">调试</string>
   <string name="app_settings_log_to_external_storage">外部文件日志</string>
   <string name="app_settings_log_to_external_storage_on">记录日志到外部存储（如果可用）</string>
@@ -69,6 +85,9 @@
   <string name="account_synchronize_now"> 立即同步</string>
   <string name="account_synchronizing_now">正在同步</string>
   <string name="account_settings">账户设置</string>
+  <string name="account_rename">重命名账户</string>
+  <string name="account_rename_new_name">重命名后，未上传的本地修改会被撤销，您需要重新执行同步。新账户名：</string>
+  <string name="account_rename_rename">重命名</string>
   <string name="account_delete">删除账户</string>
   <string name="account_delete_confirmation_title">真的要删除账户吗？</string>
   <string name="account_delete_confirmation_text">所有通讯录、日历和任务列表的本机存储将被删除。</string>
@@ -88,6 +107,7 @@
   <string name="permissions_opentasks_details">要把 CalDAV 任务与本地任务列表同步，DAVdroid 需要访问 OpenTasks。</string>
   <string name="permissions_opentasks_request">请求 OpenTasks 权限</string>
   <!--AddAccountActivity-->
+  <string name="login_help_url">https://davdroid.bitfire.at/configuration/?pk_campaign=davdroid-app</string>
   <string name="login_title">增加账户</string>
   <string name="login_type_email">使用邮箱地址登录</string>
   <string name="login_email_address">Email 地址</string>
@@ -100,7 +120,6 @@
   <string name="login_user_name">用户名</string>
   <string name="login_user_name_required">请输入用户名</string>
   <string name="login_base_url">根地址</string>
-  <string name="login_auth_preemptive">强制认证模式（推荐使用，但不兼容 Digest 认证方式）</string>
   <string name="login_login">登录</string>
   <string name="login_back">返回</string>
   <string name="login_create_account">创建账户</string>
@@ -121,9 +140,6 @@
   <string name="settings_password">密码</string>
   <string name="settings_password_summary">修改服务器密码</string>
   <string name="settings_enter_password">输入密码</string>
-  <string name="settings_preemptive">强制认证模式</string>
-  <string name="settings_preemptive_on">认证信息在每次请求中发送（推荐）</string>
-  <string name="settings_preemptive_off">认证信息在服务器要求后才发送</string>
   <string name="settings_sync">同步</string>
   <string name="settings_sync_interval_contacts">通讯录自动同步间隔</string>
   <string name="settings_sync_summary_manually">手动同步</string>
@@ -168,9 +184,6 @@
     <item>分为不同的 VCards</item>
     <item>每个联系人的分类</item>
   </string-array>
-  <string name="settings_rfc6868_for_vcards">为 VCards 启用 RFC6868</string>
-  <string name="settings_rfc6868_for_vcards_on">属性值中可使用双引号</string>
-  <string name="settings_rfc6868_for_vcards_off">属性值中不可使用双引号</string>
   <string name="settings_caldav">CalDAV</string>
   <string name="settings_sync_time_range_past">旧日程时间限制</string>
   <string name="settings_sync_time_range_past_none">同步所有日程</string>
@@ -181,9 +194,6 @@
   <string name="settings_manage_calendar_colors">管理日历颜色</string>
   <string name="settings_manage_calendar_colors_on">日历颜色由 DAVdroid 设置</string>
   <string name="settings_manage_calendar_colors_off">日历颜色不由 DAVdroid 设置</string>
-  <string name="settings_version_update">DAVdroid 版本升级</string>
-  <string name="settings_version_update_settings_updated">应用设置已更新。</string>
-  <string name="settings_version_update_install_hint">出现问题了？请卸载 DAVdroid，再重新安装。</string>
   <!--collection management-->
   <string name="create_addressbook">创建通讯录</string>
   <string name="create_addressbook_display_name_hint">我的通讯录</string>
@@ -235,4 +245,7 @@
     <item>保存同步状态</item>
   </string-array>
   <string name="sync_error_unauthorized">用户名或密码错误</string>
+  <!--cert4android-->
+  <string name="certificate_notification_connection_security">DAVdroid: 连接安全性</string>
+  <string name="trust_certificate_unknown_certificate_found">DAVdroid 遇到了未知证书。你是否要信任该证书？</string>
 </resources>

app/src/gplay/AndroidManifest.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest package="at.bitfire.davdroid"
+          xmlns:android="http://schemas.android.com/apk/res/android">
+
+    <uses-permission android:name="com.android.vending.CHECK_LICENSE" />
+
+</manifest>

app/src/gplay/java/at/bitfire/davdroid/syncadapter/LicenseCheckSyncPlugin.java

@@ -0,0 +1,118 @@
+package at.bitfire.davdroid.syncadapter;
+
+import android.annotation.SuppressLint;
+import android.app.PendingIntent;
+import android.content.Context;
+import android.content.Intent;
+import android.content.SyncResult;
+import android.net.Uri;
+import android.provider.Settings;
+import android.support.annotation.NonNull;
+import android.support.v4.app.NotificationManagerCompat;
+import android.support.v7.app.NotificationCompat;
+
+import com.google.android.vending.licensing.AESObfuscator;
+import com.google.android.vending.licensing.LicenseChecker;
+import com.google.android.vending.licensing.LicenseCheckerCallback;
+import com.google.android.vending.licensing.ServerManagedPolicy;
+
+import at.bitfire.davdroid.App;
+import at.bitfire.davdroid.BuildConfig;
+import at.bitfire.davdroid.Constants;
+import at.bitfire.davdroid.R;
+
+public class LicenseCheckSyncPlugin implements ISyncPlugin, LicenseCheckerCallback {
+
+    private static final String LICENSE_PUBLIC_KEY = "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA046s5AzGwaRpSYu4FJ5bTkRvIc93P8dhVXDhgAD7M946R8PE1zKCLPSep4eupw8nxQThXOK1OOJUeh8UbtBBlK+V51UNCjFXQcrLT9XmVmd2OpqhUHszhp3ESg6XpqRwKM7cX4uccpFWKRnn+epTzWoUMTlzaqGQWfF+YSCGMnkJzttdXWzYswhHebQPKYwnaTlGGc0sGl+K6XV/ewe/G47K5sKpX1qdFSBmloH79jFlOumpGooHn51YQ0mTTNu1ErNHi0iugYTDN9QNpLVEtWmxFLwDgwzgXOgd2X2UQDMPCgWapatQWfzUWcIjGLqprcPn29VW3ckQyIx0YMaEzQIDAQAB";
+    private static final byte OBFUSCATOR_SALT[] = { 72, 52, 61, -90, -65, 114, 99, 77, -54, 56, 44, 124, 57, 45, -91, 67, -88, 35, -102, 21 };
+
+    private LicenseChecker licenseChecker;
+
+    private static Boolean licenseOk;
+    private static final Object licenseLock = new Object();
+    private static final int TIMEOUT = 30000;
+
+
+    @Override
+    public synchronized boolean beforeSync(@NonNull Context context, @NonNull SyncResult syncResult) {
+        synchronized(licenseLock) {
+            if (licenseOk == null || !licenseOk) {
+                App.log.info("Checking Google Play license");
+                licenseOk = null;
+
+                @SuppressLint("HardwareIds") final String deviceId = Settings.Secure.getString(context.getContentResolver(), android.provider.Settings.Secure.ANDROID_ID);
+                licenseChecker = new LicenseChecker(context, new ServerManagedPolicy(context, new AESObfuscator(OBFUSCATOR_SALT, BuildConfig.APPLICATION_ID, deviceId)), LICENSE_PUBLIC_KEY);
+                licenseChecker.checkAccess(this);
+                if (licenseOk == null)
+                    try {
+                        licenseLock.wait(TIMEOUT);
+                    } catch(InterruptedException ignored) {
+                    }
+            }
+
+            if (licenseOk == null)
+                licenseOk = false;
+        }
+
+        if (licenseChecker != null) {
+            licenseChecker.onDestroy();
+            licenseChecker = null;
+        }
+
+        NotificationManagerCompat nm = NotificationManagerCompat.from(context);
+        if (!licenseOk) {
+            Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse("market://details?id=" + BuildConfig.APPLICATION_ID));
+            intent.setPackage("com.android.vending");   // open only with Play Store
+
+            NotificationCompat.Builder builder = new NotificationCompat.Builder(context);
+            builder .setSmallIcon(R.drawable.ic_error_light)
+                    .setLargeIcon(App.getLauncherBitmap(context))
+                    .setContentTitle("License check failed")
+                    .setContentText("Couldn't verify Google Play purchase")
+                    .setContentIntent(PendingIntent.getActivity(context, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT))
+                    .setCategory(NotificationCompat.CATEGORY_ERROR)
+                    .setPriority(NotificationCompat.PRIORITY_HIGH);
+            nm.notify(Constants.NOTIFICATION_SUBSCRIPTION, builder.build());
+
+            App.log.warning("No valid license, skipping sync");
+            syncResult.stats.numIoExceptions++;
+            syncResult.delayUntil = 15;     // wait 15 seconds before trying again
+        } else
+            nm.cancel(Constants.NOTIFICATION_SUBSCRIPTION);
+
+        return licenseOk;
+    }
+
+    @Override
+    public void afterSync(@NonNull Context context, @NonNull SyncResult syncResult) {
+    }
+
+
+    @Override
+    public void allow(int reason) {
+        App.log.info("Google Play license valid: " + reason);
+        synchronized(licenseLock) {
+            licenseOk = true;
+            licenseLock.notify();
+        }
+    }
+
+    @Override
+    public void dontAllow(int reason) {
+        App.log.warning("Google Play license invalid: " + reason);
+        synchronized(licenseLock) {
+            licenseOk = false;
+            licenseLock.notify();
+        }
+    }
+
+    @Override
+    public void applicationError(int errorCode) {
+        App.log.severe("Application error " + errorCode + " when checking Google Play license");
+        synchronized(licenseLock) {
+            licenseOk = false;
+            licenseLock.notify();
+        }
+    }
+
+}

app/src/gplay/res/menu/activity_accounts_drawer.xml

@@ -16,7 +16,7 @@
         android:title="@string/navigation_drawer_about"/>
     <item
         android:id="@+id/nav_app_settings"
-        android:icon="@drawable/ic_settings_dark"
+        android:icon="@drawable/ic_settings_action"
         android:title="@string/navigation_drawer_settings"/>
 
     <item android:title="@string/navigation_drawer_news_updates">
@@ -37,7 +37,7 @@
                 android:title="@string/navigation_drawer_website"/>
             <item
                 android:id="@+id/nav_faq"
-                android:icon="@drawable/ic_help_dark"
+                android:icon="@drawable/ic_help_action"
                 android:title="@string/navigation_drawer_faq"/>
             <item
                 android:id="@+id/nav_forums"
@@ -46,9 +46,8 @@
             <item
                 android:id="@+id/nav_donate"
                 android:icon="@drawable/ic_attach_money_dark"
-                android:title="(entry disabled)"
-                android:visible="false"
-                tools:ignore="HardcodedText"/>
+                android:title="@string/navigation_drawer_donate"
+                android:visible="false"/>
         </menu>
     </item>
 

app/src/gplay/resources/META-INF/services/at.bitfire.davdroid.syncadapter.ISyncPlugin

@@ -0,0 +1 @@
+at.bitfire.davdroid.syncadapter.LicenseCheckSyncPlugin

app/src/main/AndroidManifest.xml

@@ -15,28 +15,22 @@
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
     <uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
     <uses-permission android:name="android.permission.INTERNET"/>
-    <uses-permission android:name="android.permission.GET_ACCOUNTS"/>
-    <uses-permission android:name="android.permission.MANAGE_ACCOUNTS"/>
     <uses-permission android:name="android.permission.READ_SYNC_SETTINGS"/>
+    <uses-permission android:name="android.permission.READ_SYNC_STATS"/>
     <uses-permission android:name="android.permission.WRITE_SYNC_SETTINGS"/>
+    <uses-permission android:name="android.permission.REQUEST_IGNORE_BATTERY_OPTIMIZATIONS"/>
+
+    <!-- account management permissions not required for own accounts since API level 22 -->
+    <uses-permission android:name="android.permission.AUTHENTICATE_ACCOUNTS" android:maxSdkVersion="22"/>
+    <uses-permission android:name="android.permission.GET_ACCOUNTS" android:maxSdkVersion="22"/>
+    <uses-permission android:name="android.permission.MANAGE_ACCOUNTS" android:maxSdkVersion="22"/>
 
-    <!-- legacy permissions -->
-    <uses-permission
-        android:name="android.permission.AUTHENTICATE_ACCOUNTS"
-        android:maxSdkVersion="22"
-        tools:ignore="UnusedAttribute"/>
     <!--
          for writing external log files; permission only required for SDK <= 18 because since then,
          writing to app-private directory doesn't require extra permissions
     -->
-    <uses-permission
-        android:name="android.permission.READ_EXTERNAL_STORAGE"
-        android:maxSdkVersion="18"
-        tools:ignore="UnusedAttribute"/>
-    <uses-permission
-        android:name="android.permission.WRITE_EXTERNAL_STORAGE"
-        android:maxSdkVersion="18"
-        tools:ignore="UnusedAttribute"/>
+    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" android:maxSdkVersion="18"/>
+    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" android:maxSdkVersion="18"/>
 
     <!-- other permissions -->
     <!-- android.permission-group.CONTACTS -->
@@ -52,17 +46,18 @@
         android:name=".App"
         android:allowBackup="true"
         android:fullBackupContent="false"
-        android:icon="@drawable/ic_launcher"
+        android:networkSecurityConfig="@xml/network_security_config"
+        android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
         android:theme="@style/AppTheme"
         tools:ignore="UnusedAttribute">
 
         <receiver
-            android:name=".App$ReinitLoggingReceiver"
+            android:name=".App$ReinitSettingsReceiver"
             android:exported="false"
             android:process=":sync">
             <intent-filter>
-                <action android:name="at.bitfire.davdroid.REINIT_LOGGER"/>
+                <action android:name="at.bitfire.davdroid.REINIT_SETTINGS"/>
             </intent-filter>
         </receiver>
         <receiver
@@ -74,6 +69,7 @@
             </intent-filter>
         </receiver>
 
+        <!-- account type "DAVdroid" -->
         <service
             android:name=".syncadapter.AccountAuthenticatorService"
             android:exported="false">
@@ -85,6 +81,65 @@
                 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"
@@ -101,46 +156,26 @@
                 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>
-        <receiver
-            android:name=".AccountsChangedReceiver"
-            android:enabled="true"
-            android:exported="true">
+
+        <receiver android:name=".AccountsChangedReceiver">
             <intent-filter>
                 <action android:name="android.accounts.LOGIN_ACCOUNTS_CHANGED"/>
             </intent-filter>
         </receiver>
-        
+
+        <receiver android:name=".PackageChangedReceiver">
+            <intent-filter>
+                <action android:name="android.intent.action.PACKAGE_ADDED"/>
+                <action android:name="android.intent.action.PACKAGE_FULLY_REMOVED"/>
+                <data android:scheme="package"/>
+            </intent-filter>
+        </receiver>
+
         <activity
             android:name=".ui.AccountsActivity"
             android:label="@string/app_name"
@@ -190,11 +225,16 @@
             android:exported="true"
             android:label="@string/debug_info_title">
         </activity>
+        <provider
+            android:name="android.support.v4.content.FileProvider"
+            android:authorities="@string/authority_log_provider"
+            android:grantUriPermissions="true"
+            android:exported="false">
+            <meta-data
+                android:name="android.support.FILE_PROVIDER_PATHS"
+                android:resource="@xml/log_paths" />
+        </provider>
 
-        <!-- MemorizingTrustManager -->
-        <activity
-            android:name="de.duenndns.ssl.MemorizingActivity"
-            android:theme="@android:style/Theme.Holo.Light.Dialog.NoActionBar"/>
 
     </application>
 

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

@@ -10,8 +10,7 @@ package at.bitfire.davdroid;
 import android.accounts.Account;
 import android.accounts.AccountManager;
 import android.annotation.SuppressLint;
-import android.app.Notification;
-import android.app.NotificationManager;
+import android.annotation.TargetApi;
 import android.content.BroadcastReceiver;
 import android.content.ContentProviderClient;
 import android.content.ContentResolver;
@@ -20,13 +19,14 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.PeriodicSync;
 import android.database.sqlite.SQLiteDatabase;
-import android.graphics.drawable.BitmapDrawable;
+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 android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
-import android.support.v7.app.NotificationCompat;
 import android.text.TextUtils;
 
 import java.lang.reflect.Method;
@@ -35,6 +35,7 @@ import java.util.List;
 import java.util.Set;
 import java.util.logging.Level;
 
+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.HomeSets;
@@ -50,22 +51,15 @@ import lombok.Cleanup;
 import okhttp3.HttpUrl;
 
 public class AccountSettings {
-    private final static int CURRENT_VERSION = 4;
+    private final static int CURRENT_VERSION = 6;
     private final static String
             KEY_SETTINGS_VERSION = "version",
 
             KEY_USERNAME = "user_name",
-            KEY_AUTH_PREEMPTIVE = "auth_preemptive",
 
             KEY_WIFI_ONLY = "wifi_only",            // sync on WiFi only (default: false)
             KEY_WIFI_ONLY_SSID = "wifi_only_ssid";  // restrict sync to specific WiFi SSID
 
-    /** Whether to use RFC 6868 for VCards
-     *  value = null (not existing)      use RFC6868-style encoding (default value)
-     *          "0"                      don't use RFC 6868-style encoding
-     */
-    private final static String KEY_VCARD_RFC6868 = "vcard_rfc6868";
-
     /** Time range limitation to the past [in days]
         value = null            default value (DEFAULT_TIME_RANGE_PAST_DAYS)
               < 0 (-1)          no limit
@@ -92,6 +86,7 @@ public class AccountSettings {
     final Account account;
 
 
+    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
     public AccountSettings(@NonNull Context context, @NonNull Account account) throws InvalidAccountException {
         this.context = context;
         this.account = account;
@@ -108,34 +103,17 @@ public class AccountSettings {
                 version = Integer.parseInt(versionStr);
             } catch (NumberFormatException ignored) {
             }
-            App.log.info("Account " + account.name + " has version " + version + ", current version: " + CURRENT_VERSION);
-
-            if (version < CURRENT_VERSION) {
-                Notification notify = new NotificationCompat.Builder(context)
-                        .setSmallIcon(R.drawable.ic_new_releases_light)
-                        .setLargeIcon(((BitmapDrawable)context.getResources().getDrawable(R.drawable.ic_launcher)).getBitmap())
-                        .setContentTitle(context.getString(R.string.settings_version_update))
-                        .setContentText(context.getString(R.string.settings_version_update_settings_updated))
-                        .setSubText(context.getString(R.string.settings_version_update_install_hint))
-                        .setStyle(new NotificationCompat.BigTextStyle()
-                                .bigText(context.getString(R.string.settings_version_update_settings_updated)))
-                        .setCategory(NotificationCompat.CATEGORY_SYSTEM)
-                        .setPriority(NotificationCompat.PRIORITY_HIGH)
-                        .setLocalOnly(true)
-                        .build();
-                NotificationManager nm = (NotificationManager)context.getSystemService(Context.NOTIFICATION_SERVICE);
-                nm.notify(Constants.NOTIFICATION_ACCOUNT_SETTINGS_UPDATED, notify);
+            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, boolean preemptive) {
+    public static Bundle initialUserData(String userName) {
         Bundle bundle = new Bundle();
         bundle.putString(KEY_SETTINGS_VERSION, String.valueOf(CURRENT_VERSION));
         bundle.putString(KEY_USERNAME, userName);
-        bundle.putString(KEY_AUTH_PREEMPTIVE, Boolean.toString(preemptive));
         return bundle;
     }
 
@@ -148,9 +126,6 @@ public class AccountSettings {
     public String password() { return accountManager.getPassword(account); }
     public void password(@NonNull String password) { accountManager.setPassword(account, password); }
 
-    public boolean preemptiveAuth() { return Boolean.parseBoolean(accountManager.getUserData(account, KEY_AUTH_PREEMPTIVE)); }
-    public void preemptiveAuth(boolean preemptive) { accountManager.setUserData(account, KEY_AUTH_PREEMPTIVE, Boolean.toString(preemptive)); }
-
 
     // sync. settings
 
@@ -195,17 +170,6 @@ public class AccountSettings {
     }
 
 
-    // CardDAV settings
-
-    public boolean getVCardRFC6868() {
-        return accountManager.getUserData(account, KEY_VCARD_RFC6868) == null;
-    }
-
-    public void setVCardRFC6868(boolean use) {
-        accountManager.setUserData(account, KEY_VCARD_RFC6868, use ? null : "0");
-    }
-
-
     // CalDAV settings
 
     @Nullable
@@ -235,6 +199,9 @@ public class AccountSettings {
 
     @NonNull
     public GroupMethod getGroupMethod() {
+        if (BuildConfig.settingContactGroupMethod != null)
+            return BuildConfig.settingContactGroupMethod;
+
         final String name = accountManager.getUserData(account, KEY_CONTACT_GROUP_METHOD);
         return name != null ?
                 GroupMethod.valueOf(name) :
@@ -242,8 +209,11 @@ public class AccountSettings {
     }
 
     public void setGroupMethod(@NonNull GroupMethod method) {
-        final String name = method == GroupMethod.GROUP_VCARDS ? null : method.name();
-        accountManager.setUserData(account, KEY_CONTACT_GROUP_METHOD, name);
+        if (BuildConfig.settingContactGroupMethod == null) {
+            final String name = method == GroupMethod.GROUP_VCARDS ? null : method.name();
+            accountManager.setUserData(account, KEY_CONTACT_GROUP_METHOD, name);
+        } else if (BuildConfig.settingContactGroupMethod != method)
+            throw new UnsupportedOperationException("Setting is read-only");
     }
 
 
@@ -276,7 +246,7 @@ public class AccountSettings {
         if (provider == null)
             throw new ContactsStorageException("Couldn't access Contacts provider");
 
-        LocalAddressBook addr = new LocalAddressBook(account, provider);
+        LocalAddressBook addr = new LocalAddressBook(context, account, provider);
 
         // until now, ContactsContract.Settings.UNGROUPED_VISIBLE was not set explicitly
         ContentValues values = new ContentValues();
@@ -310,7 +280,7 @@ public class AccountSettings {
             ContentProviderClient client = context.getContentResolver().acquireContentProviderClient(ContactsContract.AUTHORITY);
             if (client != null)
                 try {
-                    LocalAddressBook addrBook = new LocalAddressBook(account, client);
+                    LocalAddressBook addrBook = new LocalAddressBook(context, account, client);
                     String url = addrBook.getURL();
                     if (url != null) {
                         App.log.fine("Migrating address book " + url);
@@ -349,7 +319,7 @@ public class AccountSettings {
             client = context.getContentResolver().acquireContentProviderClient(CalendarContract.AUTHORITY);
             if (client != null)
                 try {
-                    LocalCalendar calendars[] = (LocalCalendar[])LocalCalendar.find(account, client, LocalCalendar.Factory.INSTANCE, null, null);
+                    List<LocalCalendar> calendars = LocalCalendar.find(account, client, LocalCalendar.Factory.INSTANCE, null, null);
                     for (LocalCalendar calendar : calendars) {
                         String url = calendar.getName();
                         App.log.fine("Migrating calendar " + url);
@@ -365,7 +335,7 @@ public class AccountSettings {
             TaskProvider provider = LocalTaskList.acquireTaskProvider(context.getContentResolver());
             if (provider != null)
                 try {
-                    LocalTaskList[] taskLists = (LocalTaskList[])LocalTaskList.find(account, provider, LocalTaskList.Factory.INSTANCE, null, null);
+                    List<LocalTaskList> taskLists = LocalTaskList.find(account, provider, LocalTaskList.Factory.INSTANCE, null, null);
                     for (LocalTaskList taskList : taskLists) {
                         String url = taskList.getSyncId();
                         App.log.fine("Migrating task list " + url);
@@ -424,17 +394,90 @@ public class AccountSettings {
         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);
+    }
+
+    @SuppressWarnings({ "Recycle", "unused" })
+    private void update_5_6() throws ContactsStorageException {
+        @Cleanup("release") ContentProviderClient provider = context.getContentResolver().acquireContentProviderClient(ContactsContract.AUTHORITY);
+        if (provider == null)
+            // no access to contacts provider
+            return;
+
+        // don't run syncs during the migration
+        ContentResolver.setIsSyncable(account, ContactsContract.AUTHORITY, 0);
+        ContentResolver.setIsSyncable(account, App.getAddressBooksAuthority(), 0);
+        ContentResolver.cancelSync(account, null);
+
+        try {
+            // get previous address book settings (including URL)
+            @Cleanup("recycle") Parcel parcel = Parcel.obtain();
+            byte[] raw = ContactsContract.SyncState.get(provider, account);
+            if (raw == null)
+                App.log.info("No contacts sync state, ignoring account");
+            else {
+                parcel.unmarshall(raw, 0, raw.length);
+                parcel.setDataPosition(0);
+                Bundle params = parcel.readBundle();
+                String url = params.getString("url");
+                if (url == null)
+                    App.log.info("No address book URL, ignoring account");
+                else {
+                    // create new address book
+                    CollectionInfo info = new CollectionInfo();
+                    info.type = CollectionInfo.Type.ADDRESS_BOOK;
+                    info.url = url;
+                    info.displayName = account.name;
+                    App.log.log(Level.INFO, "Creating new address book account", url);
+                    Account addressBookAccount = new Account(LocalAddressBook.accountName(account, info), App.getAddressBookAccountType());
+                    if (!accountManager.addAccountExplicitly(addressBookAccount, null, LocalAddressBook.initialUserData(account, info.url)))
+                        throw new ContactsStorageException("Couldn't create address book account");
+                    LocalAddressBook addressBook = new LocalAddressBook(context, addressBookAccount, provider);
+
+                    // move contacts to new address book
+                    App.log.info("Moving contacts from " + account + " to " + addressBookAccount);
+                    ContentValues newAccount = new ContentValues(2);
+                    newAccount.put(ContactsContract.RawContacts.ACCOUNT_NAME, addressBookAccount.name);
+                    newAccount.put(ContactsContract.RawContacts.ACCOUNT_TYPE, addressBookAccount.type);
+                    int 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 + "=?",
+                            new String[]{account.name, account.type});
+                    App.log.info(affected + " contacts moved to new address book");
+                }
+
+                ContactsContract.SyncState.set(provider, account, null);
+            }
+        } catch(RemoteException e) {
+            throw new ContactsStorageException("Couldn't migrate contacts to new address book", e);
+        }
+
+        // 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, App.getAddressBooksAuthority(), 1);
+        setSyncInterval(App.getAddressBooksAuthority(), Constants.DEFAULT_SYNC_INTERVAL);
+    }
+
 
     public static class AppUpdatedReceiver extends BroadcastReceiver {
 
         @Override
-        @SuppressLint("UnsafeProtectedBroadcastReceiver")
+        @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))
+            for (Account account : accountManager.getAccountsByType(context.getString(R.string.account_type)))
                 try {
                     App.log.info("Checking account " + account.name);
                     new AccountSettings(context, account);

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

@@ -8,6 +8,7 @@
 
 package at.bitfire.davdroid;
 
+import android.accounts.AccountManager;
 import android.accounts.OnAccountsUpdateListener;
 import android.content.BroadcastReceiver;
 import android.content.Context;
@@ -22,12 +23,14 @@ public class AccountsChangedReceiver extends BroadcastReceiver {
 
     @Override
     public void onReceive(Context context, Intent intent) {
-        Intent serviceIntent = new Intent(context, DavService.class);
-        serviceIntent.setAction(DavService.ACTION_ACCOUNTS_UPDATED);
-        context.startService(serviceIntent);
+        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);
+            for (OnAccountsUpdateListener listener : listeners)
+                listener.onAccountsUpdated(null);
+        }
     }
 
     public static void registerListener(OnAccountsUpdateListener listener, boolean callImmediately) {

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

@@ -8,12 +8,20 @@
 
 package at.bitfire.davdroid;
 
+import android.annotation.SuppressLint;
+import android.annotation.TargetApi;
 import android.app.Application;
-import android.app.NotificationManager;
 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;
 
@@ -28,22 +36,34 @@ 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 de.duenndns.ssl.MemorizingTrustManager;
 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
+            FLAVOR_GOOGLE_PLAY = "gplay",
+            FLAVOR_ICLOUD = "icloud",
+            FLAVOR_SOLDUPE = "soldupe",
+            FLAVOR_STANDARD = "standard";
 
-    public static final String LOG_TO_EXTERNAL_STORAGE = "logToExternalStorage";
+    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 static MemorizingTrustManager memorizingTrustManager;
+    private CustomCertManager certManager;
 
     @Getter
     private static SSLSocketFactoryCompat sslSocketFactoryCompat;
@@ -54,54 +74,72 @@ public class App extends Application {
     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");
     }
 
+    @Getter
+    private static String addressBookAccountType;
+    @Getter
+    private static String addressBooksAuthority;
+
     @Override
+    @SuppressLint("HardwareIds")
     public void onCreate() {
         super.onCreate();
 
-        // initialize MemorizingTrustManager
-        memorizingTrustManager = new MemorizingTrustManager(this);
-        sslSocketFactoryCompat = new SSLSocketFactoryCompat(memorizingTrustManager);
-        hostnameVerifier = memorizingTrustManager.wrapHostnameVerifier(OkHostnameVerifier.INSTANCE);
-
-        // initializer logger
+        reinitCertManager();
         reinitLogger();
+
+        addressBookAccountType = getString(R.string.account_type_address_book);
+        addressBooksAuthority = getString(R.string.address_books_authority);
+    }
+
+    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() {
-        // don't use Android default logging, we have our own handlers
-        log.setUseParentHandlers(false);
-
         @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
-        log.setLevel(logVerbose ? Level.ALL : Level.INFO);
+        final Logger rootLogger = Logger.getLogger("");
+        rootLogger.setLevel(logVerbose ? Level.ALL : Level.INFO);
 
-        // remove all handlers
-        for (Handler handler : log.getHandlers())
-            log.removeHandler(handler);
+        // remove all handlers and add our own logcat handler
+        rootLogger.setUseParentHandlers(false);
+        for (Handler handler : rootLogger.getHandlers())
+            rootLogger.removeHandler(handler);
+        rootLogger.addHandler(LogcatHandler.INSTANCE);
 
-        // add logcat handler
-        log.addHandler(LogcatHandler.INSTANCE);
-
-        NotificationManager nm = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
+        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(((BitmapDrawable)getResources().getDrawable(R.drawable.ic_launcher)).getBitmap())
+                    .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-" + android.os.Process.myPid() + "-" +
+                    String fileName = new File(dir, "davdroid-" + Process.myPid() + "-" +
                             DateFormatUtils.format(System.currentTimeMillis(), "yyyyMMdd-HHmmss") + ".txt").toString();
                     log.info("Logging to " + fileName);
 
@@ -130,15 +168,30 @@ public class App extends Application {
             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 {
+
+    public static class ReinitSettingsReceiver extends BroadcastReceiver {
+
+        public static final String ACTION_REINIT_SETTINGS = "at.bitfire.davdroid.REINIT_SETTINGS";
 
         @Override
         public void onReceive(Context context, Intent intent) {
-            log.info("Received broadcast: re-initializing logger");
+            log.info("Received broadcast: re-initializing settings (logger/cert manager)");
 
             App app = (App)context.getApplicationContext();
             app.reinitLogger();
+            app.reinitCertManager();
         }
 
     }

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

@@ -11,19 +11,16 @@ import android.net.Uri;
 
 public class Constants {
 
-	public static final String
-		ACCOUNT_TYPE = "bitfire.at.davdroid";
-
     // notification IDs
     public final static int
-            NOTIFICATION_ACCOUNT_SETTINGS_UPDATED = 0,
             NOTIFICATION_EXTERNAL_FILE_LOGGING = 1,
             NOTIFICATION_REFRESH_COLLECTIONS = 2,
             NOTIFICATION_CONTACTS_SYNC = 10,
             NOTIFICATION_CALENDAR_SYNC = 11,
             NOTIFICATION_TASK_SYNC = 12,
-            NOTIFICATION_PERMISSIONS = 20;
+            NOTIFICATION_PERMISSIONS = 20,
+            NOTIFICATION_SUBSCRIPTION = 21;
 
-    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/DavService.java

@@ -10,8 +10,8 @@ package at.bitfire.davdroid;
 
 import android.accounts.Account;
 import android.accounts.AccountManager;
+import android.annotation.SuppressLint;
 import android.app.Notification;
-import android.app.NotificationManager;
 import android.app.PendingIntent;
 import android.app.Service;
 import android.content.ContentValues;
@@ -19,11 +19,11 @@ import android.content.Intent;
 import android.database.Cursor;
 import android.database.DatabaseUtils;
 import android.database.sqlite.SQLiteDatabase;
-import android.graphics.drawable.BitmapDrawable;
 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;
 
@@ -43,6 +43,7 @@ import java.util.Set;
 import java.util.logging.Level;
 
 import at.bitfire.dav4android.DavResource;
+import at.bitfire.dav4android.Property;
 import at.bitfire.dav4android.UrlUtils;
 import at.bitfire.dav4android.exception.DavException;
 import at.bitfire.dav4android.exception.HttpException;
@@ -56,7 +57,10 @@ 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.resource.LocalAddressBook;
 import at.bitfire.davdroid.ui.DebugInfoActivity;
+import at.bitfire.vcard4android.ContactsStorageException;
+import kotlin.Pair;
 import lombok.Cleanup;
 import okhttp3.HttpUrl;
 import okhttp3.OkHttpClient;
@@ -140,6 +144,7 @@ public class DavService extends Service {
        which actually do the work
      */
 
+    @SuppressLint("MissingPermission")
     void cleanupAccounts() {
         App.log.info("Cleaning up orphaned accounts");
 
@@ -148,10 +153,25 @@ public class DavService extends Service {
             SQLiteDatabase db = dbHelper.getWritableDatabase();
 
             List<String> sqlAccountNames = new LinkedList<>();
+            Set<String> accountNames = new HashSet<>();
             AccountManager am = AccountManager.get(this);
-            for (Account account : am.getAccountsByType(Constants.ACCOUNT_TYPE))
+            for (Account account : am.getAccountsByType(getString(R.string.account_type))) {
                 sqlAccountNames.add(DatabaseUtils.sqlEscapeString(account.name));
+                accountNames.add(account.name);
+            }
 
+            // delete orphaned address book accounts
+            for (Account addrBookAccount : am.getAccountsByType(App.getAddressBookAccountType())) {
+                LocalAddressBook addressBook = new LocalAddressBook(this, addrBookAccount, null);
+                try {
+                    if (!accountNames.contains(addressBook.getMainAccount().name))
+                        addressBook.delete();
+                } catch(ContactsStorageException e) {
+                    App.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
@@ -196,25 +216,27 @@ public class DavService extends Service {
                     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) {
+                    for (Pair<DavResource, Property> result : dav.findProperties(CalendarProxyReadFor.NAME)) {
+                        CalendarProxyReadFor proxyRead = (CalendarProxyReadFor)result.getSecond();
+                        for (String href : proxyRead.getHrefs()) {
                             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);
+                            queryHomeSets(serviceType, new DavResource(httpClient, result.getFirst().getLocation().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);
+                    }
+                    for (Pair<DavResource, Property> result : dav.findProperties(CalendarProxyWriteFor.NAME)) {
+                        CalendarProxyWriteFor proxyWrite = (CalendarProxyWriteFor)result.getSecond();
+                        for (String href : proxyWrite.getHrefs()) {
+                            App.log.fine("Principal is a read/write proxy for " + href + ", checking for home sets");
+                            queryHomeSets(serviceType, new DavResource(httpClient, result.getFirst().getLocation().resolve(href)), homeSets);
                         }
+                    }
 
                     // refresh home sets: direct group memberships
-                    GroupMembership groupMembership = (GroupMembership)dav.properties.get(GroupMembership.NAME);
+                    GroupMembership groupMembership = (GroupMembership)dav.getProperties().get(GroupMembership.NAME);
                     if (groupMembership != null)
-                        for (String href : groupMembership.hrefs) {
+                        for (String href : groupMembership.getHrefs()) {
                             App.log.fine("Principal is member of group " + href + ", checking for home sets");
-                            DavResource group = new DavResource(httpClient, dav.location.resolve(href));
+                            DavResource group = new DavResource(httpClient, dav.getLocation().resolve(href));
                             try {
                                 queryHomeSets(serviceType, group, homeSets);
                             } catch(HttpException|DavException e) {
@@ -239,7 +261,7 @@ public class DavService extends Service {
                     DavResource dav = new DavResource(httpClient, homeSet);
                     try {
                         dav.propfind(1, CollectionInfo.DAV_PROPERTIES);
-                        IteratorChain<DavResource> itCollections = new IteratorChain<>(dav.members.iterator(), new SingletonIterator(dav));
+                        IteratorChain<DavResource> itCollections = new IteratorChain<>(dav.getMembers().iterator(), new SingletonIterator(dav));
                         while (itCollections.hasNext()) {
                             DavResource member = itCollections.next();
                             CollectionInfo info = CollectionInfo.fromDavResource(member);
@@ -248,10 +270,10 @@ public class DavService extends Service {
 
                             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);
+                                collections.put(member.getLocation(), info);
                         }
                     } catch(HttpException e) {
-                        if (e.status == 403 || e.status == 404 || e.status == 410)
+                        if (e.getStatus() == 403 || e.getStatus() == 404 || e.getStatus() == 410)
                             // delete home set only if it was not accessible (40x)
                             itHomeSets.remove();
                     }
@@ -275,7 +297,7 @@ public class DavService extends Service {
                                 (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)
+                            if (e.getStatus()== 403 || e.getStatus()== 404 || e.getStatus()== 410)
                                 // delete collection only if it was not accessible (40x)
                                 iterator.remove();
                             else
@@ -290,8 +312,8 @@ public class DavService extends Service {
                         info.selected = true;
                 }
 
+                db.beginTransactionNonExclusive();
                 try {
-                    db.beginTransactionNonExclusive();
                     saveHomeSets(homeSets);
                     saveCollections(collections.values());
                     db.setTransactionSuccessful();
@@ -309,10 +331,10 @@ public class DavService extends Service {
                 if (account != null)
                     debugIntent.putExtra(DebugInfoActivity.KEY_ACCOUNT, account);
 
-                NotificationManager nm = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
+                NotificationManagerCompat nm = NotificationManagerCompat.from(DavService.this);
                 Notification notify = new NotificationCompat.Builder(DavService.this)
                         .setSmallIcon(R.drawable.ic_error_light)
-                        .setLargeIcon(((BitmapDrawable)getResources().getDrawable(R.drawable.ic_launcher)).getBitmap())
+                        .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))
@@ -339,16 +361,18 @@ public class DavService extends Service {
         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)));
+                for (Pair<DavResource, Property> result : dav.findProperties(AddressbookHomeSet.NAME)) {
+                    AddressbookHomeSet addressbookHomeSet = (AddressbookHomeSet)result.getSecond();
+                    for (String href : addressbookHomeSet.getHrefs())
+                        homeSets.add(UrlUtils.withTrailingSlash(result.getFirst().getLocation().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)));
+                for (Pair<DavResource, Property> result : dav.findProperties(CalendarHomeSet.NAME)) {
+                    CalendarHomeSet calendarHomeSet = (CalendarHomeSet)result.getSecond();
+                    for (String href : calendarHomeSet.getHrefs())
+                        homeSets.add(UrlUtils.withTrailingSlash(result.getFirst().getLocation().resolve(href)));
+                }
             }
         }
 
@@ -357,7 +381,7 @@ public class DavService extends Service {
         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);
+                return new Account(cursor.getString(0), getString(R.string.account_type));
             } else
                 throw new IllegalArgumentException("Service not found");
         }

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

@@ -10,10 +10,14 @@ 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;
@@ -21,9 +25,10 @@ import java.util.concurrent.TimeUnit;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
-import at.bitfire.dav4android.BasicDigestAuthenticator;
-import lombok.RequiredArgsConstructor;
-import okhttp3.Credentials;
+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;
@@ -34,49 +39,60 @@ public class HttpClient {
     private static final OkHttpClient client = new OkHttpClient();
     private static final UserAgentInterceptor userAgentInterceptor = new UserAgentInterceptor();
 
-    private static final String userAgent;
+    private static final String productName, userAgent;
     static {
+        if (BuildConfig.FLAVOR == App.FLAVOR_ICLOUD)
+            productName = "MultiSync for Cloud";
+        else if (BuildConfig.FLAVOR == App.FLAVOR_SOLDUPE)
+            productName = "Soldupe Sync";
+        else
+            productName = "DAVdroid";
+
         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;
+        userAgent = productName + "/" + BuildConfig.VERSION_NAME + " (" + date + "; dav4android; okhttp3) Android/" + Build.VERSION.RELEASE;
     }
 
     private HttpClient() {
     }
 
-    public static OkHttpClient create(@NonNull Context context, @NonNull Account account, @NonNull final Logger logger) throws InvalidAccountException {
-        OkHttpClient.Builder builder = defaultBuilder(logger);
+    public static OkHttpClient create(@Nullable Context context, @NonNull AccountSettings settings, @NonNull final Logger logger) {
+        OkHttpClient.Builder builder = defaultBuilder(context, logger);
 
-        // use account settings for authentication and logging
-        AccountSettings settings = new AccountSettings(context, account);
-
-        if (settings.preemptiveAuth())
-            builder.addNetworkInterceptor(new PreemptiveAuthenticationInterceptor(settings.username(), settings.password()));
-        else
-            builder.authenticator(new BasicDigestAuthenticator(null, settings.username(), settings.password()));
+        // use account settings for authentication
+        builder = addAuthentication(builder, null, settings.username(), settings.password());
 
         return builder.build();
     }
 
-    public static OkHttpClient create(@NonNull Logger logger) {
-        return defaultBuilder(logger).build();
+    public static OkHttpClient create(@NonNull Context context, @NonNull Logger logger) {
+        return defaultBuilder(context, logger).build();
+    }
+
+    public static OkHttpClient create(@NonNull Context context, @NonNull AccountSettings settings) {
+        return create(context, settings, App.log);
     }
 
     public static OkHttpClient create(@NonNull Context context, @NonNull Account account) throws InvalidAccountException {
-        return create(context, account, App.log);
+        AccountSettings settings = new AccountSettings(context, account);
+        return create(context, settings, App.log);
     }
 
-    public static OkHttpClient create() {
-        return create(App.log);
+    public static OkHttpClient create(@Nullable Context context) {
+        return create(context, App.log);
     }
 
-    private static OkHttpClient.Builder defaultBuilder(@NonNull final Logger logger) {
+
+    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 (App.getSslSocketFactoryCompat() != null)
-            builder.sslSocketFactory(App.getSslSocketFactoryCompat(), App.getMemorizingTrustManager());
-        if (App.getHostnameVerifier() != null)
-            builder.hostnameVerifier(App.getHostnameVerifier());
+        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);
@@ -86,6 +102,28 @@ public class HttpClient {
         // 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);
 
@@ -107,24 +145,23 @@ public class HttpClient {
         return builder;
     }
 
-    private static OkHttpClient.Builder addAuthentication(@NonNull OkHttpClient.Builder builder, @NonNull String username, @NonNull String password, boolean preemptive) {
-        if (preemptive)
-            builder.addNetworkInterceptor(new PreemptiveAuthenticationInterceptor(username, password));
-        else
-            builder.authenticator(new BasicDigestAuthenticator(null, username, password));
-        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, boolean preemptive) {
+    public static OkHttpClient addAuthentication(@NonNull OkHttpClient client, @NonNull String username, @NonNull String password) {
         OkHttpClient.Builder builder = client.newBuilder();
-        addAuthentication(builder, username, password, preemptive);
+        addAuthentication(builder, null, username, password);
         return builder.build();
     }
 
     public static OkHttpClient addAuthentication(@NonNull OkHttpClient client, @NonNull String host, @NonNull String username, @NonNull String password) {
-        return client.newBuilder()
-                .authenticator(new BasicDigestAuthenticator(host, username, password))
-                .build();
+        OkHttpClient.Builder builder = client.newBuilder();
+        addAuthentication(builder, host, username, password);
+        return builder.build();
     }
 
 
@@ -140,18 +177,4 @@ public class HttpClient {
         }
     }
 
-    @RequiredArgsConstructor
-    static class PreemptiveAuthenticationInterceptor implements Interceptor {
-        final String username, password;
-
-        @Override
-        public Response intercept(Chain chain) throws IOException {
-            App.log.fine("Adding basic authorization header for user " + username);
-            Request request = chain.request().newBuilder()
-                    .header("Authorization", Credentials.basic(username, password))
-                    .build();
-            return chain.proceed(request);
-        }
-    }
-
 }

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

@@ -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 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), context.getString(R.string.account_type));
+
+            if (tasksInstalled) {
+                if (ContentResolver.getIsSyncable(account, TaskProvider.ProviderName.OpenTasks.getAuthority()) <= 0) {
+                    ContentResolver.setIsSyncable(account, TaskProvider.ProviderName.OpenTasks.getAuthority(), 1);
+                    ContentResolver.setSyncAutomatically(account, TaskProvider.ProviderName.OpenTasks.getAuthority(), true);
+                    ContentResolver.addPeriodicSync(account, TaskProvider.ProviderName.OpenTasks.getAuthority(), new Bundle(), Constants.DEFAULT_SYNC_INTERVAL);
+                }
+            } else
+                ContentResolver.setIsSyncable(account, TaskProvider.ProviderName.OpenTasks.getAuthority(), 0);
+
+        }
+    }
+
+}

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

@@ -27,7 +27,6 @@ import javax.net.ssl.SSLSocket;
 import javax.net.ssl.SSLSocketFactory;
 import javax.net.ssl.X509TrustManager;
 
-import de.duenndns.ssl.MemorizingTrustManager;
 import lombok.Cleanup;
 
 public class SSLSocketFactoryCompat extends SSLSocketFactory {
@@ -53,56 +52,55 @@ public class SSLSocketFactoryCompat extends SSLSocketFactory {
                 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()));
+                // 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",
+                        "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"
+                );
+                List<String> availableCiphers = Arrays.asList(socket.getSupportedCipherSuites());
+                App.log.info("Available cipher suites: " + TextUtils.join(", ", availableCiphers));
 
-                    // 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 for
+                 * the security level of DAVdroid and maximum compatibility, disabling of insecure
+                 * ciphers should be a server-side task */
 
-                    /* 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 */
+                // for the final set of enabled ciphers, take the ciphers enabled by default, ...
+                HashSet<String> enabledCiphers = new HashSet<>(Arrays.asList(socket.getEnabledCipherSuites()));
+                App.log.info("Cipher suites enabled by default: " + TextUtils.join(", ", enabledCiphers));
+                // ... add explicitly allowed ciphers ...
+                enabledCiphers.addAll(allowedCiphers);
+                // ... and keep only those which are actually available
+                enabledCiphers.retainAll(availableCiphers);
 
-                    // 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()]);
-                }
+                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 MemorizingTrustManager mtm) {
+    public SSLSocketFactoryCompat(@NonNull X509TrustManager trustManager) {
         try {
             SSLContext sslContext = SSLContext.getInstance("TLS");
-            sslContext.init(null, new X509TrustManager[] { mtm }, null);
+            sslContext.init(null, new X509TrustManager[] { trustManager }, null);
             delegate = sslContext.getSocketFactory();
         } catch (GeneralSecurityException e) {
             throw new AssertionError(); // The system has no TLS. Just give up.

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

@@ -35,7 +35,10 @@ public class PlainTextFormatter extends Formatter {
             builder .append(DateFormatUtils.format(r.getMillis(), "yyyy-MM-dd HH:mm:ss"))
                     .append(" ").append(r.getThreadID()).append(" ");
 
-        builder.append(String.format("[%s] %s", shortClassName(r.getSourceClassName()), r.getMessage()));
+        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 ")

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

@@ -65,48 +65,48 @@ public class CollectionInfo implements Serializable {
 
     public static CollectionInfo fromDavResource(DavResource dav) {
         CollectionInfo info = new CollectionInfo();
-        info.url = dav.location.toString();
+        info.url = dav.getLocation().toString();
 
-        ResourceType type = (ResourceType)dav.properties.get(ResourceType.NAME);
+        ResourceType type = (ResourceType)dav.getProperties().get(ResourceType.NAME);
         if (type != null) {
-            if (type.types.contains(ResourceType.ADDRESSBOOK))
+            if (type.getTypes().contains(ResourceType.ADDRESSBOOK))
                 info.type = Type.ADDRESS_BOOK;
-            else if (type.types.contains(ResourceType.CALENDAR))
+            else if (type.getTypes().contains(ResourceType.CALENDAR))
                 info.type = Type.CALENDAR;
         }
 
         info.readOnly = false;
-        CurrentUserPrivilegeSet privilegeSet = (CurrentUserPrivilegeSet)dav.properties.get(CurrentUserPrivilegeSet.NAME);
+        CurrentUserPrivilegeSet privilegeSet = (CurrentUserPrivilegeSet)dav.getProperties().get(CurrentUserPrivilegeSet.NAME);
         if (privilegeSet != null)
-            info.readOnly = !privilegeSet.mayWriteContent;
+            info.readOnly = !privilegeSet.getMayWriteContent();
 
-        DisplayName displayName = (DisplayName)dav.properties.get(DisplayName.NAME);
-        if (displayName != null && !StringUtils.isEmpty(displayName.displayName))
-            info.displayName = displayName.displayName;
+        DisplayName displayName = (DisplayName)dav.getProperties().get(DisplayName.NAME);
+        if (displayName != null && !StringUtils.isEmpty(displayName.getDisplayName()))
+            info.displayName = displayName.getDisplayName();
 
         if (info.type == Type.ADDRESS_BOOK) {
-            AddressbookDescription addressbookDescription = (AddressbookDescription)dav.properties.get(AddressbookDescription.NAME);
+            AddressbookDescription addressbookDescription = (AddressbookDescription)dav.getProperties().get(AddressbookDescription.NAME);
             if (addressbookDescription != null)
-                info.description = addressbookDescription.description;
+                info.description = addressbookDescription.getDescription();
 
         } else if (info.type == Type.CALENDAR) {
-            CalendarDescription calendarDescription = (CalendarDescription)dav.properties.get(CalendarDescription.NAME);
+            CalendarDescription calendarDescription = (CalendarDescription)dav.getProperties().get(CalendarDescription.NAME);
             if (calendarDescription != null)
-                info.description = calendarDescription.description;
+                info.description = calendarDescription.getDescription();
 
-            CalendarColor calendarColor = (CalendarColor)dav.properties.get(CalendarColor.NAME);
+            CalendarColor calendarColor = (CalendarColor)dav.getProperties().get(CalendarColor.NAME);
             if (calendarColor != null)
-                info.color = calendarColor.color;
+                info.color = calendarColor.getColor();
 
-            CalendarTimezone timeZone = (CalendarTimezone)dav.properties.get(CalendarTimezone.NAME);
+            CalendarTimezone timeZone = (CalendarTimezone)dav.getProperties().get(CalendarTimezone.NAME);
             if (timeZone != null)
-                info.timeZone = timeZone.vTimeZone;
+                info.timeZone = timeZone.getVTimeZone();
 
             info.supportsVEVENT = info.supportsVTODO = true;
-            SupportedCalendarComponentSet supportedCalendarComponentSet = (SupportedCalendarComponentSet)dav.properties.get(SupportedCalendarComponentSet.NAME);
+            SupportedCalendarComponentSet supportedCalendarComponentSet = (SupportedCalendarComponentSet)dav.getProperties().get(SupportedCalendarComponentSet.NAME);
             if (supportedCalendarComponentSet != null) {
-                info.supportsVEVENT = supportedCalendarComponentSet.supportsEvents;
-                info.supportsVTODO = supportedCalendarComponentSet.supportsTasks;
+                info.supportsVEVENT = supportedCalendarComponentSet.getSupportsEvents();
+                info.supportsVTODO = supportedCalendarComponentSet.getSupportsTasks();
             }
         }
 

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

@@ -8,12 +8,15 @@
 
 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;
@@ -72,21 +75,19 @@ public class ServiceDB {
 
         public OpenHelper(Context context) {
             super(context, DATABASE_NAME, null, DATABASE_VERSION);
-
-            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN)
-                setWriteAheadLoggingEnabled(true);
         }
 
         @Override
         public void onOpen(SQLiteDatabase db) {
-            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN)
-                db.setForeignKeyConstraintsEnabled(true);
-            else {
-                if (!db.enableWriteAheadLogging())
-                    App.log.warning("Couldn't enable write-ahead logging");
-
+            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
@@ -132,6 +133,7 @@ public class ServiceDB {
 
         @Override
         public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
+            // no different versions yet
         }
 
 
@@ -183,4 +185,11 @@ public class ServiceDB {
         }
     }
 
+
+    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/Settings.java

@@ -11,6 +11,7 @@ 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;
 
@@ -22,10 +23,11 @@ public class Settings {
         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())
+        if (cursor.moveToNext() && !cursor.isNull(0))
             return cursor.getInt(0) != 0;
         else
             return defaultValue;
@@ -38,6 +40,42 @@ public class Settings {
         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/resource/LocalAddressBook.java

@@ -8,36 +8,60 @@
 package at.bitfire.davdroid.resource;
 
 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.content.ContentProviderClient;
+import android.content.ContentResolver;
 import android.content.ContentUris;
 import android.content.ContentValues;
+import android.content.Context;
 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 android.support.annotation.Nullable;
+import android.text.TextUtils;
+import android.util.Base64;
 
+import java.io.ByteArrayOutputStream;
 import java.io.FileNotFoundException;
+import java.io.IOException;
 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.davdroid.DavUtils;
+import at.bitfire.davdroid.model.CollectionInfo;
 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 {
+public class LocalAddressBook extends AndroidAddressBook implements LocalCollection<LocalResource> {
 
     protected static final String
-            SYNC_STATE_CTAG = "ctag",
-            SYNC_STATE_URL = "url";
+            USER_DATA_MAIN_ACCOUNT_TYPE = "real_account_type",
+            USER_DATA_MAIN_ACCOUNT_NAME = "real_account_name",
+            USER_DATA_URL = "url",
+            USER_DATA_CTAG = "ctag";
 
+    protected final Context context;
     private final Bundle syncState = new Bundle();
 
     /**
@@ -48,10 +72,69 @@ public class LocalAddressBook extends AndroidAddressBook implements LocalCollect
     public boolean includeGroups = true;
 
 
-    public LocalAddressBook(Account account, ContentProviderClient provider) {
-        super(account, provider, LocalGroup.Factory.INSTANCE, LocalContact.Factory.INSTANCE);
+    public static LocalAddressBook[] find(@NonNull Context context, @NonNull ContentProviderClient provider, @Nullable Account mainAccount) throws ContactsStorageException {
+        AccountManager accountManager = AccountManager.get(context);
+
+        List<LocalAddressBook> result = new LinkedList<>();
+        for (Account account : accountManager.getAccountsByType(App.getAddressBookAccountType())) {
+            LocalAddressBook addressBook = new LocalAddressBook(context, account, provider);
+            if (mainAccount == null || addressBook.getMainAccount().equals(mainAccount))
+                result.add(addressBook);
+        }
+
+        return result.toArray(new LocalAddressBook[result.size()]);
     }
 
+    public static LocalAddressBook create(@NonNull Context context, @NonNull ContentProviderClient provider, @NonNull Account mainAccount, @NonNull CollectionInfo info) throws ContactsStorageException {
+        AccountManager accountManager = AccountManager.get(context);
+
+        Account account = new Account(accountName(mainAccount, info), App.getAddressBookAccountType());
+        if (!accountManager.addAccountExplicitly(account, null, initialUserData(mainAccount, info.url)))
+            throw new ContactsStorageException("Couldn't create address book account");
+
+        LocalAddressBook addressBook = new LocalAddressBook(context, account, provider);
+        ContentResolver.setSyncAutomatically(account, ContactsContract.AUTHORITY, true);
+        return addressBook;
+    }
+
+    public void update(@NonNull CollectionInfo info) throws AuthenticatorException, OperationCanceledException, IOException, ContactsStorageException {
+        final String newAccountName = accountName(getMainAccount(), info);
+        if (!account.name.equals(newAccountName) && Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+            final AccountManager accountManager = AccountManager.get(context);
+            AccountManagerFuture<Account> future = accountManager.renameAccount(account, newAccountName, new AccountManagerCallback<Account>() {
+                @Override
+                public void run(AccountManagerFuture<Account> future) {
+                    try {
+                        // update raw contacts to new account name
+                        if (provider != null) {
+                            ContentValues values = new ContentValues(1);
+                            values.put(RawContacts.ACCOUNT_NAME, newAccountName);
+                            provider.update(syncAdapterURI(RawContacts.CONTENT_URI), values, RawContacts.ACCOUNT_NAME + "=?", new String[] { account.name });
+                        }
+                    } catch(RemoteException e) {
+                        App.log.log(Level.WARNING, "Couldn't re-assign contacts to new account name", e);
+                    }
+                }
+            }, null);
+            account = future.getResult();
+        }
+
+        // make sure it will still be synchronized when contacts are updated
+        ContentResolver.setSyncAutomatically(account, ContactsContract.AUTHORITY, true);
+    }
+
+    public void delete() {
+        AccountManager accountManager = AccountManager.get(context);
+        accountManager.removeAccount(account, null, null);
+    }
+
+
+    public LocalAddressBook(Context context, Account account, ContentProviderClient provider) {
+        super(account, provider, LocalGroup.Factory.INSTANCE, LocalContact.Factory.INSTANCE);
+        this.context = context;
+    }
+
+    @NonNull
     public LocalContact findContactByUID(String uid) throws ContactsStorageException, FileNotFoundException {
         LocalContact[] contacts = (LocalContact[])queryContacts(LocalContact.COLUMN_UID + "=?", new String[] { uid });
         if (contacts.length == 0)
@@ -60,50 +143,133 @@ public class LocalAddressBook extends AndroidAddressBook implements LocalCollect
     }
 
     @Override
-    public LocalResource[] getAll() throws ContactsStorageException {
+    @NonNull
+    public List<LocalResource> getAll() throws ContactsStorageException {
         List<LocalResource> all = new LinkedList<>();
-        Collections.addAll(all, (LocalResource[])queryContacts(null, null));
+        Collections.addAll(all, (LocalContact[])queryContacts(null, null));
         if (includeGroups)
-            Collections.addAll(all, (LocalResource[])queryGroups(null, null));
-        return all.toArray(new LocalResource[all.size()]);
+            Collections.addAll(all, (LocalGroup[])queryGroups(null, null));
+        return all;
     }
 
     /**
      * Returns an array of local contacts/groups which have been deleted locally. (DELETED != 0).
      */
     @Override
-    public LocalResource[] getDeleted() throws ContactsStorageException {
+    @NonNull
+    public List<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()]);
+        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
+     */
+    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
-    public LocalResource[] getDirty() throws ContactsStorageException {
+    @NonNull
+    public List<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()]);
+        return dirty;
     }
 
     /**
      * Returns an array of local contacts which don't have a file name yet.
      */
     @Override
-    public LocalResource[] getWithoutFileName() throws ContactsStorageException {
+    @NonNull
+    public List<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()]);
+        return nameless;
     }
 
+
+    @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);
@@ -114,23 +280,6 @@ public class LocalAddressBook extends AndroidAddressBook implements LocalCollect
     }
 
 
-    public LocalContact[] getDeletedContacts() throws ContactsStorageException {
-        return (LocalContact[])queryContacts(RawContacts.DELETED + "!= 0", null);
-    }
-
-    public LocalContact[] getDirtyContacts() throws ContactsStorageException {
-        return (LocalContact[])queryContacts(RawContacts.DIRTY + "!= 0", null);
-    }
-
-    public LocalGroup[] getDeletedGroups() throws ContactsStorageException {
-        return (LocalGroup[])queryGroups(Groups.DELETED + "!= 0", null);
-    }
-
-    public LocalGroup[] getDirtyGroups() throws ContactsStorageException {
-        return (LocalGroup[])queryGroups(Groups.DIRTY + "!= 0", null);
-    }
-
-
     /**
      * Finds the first group with the given title. If there is no group with this
      * title, a new group is created.
@@ -160,8 +309,10 @@ public class LocalAddressBook extends AndroidAddressBook implements LocalCollect
         // 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)
+            if (group.getMembers().length == 0) {
+                App.log.log(Level.FINE, "Deleting group", group);
                 group.delete();
+            }
     }
 
     public void removeGroups() throws ContactsStorageException {
@@ -173,57 +324,69 @@ public class LocalAddressBook extends AndroidAddressBook implements LocalCollect
     }
 
 
-    // SYNC STATE
+    // SETTINGS
 
-    @SuppressWarnings("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());
-        }
+    public static Bundle initialUserData(@NonNull Account mainAccount, @NonNull String url) {
+        Bundle bundle = new 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;
     }
 
-    @SuppressWarnings("Recycle")
-    protected void writeSyncState() throws ContactsStorageException {
-        @Cleanup("recycle") Parcel parcel = Parcel.obtain();
-        parcel.writeBundle(syncState);
-        setSyncState(parcel.marshall());
+    public Account getMainAccount() throws ContactsStorageException {
+        AccountManager accountManager = AccountManager.get(context);
+        String  name = accountManager.getUserData(account, USER_DATA_MAIN_ACCOUNT_NAME),
+                type = accountManager.getUserData(account, USER_DATA_MAIN_ACCOUNT_TYPE);
+        if (name != null && type != null)
+            return new Account(name, type);
+        else
+            throw new ContactsStorageException("Address book doesn't exist anymore");
+    }
+
+    public void setMainAccount(@NonNull Account mainAccount) throws ContactsStorageException {
+        AccountManager accountManager = AccountManager.get(context);
+        accountManager.setUserData(account, USER_DATA_MAIN_ACCOUNT_NAME, mainAccount.name);
+        accountManager.setUserData(account, USER_DATA_MAIN_ACCOUNT_TYPE, mainAccount.type);
     }
 
     public String getURL() throws ContactsStorageException {
-        synchronized (syncState) {
-            readSyncState();
-            return syncState.getString(SYNC_STATE_URL);
-        }
+        AccountManager accountManager = AccountManager.get(context);
+        return accountManager.getUserData(account, USER_DATA_URL);
     }
 
     public void setURL(String url) throws ContactsStorageException {
-        synchronized (syncState) {
-            readSyncState();
-            syncState.putString(SYNC_STATE_URL, url);
-            writeSyncState();
-        }
+        AccountManager accountManager = AccountManager.get(context);
+        accountManager.setUserData(account, USER_DATA_URL, url);
     }
 
     @Override
     public String getCTag() throws ContactsStorageException {
-        synchronized (syncState) {
-            readSyncState();
-            return syncState.getString(SYNC_STATE_CTAG);
-        }
+        AccountManager accountManager = AccountManager.get(context);
+        return accountManager.getUserData(account, USER_DATA_CTAG);
     }
 
     @Override
     public void setCTag(String cTag) throws ContactsStorageException {
-        synchronized (syncState) {
-            readSyncState();
-            syncState.putString(SYNC_STATE_CTAG, cTag);
-            writeSyncState();
-        }
+        AccountManager accountManager = AccountManager.get(context);
+        accountManager.setUserData(account, USER_DATA_CTAG, cTag);
+    }
+
+
+    // HELPERS
+
+    public static String accountName(@NonNull Account mainAccount, @NonNull CollectionInfo info) {
+        ByteArrayOutputStream baos = new ByteArrayOutputStream();
+        baos.write(info.url.hashCode());
+        String hash = Base64.encodeToString(baos.toByteArray(), Base64.NO_WRAP | Base64.NO_PADDING);
+
+        StringBuilder sb = new StringBuilder(!TextUtils.isEmpty(info.displayName) ? info.displayName : DavUtils.lastSegmentOfUrl(info.url));
+        sb      .append(" (")
+                .append(mainAccount.name)
+                .append(" ")
+                .append(hash)
+                .append(")");
+        return sb.toString();
     }
 
 }

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

@@ -9,14 +9,12 @@
 package at.bitfire.davdroid.resource;
 
 import android.accounts.Account;
-import android.annotation.TargetApi;
 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.Build;
 import android.os.RemoteException;
 import android.provider.CalendarContract;
 import android.provider.CalendarContract.Calendars;
@@ -30,9 +28,9 @@ import net.fortuna.ical4j.model.component.VTimeZone;
 import org.apache.commons.lang3.StringUtils;
 
 import java.io.FileNotFoundException;
-import java.util.Collections;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.logging.Level;
 
 import at.bitfire.davdroid.App;
 import at.bitfire.davdroid.DavUtils;
@@ -41,26 +39,24 @@ import at.bitfire.ical4android.AndroidCalendar;
 import at.bitfire.ical4android.AndroidCalendarFactory;
 import at.bitfire.ical4android.BatchOperation;
 import at.bitfire.ical4android.CalendarStorageException;
+import at.bitfire.ical4android.Constants;
 import at.bitfire.ical4android.DateUtils;
 import at.bitfire.vcard4android.ContactsStorageException;
 import lombok.Cleanup;
 
-public class LocalCalendar extends AndroidCalendar implements LocalCollection {
+public class LocalCalendar extends AndroidCalendar<LocalEvent> implements LocalCollection<LocalEvent> {
 
     public static final int defaultColor = 0xFF8bc34a;     // light green 500
 
     public static final String COLUMN_CTAG = Calendars.CAL_SYNC1;
 
-    protected static final int
-            DIRTY_INCREASE_SEQUENCE = 1,
-            DIRTY_DONT_INCREASE_SEQUENCE = 2;
-
     static String[] BASE_INFO_COLUMNS = new String[] {
             Events._ID,
             Events._SYNC_ID,
             LocalEvent.COLUMN_ETAG
     };
 
+    @NonNull
     @Override
     protected String[] eventBaseInfoColumns() {
         return BASE_INFO_COLUMNS;
@@ -90,7 +86,6 @@ public class LocalCalendar extends AndroidCalendar implements LocalCollection {
         update(valuesFromCollectionInfo(info, updateColor));
     }
 
-    @TargetApi(15)
     private static ContentValues valuesFromCollectionInfo(CollectionInfo info, boolean withColor) {
         ContentValues values = new ContentValues();
         values.put(Calendars.NAME, info.url);
@@ -107,52 +102,50 @@ public class LocalCalendar extends AndroidCalendar implements LocalCollection {
             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()));
-        }
+        if (!TextUtils.isEmpty(info.timeZone))
+            try {
+                VTimeZone timeZone = DateUtils.parseVTimeZone(info.timeZone);
+                if (timeZone.getTimeZoneId() != null)
+                    values.put(Calendars.CALENDAR_TIME_ZONE, DateUtils.findAndroidTimezoneID(timeZone.getTimeZoneId().getValue()));
+            } catch(IllegalArgumentException e) {
+                App.log.log(Level.WARNING, "Couldn't parse calendar default time zone", e);
+            }
         values.put(Calendars.ALLOWED_REMINDERS, Reminders.METHOD_ALERT);
-        if (Build.VERSION.SDK_INT >= 15) {
-            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 }, ", "));
-        }
+        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);
+    public List<LocalEvent> getAll() throws CalendarStorageException, ContactsStorageException {
+        return 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);
+    public List<LocalEvent> getDeleted() throws CalendarStorageException {
+        return 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);
+    public List<LocalEvent> getWithoutFileName() throws CalendarStorageException {
+        return 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 not required to have an increased SEQUENCE value
-        Collections.addAll(dirty, (LocalEvent[])queryEvents(Events.DIRTY + "=" + DIRTY_DONT_INCREASE_SEQUENCE + " AND " + Events.ORIGINAL_ID + " IS NULL", null));
+    public List<LocalEvent> getDirty() throws CalendarStorageException, FileNotFoundException {
+        List<LocalEvent> dirty = new LinkedList<>();
 
         // get dirty events which are required to have an increased SEQUENCE value
-        for (LocalEvent event : (LocalEvent[])queryEvents(Events.DIRTY + "=" + DIRTY_INCREASE_SEQUENCE + " 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
-                event.getEvent().sequence++;
+        for (LocalEvent event : queryEvents(Events.DIRTY + "!=0 AND " + Events.ORIGINAL_ID + " IS NULL", null)) {
+            if (event.getEvent().getSequence() == null)      // sequence has not been assigned yet (i.e. this event was just locally created)
+                event.getEvent().setSequence(0);
+            else if (event.weAreOrganizer)
+                event.getEvent().setSequence(event.getEvent().getSequence() + 1);
             dirty.add(event);
         }
 
-        return dirty.toArray(new LocalResource[dirty.size()]);
+        return dirty;
     }
 
 
@@ -160,7 +153,7 @@ public class LocalCalendar extends AndroidCalendar implements LocalCollection {
     @SuppressWarnings("Recycle")
     public String getCTag() throws CalendarStorageException {
         try {
-            @Cleanup Cursor cursor = provider.query(calendarSyncURI(), new String[] { COLUMN_CTAG }, null, null, null);
+            @Cleanup Cursor cursor = getProvider().query(calendarSyncURI(), new String[] { COLUMN_CTAG }, null, null, null);
             if (cursor != null && cursor.moveToNext())
                 return cursor.getString(0);
         } catch (RemoteException e) {
@@ -174,7 +167,7 @@ public class LocalCalendar extends AndroidCalendar implements LocalCollection {
         try {
             ContentValues values = new ContentValues(1);
             values.put(COLUMN_CTAG, cTag);
-            provider.update(calendarSyncURI(), values, null, null);
+            getProvider().update(calendarSyncURI(), values, null, null);
         } catch (RemoteException e) {
             throw new CalendarStorageException("Couldn't write local (last known) CTag", e);
         }
@@ -185,7 +178,7 @@ public class LocalCalendar extends AndroidCalendar implements LocalCollection {
         // process deleted exceptions
         App.log.info("Processing deleted exceptions");
         try {
-            @Cleanup Cursor cursor = provider.query(
+            @Cleanup Cursor cursor = getProvider().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);
@@ -195,22 +188,23 @@ public class LocalCalendar extends AndroidCalendar implements LocalCollection {
                         originalID = cursor.getLong(1);     // can't be null (by query)
 
                 // get original event's SEQUENCE
-                @Cleanup Cursor cursor2 = provider.query(
+                @Cleanup Cursor cursor2 = getProvider().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);
+                BatchOperation batch = new BatchOperation(getProvider());
                 // re-schedule original event and set it to DIRTY
-                batch.enqueue(ContentProviderOperation.newUpdate(
-                        syncAdapterURI(ContentUris.withAppendedId(Events.CONTENT_URI, originalID)))
-                        .withValue(LocalEvent.COLUMN_SEQUENCE, originalSequence + 1)
-                        .withValue(Events.DIRTY, DIRTY_INCREASE_SEQUENCE)
-                        .build());
+                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(ContentProviderOperation.newDelete(
-                        syncAdapterURI(ContentUris.withAppendedId(Events.CONTENT_URI, id))).build());
+                batch.enqueue(new BatchOperation.Operation(
+                        ContentProviderOperation.newDelete(syncAdapterURI(ContentUris.withAppendedId(Events.CONTENT_URI, id)))
+                ));
                 batch.commit();
             }
         } catch (RemoteException e) {
@@ -220,7 +214,7 @@ public class LocalCalendar extends AndroidCalendar implements LocalCollection {
         // process dirty exceptions
         App.log.info("Processing dirty exceptions");
         try {
-            @Cleanup Cursor cursor = provider.query(
+            @Cleanup Cursor cursor = getProvider().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);
@@ -230,18 +224,18 @@ public class LocalCalendar extends AndroidCalendar implements LocalCollection {
                         originalID = cursor.getLong(1);     // can't be null (by query)
                 int sequence = cursor.isNull(2) ? 0 : cursor.getInt(2);
 
-                BatchOperation batch = new BatchOperation(provider);
+                BatchOperation batch = new BatchOperation(getProvider());
                 // original event to DIRTY
-                batch.enqueue(ContentProviderOperation.newUpdate(
-                        syncAdapterURI(ContentUris.withAppendedId(Events.CONTENT_URI, originalID)))
-                        .withValue(Events.DIRTY, DIRTY_DONT_INCREASE_SEQUENCE)
-                        .build());
+                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(ContentProviderOperation.newUpdate(
-                                syncAdapterURI(ContentUris.withAppendedId(Events.CONTENT_URI, id)))
+                batch.enqueue(new BatchOperation.Operation(
+                        ContentProviderOperation.newUpdate(syncAdapterURI(ContentUris.withAppendedId(Events.CONTENT_URI, id)))
                                 .withValue(LocalEvent.COLUMN_SEQUENCE, sequence + 1)
                                 .withValue(Events.DIRTY, 0)
-                                .build());
+                ));
                 batch.commit();
             }
         } catch (RemoteException e) {
@@ -250,17 +244,14 @@ public class LocalCalendar extends AndroidCalendar implements LocalCollection {
     }
 
 
-    public static class Factory implements AndroidCalendarFactory {
+    public static class Factory implements AndroidCalendarFactory<LocalCalendar> {
         public static final Factory INSTANCE = new Factory();
 
         @Override
-        public AndroidCalendar newInstance(Account account, ContentProviderClient provider, long id) {
+        public LocalCalendar 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/LocalCollection.java

@@ -9,17 +9,18 @@
 package at.bitfire.davdroid.resource;
 
 import java.io.FileNotFoundException;
+import java.util.List;
 
 import at.bitfire.ical4android.CalendarStorageException;
 import at.bitfire.vcard4android.ContactsStorageException;
 
-public interface LocalCollection {
+public interface LocalCollection<T extends LocalResource> {
 
-    LocalResource[] getDeleted() throws CalendarStorageException, ContactsStorageException;
-    LocalResource[] getWithoutFileName()  throws CalendarStorageException, ContactsStorageException;
-    LocalResource[] getDirty() throws CalendarStorageException, ContactsStorageException, FileNotFoundException;
+    List<T> getDeleted() throws CalendarStorageException, ContactsStorageException;
+    List<T> getWithoutFileName()  throws CalendarStorageException, ContactsStorageException;
+    List<T> getDirty() throws CalendarStorageException, ContactsStorageException, FileNotFoundException;
 
-    LocalResource[] getAll() throws CalendarStorageException, ContactsStorageException;
+    List<T> getAll() throws CalendarStorageException, ContactsStorageException;
 
     String getCTag() throws CalendarStorageException, ContactsStorageException;
     void setCTag(String cTag) throws CalendarStorageException, ContactsStorageException;

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

@@ -10,16 +10,21 @@ 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;
@@ -30,11 +35,13 @@ 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;
+        Contact.productID = "+//IDN bitfire.at//DAVdroid/" + BuildConfig.VERSION_NAME + " ez-vcard/" + Ezvcard.VERSION;
     }
+    public static final String COLUMN_HASHCODE = ContactsContract.RawContacts.SYNC3;
 
     protected final Set<Long>
             cachedGroupMemberships = new HashSet<>(),
@@ -49,22 +56,41 @@ public class LocalContact extends AndroidContact implements LocalResource {
         super(addressBook, contact, fileName, eTag);
     }
 
-    public void clearDirty(String eTag) throws ContactsStorageException {
+    public void resetDirty() throws ContactsStorageException {
+        ContentValues values = new ContentValues(1);
+        values.put(ContactsContract.RawContacts.DIRTY, 0);
         try {
-            ContentValues values = new ContentValues(1);
-            values.put(ContactsContract.RawContacts.DIRTY, 0);
-            values.put(COLUMN_ETAG, eTag);
             addressBook.provider.update(rawContactSyncURI(), values, null, null);
-
-            this.eTag = eTag;
-        } catch (RemoteException e) {
+        } catch(RemoteException e) {
             throw new ContactsStorageException("Couldn't clear dirty flag", e);
         }
     }
 
-    public void updateFileNameAndUID(String uid) throws ContactsStorageException {
+    public void clearDirty(String eTag) throws ContactsStorageException {
         try {
-            String newFileName = uid + ".vcf";
+            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);
@@ -98,50 +124,112 @@ public class LocalContact extends AndroidContact implements LocalResource {
         super.insertDataRows(batch);
 
         if (contact.unknownProperties != null) {
-            ContentProviderOperation.Builder builder = ContentProviderOperation.newInsert(dataSyncURI());
-            if (id == null)
-                builder.withValueBackReference(UnknownProperties.RAW_CONTACT_ID, 0);
-            else
+            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(builder.build());
+            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(ContentProviderOperation
-                .newInsert(dataSyncURI())
-                .withValue(GroupMembership.MIMETYPE, GroupMembership.CONTENT_ITEM_TYPE)
-                .withValue(GroupMembership.RAW_CONTACT_ID, id)
-                .withValue(GroupMembership.GROUP_ROW_ID, groupID)
-                .build()
-        );
 
-        batch.enqueue(ContentProviderOperation
-                .newInsert(dataSyncURI())
-                .withValue(CachedGroupMembership.MIMETYPE, CachedGroupMembership.CONTENT_ITEM_TYPE)
-                .withValue(CachedGroupMembership.RAW_CONTACT_ID, id)
-                .withValue(CachedGroupMembership.GROUP_ID, groupID)
-                .withYieldAllowed(true)
-                .build()
-        );
+        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(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)
-                .build()
-        );
+        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();
     }
 
     /**

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

@@ -11,6 +11,7 @@ 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;
@@ -19,19 +20,26 @@ import android.support.annotation.NonNull;
 
 import net.fortuna.ical4j.model.property.ProdId;
 
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.util.UUID;
+
 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");
+        Event.setProdId(new ProdId("+//IDN bitfire.at//DAVdroid/" + BuildConfig.VERSION_NAME + " ical4j/2.x"));
     }
 
     static final String COLUMN_ETAG = CalendarContract.Events.SYNC_DATA1,
@@ -41,6 +49,8 @@ public class LocalEvent extends AndroidEvent implements LocalResource {
     @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;
@@ -59,24 +69,31 @@ public class LocalEvent extends AndroidEvent implements LocalResource {
     /* process LocalEvent-specific fields */
 
     @Override
-    protected void populateEvent(ContentValues values) {
+    protected void populateEvent(ContentValues values) throws FileNotFoundException, CalendarStorageException {
         super.populateEvent(values);
         fileName = values.getAsString(Events._SYNC_ID);
         eTag = values.getAsString(COLUMN_ETAG);
-        event.uid = values.getAsString(COLUMN_UID);
+        getEvent().setUid(values.getAsString(COLUMN_UID));
 
-        event.sequence = values.getAsInteger(COLUMN_SEQUENCE);
+        getEvent().setSequence(values.getAsInteger(COLUMN_SEQUENCE));
+        if (Build.VERSION.SDK_INT >= 17) {
+            Integer isOrganizer = values.getAsInteger(Events.IS_ORGANIZER);
+            weAreOrganizer = isOrganizer != null && isOrganizer != 0;
+        } else {
+            String organizer = values.getAsString(Events.ORGANIZER);
+            weAreOrganizer = organizer == null || organizer.equals(getCalendar().getAccount().name);
+        }
     }
 
     @Override
-    protected void buildEvent(Event recurrence, ContentProviderOperation.Builder builder) {
+    protected void buildEvent(Event recurrence, ContentProviderOperation.Builder builder) throws FileNotFoundException, CalendarStorageException {
         super.buildEvent(recurrence, builder);
 
         boolean buildException = recurrence != null;
-        Event eventToBuild = buildException ? recurrence : event;
+        Event eventToBuild = buildException ? recurrence : getEvent();
 
-        builder .withValue(COLUMN_UID, event.uid)
-                .withValue(COLUMN_SEQUENCE, eventToBuild.sequence)
+        builder .withValue(COLUMN_UID, getEvent().getUid())
+                .withValue(COLUMN_SEQUENCE, eventToBuild.getSequence())
                 .withValue(CalendarContract.Events.DIRTY, 0)
                 .withValue(CalendarContract.Events.DELETED, 0);
 
@@ -90,20 +107,27 @@ public class LocalEvent extends AndroidEvent implements LocalResource {
 
     /* custom queries */
 
-    public void updateFileNameAndUID(String uid) throws CalendarStorageException {
+    public void prepareForUpload() throws CalendarStorageException {
         try {
-            String newFileName = uid + ".ics";
+            String uid = null;
+            @Cleanup Cursor c = getCalendar().getProvider().query(eventSyncURI(), new String[] { COLUMN_UID }, null, null, null);
+            if (c.moveToNext())
+                uid = c.getString(0);
+            if (uid == null)
+                uid = UUID.randomUUID().toString();
+
+            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);
+            getCalendar().getProvider().update(eventSyncURI(), values, null, null);
 
             fileName = newFileName;
-            if (event != null)
-                event.uid = uid;
+            if (getEvent() != null)
+                getEvent().setUid(uid);
 
-        } catch (RemoteException e) {
+        } catch (FileNotFoundException|RemoteException e) {
             throw new CalendarStorageException("Couldn't update UID", e);
         }
     }
@@ -114,33 +138,29 @@ public class LocalEvent extends AndroidEvent implements LocalResource {
             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);
+            if (getEvent() != null)
+                values.put(COLUMN_SEQUENCE, getEvent().getSequence());
+            getCalendar().getProvider().update(eventSyncURI(), values, null, null);
 
             this.eTag = eTag;
-        } catch (RemoteException e) {
+        } catch (IOException|RemoteException e) {
             throw new CalendarStorageException("Couldn't update UID", e);
         }
     }
 
 
-    static class Factory implements AndroidEventFactory {
+    static class Factory implements AndroidEventFactory<LocalEvent> {
         static final Factory INSTANCE = new Factory();
 
         @Override
-        public AndroidEvent newInstance(AndroidCalendar calendar, long id, ContentValues baseInfo) {
+        public LocalEvent newInstance(AndroidCalendar calendar, long id, ContentValues baseInfo) {
             return new LocalEvent(calendar, id, baseInfo);
         }
 
         @Override
-        public AndroidEvent newInstance(AndroidCalendar calendar, Event event) {
+        public LocalEvent 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/LocalGroup.java

@@ -12,6 +12,7 @@ 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;
@@ -19,13 +20,15 @@ import android.provider.ContactsContract.CommonDataKinds.GroupMembership;
 import android.provider.ContactsContract.Groups;
 import android.provider.ContactsContract.RawContacts;
 import android.provider.ContactsContract.RawContacts.Data;
-import android.provider.ContactsContract.RawContactsEntity;
 
 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;
@@ -66,31 +69,31 @@ public class LocalGroup extends AndroidGroup implements LocalResource {
         BatchOperation batch = new BatchOperation(addressBook.provider);
 
         // delete cached group memberships
-        batch.enqueue(ContentProviderOperation
-                .newDelete(addressBook.syncAdapterURI(ContactsContract.Data.CONTENT_URI))
-                .withSelection(
-                        CachedGroupMembership.MIMETYPE + "=? AND " + CachedGroupMembership.GROUP_ID + "=?",
-                        new String[] { CachedGroupMembership.CONTENT_ITEM_TYPE, String.valueOf(id) }
-                ).build()
-        );
+        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(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)
-                    .build()
-            );
+            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 updateFileNameAndUID(String uid) throws ContactsStorageException {
-        String newFileName = uid + ".vcf";
+    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);
@@ -120,12 +123,11 @@ public class LocalGroup extends AndroidGroup implements LocalResource {
         BatchOperation batch = new BatchOperation(addressBook.provider);
 
         for (long member : getMembers())
-            batch.enqueue(ContentProviderOperation
-                    .newUpdate(addressBook.syncAdapterURI(ContentUris.withAppendedId(RawContacts.CONTENT_URI, member)))
-                    .withValue(RawContacts.DIRTY, 1)
-                    .withYieldAllowed(true)
-                    .build()
-            );
+            batch.enqueue(new BatchOperation.Operation(
+                    ContentProviderOperation.newUpdate(addressBook.syncAdapterURI(ContentUris.withAppendedId(RawContacts.CONTENT_URI, member)))
+                            .withValue(RawContacts.DIRTY, 1)
+                            .withYieldAllowed(true)
+            ));
 
         batch.commit();
     }
@@ -150,16 +152,14 @@ public class LocalGroup extends AndroidGroup implements LocalResource {
                 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
-                batch.enqueue(ContentProviderOperation
-                        .newDelete(addressBook.syncAdapterURI(ContactsContract.Data.CONTENT_URI))
-                        .withSelection(
-                                "(" + GroupMembership.MIMETYPE + "=? AND " + GroupMembership.GROUP_ROW_ID + "=?) OR (" +
-                                      CachedGroupMembership.MIMETYPE + "=? AND " + CachedGroupMembership.GROUP_ID + "=?)",
-                                new String[] { GroupMembership.CONTENT_ITEM_TYPE, String.valueOf(id), CachedGroupMembership.CONTENT_ITEM_TYPE, String.valueOf(id) })
-                        .withYieldAllowed(true)
-                        .build()
-                );
+                for (LocalContact contact : addressBook.getByGroupMembership(id)) {
+                    contact.removeGroupMemberships(batch);
+                    changeContactIDs.add(contact.getId());
+                }
 
                 // extract list of member UIDs
                 List<String> members = new LinkedList<>();
@@ -175,18 +175,25 @@ public class LocalGroup extends AndroidGroup implements LocalResource {
                     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(ContentProviderOperation
-                        .newUpdate(addressBook.syncAdapterURI(ContentUris.withAppendedId(Groups.CONTENT_URI, id)))
-                        .withValue(COLUMN_PENDING_MEMBERS, null)
-                        .withYieldAllowed(true)
-                        .build()
-                );
+                batch.enqueue(new BatchOperation.Operation(
+                        ContentProviderOperation.newUpdate(addressBook.syncAdapterURI(ContentUris.withAppendedId(Groups.CONTENT_URI, id)))
+                                .withValue(COLUMN_PENDING_MEMBERS, null)
+                                .withYieldAllowed(true)
+                ));
 
                 batch.commit();
             }

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

@@ -20,7 +20,7 @@ public interface LocalResource {
 
     int delete() throws CalendarStorageException, ContactsStorageException;
 
-    void updateFileNameAndUID(String uuid) throws CalendarStorageException, ContactsStorageException;
+    void prepareForUpload() throws CalendarStorageException, ContactsStorageException;
     void clearDirty(String eTag) throws CalendarStorageException, ContactsStorageException;
 
 }

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

@@ -20,6 +20,7 @@ import org.dmfs.provider.tasks.TaskContract.Tasks;
 
 import java.io.FileNotFoundException;
 import java.text.ParseException;
+import java.util.UUID;
 
 import at.bitfire.davdroid.BuildConfig;
 import at.bitfire.ical4android.AndroidTask;
@@ -29,10 +30,12 @@ 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");
+        Task.setProdId(new ProdId("+//IDN bitfire.at//DAVdroid/" + BuildConfig.VERSION_NAME + " ical4j/2.x"));
     }
 
     static final String COLUMN_ETAG = Tasks.SYNC1,
@@ -65,37 +68,54 @@ public class LocalTask extends AndroidTask implements LocalResource {
 
         fileName = values.getAsString(Events._SYNC_ID);
         eTag = values.getAsString(COLUMN_ETAG);
-        task.uid = values.getAsString(COLUMN_UID);
 
-        task.sequence = values.getAsInteger(COLUMN_SEQUENCE);
+        final Task task;
+        try {
+            task = getTask();
+        } catch(Exception e) {
+            throw new IllegalStateException(e);
+        }
+        task.setUid(values.getAsString(COLUMN_UID));
+
+        task.setSequence(values.getAsInteger(COLUMN_SEQUENCE));
     }
 
     @Override
     protected void buildTask(ContentProviderOperation.Builder builder, boolean update) {
         super.buildTask(builder, update);
+
+        Task task = null;
+        try {
+            task = getTask();
+        } catch(Exception e) {
+            throw new IllegalStateException(e);
+        }
+
         builder .withValue(Tasks._SYNC_ID, fileName)
-                .withValue(COLUMN_UID, task.uid)
-                .withValue(COLUMN_SEQUENCE, task.sequence)
+                .withValue(COLUMN_UID, task.getUid())
+                .withValue(COLUMN_SEQUENCE, task.getSequence())
                 .withValue(COLUMN_ETAG, eTag);
     }
 
 
     /* custom queries */
 
-    public void updateFileNameAndUID(String uid) throws CalendarStorageException {
+    public void prepareForUpload() throws CalendarStorageException {
         try {
-            String newFileName = uid + ".ics";
+            final String uid = UUID.randomUUID().toString();
+            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);
+            getTaskList().getProvider().getClient().update(taskSyncURI(), values, null, null);
 
             fileName = newFileName;
-            if (task != null)
-                task.uid = uid;
 
-        } catch (RemoteException e) {
+            Task task = getTask();
+            task.setUid(uid);
+
+        } catch (FileNotFoundException|RemoteException e) {
             throw new CalendarStorageException("Couldn't update UID", e);
         }
     }
@@ -106,18 +126,19 @@ public class LocalTask extends AndroidTask implements LocalResource {
             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);
+
+            Task task = getTask();
+            values.put(COLUMN_SEQUENCE, task.getSequence());
+            getTaskList().getProvider().getClient().update(taskSyncURI(), values, null, null);
 
             this.eTag = eTag;
-        } catch (RemoteException e) {
+        } catch (FileNotFoundException|RemoteException e) {
             throw new CalendarStorageException("Couldn't update _DIRTY/ETag/SEQUENCE", e);
         }
     }
 
 
-    static class Factory implements AndroidTaskFactory {
+    static class Factory implements AndroidTaskFactory<LocalTask> {
         static final Factory INSTANCE = new Factory();
 
         @Override
@@ -130,9 +151,5 @@ public class LocalTask extends AndroidTask implements LocalResource {
             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/LocalTaskList.java

@@ -9,6 +9,8 @@
 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;
@@ -22,6 +24,7 @@ import org.dmfs.provider.tasks.TaskContract.TaskLists;
 import org.dmfs.provider.tasks.TaskContract.Tasks;
 
 import java.io.FileNotFoundException;
+import java.util.List;
 
 import at.bitfire.davdroid.DavUtils;
 import at.bitfire.davdroid.model.CollectionInfo;
@@ -31,7 +34,7 @@ import at.bitfire.ical4android.CalendarStorageException;
 import at.bitfire.ical4android.TaskProvider;
 import lombok.Cleanup;
 
-public class LocalTaskList extends AndroidTaskList implements LocalCollection {
+public class LocalTaskList extends AndroidTaskList<LocalTask> implements LocalCollection<LocalTask> {
 
     public static final int defaultColor = 0xFFC3EA6E;     // "DAVdroid green"
 
@@ -43,10 +46,8 @@ public class LocalTaskList extends AndroidTaskList implements LocalCollection {
             LocalTask.COLUMN_ETAG
     };
 
-    // can be cached, because after installing OpenTasks, you have to re-install DAVdroid anyway
-    private static Boolean tasksProviderAvailable;
-
 
+    @NonNull
     @Override
     protected String[] taskBaseInfoColumns() {
         return BASE_INFO_COLUMNS;
@@ -82,29 +83,28 @@ public class LocalTaskList extends AndroidTaskList implements LocalCollection {
 
 
     @Override
-    public LocalTask[] getAll() throws CalendarStorageException {
-        return (LocalTask[])queryTasks(null, null);
+    public List<LocalTask> getAll() throws CalendarStorageException {
+        return queryTasks(null, null);
     }
 
     @Override
-    public LocalTask[] getDeleted() throws CalendarStorageException {
-        return (LocalTask[])queryTasks(Tasks._DELETED + "!=0", null);
+    public List<LocalTask> getDeleted() throws CalendarStorageException {
+        return queryTasks(Tasks._DELETED + "!=0", null);
     }
 
     @Override
-    public LocalTask[] getWithoutFileName() throws CalendarStorageException {
-        return (LocalTask[])queryTasks(Tasks._SYNC_ID + " IS NULL", null);
+    public List<LocalTask> getWithoutFileName() throws CalendarStorageException {
+        return 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)
+    public List<LocalTask> getDirty() throws CalendarStorageException, FileNotFoundException {
+        List<LocalTask> tasks = queryTasks(Tasks._DIRTY + "!=0", 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;
+            if (task.getTask().getSequence() == null)    // sequence has not been assigned yet (i.e. this task was just locally created)
+                task.getTask().setSequence(0);
             else
-                task.getTask().sequence++;
+                task.getTask().setSequence(task.getTask().getSequence() + 1);
         }
         return tasks;
     }
@@ -114,7 +114,7 @@ public class LocalTaskList extends AndroidTaskList implements LocalCollection {
     @SuppressWarnings("Recycle")
     public String getCTag() throws CalendarStorageException {
         try {
-            @Cleanup Cursor cursor = provider.client.query(taskListSyncUri(), new String[] { COLUMN_CTAG }, null, null, null);
+            @Cleanup Cursor cursor = getProvider().getClient().query(taskListSyncUri(), new String[] { COLUMN_CTAG }, null, null, null);
             if (cursor != null && cursor.moveToNext())
                 return cursor.getString(0);
         } catch (RemoteException e) {
@@ -128,7 +128,7 @@ public class LocalTaskList extends AndroidTaskList implements LocalCollection {
         try {
             ContentValues values = new ContentValues(1);
             values.put(COLUMN_CTAG, cTag);
-            provider.client.update(taskListSyncUri(), values, null, null);
+            getProvider().getClient().update(taskListSyncUri(), values, null, null);
         } catch (RemoteException e) {
             throw new CalendarStorageException("Couldn't write local (last known) CTag", e);
         }
@@ -138,30 +138,35 @@ public class LocalTaskList extends AndroidTaskList implements LocalCollection {
     // helpers
 
     public static boolean tasksProviderAvailable(@NonNull Context context) {
-        if (tasksProviderAvailable != null)
-            return tasksProviderAvailable;
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M)
+            return context.getPackageManager().resolveContentProvider(TaskProvider.ProviderName.OpenTasks.getAuthority(), 0) != null;
         else {
-            if (Build.VERSION.SDK_INT >= 23)
-                return context.getPackageManager().resolveContentProvider(TaskProvider.ProviderName.OpenTasks.authority, 0) != null;
-            else {
-                @Cleanup TaskProvider provider = TaskProvider.acquire(context.getContentResolver(), TaskProvider.ProviderName.OpenTasks);
-                return tasksProviderAvailable = (provider != null);
-            }
+            @Cleanup TaskProvider provider = TaskProvider.acquire(context.getContentResolver(), TaskProvider.ProviderName.OpenTasks);
+            return provider != null;
         }
     }
 
 
-    public static class Factory implements AndroidTaskListFactory {
+    public static class Factory implements AndroidTaskListFactory<LocalTaskList> {
         public static final Factory INSTANCE = new Factory();
 
         @Override
-        public AndroidTaskList newInstance(Account account, TaskProvider provider, long id) {
+        public LocalTaskList 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.getAuthority());
+        if (client != null) {
+            ContentValues values = new ContentValues(1);
+            values.put(Tasks.ACCOUNT_NAME, newName);
+            client.update(Tasks.getContentUri(TaskProvider.ProviderName.OpenTasks.getAuthority()), values, Tasks.ACCOUNT_NAME + "=?", new String[]{oldName});
         }
     }
+
 }

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

@@ -21,68 +21,69 @@ import android.os.IBinder;
 import at.bitfire.davdroid.ui.setup.LoginActivity;
 
 public class AccountAuthenticatorService extends Service {
-	private static AccountAuthenticator accountAuthenticator;
 
-	private AccountAuthenticator getAuthenticator() {
-		if (accountAuthenticator != null)
-			return accountAuthenticator;
-		return accountAuthenticator = new AccountAuthenticator(this);
-	}
-	
-	@Override
-	public IBinder onBind(Intent intent) {
-		if (intent.getAction().equals(android.accounts.AccountManager.ACTION_AUTHENTICATOR_INTENT))
-			return getAuthenticator().getIBinder(); 
-		return null;
-	}
-	
-	
-	private static class AccountAuthenticator extends AbstractAccountAuthenticator {
-		final Context context;
-		
-		public AccountAuthenticator(Context context) {
-			super(context);
-			this.context = context;
-		}
+    private AccountAuthenticator accountAuthenticator;
 
-		@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 void onCreate() {
+        accountAuthenticator = new AccountAuthenticator(this);
+    }
 
-		@Override
-		public Bundle confirmCredentials(AccountAuthenticatorResponse response, Account account, Bundle options) throws NetworkErrorException {
-			return null;
-		}
+    @Override
+    public IBinder onBind(Intent intent) {
+        if (intent.getAction().equals(android.accounts.AccountManager.ACTION_AUTHENTICATOR_INTENT))
+            return accountAuthenticator.getIBinder();
+        return null;
+    }
 
-		@Override
-		public Bundle editProperties(AccountAuthenticatorResponse response, String accountType) {
-			return null;
-		}
+
+    private static class AccountAuthenticator extends AbstractAccountAuthenticator {
+        final Context context;
+
+        public AccountAuthenticator(Context context) {
+            super(context);
+            this.context = context;
+        }
 
         @Override
-		public Bundle getAuthToken(AccountAuthenticatorResponse response, Account account, String authTokenType, Bundle options) throws NetworkErrorException {
-			return null;
-		}
+        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 String getAuthTokenLabel(String authTokenType) {
-			return null;
-		}
+        @Override
+        public Bundle confirmCredentials(AccountAuthenticatorResponse response, Account account, Bundle options) throws NetworkErrorException {
+            return null;
+        }
 
-		@Override
-		public Bundle hasFeatures(AccountAuthenticatorResponse response, Account account, String[] features) throws NetworkErrorException {
-			return null;
-		}
+        @Override
+        public Bundle editProperties(AccountAuthenticatorResponse response, String accountType) {
+            return null;
+        }
 
-		@Override
-		public Bundle updateCredentials(AccountAuthenticatorResponse response, Account account, String authTokenType, Bundle options) throws NetworkErrorException {
-			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/AddressBookProvider.java

@@ -0,0 +1,53 @@
+/*
+ * 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.database.Cursor;
+import android.net.Uri;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+
+public class AddressBookProvider extends ContentProvider {
+
+    @Override
+    public boolean onCreate() {
+        return false;
+    }
+
+    @Nullable
+    @Override
+    public Cursor query(@NonNull Uri uri, @Nullable String[] projection, @Nullable String selection, @Nullable String[] selectionArgs, @Nullable String sortOrder) {
+        return null;
+    }
+
+    @Nullable
+    @Override
+    public String getType(@NonNull Uri uri) {
+        return null;
+    }
+
+    @Nullable
+    @Override
+    public Uri insert(@NonNull Uri uri, @Nullable ContentValues values) {
+        return null;
+    }
+
+    @Override
+    public int delete(@NonNull Uri uri, @Nullable String selection, @Nullable String[] selectionArgs) {
+        return 0;
+    }
+
+    @Override
+    public int update(@NonNull Uri uri, @Nullable ContentValues values, @Nullable String selection, @Nullable String[] selectionArgs) {
+        return 0;
+    }
+
+}

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

@@ -0,0 +1,160 @@
+/*
+ * 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.accounts.AccountManager;
+import android.accounts.AuthenticatorException;
+import android.accounts.OperationCanceledException;
+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.provider.ContactsContract;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+
+import java.io.IOException;
+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.R;
+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 AddressBooksSyncAdapterService extends SyncAdapterService {
+
+    @Override
+    protected AbstractThreadedSyncAdapter syncAdapter() {
+        return new AddressBooksSyncAdapter(this);
+    }
+
+
+	private static class AddressBooksSyncAdapter extends SyncAdapter {
+
+        public AddressBooksSyncAdapter(Context context) {
+            super(context);
+        }
+
+        @Override
+        public void sync(Account account, Bundle extras, String authority, ContentProviderClient addressBooksProvider, SyncResult syncResult) {
+            @Cleanup("release") ContentProviderClient contactsProvider = getContext().getContentResolver().acquireContentProviderClient(ContactsContract.AUTHORITY);
+            if (contactsProvider == null) {
+                App.log.severe("Couldn't access contacts provider");
+                syncResult.databaseError = true;
+                return;
+            }
+
+            SQLiteOpenHelper dbHelper = new ServiceDB.OpenHelper(getContext());
+            try {
+                AccountSettings settings = new AccountSettings(getContext(), account);
+                if (!extras.containsKey(ContentResolver.SYNC_EXTRAS_MANUAL) && !checkSyncConditions(settings))
+                    return;
+
+                updateLocalAddressBooks(contactsProvider, account);
+
+                AccountManager accountManager = AccountManager.get(getContext());
+                for (Account addressBookAccount : accountManager.getAccountsByType(getContext().getString(R.string.account_type_address_book))) {
+                    App.log.log(Level.INFO, "Running sync for address book", addressBookAccount);
+                    Bundle syncExtras = new 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(InvalidAccountException e) {
+                App.log.log(Level.SEVERE, "Couldn't get account settings", e);
+            } catch(ContactsStorageException e) {
+                App.log.log(Level.SEVERE, "Couldn't prepare local address books", e);
+            } finally {
+                dbHelper.close();
+            }
+
+            App.log.info("Address book sync complete");
+        }
+
+        private void updateLocalAddressBooks(ContentProviderClient provider, Account account) throws ContactsStorageException {
+            final Context context = getContext();
+            @Cleanup SQLiteOpenHelper dbHelper = new ServiceDB.OpenHelper(context);
+
+            // enumerate remote and local address books
+            SQLiteDatabase db = dbHelper.getReadableDatabase();
+            Long service = getService(db, account);
+            Map<String, CollectionInfo> remote = remoteAddressBooks(db, service);
+
+            LocalAddressBook[] local = LocalAddressBook.find(context, provider, account);
+
+            // delete obsolete local address books
+            for (LocalAddressBook addressBook : local) {
+                String url = addressBook.getURL();
+                if (!remote.containsKey(url)) {
+                    App.log.log(Level.FINE, "Deleting obsolete local address book", url);
+                    addressBook.delete();
+                } else {
+                    // we already have a local address book for this remote collection, don't take into consideration anymore
+                    try {
+                        addressBook.update(remote.get(url));
+                    } catch(AuthenticatorException|OperationCanceledException|IOException e) {
+                        App.log.log(Level.WARNING, "Couldn't rename address book account", e);
+                    }
+                    remote.remove(url);
+                }
+            }
+
+            // create new local address books
+            for (String url : remote.keySet()) {
+                CollectionInfo info = remote.get(url);
+                App.log.info("Adding local address book " + info);
+                LocalAddressBook.create(context, provider, account, info);
+            }
+        }
+
+        @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;
+        }
+
+        @NonNull
+        private Map<String, CollectionInfo> remoteAddressBooks(@NonNull SQLiteDatabase db, Long service) {
+            Map<String, CollectionInfo> collections = new LinkedHashMap<>();
+            if (service != null) {
+                @Cleanup Cursor c = db.query(Collections._TABLE, null,
+                        Collections.SERVICE_ID + "=? AND " + Collections.SYNC, new String[] { String.valueOf(service) }, null, null, null);
+                while (c.moveToNext()) {
+                    ContentValues values = new ContentValues();
+                    DatabaseUtils.cursorRowToContentValues(c, values);
+                    CollectionInfo info = CollectionInfo.fromDB(values);
+                    collections.put(info.url, info);
+                }
+            }
+            return collections;
+        }
+
+    }
+
+}

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

@@ -40,7 +40,6 @@ 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;
@@ -63,7 +62,7 @@ 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 {
+    public CalendarSyncManager(Context context, Account account, AccountSettings settings, Bundle extras, String authority, SyncResult result, LocalCalendar calendar) {
         super(context, account, settings, extras, authority, result, "calendar/" + calendar.getId());
         localCollection = calendar;
     }
@@ -80,9 +79,10 @@ public class CalendarSyncManager extends SyncManager {
 
 
     @Override
-    protected void prepare() {
+    protected boolean prepare() {
         collectionURL = HttpUrl.parse(localCalendar().getName());
         davCollection = new DavCalendar(httpClient, collectionURL);
+        return true;
     }
 
     @Override
@@ -123,14 +123,18 @@ public class CalendarSyncManager extends SyncManager {
         }
 
         // fetch list of remote VEVENTs and build hash table to index file name
-        davCalendar().calendarQuery("VEVENT", limitStart, null);
+        final DavCalendar calendar = davCalendar();
+        currentDavResource = calendar;
+        calendar.calendarQuery("VEVENT", limitStart, null);
 
-        remoteResources = new HashMap<>(davCollection.members.size());
-        for (DavResource iCal : davCollection.members) {
+        remoteResources = new HashMap<>(davCollection.getMembers().size());
+        for (DavResource iCal : davCollection.getMembers()) {
             String fileName = iCal.fileName();
             App.log.fine("Found remote VEVENT: " + fileName);
             remoteResources.put(fileName, iCal);
         }
+
+        currentDavResource = null;
     }
 
     @Override
@@ -145,14 +149,15 @@ public class CalendarSyncManager extends SyncManager {
 
             if (bunch.length == 1) {
                 // only one contact, use GET
-                DavResource remote = bunch[0];
+                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);
+                GetETag eTag = (GetETag)remote.getProperties().get(GetETag.NAME);
+                if (eTag == null || StringUtils.isEmpty(eTag.getETag()))
+                    throw new DavException("Received CalDAV GET response without ETag for " + remote.getLocation());
 
                 Charset charset = Charsets.UTF_8;
                 MediaType contentType = body.contentType();
@@ -160,40 +165,47 @@ public class CalendarSyncManager extends SyncManager {
                     charset = contentType.charset(Charsets.UTF_8);
 
                 @Cleanup InputStream stream = body.byteStream();
-                processVEvent(remote.fileName(), eTag.eTag, stream, charset);
+                processVEvent(remote.fileName(), eTag.getETag(), stream, charset);
 
             } else {
                 // multiple contacts, use multi-get
                 List<HttpUrl> urls = new LinkedList<>();
                 for (DavResource remote : bunch)
-                    urls.add(remote.location);
-                davCalendar().multiget(urls.toArray(new HttpUrl[urls.size()]));
+                    urls.add(remote.getLocation());
+
+                final DavCalendar calendar = davCalendar();
+                currentDavResource = calendar;
+                calendar.multiget(urls.toArray(new HttpUrl[urls.size()]));
 
                 // process multiget results
-                for (DavResource remote : davCollection.members) {
+                for (final DavResource remote : davCollection.getMembers()) {
+                    currentDavResource = remote;
+
                     String eTag;
-                    GetETag getETag = (GetETag)remote.properties.get(GetETag.NAME);
+                    GetETag getETag = (GetETag)remote.getProperties().get(GetETag.NAME);
                     if (getETag != null)
-                        eTag = getETag.eTag;
+                        eTag = getETag.getETag();
                     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);
+                    GetContentType getContentType = (GetContentType)remote.getProperties().get(GetContentType.NAME);
+                    if (getContentType != null && getContentType.getType() != null) {
+                        MediaType type = MediaType.parse(getContentType.getType());
                         if (type != null)
                             charset = type.charset(Charsets.UTF_8);
                     }
 
-                    CalendarData calendarData = (CalendarData)remote.properties.get(CalendarData.NAME);
-                    if (calendarData == null || calendarData.iCalendar == null)
+                    CalendarData calendarData = (CalendarData)remote.getProperties().get(CalendarData.NAME);
+                    if (calendarData == null || calendarData.getICalendar() == null)
                         throw new DavException("Received multi-get response without address data");
 
-                    @Cleanup InputStream stream = new ByteArrayInputStream(calendarData.iCalendar.getBytes());
+                    @Cleanup InputStream stream = new ByteArrayInputStream(calendarData.getICalendar().getBytes());
                     processVEvent(remote.fileName(), eTag, stream, charset);
                 }
             }
+
+            currentDavResource = null;
         }
     }
 
@@ -217,6 +229,7 @@ public class CalendarSyncManager extends SyncManager {
 
             // 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);
@@ -225,11 +238,14 @@ public class CalendarSyncManager extends SyncManager {
             } 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/CalendarsSyncAdapterService.java

@@ -17,6 +17,7 @@ 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;
@@ -24,6 +25,7 @@ import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 
 import java.util.LinkedHashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.logging.Level;
 
@@ -53,9 +55,7 @@ public class CalendarsSyncAdapterService extends SyncAdapterService {
         }
 
         @Override
-        public void onPerformSync(Account account, Bundle extras, String authority, ContentProviderClient provider, SyncResult syncResult) {
-            super.onPerformSync(account, extras, authority, provider, syncResult);
-
+        public void sync(Account account, Bundle extras, String authority, ContentProviderClient provider, SyncResult syncResult) {
             try {
                 AccountSettings settings = new AccountSettings(getContext(), account);
                 if (!extras.containsKey(ContentResolver.SYNC_EXTRAS_MANUAL) && !checkSyncConditions(settings))
@@ -63,57 +63,54 @@ public class CalendarsSyncAdapterService extends SyncAdapterService {
 
                 updateLocalCalendars(provider, account, settings);
 
-                for (LocalCalendar calendar : (LocalCalendar[])LocalCalendar.find(account, provider, LocalCalendar.Factory.INSTANCE, CalendarContract.Calendars.SYNC_EVENTS + "!=0", null)) {
+                for (LocalCalendar calendar : 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 e) {
-                App.log.log(Level.SEVERE, "Couldn't enumerate local calendars", e);
-                syncResult.databaseError = true;
-            } catch (InvalidAccountException e) {
+            } catch(InvalidAccountException e) {
                 App.log.log(Level.SEVERE, "Couldn't get account settings", e);
+            } catch(CalendarStorageException|SQLiteException e) {
+                App.log.log(Level.SEVERE, "Couldn't prepare local calendars", e);
+                syncResult.databaseError = true;
             }
 
             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);
+            @Cleanup SQLiteOpenHelper dbHelper = new ServiceDB.OpenHelper(getContext());
 
-                LocalCalendar[] local = (LocalCalendar[])LocalCalendar.find(account, provider, LocalCalendar.Factory.INSTANCE, null, null);
+            // enumerate remote and local calendars
+            SQLiteDatabase db = dbHelper.getReadableDatabase();
+            Long service = getService(db, account);
+            Map<String, CollectionInfo> remote = remoteCalendars(db, service);
 
-                boolean updateColors = settings.getManageCalendarColors();
+            List<LocalCalendar> local = LocalCalendar.find(account, provider, LocalCalendar.Factory.INSTANCE, null, null);
 
-                // 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);
-                    }
-                }
+            boolean updateColors = settings.getManageCalendarColors();
 
-                // create new local calendars
-                for (String url : remote.keySet()) {
+            // delete obsolete local calendars
+            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.info("Adding local calendar list " + info);
-                    LocalCalendar.create(account, provider, info);
+                    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);
                 }
-            } finally {
-                dbHelper.close();
+            }
+
+            // 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);
             }
         }
 

app/src/main/java/at/bitfire/davdroid/syncadapter/ContactsSyncAdapterService.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
@@ -22,14 +22,19 @@ import android.os.Bundle;
 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.R;
 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 {
@@ -47,59 +52,29 @@ public class ContactsSyncAdapterService extends SyncAdapterService {
         }
 
         @Override
-        public void onPerformSync(Account account, Bundle extras, String authority, ContentProviderClient provider, SyncResult syncResult) {
-            super.onPerformSync(account, extras, authority, provider, syncResult);
-
+        public void sync(Account account, Bundle extras, String authority, ContentProviderClient provider, SyncResult syncResult) {
             SQLiteOpenHelper dbHelper = new ServiceDB.OpenHelper(getContext());
             try {
-                AccountSettings settings = new AccountSettings(getContext(), account);
+                LocalAddressBook addressBook = new LocalAddressBook(getContext(), account, provider);
+
+                AccountSettings settings = new AccountSettings(getContext(), addressBook.getMainAccount());
                 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");
-                } else
-                    App.log.info("No CardDAV service found in DB");
-            } catch (InvalidAccountException e) {
+                App.log.info("Synchronizing address book: "  + addressBook.getURL());
+                App.log.info("Taking settings from: "  + addressBook.getMainAccount());
+
+                ContactsSyncManager syncManager = new ContactsSyncManager(getContext(), account, settings, extras, authority, provider, syncResult, addressBook);
+                syncManager.performSync();
+            } catch(InvalidAccountException e) {
                 App.log.log(Level.SEVERE, "Couldn't get account settings", e);
+            } catch(ContactsStorageException e) {
+                App.log.log(Level.SEVERE, "Couldn't prepare local address books", 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.log.info("Contacts sync complete");
         }
 
     }

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

@@ -11,11 +11,13 @@ 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;
@@ -25,6 +27,7 @@ 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;
@@ -47,15 +50,14 @@ 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.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;
@@ -66,7 +68,6 @@ import at.bitfire.vcard4android.Contact;
 import at.bitfire.vcard4android.ContactsStorageException;
 import at.bitfire.vcard4android.GroupMethod;
 import ezvcard.VCardVersion;
-import ezvcard.util.IOUtils;
 import lombok.Cleanup;
 import lombok.RequiredArgsConstructor;
 import okhttp3.HttpUrl;
@@ -116,16 +117,16 @@ 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 {
+    public ContactsSyncManager(Context context, Account account, AccountSettings settings, Bundle extras, String authority, ContentProviderClient provider, SyncResult result, LocalAddressBook localAddressBook) {
         super(context, account, settings, extras, authority, result, "addressBook");
         this.provider = provider;
-        this.remote = remote;
+
+        localCollection = localAddressBook;
     }
 
     @Override
@@ -140,16 +141,17 @@ public class ContactsSyncManager extends SyncManager {
 
 
     @Override
-    protected void prepare() throws ContactsStorageException {
-        // prepare local address book
-        localCollection = new LocalAddressBook(account, provider);
+    protected boolean prepare() throws ContactsStorageException {
         LocalAddressBook localAddressBook = localAddressBook();
 
-        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();
+        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().size();
+            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;
+            }
         }
 
         // set up Contacts Provider Settings
@@ -158,15 +160,17 @@ public class ContactsSyncManager extends SyncManager {
         values.put(ContactsContract.Settings.UNGROUPED_VISIBLE, 1);
         localAddressBook.updateSettings(values);
 
-        collectionURL = HttpUrl.parse(url);
+        collectionURL = HttpUrl.parse(localAddressBook.getURL());
         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);
+        SupportedAddressData supportedAddressData = (SupportedAddressData)davCollection.getProperties().get(SupportedAddressData.NAME);
         hasVCard4 = supportedAddressData != null && supportedAddressData.hasVCard4();
         App.log.info("Server advertises VCard/4 support: " + hasVCard4);
 
@@ -211,12 +215,11 @@ public class ContactsSyncManager extends SyncManager {
                                 currentGroups = contact.getGroupMemberships();
                     for (Long groupID : SetUtils.disjunction(cachedGroups, currentGroups)) {
                         App.log.fine("Marking group as dirty: " + groupID);
-                        batch.enqueue(ContentProviderOperation
-                                .newUpdate(addressBook.syncAdapterURI(ContentUris.withAppendedId(Groups.CONTENT_URI, groupID)))
+                        batch.enqueue(new BatchOperation.Operation(
+                                ContentProviderOperation.newUpdate(addressBook.syncAdapterURI(ContentUris.withAppendedId(Groups.CONTENT_URI, groupID)))
                                 .withValue(Groups.DIRTY, 1)
                                 .withYieldAllowed(true)
-                                .build()
-                        );
+                        ));
                     }
                 } catch(FileNotFoundException ignored) {
                 }
@@ -259,7 +262,7 @@ public class ContactsSyncManager extends SyncManager {
         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, settings.getVCardRFC6868(), os);
+        contact.write(hasVCard4 ? VCardVersion.V4_0 : VCardVersion.V3_0, groupMethod, os);
 
         return RequestBody.create(
                 hasVCard4 ? DavAddressBook.MIME_VCARD4 : DavAddressBook.MIME_VCARD3_UTF8,
@@ -269,31 +272,25 @@ public class ContactsSyncManager extends SyncManager {
 
     @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);
 
-        try {
-            davAddressBook().addressbookQuery();
-        } catch(HttpException e) {
-            /*  non-successful responses to CARDDAV:addressbook-query with empty filter, tested on 2015/10/21
-             *  fastmail.com                 403 Forbidden (DAV:error CARDDAV:supported-filter)
-             *  mailbox.org (OpenXchange)    400 Bad Request
-             *  SOGo                         207 Multi-status, but without entries       http://www.sogo.nu/bugs/view.php?id=3370
-             *  Zimbra ZCS                   500 Server Error                            https://bugzilla.zimbra.com/show_bug.cgi?id=101902
-             */
-            if (e.status == 400 || e.status == 403 || e.status == 500 || e.status == 501) {
-                App.log.log(Level.WARNING, "Server error on REPORT addressbook-query, falling back to PROPFIND", e);
-                davAddressBook().propfind(1, GetETag.NAME);
-            } else
-                // no defined fallback, pass through exception
-                throw e;
-        }
+        remoteResources = new HashMap<>(davCollection.getMembers().size());
+        for (DavResource vCard : davCollection.getMembers()) {
+            // ignore member collections
+            ResourceType type = (ResourceType)vCard.getProperties().get(ResourceType.NAME);
+            if (type != null && type.getTypes().contains(ResourceType.COLLECTION))
+                continue;
 
-        remoteResources = new HashMap<>(davCollection.members.size());
-        for (DavResource vCard : davCollection.members) {
             String fileName = vCard.fileName();
             App.log.fine("Found remote VCard: " + fileName);
             remoteResources.put(fileName, vCard);
         }
+
+        currentDavResource = null;
     }
 
     @Override
@@ -312,14 +309,15 @@ public class ContactsSyncManager extends SyncManager {
 
             if (bunch.length == 1) {
                 // only one contact, use GET
-                DavResource remote = bunch[0];
+                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);
+                GetETag eTag = (GetETag)remote.getProperties().get(GetETag.NAME);
+                if (eTag == null || StringUtils.isEmpty(eTag.getETag()))
+                    throw new DavException("Received CardDAV GET response without ETag for " + remote.getLocation());
 
                 Charset charset = Charsets.UTF_8;
                 MediaType contentType = body.contentType();
@@ -327,40 +325,47 @@ public class ContactsSyncManager extends SyncManager {
                     charset = contentType.charset(Charsets.UTF_8);
 
                 @Cleanup InputStream stream = body.byteStream();
-                processVCard(remote.fileName(), eTag.eTag, stream, charset, downloader);
+                processVCard(remote.fileName(), eTag.getETag(), stream, charset, downloader);
 
             } else {
                 // multiple contacts, use multi-get
                 List<HttpUrl> urls = new LinkedList<>();
                 for (DavResource remote : bunch)
-                    urls.add(remote.location);
-                davAddressBook().multiget(urls.toArray(new HttpUrl[urls.size()]), hasVCard4);
+                    urls.add(remote.getLocation());
+
+                final DavAddressBook addressBook = davAddressBook();
+                currentDavResource = addressBook;
+                addressBook.multiget(urls.toArray(new HttpUrl[urls.size()]), hasVCard4);
+
+                // process multi-get results
+                for (final DavResource remote : davCollection.getMembers()) {
+                    currentDavResource = remote;
 
-                // process multiget results
-                for (DavResource remote : davCollection.members) {
                     String eTag;
-                    GetETag getETag = (GetETag)remote.properties.get(GetETag.NAME);
+                    GetETag getETag = (GetETag)remote.getProperties().get(GetETag.NAME);
                     if (getETag != null)
-                        eTag = getETag.eTag;
+                        eTag = getETag.getETag();
                     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);
+                    GetContentType getContentType = (GetContentType)remote.getProperties().get(GetContentType.NAME);
+                    if (getContentType != null && getContentType.getType() != null) {
+                        MediaType type = MediaType.parse(getContentType.getType());
                         if (type != null)
                             charset = type.charset(Charsets.UTF_8);
                     }
 
-                    AddressData addressData = (AddressData)remote.properties.get(AddressData.NAME);
-                    if (addressData == null || addressData.vCard == null)
+                    AddressData addressData = (AddressData)remote.getProperties().get(AddressData.NAME);
+                    if (addressData == null || addressData.getVCard() == null)
                         throw new DavException("Received multi-get response without address data");
 
-                    @Cleanup InputStream stream = new ByteArrayInputStream(addressData.vCard.getBytes());
+                    @Cleanup InputStream stream = new ByteArrayInputStream(addressData.getVCard().getBytes());
                     processVCard(remote.fileName(), eTag, stream, charset, downloader);
                 }
             }
+
+            currentDavResource = null;
         }
     }
 
@@ -380,12 +385,6 @@ public class ContactsSyncManager extends SyncManager {
         }
     }
 
-    @Override
-    protected void saveSyncState() throws CalendarStorageException, ContactsStorageException {
-        super.saveSyncState();
-        ((LocalAddressBook)localCollection).setURL(remote.url);
-    }
-
 
     // helpers
 
@@ -412,6 +411,7 @@ public class ContactsSyncManager extends SyncManager {
 
         // 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);
 
@@ -444,12 +444,14 @@ public class ContactsSyncManager extends SyncManager {
             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;
@@ -460,17 +462,26 @@ public class ContactsSyncManager extends SyncManager {
         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;
     }
 
 
@@ -495,7 +506,7 @@ public class ContactsSyncManager extends SyncManager {
                 return null;
             }
 
-            OkHttpClient resourceClient = HttpClient.create();
+            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());

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

@@ -0,0 +1,12 @@
+package at.bitfire.davdroid.syncadapter;
+
+import android.content.Context;
+import android.content.SyncResult;
+import android.support.annotation.NonNull;
+
+interface ISyncPlugin {
+
+    boolean beforeSync(@NonNull Context context, @NonNull SyncResult syncResult);
+    void afterSync(@NonNull Context context, @NonNull SyncResult syncResult);
+
+}

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

@@ -0,0 +1,90 @@
+/*
+ * 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.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.AccountsActivity;
+
+public class NullAuthenticatorService extends Service {
+
+    private AccountAuthenticator accountAuthenticator;
+
+    @Override
+    public void onCreate() {
+        accountAuthenticator = new NullAuthenticatorService.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 editProperties(AccountAuthenticatorResponse response, String accountType) {
+            return null;
+        }
+
+        @Override
+        public Bundle addAccount(AccountAuthenticatorResponse response, String accountType, String authTokenType, String[] requiredFeatures, Bundle options) throws NetworkErrorException {
+            Intent intent = new Intent(context, AccountsActivity.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 getAuthToken(AccountAuthenticatorResponse response, Account account, String authTokenType, Bundle options) throws NetworkErrorException {
+            return null;
+        }
+
+        @Override
+        public String getAuthTokenLabel(String authTokenType) {
+            return null;
+        }
+
+        @Override
+        public Bundle updateCredentials(AccountAuthenticatorResponse response, Account account, String authTokenType, Bundle options) throws NetworkErrorException {
+            return null;
+        }
+
+        @Override
+        public Bundle hasFeatures(AccountAuthenticatorResponse response, Account account, String[] features) throws NetworkErrorException {
+            return null;
+        }
+
+    }
+
+}

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

@@ -10,7 +10,6 @@ package at.bitfire.davdroid.syncadapter;
 
 import android.accounts.Account;
 import android.app.Notification;
-import android.app.NotificationManager;
 import android.app.PendingIntent;
 import android.app.Service;
 import android.content.AbstractThreadedSyncAdapter;
@@ -18,7 +17,6 @@ import android.content.ContentProviderClient;
 import android.content.Context;
 import android.content.Intent;
 import android.content.SyncResult;
-import android.graphics.drawable.BitmapDrawable;
 import android.net.ConnectivityManager;
 import android.net.NetworkInfo;
 import android.net.wifi.WifiInfo;
@@ -28,7 +26,12 @@ 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 org.apache.commons.collections4.IteratorUtils;
+
+import java.util.List;
+import java.util.ServiceLoader;
 import java.util.logging.Level;
 
 import at.bitfire.davdroid.AccountSettings;
@@ -37,6 +40,8 @@ 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();
@@ -50,16 +55,39 @@ public abstract class SyncAdapterService extends Service {
 
     public static abstract class SyncAdapter extends AbstractThreadedSyncAdapter {
 
+        private static final ServiceLoader<ISyncPlugin> syncPluginLoader = ServiceLoader.load(ISyncPlugin.class);
+        private final List<ISyncPlugin> syncPlugins = IteratorUtils.toList(syncPluginLoader.iterator());
+
+
         public SyncAdapter(Context context) {
             super(context, false);
+
+            for (ISyncPlugin plugin : syncPlugins)
+                App.log.info("Registered sync plugin: " + plugin.getClass().getName());
         }
 
+        abstract void sync(Account account, Bundle extras, String authority, ContentProviderClient provider, SyncResult syncResult);
+
         @Override
         public void onPerformSync(Account account, Bundle extras, String authority, ContentProviderClient provider, SyncResult syncResult) {
-            App.log.info("Sync for " + authority + " has been initiated");
+            App.log.log(Level.INFO, authority + " sync of " + account + " has been initiated.", extras.keySet().toArray());
 
             // required for dav4android (ServiceLoader)
-            Thread.currentThread().setContextClassLoader(getContext().getClassLoader());
+            final Context context = getContext();
+            Thread.currentThread().setContextClassLoader(context.getClassLoader());
+
+            boolean runSync = true;
+            for (ISyncPlugin plugin : syncPlugins)
+                if (!plugin.beforeSync(context, syncResult))
+                    runSync = false;
+
+            if (runSync)
+                sync(account, extras, authority, provider, syncResult);
+
+            for (ISyncPlugin plugin : syncPlugins)
+                plugin.afterSync(context, syncResult);
+
+            App.log.info("Sync for " + authority + " complete");
         }
 
         @Override
@@ -72,14 +100,13 @@ public abstract class SyncAdapterService extends Service {
 
             Notification notify = new NotificationCompat.Builder(getContext())
                     .setSmallIcon(R.drawable.ic_error_light)
-                    .setLargeIcon(((BitmapDrawable)getContext().getResources().getDrawable(R.drawable.ic_launcher)).getBitmap())
+                    .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_CANCEL_CURRENT))
+                    .setContentIntent(PendingIntent.getActivity(getContext(), 0, intent, PendingIntent.FLAG_UPDATE_CURRENT))
                     .setCategory(NotificationCompat.CATEGORY_ERROR)
-                    .setLocalOnly(true)
                     .build();
-            NotificationManager nm = (NotificationManager)getContext().getSystemService(NOTIFICATION_SERVICE);
+            NotificationManagerCompat nm = NotificationManagerCompat.from(getContext());
             nm.notify(Constants.NOTIFICATION_PERMISSIONS, notify);
         }
 
@@ -99,7 +126,7 @@ public abstract class SyncAdapterService extends Service {
                 String onlySSID = settings.getSyncWifiOnlySSID();
                 if (onlySSID != null) {
                     onlySSID = "\"" + onlySSID + "\"";
-                    WifiManager wifi = (WifiManager)getContext().getSystemService(WIFI_SERVICE);
+                    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");

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

@@ -1,4 +1,4 @@
-    /*
+/*
  * 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
@@ -9,15 +9,14 @@ package at.bitfire.davdroid.syncadapter;
 
 import android.accounts.Account;
 import android.annotation.TargetApi;
-import android.app.NotificationManager;
 import android.app.PendingIntent;
 import android.content.ContentResolver;
 import android.content.Context;
 import android.content.Intent;
 import android.content.SyncResult;
-import android.graphics.drawable.BitmapDrawable;
 import android.net.Uri;
 import android.os.Bundle;
+import android.support.v4.app.NotificationManagerCompat;
 import android.support.v7.app.NotificationCompat;
 import android.text.TextUtils;
 
@@ -25,9 +24,9 @@ import java.io.IOException;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import java.util.UUID;
 import java.util.logging.Level;
 
 import at.bitfire.dav4android.DavResource;
@@ -42,7 +41,6 @@ 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;
@@ -69,7 +67,7 @@ abstract public class SyncManager {
                         SYNC_PHASE_POST_PROCESSING = 10,
                         SYNC_PHASE_SAVE_SYNC_STATE = 11;
 
-    protected final NotificationManager notificationManager;
+    protected final NotificationManagerCompat notificationManager;
     protected final String uniqueCollectionId;
 
     protected final Context context;
@@ -86,6 +84,13 @@ abstract public class SyncManager {
     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;
 
@@ -100,7 +105,7 @@ abstract public class SyncManager {
 
 
 
-    public SyncManager(Context context, Account account, AccountSettings settings, Bundle extras, String authority, SyncResult syncResult, String uniqueCollectionId) throws InvalidAccountException {
+    public SyncManager(Context context, Account account, AccountSettings settings, Bundle extras, String authority, SyncResult syncResult, String uniqueCollectionId) {
         this.context = context;
         this.account = account;
         this.settings = settings;
@@ -109,11 +114,11 @@ abstract public class SyncManager {
         this.syncResult = syncResult;
 
         // create HttpClient with given logger
-        httpClient = HttpClient.create(context, account);
+        httpClient = HttpClient.create(context, settings);
 
         // dismiss previous error notifications
         this.uniqueCollectionId = uniqueCollectionId;
-        notificationManager = (NotificationManager)context.getSystemService(Context.NOTIFICATION_SERVICE);
+        notificationManager = NotificationManagerCompat.from(context);
         notificationManager.cancel(uniqueCollectionId, notificationId());
     }
 
@@ -125,7 +130,10 @@ abstract public class SyncManager {
         int syncPhase = SYNC_PHASE_PREPARE;
         try {
             App.log.info("Preparing synchronization");
-            prepare();
+            if (!prepare()) {
+                App.log.info("No reason to synchronize, aborting");
+                return;
+            }
 
             if (Thread.interrupted())
                 return;
@@ -180,12 +188,12 @@ abstract public class SyncManager {
             } else
                 App.log.info("Remote collection didn't change, skipping remote sync");
 
-        } catch (IOException|ServiceUnavailableException e) {
+        } 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;
+                Date retryAfter = ((ServiceUnavailableException) e).getRetryAfter();
                 if (retryAfter != null) {
                     // how many seconds to wait? getTime() returns ms, so divide by 1000
                     syncResult.delayUntil = (retryAfter.getTime() - new Date().getTime()) / 1000;
@@ -223,6 +231,10 @@ abstract public class SyncManager {
                 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
@@ -230,11 +242,10 @@ abstract public class SyncManager {
 
             NotificationCompat.Builder builder = new NotificationCompat.Builder(context);
             builder .setSmallIcon(R.drawable.ic_error_light)
-                    .setLargeIcon(((BitmapDrawable)context.getResources().getDrawable(R.drawable.ic_launcher)).getBitmap())
+                    .setLargeIcon(App.getLauncherBitmap(context))
                     .setContentTitle(getSyncErrorTitle())
                     .setContentIntent(PendingIntent.getActivity(context, 0, detailsIntent, PendingIntent.FLAG_CANCEL_CURRENT))
-                    .setCategory(NotificationCompat.CATEGORY_ERROR)
-                    .setLocalOnly(true);
+                    .setCategory(NotificationCompat.CATEGORY_ERROR);
 
             try {
                 String[] phases = context.getResources().getStringArray(R.array.sync_error_phases);
@@ -249,7 +260,10 @@ abstract public class SyncManager {
     }
 
 
-    abstract protected void prepare() throws ContactsStorageException;
+    /** 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;
 
@@ -260,17 +274,21 @@ abstract public class SyncManager {
     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 (LocalResource local : localList) {
+        List<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 {
-                    new DavResource(httpClient, collectionURL.newBuilder().addPathSegment(fileName).build())
-                            .delete(local.getETag());
+                    remote.delete(local.getETag());
                 } catch (IOException|HttpException e) {
                     App.log.warning("Couldn't delete " + fileName + " from server; ignoring (may be downloaded again)");
                 }
@@ -278,16 +296,22 @@ abstract public class SyncManager {
                 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 (LocalResource local : localCollection.getWithoutFileName()) {
-            String uuid = UUID.randomUUID().toString();
-            App.log.fine("Found local record #" + local.getId() + " without file name; assigning file name/UID based on " + uuid);
-            local.updateFileNameAndUID(uuid);
+        for (final LocalResource local : (Iterable<LocalResource>)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;
         }
     }
 
@@ -299,13 +323,15 @@ abstract public class SyncManager {
      */
     protected void uploadDirty() throws IOException, HttpException, CalendarStorageException, ContactsStorageException {
         // upload dirty contacts
-        for (LocalResource local : localCollection.getDirty()) {
+        for (final LocalResource local : (Iterable<LocalResource>)localCollection.getDirty()) {
             if (Thread.interrupted())
                 return;
 
+            currentLocalResource = local;
             final String fileName = local.getFileName();
 
-            DavResource remote = new DavResource(httpClient, collectionURL.newBuilder().addPathSegment(fileName).build());
+            final DavResource remote = new DavResource(httpClient, collectionURL.newBuilder().addPathSegment(fileName).build());
+            currentDavResource = remote;
 
             // generate entity to upload (VCard, iCal, whatever)
             RequestBody body = prepareUpload(local);
@@ -324,14 +350,17 @@ abstract public class SyncManager {
             }
 
             String eTag = null;
-            GetETag newETag = (GetETag) remote.properties.get(GetETag.NAME);
+            GetETag newETag = (GetETag) remote.getProperties().get(GetETag.NAME);
             if (newETag != null) {
-                eTag = newETag.eTag;
+                eTag = newETag.getETag();
                 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;
         }
     }
 
@@ -344,9 +373,9 @@ abstract public class SyncManager {
      */
     protected boolean checkSyncState() throws CalendarStorageException, ContactsStorageException {
         // check CTag (ignore on manual sync)
-        GetCTag getCTag = (GetCTag)davCollection.properties.get(GetCTag.NAME);
+        GetCTag getCTag = (GetCTag)davCollection.getProperties().get(GetCTag.NAME);
         if (getCTag != null)
-            remoteCTag = getCTag.cTag;
+            remoteCTag = getCTag.getCTag();
 
         String localCTag = null;
         if (extras.containsKey(ContentResolver.SYNC_EXTRAS_MANUAL))
@@ -366,8 +395,8 @@ abstract public class SyncManager {
      */
     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);
+        List<LocalResource> localList = localCollection.getAll();
+        localResources = new HashMap<>(localList.size());
         for (LocalResource resource : localList) {
             App.log.fine("Found local resource: " + resource.getFileName());
             localResources.put(resource.getFileName(), resource);
@@ -394,18 +423,22 @@ abstract public class SyncManager {
          */
         toDownload = new HashSet<>();
         for (String localName : localResources.keySet()) {
-            DavResource remote = remoteResources.get(localName);
+            final DavResource remote = remoteResources.get(localName);
+            currentDavResource = remote;
+
             if (remote == null) {
                 App.log.info(localName + " is not on server anymore, deleting");
-                localResources.get(localName).delete();
+                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)
+                GetETag getETag = (GetETag)remote.getProperties().get(GetETag.NAME);
+                if (getETag == null || getETag.getETag() == null)
                     throw new DavException("Server didn't provide ETag");
                 String localETag = localResources.get(localName).getETag(),
-                        remoteETag = getETag.eTag;
+                        remoteETag = getETag.getETag();
                 if (remoteETag.equals(localETag))
                     syncResult.stats.numSkippedEntries++;
                 else {
@@ -415,6 +448,9 @@ abstract public class SyncManager {
 
                 // remote entry has been seen, remove from list
                 remoteResources.remove(localName);
+
+                currentDavResource = null;
+                currentLocalResource = null;
             }
         }
 

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

@@ -25,6 +25,7 @@ import android.support.annotation.Nullable;
 import org.dmfs.provider.tasks.TaskContract;
 
 import java.util.LinkedHashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.logging.Level;
 
@@ -58,9 +59,7 @@ public class TasksSyncAdapterService extends SyncAdapterService {
         }
 
         @Override
-        public void onPerformSync(Account account, Bundle extras, String authority, ContentProviderClient providerClient, SyncResult syncResult) {
-            super.onPerformSync(account, extras, authority, providerClient, syncResult);
-
+        public void sync(Account account, Bundle extras, String authority, ContentProviderClient providerClient, SyncResult syncResult) {
             try {
                 @Cleanup TaskProvider provider = TaskProvider.acquire(getContext().getContentResolver(), TaskProvider.ProviderName.OpenTasks);
                 if (provider == null)
@@ -72,7 +71,7 @@ public class TasksSyncAdapterService extends SyncAdapterService {
 
                 updateLocalTaskLists(provider, account, settings);
 
-                for (LocalTaskList taskList : (LocalTaskList[])LocalTaskList.find(account, provider, LocalTaskList.Factory.INSTANCE, TaskContract.TaskLists.SYNC_ENABLED + "!=0", null)) {
+                for (LocalTaskList taskList : 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();
@@ -93,7 +92,7 @@ public class TasksSyncAdapterService extends SyncAdapterService {
                 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);
+                List<LocalTaskList> local = LocalTaskList.find(account, provider, LocalTaskList.Factory.INSTANCE, null, null);
 
                 boolean updateColors = settings.getManageCalendarColors();
 
@@ -101,7 +100,7 @@ public class TasksSyncAdapterService extends SyncAdapterService {
                 for (LocalTaskList list : local) {
                     String url = list.getSyncId();
                     if (!remote.containsKey(url)) {
-                        App.log.fine("Deleting obsolete local task list" + url);
+                        App.log.fine("Deleting obsolete local task list " + url);
                         list.delete();
                     } else {
                         // remote CollectionInfo found for this local collection, update data

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

@@ -38,7 +38,6 @@ 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;
@@ -60,7 +59,7 @@ public class TasksSyncManager extends SyncManager {
     final protected TaskProvider provider;
 
 
-    public TasksSyncManager(Context context, Account account, AccountSettings settings, Bundle extras, String authority, TaskProvider provider, SyncResult result, LocalTaskList taskList) throws InvalidAccountException {
+    public TasksSyncManager(Context context, Account account, AccountSettings settings, Bundle extras, String authority, TaskProvider provider, SyncResult result, LocalTaskList taskList) {
         super(context, account, settings, extras, authority, result, "taskList/" + taskList.getId());
         this.provider = provider;
         localCollection = taskList;
@@ -78,9 +77,10 @@ public class TasksSyncManager extends SyncManager {
 
 
     @Override
-    protected void prepare() {
+    protected boolean prepare() {
         collectionURL = HttpUrl.parse(localTaskList().getSyncId());
         davCollection = new DavCalendar(httpClient, collectionURL);
+        return true;
     }
 
     @Override
@@ -105,13 +105,18 @@ public class TasksSyncManager extends SyncManager {
     @Override
     protected void listRemote() throws IOException, HttpException, DavException {
         // fetch list of remote VTODOs and build hash table to index file name
-        davCalendar().calendarQuery("VTODO", null, null);
-        remoteResources = new HashMap<>(davCollection.members.size());
-        for (DavResource vCard : davCollection.members) {
+        final DavCalendar calendar = davCalendar();
+        currentDavResource = calendar;
+        calendar.calendarQuery("VTODO", null, null);
+
+        remoteResources = new HashMap<>(davCollection.getMembers().size());
+        for (DavResource vCard : davCollection.getMembers()) {
             String fileName = vCard.fileName();
             App.log.fine("Found remote VTODO: " + fileName);
             remoteResources.put(fileName, vCard);
         }
+
+        currentDavResource = null;
     }
 
     @Override
@@ -127,14 +132,15 @@ public class TasksSyncManager extends SyncManager {
 
             if (bunch.length == 1) {
                 // only one contact, use GET
-                DavResource remote = bunch[0];
+                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);
+                GetETag eTag = (GetETag)remote.getProperties().get(GetETag.NAME);
+                if (eTag == null || StringUtils.isEmpty(eTag.getETag()))
+                    throw new DavException("Received CalDAV GET response without ETag for " + remote.getLocation());
 
                 Charset charset = Charsets.UTF_8;
                 MediaType contentType = body.contentType();
@@ -142,40 +148,47 @@ public class TasksSyncManager extends SyncManager {
                     charset = contentType.charset(Charsets.UTF_8);
 
                 @Cleanup InputStream stream = body.byteStream();
-                processVTodo(remote.fileName(), eTag.eTag, stream, charset);
+                processVTodo(remote.fileName(), eTag.getETag(), stream, charset);
 
             } else {
                 // multiple contacts, use multi-get
                 List<HttpUrl> urls = new LinkedList<>();
                 for (DavResource remote : bunch)
-                    urls.add(remote.location);
-                davCalendar().multiget(urls.toArray(new HttpUrl[urls.size()]));
+                    urls.add(remote.getLocation());
+
+                final DavCalendar calendar = davCalendar();
+                currentDavResource = calendar;
+                calendar.multiget(urls.toArray(new HttpUrl[urls.size()]));
 
                 // process multiget results
-                for (DavResource remote : davCollection.members) {
+                for (final DavResource remote : davCollection.getMembers()) {
+                    currentDavResource = remote;
+
                     String eTag;
-                    GetETag getETag = (GetETag)remote.properties.get(GetETag.NAME);
+                    GetETag getETag = (GetETag)remote.getProperties().get(GetETag.NAME);
                     if (getETag != null)
-                        eTag = getETag.eTag;
+                        eTag = getETag.getETag();
                     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);
+                    GetContentType getContentType = (GetContentType)remote.getProperties().get(GetContentType.NAME);
+                    if (getContentType != null && getContentType.getType() != null) {
+                        MediaType type = MediaType.parse(getContentType.getType());
                         if (type != null)
                             charset = type.charset(Charsets.UTF_8);
                     }
 
-                    CalendarData calendarData = (CalendarData)remote.properties.get(CalendarData.NAME);
-                    if (calendarData == null || calendarData.iCalendar == null)
+                    CalendarData calendarData = (CalendarData)remote.getProperties().get(CalendarData.NAME);
+                    if (calendarData == null || calendarData.getICalendar() == null)
                         throw new DavException("Received multi-get response without address data");
 
-                    @Cleanup InputStream stream = new ByteArrayInputStream(calendarData.iCalendar.getBytes());
+                    @Cleanup InputStream stream = new ByteArrayInputStream(calendarData.getICalendar().getBytes());
                     processVTodo(remote.fileName(), eTag, stream, charset);
                 }
             }
+
+            currentDavResource = null;
         }
     }
 
@@ -186,7 +199,7 @@ public class TasksSyncManager extends SyncManager {
     private DavCalendar davCalendar() { return (DavCalendar)davCollection; }
 
     private void processVTodo(String fileName, String eTag, InputStream stream, Charset charset) throws IOException, CalendarStorageException {
-        Task[] tasks;
+        List<Task> tasks;
         try {
             tasks = Task.fromStream(stream, charset);
         } catch (InvalidCalendarException e) {
@@ -194,11 +207,12 @@ public class TasksSyncManager extends SyncManager {
             return;
         }
 
-        if (tasks.length == 1) {
-            Task newData = tasks[0];
+        if (tasks.size() == 1) {
+            Task newData = tasks.get(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);
@@ -207,6 +221,7 @@ public class TasksSyncManager extends SyncManager {
             } else {
                 App.log.info("Adding " + fileName + " to local task list");
                 localTask = new LocalTask(localTaskList(), newData, fileName, eTag);
+                currentLocalResource = localTask;
                 localTask.add();
                 syncResult.stats.numInserts++;
             }

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

@@ -30,7 +30,7 @@ import android.view.View;
 import android.view.ViewGroup;
 import android.widget.TextView;
 
-import org.apache.commons.lang3.time.DateFormatUtils;
+import org.apache.commons.io.IOUtils;
 
 import java.io.IOException;
 import java.io.InputStream;
@@ -40,40 +40,28 @@ import at.bitfire.davdroid.App;
 import at.bitfire.davdroid.BuildConfig;
 import at.bitfire.davdroid.R;
 import ezvcard.Ezvcard;
-import ezvcard.util.IOUtils;
 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 Integer licenseInfo;
         final String licenseTextFile;
     }
+    private ComponentInfo components[];
 
-    private final static ComponentInfo components[] = {
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        components = new ComponentInfo[] {
             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"
+                    null, BuildConfig.VERSION_NAME, getString(R.string.homepage_url),
+                    "Ricki Hirner, Bernhard Stockmann (bitfire web engineering)",
+                    null, null
             ), new ComponentInfo(
                     "AmbilWarna", null, "https://github.com/yukuku/ambilwarna",
                     "Yuku", R.string.about_license_info_no_warranty, "apache2.html"
@@ -89,9 +77,6 @@ public class AboutActivity extends AppCompatActivity {
             ), new ComponentInfo(
                     "ical4j", "2.x", "https://ical4j.github.io/",
                     "Ben Fortuna", R.string.about_license_info_no_warranty, "bsd-3clause.html"
-            ), new ComponentInfo(
-                    "MemorizingTrustManager", null, "https://github.com/ge0rg/MemorizingTrustManager",
-                    "Georg Lukas", R.string.about_license_info_no_warranty, "mit.html"
             ), new ComponentInfo(
                     "OkHttp", null, "https://square.github.io/okhttp/",
                     "Square, Inc.", R.string.about_license_info_no_warranty, "apache2.html"
@@ -99,10 +84,22 @@ public class AboutActivity extends AppCompatActivity {
                     "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)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);
+    }
 
 
-    private static class TabsAdapter extends FragmentPagerAdapter {
+    private class TabsAdapter extends FragmentPagerAdapter {
         public TabsAdapter(FragmentManager fm) {
             super(fm);
         }
@@ -114,7 +111,7 @@ public class AboutActivity extends AppCompatActivity {
 
         @Override
         public CharSequence getPageTitle(int position) {
-            return components[position].title;
+            return components[position].title != null ? components[position].title : getString(R.string.app_name);
         }
 
         @Override
@@ -140,12 +137,13 @@ public class AboutActivity extends AppCompatActivity {
         @Override
         @SuppressLint("SetTextI18n")
         public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
-            ComponentInfo info = components[getArguments().getInt(KEY_POSITION)];
+            ComponentInfo info = ((AboutActivity)getActivity()).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.setText((info.title == null ? getString(R.string.app_name) : info.title) +
+                    (info.version != null ? (" " + info.version) : ""));
 
             tv = (TextView)v.findViewById(R.id.website);
             tv.setAutoLinkMask(Linkify.WEB_URLS);
@@ -155,12 +153,20 @@ public class AboutActivity extends AppCompatActivity {
             tv.setText("© " + info.copyright);
 
             tv = (TextView)v.findViewById(R.id.license_info);
-            tv.setText(info.licenseInfo);
+            if (info.licenseInfo == null)
+                tv.setVisibility(View.GONE);
+            else
+                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);
+            if (info.licenseTextFile == null) {
+                v.findViewById(R.id.license_header).setVisibility(View.GONE);
+                v.findViewById(R.id.license_text).setVisibility(View.GONE);
+            } else {
+                Bundle args = new Bundle(1);
+                args.putString(KEY_FILE_NAME, info.licenseTextFile);
+                getLoaderManager().initLoader(0, args, this);
+            }
 
             return v;
         }

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

@@ -14,6 +14,8 @@ import android.accounts.AccountManagerCallback;
 import android.accounts.AccountManagerFuture;
 import android.accounts.AuthenticatorException;
 import android.accounts.OperationCanceledException;
+import android.annotation.TargetApi;
+import android.app.Dialog;
 import android.app.LoaderManager;
 import android.content.AsyncTaskLoader;
 import android.content.ComponentName;
@@ -24,6 +26,7 @@ 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;
@@ -31,10 +34,12 @@ 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;
@@ -45,14 +50,13 @@ 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;
@@ -62,6 +66,7 @@ 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;
@@ -70,9 +75,14 @@ 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 at.bitfire.vcard4android.ContactsStorageException;
 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";
 
@@ -83,6 +93,7 @@ public class AccountActivity extends AppCompatActivity implements Toolbar.OnMenu
     Toolbar tbCardDAV, tbCalDAV;
 
     @Override
+    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
 
@@ -110,12 +121,36 @@ public class AccountActivity extends AppCompatActivity implements Toolbar.OnMenu
         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()) {
@@ -127,6 +162,9 @@ public class AccountActivity extends AppCompatActivity implements Toolbar.OnMenu
                 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)
@@ -152,7 +190,7 @@ public class AccountActivity extends AppCompatActivity implements Toolbar.OnMenu
         Intent intent;
         switch (item.getItemId()) {
             case R.id.refresh_address_books:
-                if (accountInfo.carddav != null) {
+                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);
@@ -165,7 +203,7 @@ public class AccountActivity extends AppCompatActivity implements Toolbar.OnMenu
                 startActivity(intent);
                 break;
             case R.id.refresh_calendars:
-                if (accountInfo.caldav != null) {
+                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);
@@ -191,23 +229,11 @@ public class AccountActivity extends AppCompatActivity implements Toolbar.OnMenu
 
             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) });
@@ -267,7 +293,7 @@ public class AccountActivity extends AppCompatActivity implements Toolbar.OnMenu
 
     @Override
     public Loader<AccountInfo> onCreateLoader(int id, Bundle args) {
-        return new AccountLoader(this, account.name);
+        return new AccountLoader(this, account);
     }
 
     public void reload() {
@@ -278,12 +304,6 @@ public class AccountActivity extends AppCompatActivity implements Toolbar.OnMenu
     public void onLoadFinished(Loader<AccountInfo> loader, final AccountInfo info) {
         accountInfo = info;
 
-        if (accountInfo == null) {
-            // account doesn't exist anymore
-            finish();
-            return;
-        }
-
         CardView card = (CardView)findViewById(R.id.carddav);
         if (info.carddav != null) {
             ProgressBar progress = (ProgressBar)findViewById(R.id.carddav_refreshing);
@@ -333,19 +353,20 @@ public class AccountActivity extends AppCompatActivity implements Toolbar.OnMenu
     }
 
 
-    private static class AccountLoader extends AsyncTaskLoader<AccountInfo> implements DavService.RefreshingStatusListener, ServiceConnection {
-        private final String accountName;
-        private final OpenHelper dbHelper;
+    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, String accountName) {
+        public AccountLoader(Context context, Account account) {
             super(context);
-            this.accountName = accountName;
-            dbHelper = new OpenHelper(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);
         }
 
@@ -353,6 +374,9 @@ public class AccountActivity extends AppCompatActivity implements Toolbar.OnMenu
         protected void onStopLoading() {
             davService.removeRefreshingStatusListener(this);
             getContext().unbindService(this);
+
+            if (syncStatusListener != null)
+                ContentResolver.removeStatusChangeListener(syncStatusListener);
         }
 
         @Override
@@ -373,42 +397,55 @@ public class AccountActivity extends AppCompatActivity implements Toolbar.OnMenu
             forceLoad();
         }
 
+        @Override
+        public void onStatusChanged(int which) {
+            forceLoad();
+        }
+
         @Override
         public AccountInfo loadInBackground() {
             AccountInfo info = new AccountInfo();
-            try {
-                SQLiteDatabase db = dbHelper.getReadableDatabase();
 
-                @Cleanup Cursor cursor = db.query(
-                        Services._TABLE,
-                        new String[] { Services.ID, Services.SERVICE },
-                        Services.ACCOUNT_NAME + "=?", new String[] { accountName },
-                        null, null, null);
+            @Cleanup OpenHelper dbHelper = new OpenHelper(getContext());
+            SQLiteDatabase db = dbHelper.getReadableDatabase();
 
-                if (cursor.getCount() == 0)
-                    // no services, account not useable
-                    return null;
+            @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.isRefreshing(id);
-                        info.carddav.hasHomeSets = hasHomeSets(db, id);
-                        info.carddav.collections = readCollections(db, id);
+            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, App.getAddressBooksAuthority());
 
-                    } else if (Services.SERVICE_CALDAV.equals(service)) {
-                        info.caldav = new AccountInfo.ServiceInfo();
-                        info.caldav.id = id;
-                        info.caldav.refreshing = davService.isRefreshing(id);
-                        info.caldav.hasHomeSets = hasHomeSets(db, id);
-                        info.caldav.collections = readCollections(db, id);
+                    AccountManager accountManager = AccountManager.get(getContext());
+                    for (Account addrBookAccount : accountManager.getAccountsByType(App.getAddressBookAccountType())) {
+                        LocalAddressBook addressBook = new LocalAddressBook(getContext(), addrBookAccount, null);
+                        try {
+                            if (account.equals(addressBook.getMainAccount()))
+                                info.carddav.refreshing |= ContentResolver.isSyncActive(addrBookAccount, ContactsContract.AUTHORITY);
+                        } catch(ContactsStorageException e) {
+                        }
                     }
+
+                    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.getAuthority());
+                    info.caldav.hasHomeSets = hasHomeSets(db, id);
+                    info.caldav.collections = readCollections(db, id);
                 }
-            } finally {
-                dbHelper.close();
             }
             return info;
         }
@@ -430,6 +467,7 @@ public class AccountActivity extends AppCompatActivity implements Toolbar.OnMenu
             }
             return collections;
         }
+
     }
 
 
@@ -447,7 +485,7 @@ public class AccountActivity extends AppCompatActivity implements Toolbar.OnMenu
 
             final CollectionInfo info = getItem(position);
 
-            RadioButton checked = (RadioButton)v.findViewById(R.id.checked);
+            CheckBox checked = (CheckBox)v.findViewById(R.id.checked);
             checked.setChecked(info.selected);
 
             TextView tv = (TextView)v.findViewById(R.id.title);
@@ -515,6 +553,94 @@ public class AccountActivity extends AppCompatActivity implements Toolbar.OnMenu
     }
 
 
+    /* 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 maybe running synchronization
+                                                ContentResolver.cancelSync(oldAccount, null);
+                                                for (Account addrBookAccount : accountManager.getAccountsByType(App.getAddressBookAccountType()))
+                                                    ContentResolver.cancelSync(addrBookAccount, null);
+
+                                                // update account name references in database
+                                                @Cleanup OpenHelper dbHelper = new OpenHelper(getContext());
+                                                ServiceDB.onRenameAccount(dbHelper.getWritableDatabase(), oldAccount.name, newName);
+
+                                                // update main account of address book accounts
+                                                try {
+                                                    for (Account addrBookAccount : accountManager.getAccountsByType(App.getAddressBookAccountType())) {
+                                                        LocalAddressBook addressBook = new LocalAddressBook(getContext(), addrBookAccount, null);
+                                                        if (oldAccount.equals(addressBook.getMainAccount()))
+                                                            addressBook.setMainAccount(new Account(newName, oldAccount.type));
+                                                    }
+                                                } catch(ContactsStorageException e) {
+                                                    App.log.log(Level.SEVERE, "Couldn't update address book accounts", e);
+                                                }
+
+                                                // 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", e);
+                                                }
+
+                                                // 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() {
@@ -546,11 +672,11 @@ public class AccountActivity extends AppCompatActivity implements Toolbar.OnMenu
             }, null);
     }
 
-    private void requestSync() {
+    protected static void requestSync(Account account) {
         String authorities[] = {
-                ContactsContract.AUTHORITY,
+                App.getAddressBooksAuthority(),
                 CalendarContract.AUTHORITY,
-                TaskProvider.ProviderName.OpenTasks.authority
+                TaskProvider.ProviderName.OpenTasks.getAuthority()
         };
 
         for (String authority : authorities) {
@@ -559,7 +685,10 @@ public class AccountActivity extends AppCompatActivity implements Toolbar.OnMenu
             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/AccountListFragment.java

@@ -11,6 +11,7 @@ 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;
@@ -28,7 +29,6 @@ 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 {
@@ -103,8 +103,9 @@ public class AccountListFragment extends ListFragment implements LoaderManager.L
         }
 
         @Override
+        @SuppressLint("MissingPermission")
         public Account[] loadInBackground() {
-            return accountManager.getAccountsByType(Constants.ACCOUNT_TYPE);
+            return accountManager.getAccountsByType(getContext().getString(R.string.account_type));
         }
     }
 

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

@@ -9,11 +9,17 @@
 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;
@@ -23,10 +29,9 @@ import android.support.v7.preference.SwitchPreferenceCompat;
 import android.text.TextUtils;
 import android.view.MenuItem;
 
-import java.util.logging.Level;
-
 import at.bitfire.davdroid.AccountSettings;
 import at.bitfire.davdroid.App;
+import at.bitfire.davdroid.BuildConfig;
 import at.bitfire.davdroid.InvalidAccountException;
 import at.bitfire.davdroid.R;
 import at.bitfire.ical4android.TaskProvider;
@@ -64,7 +69,7 @@ public class AccountSettingsActivity extends AppCompatActivity {
     }
 
 
-    public static class AccountSettingsFragment extends PreferenceFragmentCompat {
+    public static class AccountSettingsFragment extends PreferenceFragmentCompat implements LoaderManager.LoaderCallbacks<AccountSettings> {
         Account account;
 
         @Override
@@ -72,7 +77,8 @@ public class AccountSettingsActivity extends AppCompatActivity {
             super.onCreate(savedInstanceState);
 
             account = getArguments().getParcelable(EXTRA_ACCOUNT);
-            refresh();
+
+            getLoaderManager().initLoader(0, getArguments(), this);
         }
 
         @Override
@@ -80,13 +86,14 @@ public class AccountSettingsActivity extends AppCompatActivity {
             addPreferencesFromResource(R.xml.settings_account);
         }
 
-        public void refresh() {
-            final AccountSettings settings;
+        @Override
+        public Loader<AccountSettings> onCreateLoader(int id, Bundle args) {
+            return new AccountSettingsLoader(getContext(), (Account)args.getParcelable(EXTRA_ACCOUNT));
+        }
 
-            try {
-                settings = new AccountSettings(getActivity(), account);
-            } catch(InvalidAccountException e) {
-                App.log.log(Level.INFO, "Account is invalid or doesn't exist (anymore)", e);
+        @Override
+        public void onLoadFinished(Loader<AccountSettings> loader, final AccountSettings settings) {
+            if (settings == null) {
                 getActivity().finish();
                 return;
             }
@@ -99,7 +106,7 @@ public class AccountSettingsActivity extends AppCompatActivity {
                 @Override
                 public boolean onPreferenceChange(Preference preference, Object newValue) {
                     settings.username((String)newValue);
-                    refresh();
+                    getLoaderManager().restartLoader(0, getArguments(), AccountSettingsFragment.this);
                     return false;
                 }
             });
@@ -109,25 +116,14 @@ public class AccountSettingsActivity extends AppCompatActivity {
                 @Override
                 public boolean onPreferenceChange(Preference preference, Object newValue) {
                     settings.password((String)newValue);
-                    refresh();
-                    return false;
-                }
-            });
-
-            final SwitchPreferenceCompat prefPreemptive = (SwitchPreferenceCompat)findPreference("preemptive");
-            prefPreemptive.setChecked(settings.preemptiveAuth());
-            prefPreemptive.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
-                @Override
-                public boolean onPreferenceChange(Preference preference, Object newValue) {
-                    settings.preemptiveAuth((Boolean)newValue);
-                    refresh();
+                    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);
+            final Long syncIntervalContacts = settings.getSyncInterval(App.getAddressBooksAuthority());
             if (syncIntervalContacts != null) {
                 prefSyncContacts.setValue(syncIntervalContacts.toString());
                 if (syncIntervalContacts == AccountSettings.SYNC_INTERVAL_MANUALLY)
@@ -137,8 +133,8 @@ public class AccountSettingsActivity extends AppCompatActivity {
                 prefSyncContacts.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
                     @Override
                     public boolean onPreferenceChange(Preference preference, Object newValue) {
-                        settings.setSyncInterval(ContactsContract.AUTHORITY, Long.parseLong((String)newValue));
-                        refresh();
+                        settings.setSyncInterval(App.getAddressBooksAuthority(), Long.parseLong((String)newValue));
+                        getLoaderManager().restartLoader(0, getArguments(), AccountSettingsFragment.this);
                         return false;
                     }
                 });
@@ -159,7 +155,7 @@ public class AccountSettingsActivity extends AppCompatActivity {
                     @Override
                     public boolean onPreferenceChange(Preference preference, Object newValue) {
                         settings.setSyncInterval(CalendarContract.AUTHORITY, Long.parseLong((String)newValue));
-                        refresh();
+                        getLoaderManager().restartLoader(0, getArguments(), AccountSettingsFragment.this);
                         return false;
                     }
                 });
@@ -169,7 +165,7 @@ public class AccountSettingsActivity extends AppCompatActivity {
             }
 
             final ListPreference prefSyncTasks = (ListPreference)findPreference("sync_interval_tasks");
-            final Long syncIntervalTasks = settings.getSyncInterval(TaskProvider.ProviderName.OpenTasks.authority);
+            final Long syncIntervalTasks = settings.getSyncInterval(TaskProvider.ProviderName.OpenTasks.getAuthority());
             if (syncIntervalTasks != null) {
                 prefSyncTasks.setValue(syncIntervalTasks.toString());
                 if (syncIntervalTasks == AccountSettings.SYNC_INTERVAL_MANUALLY)
@@ -179,8 +175,8 @@ public class AccountSettingsActivity extends AppCompatActivity {
                 prefSyncTasks.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
                     @Override
                     public boolean onPreferenceChange(Preference preference, Object newValue) {
-                        settings.setSyncInterval(TaskProvider.ProviderName.OpenTasks.authority, Long.parseLong((String)newValue));
-                        refresh();
+                        settings.setSyncInterval(TaskProvider.ProviderName.OpenTasks.getAuthority(), Long.parseLong((String)newValue));
+                        getLoaderManager().restartLoader(0, getArguments(), AccountSettingsFragment.this);
                         return false;
                     }
                 });
@@ -195,7 +191,7 @@ public class AccountSettingsActivity extends AppCompatActivity {
                 @Override
                 public boolean onPreferenceChange(Preference preference, Object wifiOnly) {
                     settings.setSyncWiFiOnly((Boolean)wifiOnly);
-                    refresh();
+                    getLoaderManager().restartLoader(0, getArguments(), AccountSettingsFragment.this);
                     return false;
                 }
             });
@@ -212,39 +208,28 @@ public class AccountSettingsActivity extends AppCompatActivity {
                 public boolean onPreferenceChange(Preference preference, Object newValue) {
                     String ssid = (String)newValue;
                     settings.setSyncWifiOnlySSID(!TextUtils.isEmpty(ssid) ? ssid : null);
-                    refresh();
+                    getLoaderManager().restartLoader(0, getArguments(), AccountSettingsFragment.this);
                     return false;
                 }
             });
 
             // category: CardDAV
-            final SwitchPreferenceCompat prefRFC6868 = (SwitchPreferenceCompat)findPreference("vcard_rfc6868");
-            if (syncIntervalContacts != null) {
-                prefRFC6868.setChecked(settings.getVCardRFC6868());
-                prefRFC6868.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
-                    @Override
-                    public boolean onPreferenceChange(Preference preference, Object o) {
-                        settings.setVCardRFC6868((Boolean)o);
-                        refresh();
-                        return false;
-                    }
-                });
-            } else
-                prefRFC6868.setEnabled(false);
-
             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));
-                        refresh();
-                        return false;
-                    }
-                });
+                if (BuildConfig.settingContactGroupMethod == null)
+                    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);
             } else
                 prefGroupMethod.setEnabled(false);
 
@@ -269,7 +254,7 @@ public class AccountSettingsActivity extends AppCompatActivity {
                             days = -1;
                         }
                         settings.setTimeRangePastDays(days < 0 ? null : days);
-                        refresh();
+                        getLoaderManager().restartLoader(0, getArguments(), AccountSettingsFragment.this);
                         return false;
                     }
                 });
@@ -283,7 +268,7 @@ public class AccountSettingsActivity extends AppCompatActivity {
                     @Override
                     public boolean onPreferenceChange(Preference preference, Object newValue) {
                         settings.setManageCalendarColors((Boolean)newValue);
-                        refresh();
+                        getLoaderManager().restartLoader(0, getArguments(), AccountSettingsFragment.this);
                         return false;
                     }
                 });
@@ -291,6 +276,57 @@ public class AccountSettingsActivity extends AppCompatActivity {
                 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 void abandon() {
+            onStopLoading();
+        }
+
+        @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) {
+            App.log.fine("Reloading account settings");
+            forceLoad();
+        }
+
     }
 
 }

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

@@ -8,12 +8,15 @@
 
 package at.bitfire.davdroid.ui;
 
+import android.accounts.Account;
+import android.accounts.AccountManager;
+import android.content.ContentResolver;
 import android.content.Intent;
-import android.net.Uri;
-import android.os.Build;
+import android.content.SyncStatusObserver;
 import android.os.Bundle;
 import android.support.design.widget.FloatingActionButton;
 import android.support.design.widget.NavigationView;
+import android.support.design.widget.Snackbar;
 import android.support.v4.app.FragmentTransaction;
 import android.support.v4.view.GravityCompat;
 import android.support.v4.widget.DrawerLayout;
@@ -23,13 +26,23 @@ import android.support.v7.widget.Toolbar;
 import android.view.MenuItem;
 import android.view.View;
 
+import java.util.ServiceLoader;
+
 import at.bitfire.davdroid.App;
 import at.bitfire.davdroid.BuildConfig;
-import at.bitfire.davdroid.Constants;
 import at.bitfire.davdroid.R;
 import at.bitfire.davdroid.ui.setup.LoginActivity;
 
-public class AccountsActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener {
+import static android.content.ContentResolver.SYNC_OBSERVER_TYPE_SETTINGS;
+
+public class AccountsActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener, SyncStatusObserver {
+
+    private static final ServiceLoader<IAccountsDrawerHandler> serviceLoader = ServiceLoader.load(IAccountsDrawerHandler.class);
+    private static final IAccountsDrawerHandler accountsDrawerHandler = serviceLoader.iterator().next();
+
+    private Snackbar syncStatusSnackbar;
+    private Object syncStatusObserver;
+
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -65,6 +78,51 @@ public class AccountsActivity extends AppCompatActivity implements NavigationVie
         }
     }
 
+    @Override
+    protected void onResume() {
+        super.onResume();
+
+        if (BuildConfig.FLAVOR == App.FLAVOR_SOLDUPE) {
+            AccountManager accountManager = AccountManager.get(this);
+            Account[] accounts = accountManager.getAccountsByType(getString(R.string.account_type));
+
+            FloatingActionButton fab = (FloatingActionButton)findViewById(R.id.fab);
+            fab.setVisibility(accounts.length > 0 ? View.GONE : View.VISIBLE);
+        }
+
+        onStatusChanged(SYNC_OBSERVER_TYPE_SETTINGS);
+        syncStatusObserver = ContentResolver.addStatusChangeListener(SYNC_OBSERVER_TYPE_SETTINGS, this);
+    }
+
+    @Override
+    protected void onPause() {
+        super.onPause();
+        if (syncStatusObserver != null) {
+            ContentResolver.removeStatusChangeListener(syncStatusObserver);
+            syncStatusObserver = null;
+        }
+    }
+
+    @Override
+    public void onStatusChanged(int which) {
+        if (syncStatusSnackbar != null) {
+            syncStatusSnackbar.dismiss();
+            syncStatusSnackbar = null;
+        }
+
+        if (!ContentResolver.getMasterSyncAutomatically()) {
+            syncStatusSnackbar = Snackbar.make(findViewById(R.id.coordinator), R.string.accounts_global_sync_disabled, Snackbar.LENGTH_INDEFINITE)
+                    .setAction(R.string.accounts_global_sync_enable, new View.OnClickListener() {
+                        @Override
+                        public void onClick(View v) {
+                            ContentResolver.setMasterSyncAutomatically(true);
+                        }
+                    });
+            syncStatusSnackbar.show();
+        }
+    }
+
+
     @Override
     public void onBackPressed() {
         DrawerLayout drawer = (DrawerLayout)findViewById(R.id.drawer_layout);
@@ -76,34 +134,13 @@ public class AccountsActivity extends AppCompatActivity implements NavigationVie
 
     @Override
     public boolean onNavigationItemSelected(MenuItem item) {
-        switch (item.getItemId()) {
-            case R.id.nav_about:
-                startActivity(new Intent(this, AboutActivity.class));
-                break;
-            case R.id.nav_app_settings:
-                startActivity(new Intent(this, AppSettingsActivity.class));
-                break;
-            case R.id.nav_twitter:
-                startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse("https://twitter.com/davdroidapp")));
-                break;
-            case R.id.nav_website:
-                startActivity(new Intent(Intent.ACTION_VIEW, Constants.webUri));
-                break;
-            case R.id.nav_faq:
-                startActivity(new Intent(Intent.ACTION_VIEW, Constants.webUri.buildUpon().appendEncodedPath("faq/").build()));
-                break;
-            case R.id.nav_forums:
-                startActivity(new Intent(Intent.ACTION_VIEW, Constants.webUri.buildUpon().appendEncodedPath("forums/").build()));
-                break;
-            case R.id.nav_donate:
-                if (BuildConfig.FLAVOR != App.FLAVOR_GOOGLE_PLAY)
-                    startActivity(new Intent(Intent.ACTION_VIEW, Constants.webUri.buildUpon().appendEncodedPath("donate/").build()));
-                break;
-        }
+        boolean processed = accountsDrawerHandler.onNavigationItemSelected(this, item);
 
         DrawerLayout drawer = (DrawerLayout)findViewById(R.id.drawer_layout);
         drawer.closeDrawer(GravityCompat.START);
-        return true;
+
+        return processed;
     }
 
+
 }

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

@@ -12,20 +12,18 @@ import android.content.Intent;
 import android.os.Bundle;
 import android.support.design.widget.Snackbar;
 import android.support.v7.app.AppCompatActivity;
+import android.support.v7.preference.EditTextPreference;
 import android.support.v7.preference.Preference;
 import android.support.v7.preference.PreferenceFragmentCompat;
 import android.support.v7.preference.SwitchPreferenceCompat;
 
-import java.security.KeyStoreException;
-import java.util.Enumeration;
-import java.util.logging.Level;
+import java.net.URI;
+import java.net.URISyntaxException;
 
 import at.bitfire.davdroid.App;
 import at.bitfire.davdroid.R;
 import at.bitfire.davdroid.model.ServiceDB;
 import at.bitfire.davdroid.model.Settings;
-import de.duenndns.ssl.MemorizingTrustManager;
-import lombok.Cleanup;
 
 public class AppSettingsActivity extends AppCompatActivity {
 
@@ -42,19 +40,102 @@ public class AppSettingsActivity extends AppCompatActivity {
 
 
     public static class SettingsFragment extends PreferenceFragmentCompat {
-        Preference prefResetHints,
-                    prefResetCertificates;
-        SwitchPreferenceCompat prefLogToExternalStorage;
+        ServiceDB.OpenHelper dbHelper;
+        Settings settings;
+
+        Preference
+                prefResetHints,
+                prefResetCertificates;
+        SwitchPreferenceCompat
+                prefOverrideProxy,
+                prefDistrustSystemCerts,
+                prefLogToExternalStorage;
+
+        EditTextPreference
+                prefProxyHost,
+                prefProxyPort;
+
+        @Override
+        public void onCreate(Bundle savedInstanceState) {
+            dbHelper = new ServiceDB.OpenHelper(getContext());
+            settings = new Settings(dbHelper.getReadableDatabase());
+
+            super.onCreate(savedInstanceState);
+        }
+
+        @Override
+        public void onDestroy() {
+            super.onDestroy();
+            dbHelper.close();
+        }
 
         @Override
         public void onCreatePreferences(Bundle bundle, String s) {
             addPreferencesFromResource(R.xml.settings_app);
 
             prefResetHints = findPreference("reset_hints");
-            prefResetCertificates = findPreference("reset_certificates");
 
-            @Cleanup ServiceDB.OpenHelper dbHelper = new ServiceDB.OpenHelper(getContext());
-            Settings settings = new Settings(dbHelper.getReadableDatabase());
+            prefOverrideProxy = (SwitchPreferenceCompat)findPreference("override_proxy");
+            prefOverrideProxy.setChecked(settings.getBoolean(App.OVERRIDE_PROXY, false));
+            prefOverrideProxy.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
+                @Override
+                public boolean onPreferenceChange(Preference preference, Object newValue) {
+                    settings.putBoolean(App.OVERRIDE_PROXY, (boolean)newValue);
+                    return true;
+                }
+            });
+
+            prefProxyHost = (EditTextPreference)findPreference("proxy_host");
+            String proxyHost = settings.getString(App.OVERRIDE_PROXY_HOST, App.OVERRIDE_PROXY_HOST_DEFAULT);
+            prefProxyHost.setText(proxyHost);
+            prefProxyHost.setSummary(proxyHost);
+            prefProxyHost.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
+                @Override
+                public boolean onPreferenceChange(Preference preference, Object newValue) {
+                    String host = (String)newValue;
+                    try {
+                        URI uri = new URI(null, host, null, null);
+                    } catch(URISyntaxException e) {
+                        Snackbar.make(getView(), e.getLocalizedMessage(), Snackbar.LENGTH_LONG).show();
+                        return false;
+                    }
+                    settings.putString(App.OVERRIDE_PROXY_HOST, host);
+                    prefProxyHost.setSummary(host);
+                    return true;
+                }
+            });
+
+            prefProxyPort = (EditTextPreference)findPreference("proxy_port");
+            String proxyPort = settings.getString(App.OVERRIDE_PROXY_PORT, String.valueOf(App.OVERRIDE_PROXY_PORT_DEFAULT));
+            prefProxyPort.setText(proxyPort);
+            prefProxyPort.setSummary(proxyPort);
+            prefProxyPort.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
+                @Override
+                public boolean onPreferenceChange(Preference preference, Object newValue) {
+                    int port;
+                    try {
+                        port = Integer.parseInt((String)newValue);
+                    } catch(NumberFormatException e) {
+                        port = App.OVERRIDE_PROXY_PORT_DEFAULT;
+                    }
+                    settings.putInt(App.OVERRIDE_PROXY_PORT, port);
+                    prefProxyPort.setText(String.valueOf(port));
+                    prefProxyPort.setSummary(String.valueOf(port));
+                    return true;
+                }
+            });
+
+            prefDistrustSystemCerts = (SwitchPreferenceCompat)findPreference("distrust_system_certs");
+            App app = (App)getContext().getApplicationContext();
+            if (app.getCertManager() == null)
+                prefDistrustSystemCerts.setVisible(false);
+            else
+                prefDistrustSystemCerts.setChecked(settings.getBoolean(App.DISTRUST_SYSTEM_CERTIFICATES, false));
+
+            prefResetCertificates = findPreference("reset_certificates");
+            if (app.getCertManager() == null)
+                prefResetCertificates.setVisible(false);
+
             prefLogToExternalStorage = (SwitchPreferenceCompat)findPreference("log_to_external_storage");
             prefLogToExternalStorage.setChecked(settings.getBoolean(App.LOG_TO_EXTERNAL_STORAGE, false));
         }
@@ -63,6 +144,8 @@ public class AppSettingsActivity extends AppCompatActivity {
         public boolean onPreferenceTreeClick(Preference preference) {
             if (preference == prefResetHints)
                 resetHints();
+            else if (preference == prefDistrustSystemCerts)
+                setDistrustSystemCerts(((SwitchPreferenceCompat)preference).isChecked());
             else if (preference == prefResetCertificates)
                 resetCertificates();
             else if (preference == prefLogToExternalStorage)
@@ -73,31 +156,29 @@ public class AppSettingsActivity extends AppCompatActivity {
         }
 
         private void resetHints() {
-            @Cleanup ServiceDB.OpenHelper dbHelper = new ServiceDB.OpenHelper(getContext());
-            Settings settings = new Settings(dbHelper.getWritableDatabase());
+            settings.remove(StartupDialogFragment.HINT_BATTERY_OPTIMIZATIONS);
             settings.remove(StartupDialogFragment.HINT_GOOGLE_PLAY_ACCOUNTS_REMOVED);
             settings.remove(StartupDialogFragment.HINT_OPENTASKS_NOT_INSTALLED);
             Snackbar.make(getView(), R.string.app_settings_reset_hints_success, Snackbar.LENGTH_LONG).show();
         }
 
-        private void resetCertificates() {
-            MemorizingTrustManager mtm = App.getMemorizingTrustManager();
+        private void setDistrustSystemCerts(boolean distrust) {
+            settings.putBoolean(App.DISTRUST_SYSTEM_CERTIFICATES, distrust);
 
-            int deleted = 0;
-            Enumeration<String> iterator = mtm.getCertificates();
-            while (iterator.hasMoreElements())
-                try {
-                    mtm.deleteCertificate(iterator.nextElement());
-                    deleted++;
-                } catch (KeyStoreException e) {
-                    App.log.log(Level.SEVERE, "Couldn't distrust certificate", e);
-                }
-            Snackbar.make(getView(), getResources().getQuantityString(R.plurals.app_settings_reset_trusted_certificates_success, deleted, deleted), Snackbar.LENGTH_LONG).show();
+            // re-initialize certificate manager
+            App app = (App)getContext().getApplicationContext();
+            app.reinitCertManager();
+
+            // reinitialize certificate manager of :sync process
+            getContext().sendBroadcast(new Intent(App.ReinitSettingsReceiver.ACTION_REINIT_SETTINGS));
+        }
+
+        private void resetCertificates() {
+            ((App)getContext().getApplicationContext()).getCertManager().resetCertificates();
+            Snackbar.make(getView(), getString(R.string.app_settings_reset_certificates_success), Snackbar.LENGTH_LONG).show();
         }
 
         private void setExternalLogging(boolean externalLogging) {
-            @Cleanup ServiceDB.OpenHelper dbHelper = new ServiceDB.OpenHelper(getContext());
-            Settings settings = new Settings(dbHelper.getWritableDatabase());
             settings.putBoolean(App.LOG_TO_EXTERNAL_STORAGE, externalLogging);
 
             // reinitialize logger of default process
@@ -105,7 +186,7 @@ public class AppSettingsActivity extends AppCompatActivity {
             app.reinitLogger();
 
             // reinitialize logger of :sync process
-            getContext().sendBroadcast(new Intent("at.bitfire.davdroid.REINIT_LOGGER"));
+            getContext().sendBroadcast(new Intent(App.ReinitSettingsReceiver.ACTION_REINIT_SETTINGS));
         }
     }
 

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

@@ -8,8 +8,10 @@
 
 package at.bitfire.davdroid.ui;
 
+import android.Manifest;
 import android.accounts.Account;
 import android.accounts.AccountManager;
+import android.annotation.SuppressLint;
 import android.app.LoaderManager;
 import android.content.AsyncTaskLoader;
 import android.content.ContentResolver;
@@ -17,11 +19,13 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.Loader;
 import android.content.pm.PackageManager;
-import android.net.Uri;
 import android.os.Build;
 import android.os.Bundle;
+import android.os.PowerManager;
 import android.provider.CalendarContract;
 import android.provider.ContactsContract;
+import android.support.v4.content.ContextCompat;
+import android.support.v4.content.FileProvider;
 import android.support.v7.app.AppCompatActivity;
 import android.text.TextUtils;
 import android.view.Menu;
@@ -41,10 +45,11 @@ import at.bitfire.dav4android.exception.HttpException;
 import at.bitfire.davdroid.AccountSettings;
 import at.bitfire.davdroid.App;
 import at.bitfire.davdroid.BuildConfig;
-import at.bitfire.davdroid.Constants;
 import at.bitfire.davdroid.InvalidAccountException;
 import at.bitfire.davdroid.R;
 import at.bitfire.davdroid.model.ServiceDB;
+import at.bitfire.davdroid.resource.LocalAddressBook;
+import at.bitfire.vcard4android.ContactsStorageException;
 import lombok.Cleanup;
 
 public class DebugInfoActivity extends AppCompatActivity implements LoaderManager.LoaderCallbacks<String> {
@@ -53,9 +58,9 @@ public class DebugInfoActivity extends AppCompatActivity implements LoaderManage
             KEY_LOGS = "logs",
             KEY_ACCOUNT = "account",
             KEY_AUTHORITY = "authority",
-            KEY_PHASE = "phase";
-
-    private static final int MAX_INLINE_REPORT_LENGTH = 8000;
+            KEY_PHASE = "phase",
+            KEY_LOCAL_RESOURCE = "localResource",
+            KEY_REMOTE_RESOURCE = "remoteResource";
 
     TextView tvReport;
     String report;
@@ -84,31 +89,41 @@ public class DebugInfoActivity extends AppCompatActivity implements LoaderManage
             Intent sendIntent = new Intent();
             sendIntent.setAction(Intent.ACTION_SEND);
             sendIntent.setType("text/plain");
-            sendIntent.putExtra(Intent.EXTRA_SUBJECT, "DAVdroid debug info");
+            sendIntent.putExtra(Intent.EXTRA_SUBJECT, getString(R.string.app_name) + " " + BuildConfig.VERSION_NAME + " debug info");
 
-            boolean inline = false;
+            // since Android 4.1, FileProvider permissions are handled in a useful way (using ClipData)
+            boolean asAttachment = Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN;
 
-            if (report.length() > MAX_INLINE_REPORT_LENGTH)
-                // report is too long for inline text, send it as an attachment
+            if (asAttachment)
                 try {
-                    reportFile = File.createTempFile("davdroid-debug", ".txt", getExternalCacheDir());
+                    File debugInfoDir = new File(getCacheDir(), "debug-info");
+                    debugInfoDir.mkdir();
+
+                    reportFile = new File(debugInfoDir, "debug.txt");
                     App.log.fine("Writing debug info to " + reportFile.getAbsolutePath());
                     FileWriter writer = new FileWriter(reportFile);
                     writer.write(report);
                     writer.close();
 
-                    sendIntent.putExtra(Intent.EXTRA_STREAM, Uri.fromFile(reportFile));
-                } catch (IOException e) {
-                    // let's hope the report is < 1 MB (Android IPC limit)
-                    inline = true;
-                }
-            else
-                inline = true;
+                    sendIntent.putExtra(Intent.EXTRA_STREAM, FileProvider.getUriForFile(this, getString(R.string.authority_log_provider), reportFile));
+                    sendIntent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
 
-            if (inline)
+                } catch(IOException e) {
+                    // creating an attachment failed, so send it inline
+                    asAttachment = false;
+
+                    StringBuilder builder = new StringBuilder();
+                    builder .append("Couldn't write debug info file:\n")
+                            .append(ExceptionUtils.getStackTrace(e))
+                            .append("\n\n")
+                            .append(report);
+                    report = builder.toString();
+                }
+
+            if (!asAttachment)
                 sendIntent.putExtra(Intent.EXTRA_TEXT, report);
 
-            startActivity(sendIntent);
+            startActivity(Intent.createChooser(sendIntent, null));
         }
     }
 
@@ -144,12 +159,15 @@ public class DebugInfoActivity extends AppCompatActivity implements LoaderManage
         }
 
         @Override
+        @SuppressLint("MissingPermission")
         public String loadInBackground() {
             Throwable throwable = null;
             String  logs = null,
                     authority = null;
             Account account = null;
             int phase = -1;
+            String localResource = null,
+                   remoteResource = null;
 
             if (extras != null) {
                 throwable = (Throwable)extras.getSerializable(KEY_THROWABLE);
@@ -157,9 +175,11 @@ public class DebugInfoActivity extends AppCompatActivity implements LoaderManage
                 account = extras.getParcelable(KEY_ACCOUNT);
                 authority = extras.getString(KEY_AUTHORITY);
                 phase = extras.getInt(KEY_PHASE, -1);
+                localResource = extras.getString(KEY_LOCAL_RESOURCE);
+                remoteResource = extras.getString(KEY_REMOTE_RESOURCE);
             }
 
-            StringBuilder report = new StringBuilder();
+            StringBuilder report = new StringBuilder("--- BEGIN DEBUG INFO ---\n");
 
             // begin with most specific information
 
@@ -172,12 +192,22 @@ public class DebugInfoActivity extends AppCompatActivity implements LoaderManage
 
             if (throwable instanceof HttpException) {
                 HttpException http = (HttpException)throwable;
-                if (http.request != null)
-                    report.append("\nHTTP REQUEST:\n").append(http.request).append("\n\n");
-                if (http.response != null)
-                    report.append("HTTP RESPONSE:\n").append(http.response).append("\n");
+                if (http.getRequest() != null)
+                    report.append("\nHTTP REQUEST:\n").append(http.getRequest()).append("\n\n");
+                if (http.getResponse() != null)
+                    report.append("HTTP RESPONSE:\n").append(http.getResponse()).append("\n");
             }
 
+            if (localResource != null)
+                report.append("\nCURRENT LOCAL RESOURCE:\n")
+                      .append(localResource)
+                      .append("\n");
+
+            if (remoteResource != null)
+                report.append("\nCURRENT REMOTE RESOURCE:\n")
+                        .append(remoteResource)
+                        .append("\n");
+
             if (throwable != null)
                 report  .append("\nEXCEPTION:\n")
                         .append(ExceptionUtils.getStackTrace(throwable));
@@ -185,50 +215,78 @@ public class DebugInfoActivity extends AppCompatActivity implements LoaderManage
             if (logs != null)
                 report.append("\nLOGS:\n").append(logs).append("\n");
 
+            final Context context = getContext();
+
             try {
-                PackageManager pm = getContext().getPackageManager();
+                PackageManager pm = context.getPackageManager();
                 String installedFrom = pm.getInstallerPackageName(BuildConfig.APPLICATION_ID);
                 if (TextUtils.isEmpty(installedFrom))
                     installedFrom = "APK (directly)";
                 boolean workaroundInstalled = false;
                 try {
-                    workaroundInstalled = pm.getPackageInfo("at.bitfire.davdroid.jbworkaround", 0) != null;
+                    workaroundInstalled = pm.getPackageInfo(BuildConfig.APPLICATION_ID + ".jbworkaround", 0) != null;
                 } catch(PackageManager.NameNotFoundException ignored) {}
                 report.append("\nSOFTWARE INFORMATION\n" +
-                                "DAVdroid version: ").append(BuildConfig.VERSION_NAME).append(" (").append(BuildConfig.VERSION_CODE).append(") ").append(new Date(BuildConfig.buildTime)).append("\n")
-                                .append("Installed from: ").append(installedFrom).append("\n")
-                                .append("JB Workaround installed: ").append(workaroundInstalled ? "yes" : "no").append("\n\n");
+                              "Package: ").append(BuildConfig.APPLICATION_ID).append("\n" +
+                              "Version: ").append(BuildConfig.VERSION_NAME).append(" (").append(BuildConfig.VERSION_CODE).append(") ").append(new Date(BuildConfig.buildTime)).append("\n")
+                      .append("Installed from: ").append(installedFrom).append("\n")
+                      .append("JB Workaround installed: ").append(workaroundInstalled ? "yes" : "no").append("\n\n");
             } catch(Exception ex) {
                 App.log.log(Level.SEVERE, "Couldn't get software information", ex);
             }
 
-            report.append(
-                    "CONFIGURATION\n" +
-                    "System-wide synchronization: ").append(ContentResolver.getMasterSyncAutomatically() ? "automatically" : "manually").append("\n");
-            AccountManager accountManager = AccountManager.get(getContext());
-            for (Account acct : accountManager.getAccountsByType(Constants.ACCOUNT_TYPE))
+            report.append("CONFIGURATION\n");
+            // power saving
+            PowerManager powerManager = (PowerManager)context.getSystemService(Context.POWER_SERVICE);
+            if (powerManager != null && Build.VERSION.SDK_INT >= 23)
+                report.append("Power saving disabled: ")
+                      .append(powerManager.isIgnoringBatteryOptimizations(BuildConfig.APPLICATION_ID) ? "yes" : "no")
+                      .append("\n");
+            // permissions
+            for (String permission : new String[] { Manifest.permission.READ_CONTACTS, Manifest.permission.WRITE_CONTACTS,
+                                                    Manifest.permission.READ_CALENDAR, Manifest.permission.WRITE_CALENDAR,
+                                                    PermissionsActivity.PERMISSION_READ_TASKS, PermissionsActivity.PERMISSION_WRITE_TASKS })
+                report.append(permission).append(" permission: ")
+                      .append(ContextCompat.checkSelfPermission(context, permission) == PackageManager.PERMISSION_GRANTED ? "granted" : "denied")
+                      .append("\n");
+            // system-wide sync settings
+            report.append("System-wide synchronization: ")
+                  .append(ContentResolver.getMasterSyncAutomatically() ? "automatically" : "manually")
+                  .append("\n");
+            // main accounts
+            AccountManager accountManager = AccountManager.get(context);
+            for (Account acct : accountManager.getAccountsByType(context.getString(R.string.account_type)))
                 try {
-                    AccountSettings settings = new AccountSettings(getContext(), acct);
+                    AccountSettings settings = new AccountSettings(context, acct);
                     report.append("Account: ").append(acct.name).append("\n" +
-                                  "  Address book sync. interval: ").append(syncStatus(settings, ContactsContract.AUTHORITY)).append("\n" +
+                                  "  Address book sync. interval: ").append(syncStatus(settings, context.getString(R.string.address_books_authority))).append("\n" +
                                   "  Calendar     sync. interval: ").append(syncStatus(settings, CalendarContract.AUTHORITY)).append("\n" +
                                   "  OpenTasks    sync. interval: ").append(syncStatus(settings, "org.dmfs.tasks")).append("\n" +
-                                  "  Preemptive auth: ").append(settings.preemptiveAuth()).append("\n" +
                                   "  WiFi only: ").append(settings.getSyncWifiOnly());
                     if (settings.getSyncWifiOnlySSID() != null)
                         report.append(", SSID: ").append(settings.getSyncWifiOnlySSID());
                     report.append("\n  [CardDAV] Contact group method: ").append(settings.getGroupMethod())
-                          .append("\n            RFC 6868 encoding: ").append(settings.getVCardRFC6868())
                           .append("\n  [CalDAV] Time range (past days): ").append(settings.getTimeRangePastDays())
                           .append("\n           Manage calendar colors: ").append(settings.getManageCalendarColors())
                           .append("\n");
                 } catch(InvalidAccountException e) {
                     report.append(acct).append(" is invalid (unsupported settings version) or does not exist\n");
                 }
+            // address book accounts
+            for (Account acct : accountManager.getAccountsByType(context.getString(R.string.account_type_address_book)))
+                try {
+                    LocalAddressBook addressBook = new LocalAddressBook(context, acct, null);
+                    report.append("Address book account: ").append(acct.name).append("\n" +
+                            "  Main account: ").append(addressBook.getMainAccount()).append("\n" +
+                            "  URL: ").append(addressBook.getURL()).append("\n" +
+                            "  Sync automatically: ").append(ContentResolver.getSyncAutomatically(acct, ContactsContract.AUTHORITY)).append("\n");
+                } catch(ContactsStorageException e) {
+                    report.append(acct).append(" is invalid: ").append(e.getMessage()).append("\n");
+                }
             report.append("\n");
 
             report.append("SQLITE DUMP\n");
-            @Cleanup ServiceDB.OpenHelper dbHelper = new ServiceDB.OpenHelper(getContext());
+            @Cleanup ServiceDB.OpenHelper dbHelper = new ServiceDB.OpenHelper(context);
             dbHelper.dump(report);
             report.append("\n");
 
@@ -242,6 +300,7 @@ public class DebugInfoActivity extends AppCompatActivity implements LoaderManage
                 App.log.log(Level.SEVERE, "Couldn't get system details", ex);
             }
 
+            report.append("--- END DEBUG INFO ---\n");
             return report.toString();
         }
 

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

@@ -0,0 +1,11 @@
+package at.bitfire.davdroid.ui;
+
+import android.app.Activity;
+import android.support.annotation.NonNull;
+import android.view.MenuItem;
+
+public interface IAccountsDrawerHandler {
+
+    public boolean onNavigationItemSelected(@NonNull Activity activity, MenuItem item);
+
+}

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

@@ -9,12 +9,12 @@
 package at.bitfire.davdroid.ui;
 
 import android.Manifest;
-import android.app.NotificationManager;
 import android.content.pm.PackageManager;
 import android.os.Bundle;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.support.v4.app.ActivityCompat;
+import android.support.v4.app.NotificationManagerCompat;
 import android.support.v7.app.AppCompatActivity;
 import android.view.View;
 
@@ -63,7 +63,7 @@ public class PermissionsActivity extends AppCompatActivity {
         }
 
         if (!noCalendarPermissions && !noContactsPermissions && !noTaskPermissions) {
-            NotificationManager nm = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
+            NotificationManagerCompat nm = NotificationManagerCompat.from(this);
             nm.cancel(Constants.NOTIFICATION_PERMISSIONS);
 
             finish();

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

@@ -8,15 +8,19 @@
 
 package at.bitfire.davdroid.ui;
 
+import android.annotation.SuppressLint;
+import android.annotation.TargetApi;
 import android.app.Dialog;
 import android.content.Context;
 import android.content.DialogInterface;
 import android.content.Intent;
 import android.content.pm.PackageManager;
+import android.database.sqlite.SQLiteDatabase;
 import android.graphics.drawable.Drawable;
 import android.net.Uri;
 import android.os.Build;
 import android.os.Bundle;
+import android.os.PowerManager;
 import android.support.annotation.NonNull;
 import android.support.v4.app.DialogFragment;
 import android.support.v7.app.AlertDialog;
@@ -37,14 +41,15 @@ import lombok.Cleanup;
 
 public class StartupDialogFragment extends DialogFragment {
     public static final String
+            HINT_BATTERY_OPTIMIZATIONS = "hint_BatteryOptimizations",
             HINT_GOOGLE_PLAY_ACCOUNTS_REMOVED = "hint_GooglePlayAccountsRemoved",
             HINT_OPENTASKS_NOT_INSTALLED = "hint_OpenTasksNotInstalled";
 
     private static final String ARGS_MODE = "mode";
 
     enum Mode {
+        BATTERY_OPTIMIZATIONS,
         DEVELOPMENT_VERSION,
-        FDROID_DONATE,
         GOOGLE_PLAY_ACCOUNTS_REMOVED,
         OPENTASKS_NOT_INSTALLED
     }
@@ -64,17 +69,18 @@ public class StartupDialogFragment extends DialogFragment {
                 if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP &&    // only on Android <5
                     settings.getBoolean(HINT_GOOGLE_PLAY_ACCOUNTS_REMOVED, true))      // and only when "Don't show again" hasn't been clicked yet
                     dialogs.add(StartupDialogFragment.instantiate(Mode.GOOGLE_PLAY_ACCOUNTS_REMOVED));
-            } else {
-                // other stores
-                final String installedFrom = installedFrom(context);
-                if (installedFrom == null || installedFrom.startsWith("org.fdroid"))
-                    dialogs.add(StartupDialogFragment.instantiate(Mode.FDROID_DONATE));
             }
         }
 
+        // battery optimization whitelisting
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && settings.getBoolean(HINT_BATTERY_OPTIMIZATIONS, true)) {
+            PowerManager powerManager = (PowerManager)context.getSystemService(Context.POWER_SERVICE);
+            if (powerManager != null && !powerManager.isIgnoringBatteryOptimizations(BuildConfig.APPLICATION_ID))
+                dialogs.add(StartupDialogFragment.instantiate(Mode.BATTERY_OPTIMIZATIONS));
+        }
+
         // OpenTasks information
-        if (!LocalTaskList.tasksProviderAvailable(context) &&
-                settings.getBoolean(HINT_OPENTASKS_NOT_INSTALLED, true))
+        if (!LocalTaskList.tasksProviderAvailable(context) && settings.getBoolean(HINT_OPENTASKS_NOT_INSTALLED, true))
             dialogs.add(StartupDialogFragment.instantiate(Mode.OPENTASKS_NOT_INSTALLED));
 
         Collections.reverse(dialogs);
@@ -91,16 +97,44 @@ public class StartupDialogFragment extends DialogFragment {
 
     @NonNull
     @Override
+    @TargetApi(Build.VERSION_CODES.M)
+    @SuppressLint("BatteryLife")
     public Dialog onCreateDialog(Bundle savedInstanceState) {
         setCancelable(false);
 
-        final ServiceDB.OpenHelper dbHelper = new ServiceDB.OpenHelper(getContext());
-
         Mode mode = Mode.valueOf(getArguments().getString(ARGS_MODE));
         switch (mode) {
+            case BATTERY_OPTIMIZATIONS:
+                return new AlertDialog.Builder(getActivity())
+                        .setTitle(R.string.startup_battery_optimization)
+                        .setMessage(R.string.startup_battery_optimization_message)
+                        .setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
+                            @Override
+                            public void onClick(DialogInterface dialog, int which) {
+                            }
+                        })
+                        .setNeutralButton(R.string.startup_battery_optimization_disable, new DialogInterface.OnClickListener() {
+                            @Override
+                            public void onClick(DialogInterface dialog, int which) {
+                                Intent intent = new Intent(android.provider.Settings.ACTION_REQUEST_IGNORE_BATTERY_OPTIMIZATIONS,
+                                        Uri.parse("package:" + BuildConfig.APPLICATION_ID));
+                                if (intent.resolveActivity(getContext().getPackageManager()) != null)
+                                    getContext().startActivity(intent);
+                            }
+                        })
+                        .setNegativeButton(R.string.startup_dont_show_again, new DialogInterface.OnClickListener() {
+                            @Override
+                            public void onClick(DialogInterface dialog, int which) {
+                                @Cleanup ServiceDB.OpenHelper dbHelper = new ServiceDB.OpenHelper(getContext());
+                                Settings settings = new Settings(dbHelper.getWritableDatabase());
+                                settings.putBoolean(HINT_BATTERY_OPTIMIZATIONS, false);
+                            }
+                        })
+                        .create();
+
             case DEVELOPMENT_VERSION:
                 return new AlertDialog.Builder(getActivity())
-                        .setIcon(R.drawable.ic_launcher)
+                        .setIcon(R.mipmap.ic_launcher)
                         .setTitle(R.string.startup_development_version)
                         .setMessage(R.string.startup_development_version_message)
                         .setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
@@ -111,32 +145,11 @@ public class StartupDialogFragment extends DialogFragment {
                         .setNeutralButton(R.string.startup_development_version_give_feedback, new DialogInterface.OnClickListener() {
                             @Override
                             public void onClick(DialogInterface dialog, int which) {
-                                startActivity(new Intent(Intent.ACTION_VIEW, Constants.webUri.buildUpon().appendEncodedPath("forums/").build()));
+                                startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse("https://forums.bitfire.at/category/9/beta-test-discussion")));
                             }
                         })
                         .create();
 
-            case FDROID_DONATE:
-                if (BuildConfig.FLAVOR != App.FLAVOR_GOOGLE_PLAY)
-                    return new AlertDialog.Builder(getActivity())
-                            .setIcon(R.drawable.ic_launcher)
-                            .setTitle(R.string.startup_donate)
-                            .setMessage(R.string.startup_donate_message)
-                            .setPositiveButton(R.string.startup_donate_now, new DialogInterface.OnClickListener() {
-                                @Override
-                                public void onClick(DialogInterface dialog, int which) {
-                                    startActivity(new Intent(Intent.ACTION_VIEW, Constants.webUri.buildUpon().appendEncodedPath("donate/").build()));
-                                }
-                            })
-                            .setNegativeButton(R.string.startup_donate_later, new DialogInterface.OnClickListener() {
-                                @Override
-                                public void onClick(DialogInterface dialog, int which) {
-                                }
-                            })
-                            .create();
-                else
-                    throw new IllegalArgumentException();
-
             case GOOGLE_PLAY_ACCOUNTS_REMOVED:
                 Drawable icon = null;
                 try {
@@ -156,13 +169,14 @@ public class StartupDialogFragment extends DialogFragment {
                         .setNeutralButton(R.string.startup_google_play_accounts_removed_more_info, new DialogInterface.OnClickListener() {
                             @Override
                             public void onClick(DialogInterface dialog, int which) {
-                                Intent intent = new Intent(Intent.ACTION_VIEW, Constants.webUri.buildUpon().appendEncodedPath("faq/").build());
+                                Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(getString(R.string.navigation_drawer_faq_url)));
                                 getContext().startActivity(intent);
                             }
                         })
                         .setNegativeButton(R.string.startup_dont_show_again, new DialogInterface.OnClickListener() {
                             @Override
                             public void onClick(DialogInterface dialog, int which) {
+                                @Cleanup ServiceDB.OpenHelper dbHelper = new ServiceDB.OpenHelper(getContext());
                                 Settings settings = new Settings(dbHelper.getWritableDatabase());
                                 settings.putBoolean(HINT_GOOGLE_PLAY_ACCOUNTS_REMOVED, false);
                             }
@@ -195,6 +209,7 @@ public class StartupDialogFragment extends DialogFragment {
                         .setNegativeButton(R.string.startup_dont_show_again, new DialogInterface.OnClickListener() {
                             @Override
                             public void onClick(DialogInterface dialog, int which) {
+                                @Cleanup ServiceDB.OpenHelper dbHelper = new ServiceDB.OpenHelper(getContext());
                                 Settings settings = new Settings(dbHelper.getWritableDatabase());
                                 settings.putBoolean(HINT_OPENTASKS_NOT_INSTALLED, false);
                             }

app/src/main/java/at/bitfire/davdroid/ui/setup/AccountDetailsFragment.java

@@ -10,11 +10,11 @@ package at.bitfire.davdroid.ui.setup;
 
 import android.accounts.Account;
 import android.accounts.AccountManager;
+import android.app.Activity;
 import android.content.ContentResolver;
 import android.content.ContentValues;
 import android.content.Intent;
 import android.database.sqlite.SQLiteDatabase;
-import android.os.Build;
 import android.os.Bundle;
 import android.provider.CalendarContract;
 import android.provider.ContactsContract;
@@ -32,6 +32,7 @@ import java.util.logging.Level;
 
 import at.bitfire.davdroid.AccountSettings;
 import at.bitfire.davdroid.App;
+import at.bitfire.davdroid.BuildConfig;
 import at.bitfire.davdroid.Constants;
 import at.bitfire.davdroid.DavService;
 import at.bitfire.davdroid.InvalidAccountException;
@@ -49,7 +50,6 @@ import lombok.Cleanup;
 public class AccountDetailsFragment extends Fragment {
 
     private static final String KEY_CONFIG = "config";
-    private static final int DEFAULT_SYNC_INTERVAL = 4 * 3600;  // 4 hours
 
     Spinner spnrGroupMethod;
 
@@ -78,11 +78,13 @@ public class AccountDetailsFragment extends Fragment {
         DavResourceFinder.Configuration config = (DavResourceFinder.Configuration)getArguments().getSerializable(KEY_CONFIG);
 
         final EditText editName = (EditText)v.findViewById(R.id.account_name);
-        editName.setText(config.userName);
+        editName.setText((config.calDAV != null && config.calDAV.email != null) ? config.calDAV.email : config.userName);
 
         // CardDAV-specific
         v.findViewById(R.id.carddav).setVisibility(config.cardDAV != null ? View.VISIBLE : View.GONE);
         spnrGroupMethod = (Spinner)v.findViewById(R.id.contact_group_method);
+        if (BuildConfig.settingContactGroupMethod != null)
+            spnrGroupMethod.setEnabled(false);
 
         Button btnCreate = (Button)v.findViewById(R.id.create_account);
         btnCreate.setOnClickListener(new View.OnClickListener() {
@@ -92,9 +94,10 @@ public class AccountDetailsFragment extends Fragment {
                 if (name.isEmpty())
                     editName.setError(getString(R.string.login_account_name_required));
                 else {
-                    if (createAccount(name, (DavResourceFinder.Configuration)getArguments().getSerializable(KEY_CONFIG)))
+                    if (createAccount(name, (DavResourceFinder.Configuration)getArguments().getSerializable(KEY_CONFIG))) {
+                        getActivity().setResult(Activity.RESULT_OK);
                         getActivity().finish();
-                    else
+                    } else
                         Snackbar.make(v, R.string.login_account_not_created, Snackbar.LENGTH_LONG).show();
                 }
             }
@@ -104,10 +107,10 @@ public class AccountDetailsFragment extends Fragment {
     }
 
     protected boolean createAccount(String accountName, DavResourceFinder.Configuration config) {
-        Account account = new Account(accountName, Constants.ACCOUNT_TYPE);
+        Account account = new Account(accountName, getString(R.string.account_type));
 
         // create Android account
-        Bundle userData = AccountSettings.initialUserData(config.userName, config.preemptive);
+        Bundle userData = AccountSettings.initialUserData(config.userName);
         App.log.log(Level.INFO, "Creating Android account with initial config", new Object[] { account, userData });
 
         AccountManager accountManager = AccountManager.get(getContext());
@@ -133,16 +136,16 @@ public class AccountDetailsFragment extends Fragment {
                 getActivity().startService(refreshIntent);
 
                 // initial CardDAV account settings
-                int idx = spnrGroupMethod.getSelectedItemPosition();
-                String groupMethodName = getResources().getStringArray(R.array.settings_contact_group_method_values)[idx];
-                settings.setGroupMethod(GroupMethod.valueOf(groupMethodName));
+                if (BuildConfig.settingContactGroupMethod == null) {
+                    int idx = spnrGroupMethod.getSelectedItemPosition();
+                    String groupMethodName = getResources().getStringArray(R.array.settings_contact_group_method_values)[idx];
+                    settings.setGroupMethod(GroupMethod.valueOf(groupMethodName));
+                }
 
-                // enable contact sync
-                ContentResolver.setIsSyncable(account, ContactsContract.AUTHORITY, 1);
-                settings.setSyncInterval(ContactsContract.AUTHORITY, DEFAULT_SYNC_INTERVAL);
+                // contact sync is automatically enabled by isAlwaysSyncable="true" in res/xml/sync_contacts.xml
+                settings.setSyncInterval(App.getAddressBooksAuthority(), Constants.DEFAULT_SYNC_INTERVAL);
             } else
-                // disable contact sync when CardDAV is not available
-                ContentResolver.setIsSyncable(account, ContactsContract.AUTHORITY, 0);
+                ContentResolver.setIsSyncable(account, App.getAddressBooksAuthority(), 0);
 
             if (config.calDAV != null) {
                 // insert CalDAV service
@@ -152,23 +155,17 @@ public class AccountDetailsFragment extends Fragment {
                 refreshIntent.putExtra(DavService.EXTRA_DAV_SERVICE_ID, id);
                 getActivity().startService(refreshIntent);
 
-                // enable calendar sync
-                ContentResolver.setIsSyncable(account, CalendarContract.AUTHORITY, 1);
-                settings.setSyncInterval(CalendarContract.AUTHORITY, DEFAULT_SYNC_INTERVAL);
+                // calendar sync is automatically enabled by isAlwaysSyncable="true" in res/xml/sync_contacts.xml
+                settings.setSyncInterval(CalendarContract.AUTHORITY, Constants.DEFAULT_SYNC_INTERVAL);
 
-                // enable task sync, if possible
-                if (Build.VERSION.SDK_INT >= 23 || LocalTaskList.tasksProviderAvailable(getContext())) {
-                    ContentResolver.setIsSyncable(account, TaskProvider.ProviderName.OpenTasks.authority, 1);
-                    settings.setSyncInterval(TaskProvider.ProviderName.OpenTasks.authority, DEFAULT_SYNC_INTERVAL);
-                } else
-                    // Android <6 only: disable OpenTasks sync forever when OpenTasks is not installed
-                    // because otherwise, there will be a non-catchable SecurityException as soon as OpenTasks is installed
-                    ContentResolver.setIsSyncable(account, TaskProvider.ProviderName.OpenTasks.authority, 0);
-            } else {
-                // disable calendar and task sync when CalDAV is not available
+                // enable task sync if OpenTasks is installed
+                // further changes will be handled by PackageChangedReceiver
+                if (LocalTaskList.tasksProviderAvailable(getContext())) {
+                    ContentResolver.setIsSyncable(account, TaskProvider.ProviderName.OpenTasks.getAuthority(), 1);
+                    settings.setSyncInterval(TaskProvider.ProviderName.OpenTasks.getAuthority(), Constants.DEFAULT_SYNC_INTERVAL);
+                }
+            } else
                 ContentResolver.setIsSyncable(account, CalendarContract.AUTHORITY, 0);
-                ContentResolver.setIsSyncable(account, TaskProvider.ProviderName.OpenTasks.authority, 0);
-            }
 
         } catch(InvalidAccountException e) {
             App.log.log(Level.SEVERE, "Couldn't access account settings", e);

app/src/main/java/at/bitfire/davdroid/ui/setup/DavResourceFinder.java

@@ -19,6 +19,7 @@ import org.xbill.DNS.Type;
 import java.io.IOException;
 import java.io.Serializable;
 import java.net.URI;
+import java.net.URISyntaxException;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.LinkedList;
@@ -28,7 +29,9 @@ import java.util.Set;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
+import at.bitfire.dav4android.Constants;
 import at.bitfire.dav4android.DavResource;
+import at.bitfire.dav4android.Property;
 import at.bitfire.dav4android.UrlUtils;
 import at.bitfire.dav4android.exception.DavException;
 import at.bitfire.dav4android.exception.HttpException;
@@ -39,6 +42,7 @@ import at.bitfire.dav4android.property.CalendarColor;
 import at.bitfire.dav4android.property.CalendarDescription;
 import at.bitfire.dav4android.property.CalendarHomeSet;
 import at.bitfire.dav4android.property.CalendarTimezone;
+import at.bitfire.dav4android.property.CalendarUserAddressSet;
 import at.bitfire.dav4android.property.CurrentUserPrincipal;
 import at.bitfire.dav4android.property.CurrentUserPrivilegeSet;
 import at.bitfire.dav4android.property.DisplayName;
@@ -47,6 +51,7 @@ import at.bitfire.dav4android.property.SupportedCalendarComponentSet;
 import at.bitfire.davdroid.HttpClient;
 import at.bitfire.davdroid.log.StringHandler;
 import at.bitfire.davdroid.model.CollectionInfo;
+import kotlin.Pair;
 import lombok.RequiredArgsConstructor;
 import lombok.ToString;
 import okhttp3.HttpUrl;
@@ -77,8 +82,8 @@ public class DavResourceFinder {
         log.setLevel(Level.FINEST);
         log.addHandler(logBuffer);
 
-        httpClient = HttpClient.create(log);
-        httpClient = HttpClient.addAuthentication(httpClient, credentials.userName, credentials.password, credentials.authPreemptive);
+        httpClient = HttpClient.create(context, log);
+        httpClient = HttpClient.addAuthentication(httpClient, credentials.userName, credentials.password);
 	}
 
 
@@ -88,7 +93,7 @@ public class DavResourceFinder {
                 calDavConfig = findInitialConfiguration(Service.CALDAV);
 
         return new Configuration(
-                credentials.userName, credentials.password, credentials.authPreemptive,
+                credentials.userName, credentials.password,
                 cardDavConfig, calDavConfig,
                 logBuffer.toString()
         );
@@ -140,6 +145,26 @@ public class DavResourceFinder {
             }
         }
 
+        if (config.principal != null && service == Service.CALDAV) {
+            // query email address (CalDAV scheduling: calendar-user-address-set)
+            DavResource davPrincipal = new DavResource(httpClient, HttpUrl.get(config.principal), log);
+            try {
+                davPrincipal.propfind(0, CalendarUserAddressSet.NAME);
+                CalendarUserAddressSet addressSet = (CalendarUserAddressSet)davPrincipal.getProperties().get(CalendarUserAddressSet.NAME);
+                if (addressSet != null)
+                    for (String href : addressSet.getHrefs())
+                        try {
+                            URI uri = new URI(href);
+                            if ("mailto".equals(uri.getScheme()))
+                                config.email = uri.getSchemeSpecificPart();
+                        } catch(URISyntaxException e) {
+                            Constants.log.log(Level.WARNING, "Unparseable user address", e);
+                        }
+            } catch(IOException | HttpException | DavException e) {
+                Constants.log.log(Level.WARNING, "Couldn't query user email address", e);
+            }
+        }
+
         // return config or null if config doesn't contain useful information
         boolean serviceAvailable = config.principal != null || !config.homeSets.isEmpty() || !config.collections.isEmpty();
         return serviceAvailable ? config : null;
@@ -170,15 +195,20 @@ public class DavResourceFinder {
             }
 
             // check for current-user-principal
-            CurrentUserPrincipal currentUserPrincipal = (CurrentUserPrincipal)davBase.properties.get(CurrentUserPrincipal.NAME);
-            if (currentUserPrincipal != null && currentUserPrincipal.href != null)
-                principal = davBase.location.resolve(currentUserPrincipal.href);
+            Pair<DavResource, Property> result1 = davBase.findProperty(CurrentUserPrincipal.NAME);
+            if (result1 != null) {
+                CurrentUserPrincipal currentUserPrincipal = (CurrentUserPrincipal)result1.getSecond();
+                if (currentUserPrincipal.getHref() != null)
+                    principal = result1.getFirst().getLocation().resolve(currentUserPrincipal.getHref());
+            }
 
             // check for resource type "principal"
             if (principal == null) {
-                ResourceType resourceType = (ResourceType)davBase.properties.get(ResourceType.NAME);
-                if (resourceType != null && resourceType.types.contains(ResourceType.PRINCIPAL))
-                    principal = davBase.location;
+                for (Pair<DavResource, Property> result2 : davBase.findProperties(ResourceType.NAME)) {
+                    ResourceType resourceType = (ResourceType)result2.getSecond();
+                    if (resourceType != null && resourceType.getTypes().contains(ResourceType.PRINCIPAL))
+                        principal = result2.getFirst().getLocation();
+                }
             }
 
             // If a principal has been detected successfully, ensure that it provides the required service.
@@ -191,45 +221,56 @@ public class DavResourceFinder {
     }
 
     /**
-     * If #dav is an address book or an address book home set, it will added to
+     * If #dav references an address book or an address book home set, it will added to
      * config.collections or config.homesets. Only evaluates already known properties,
      * does not call dav.propfind()! URLs will be stored with trailing "/".
      * @param dav       resource whose properties are evaluated
      * @param config    structure where the address book (collection) and/or home set is stored into (if found)
      */
     protected void rememberIfAddressBookOrHomeset(@NonNull DavResource dav, @NonNull Configuration.ServiceInfo config) {
-        // Is the collection an address book?
-        ResourceType resourceType = (ResourceType)dav.properties.get(ResourceType.NAME);
-        if (resourceType != null && resourceType.types.contains(ResourceType.ADDRESSBOOK)) {
-            dav.location = UrlUtils.withTrailingSlash(dav.location);
-            log.info("Found address book at " + dav.location);
-            config.collections.put(dav.location.uri(), CollectionInfo.fromDavResource(dav));
+        // Is there an address book?
+        for (Pair<DavResource, Property> result : dav.findProperties(ResourceType.NAME)) {
+            ResourceType resourceType = (ResourceType)result.getSecond();
+            if (resourceType.getTypes().contains(ResourceType.ADDRESSBOOK)) {
+                DavResource addressBook = result.getFirst();
+                addressBook.setLocation(UrlUtils.withTrailingSlash(addressBook.getLocation()));
+                log.info("Found address book at " + addressBook.getLocation());
+                config.collections.put(addressBook.getLocation().uri(), CollectionInfo.fromDavResource(addressBook));
+            }
         }
 
-        // Does the collection refer to address book homesets?
-        AddressbookHomeSet homeSets = (AddressbookHomeSet)dav.properties.get(AddressbookHomeSet.NAME);
-        if (homeSets != null)
-            for (String href : homeSets.hrefs) {
-                HttpUrl location = UrlUtils.withTrailingSlash(dav.location.resolve(href));
-                log.info("Found addressbook home-set at " + location);
+        // Is there an addressbook-home-set?
+        for (Pair<DavResource, Property> result : dav.findProperties(AddressbookHomeSet.NAME)) {
+            AddressbookHomeSet homeSet = (AddressbookHomeSet)result.getSecond();
+            for (String href : homeSet.getHrefs()) {
+                HttpUrl location = UrlUtils.withTrailingSlash(result.getFirst().getLocation().resolve(href));
+                log.info("Found address book home-set at " + location);
                 config.homeSets.add(location.uri());
             }
+        }
     }
 
     protected void rememberIfCalendarOrHomeset(@NonNull DavResource dav, @NonNull Configuration.ServiceInfo config) {
         // Is the collection a calendar collection?
-        ResourceType resourceType = (ResourceType)dav.properties.get(ResourceType.NAME);
-        if (resourceType != null && resourceType.types.contains(ResourceType.CALENDAR)) {
-            dav.location = UrlUtils.withTrailingSlash(dav.location);
-            log.info("Found calendar collection at " + dav.location);
-            config.collections.put(dav.location.uri(), CollectionInfo.fromDavResource(dav));
+        for (Pair<DavResource, Property> result : dav.findProperties(ResourceType.NAME)) {
+            ResourceType resourceType = (ResourceType)result.getSecond();
+            if (resourceType.getTypes().contains(ResourceType.CALENDAR)) {
+                DavResource calendar = result.getFirst();
+                calendar.setLocation(UrlUtils.withTrailingSlash(calendar.getLocation()));
+                log.info("Found calendar at " + calendar.getLocation());
+                config.collections.put(calendar.getLocation().uri(), CollectionInfo.fromDavResource(calendar));
+            }
         }
 
-        // Does the collection refer to calendar homesets?
-        CalendarHomeSet homeSets = (CalendarHomeSet)dav.properties.get(CalendarHomeSet.NAME);
-        if (homeSets != null)
-            for (String href : homeSets.hrefs)
-                config.homeSets.add(UrlUtils.withTrailingSlash(dav.location.resolve(href)).uri());
+        // Is there an calendar-home-set?
+        for (Pair<DavResource, Property> result : dav.findProperties(CalendarHomeSet.NAME)) {
+            CalendarHomeSet homeSet = (CalendarHomeSet)result.getSecond();
+            for (String href : homeSet.getHrefs()) {
+                HttpUrl location = UrlUtils.withTrailingSlash(result.getFirst().getLocation().resolve(href));
+                log.info("Found calendar home-set at " + location);
+                config.homeSets.add(location.uri());
+            }
+        }
     }
 
 
@@ -238,8 +279,8 @@ public class DavResourceFinder {
         try {
             davPrincipal.options();
 
-            if ((service == Service.CARDDAV && davPrincipal.capabilities.contains("addressbook")) ||
-                (service == Service.CALDAV && davPrincipal.capabilities.contains("calendar-access")))
+            if ((service == Service.CARDDAV && davPrincipal.getCapabilities().contains("addressbook")) ||
+                (service == Service.CALDAV && davPrincipal.getCapabilities().contains("calendar-access")))
                 return true;
 
         } catch (HttpException|DavException e) {
@@ -328,19 +369,22 @@ public class DavResourceFinder {
         DavResource dav = new DavResource(httpClient, url, log);
         dav.propfind(0, CurrentUserPrincipal.NAME);
 
-        CurrentUserPrincipal currentUserPrincipal = (CurrentUserPrincipal)dav.properties.get(CurrentUserPrincipal.NAME);
-        if (currentUserPrincipal != null && currentUserPrincipal.href != null) {
-            HttpUrl principal = dav.location.resolve(currentUserPrincipal.href);
-            if (principal != null) {
-                log.info("Found current-user-principal: " + principal);
+        Pair<DavResource, Property> result = dav.findProperty(CurrentUserPrincipal.NAME);
+        if (result != null) {
+            CurrentUserPrincipal currentUserPrincipal = (CurrentUserPrincipal)result.getSecond();
+            if (currentUserPrincipal.getHref() != null) {
+                HttpUrl principal = result.getFirst().getLocation().resolve(currentUserPrincipal.getHref());
+                if (principal != null) {
+                    log.info("Found current-user-principal: " + principal);
 
-                // service check
-                if (service != null && !providesService(principal, service)) {
-                    log.info(principal + " doesn't provide required " + service + " service");
-                    principal = null;
+                    // service check
+                    if (service != null && !providesService(principal, service)) {
+                        log.info(principal + " doesn't provide required " + service + " service");
+                        principal = null;
+                    }
+
+                    return principal != null ? principal.uri() : null;
                 }
-
-                return principal != null ? principal.uri() : null;
             }
         }
         return null;
@@ -368,10 +412,11 @@ public class DavResourceFinder {
             public URI principal;
             public final Set<URI> homeSets = new HashSet<>();
             public final Map<URI, CollectionInfo> collections = new HashMap<>();
+
+            public String email;
         }
 
         public final String userName, password;
-        public final boolean preemptive;
 
         public final ServiceInfo cardDAV;
         public final ServiceInfo calDAV;

app/src/main/java/at/bitfire/davdroid/ui/setup/ILoginCredentialsFragment.java

@@ -0,0 +1,9 @@
+package at.bitfire.davdroid.ui.setup;
+
+import android.support.v4.app.Fragment;
+
+public interface ILoginCredentialsFragment {
+
+    Fragment getFragment();
+
+}

app/src/main/java/at/bitfire/davdroid/ui/setup/LoginActivity.java

@@ -9,28 +9,76 @@
 package at.bitfire.davdroid.ui.setup;
 
 import android.content.Intent;
+import android.net.Uri;
 import android.os.Bundle;
 import android.support.v7.app.AppCompatActivity;
 import android.view.Menu;
 import android.view.MenuItem;
 
+import java.util.ServiceLoader;
+
+import at.bitfire.davdroid.App;
 import at.bitfire.davdroid.Constants;
 import at.bitfire.davdroid.R;
 
+/**
+ * Activity to initially connect to a server and create an account.
+ * Fields for server/user data can be pre-filled with extras in the Intent.
+ */
 public class LoginActivity extends AppCompatActivity {
 
+    /**
+     * When set, "login by URL" will be activated by default, and the URL field will be set to this value.
+     * When not set, "login by email" will be activated by default.
+     */
+    public static final String EXTRA_URL = "url";
+
+    /**
+     * When set, and {@link #EXTRA_PASSWORD} is set too, the user name field will be set to this value.
+     * When set, and {@link #EXTRA_URL} is not set, the email address field will be set to this value.
+     */
+    public static final String EXTRA_USERNAME = "username";
+
+    /**
+     * When set, the password field will be set to this value.
+     */
+    public static final String EXTRA_PASSWORD = "password";
+
+
+    private static final ServiceLoader<ILoginCredentialsFragment> loginFragmentLoader = ServiceLoader.load(ILoginCredentialsFragment.class);
+
+
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
 
         if (savedInstanceState == null)
             // first call, add fragment
-            getSupportFragmentManager().beginTransaction()
-                    .replace(android.R.id.content, new LoginCredentialsFragment())
-                    .commit();
+            for (ILoginCredentialsFragment fragment : loginFragmentLoader)
+                getSupportFragmentManager().beginTransaction()
+                        .replace(android.R.id.content, fragment.getFragment())
+                        .commit();
 
     }
 
+    @Override
+    protected void onResume() {
+        super.onResume();
+
+        App app = (App)getApplicationContext();
+        if (app.getCertManager() != null)
+            app.getCertManager().appInForeground = true;
+    }
+
+    @Override
+    protected void onPause() {
+        super.onPause();
+
+        App app = (App)getApplicationContext();
+        if (app.getCertManager() != null)
+            app.getCertManager().appInForeground = false;
+    }
+
     @Override
     public boolean onCreateOptionsMenu(Menu menu) {
         getMenuInflater().inflate(R.menu.activity_login, menu);
@@ -38,6 +86,6 @@ public class LoginActivity extends AppCompatActivity {
     }
 
     public void showHelp(MenuItem item) {
-        startActivity(new Intent(Intent.ACTION_VIEW, Constants.webUri.buildUpon().appendEncodedPath("configuration/").build()));
+        startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse(getString(R.string.login_help_url))));
     }
 }

app/src/main/java/at/bitfire/davdroid/ui/setup/LoginCredentials.java

@@ -19,7 +19,6 @@ import lombok.RequiredArgsConstructor;
 public class LoginCredentials implements Parcelable {
     public final URI uri;
     public final String userName, password;
-    public final boolean authPreemptive;
 
     @Override
     public int describeContents() {
@@ -31,7 +30,6 @@ public class LoginCredentials implements Parcelable {
         dest.writeSerializable(uri);
         dest.writeString(userName);
         dest.writeString(password);
-        dest.writeValue(authPreemptive);
     }
 
     public static final Creator CREATOR = new Creator<LoginCredentials>() {
@@ -39,8 +37,7 @@ public class LoginCredentials implements Parcelable {
         public LoginCredentials createFromParcel(Parcel source) {
             return new LoginCredentials(
                     (URI)source.readSerializable(),
-                    source.readString(), source.readString(),
-                    (boolean)source.readValue(null)
+                    source.readString(), source.readString()
             );
         }
 

app/src/main/res/drawable/facebook.xml

@@ -0,0 +1 @@
+<?xml version="1.0" encoding="utf-8"?> <vector xmlns:android="http://schemas.android.com/apk/res/android" android:width="266.893dp" android:height="266.895dp" android:viewportWidth="266.893" android:viewportHeight="266.895"> <path android:fillColor="#3C5A99" android:pathData="M248.082,262.307c7.854,0,14.223-6.369,14.223-14.225V18.812 c0-7.857-6.368-14.224-14.223-14.224H18.812c-7.857,0-14.224,6.367-14.224,14.224v229.27c0,7.855,6.366,14.225,14.224,14.225 H248.082z" /> <path android:fillColor="#FFFFFF" android:pathData="M182.409,262.307v-99.803h33.499l5.016-38.895h-38.515V98.777c0-11.261,3.127-18.935,19.275-18.935 l20.596-0.009V45.045c-3.562-0.474-15.788-1.533-30.012-1.533c-29.695,0-50.025,18.126-50.025,51.413v28.684h-33.585v38.895h33.585 v99.803H182.409z" /> </vector>

app/src/main/res/drawable/ic_help_action.xml

@@ -12,6 +12,6 @@
         android:viewportWidth="24.0"
         android:viewportHeight="24.0">
     <path
-        android:fillColor="#FFFFFFFF"
-        android:pathData="M23,12l-2.44,-2.78 0.34,-3.68 -3.61,-0.82 -1.89,-3.18L12,3 8.6,1.54 6.71,4.72l-3.61,0.81 0.34,3.68L1,12l2.44,2.78 -0.34,3.69 3.61,0.82 1.89,3.18L12,21l3.4,1.46 1.89,-3.18 3.61,-0.82 -0.34,-3.68L23,12zm-10,5h-2v-2h2v2zm0,-4h-2V7h2v6z"/>
+        android:fillColor="@color/actionBarButton"
+        android:pathData="M12,2C6.48,2 2,6.48 2,12s4.48,10 10,10 10,-4.48 10,-10S17.52,2 12,2zm1,17h-2v-2h2v2zm2.07,-7.75l-0.9,0.92C13.45,12.9 13,13.5 13,15h-2v-0.5c0,-1.1 0.45,-2.1 1.17,-2.83l1.24,-1.26c0.37,-0.36 0.59,-0.86 0.59,-1.41 0,-1.1 -0.9,-2 -2,-2s-2,0.9 -2,2H8c0,-2.21 1.79,-4 4,-4s4,1.79 4,4c0,0.88 -0.36,1.68 -0.93,2.25z"/>
 </vector>

app/src/main/res/drawable/ic_help_dark.xml

@@ -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
@@ -11,8 +11,8 @@
         android:height="24dp"
         android:viewportWidth="24.0"
         android:viewportHeight="24.0"
-        android:alpha="0.54" >
+    android:alpha=".54">
     <path
-        android:fillColor="#FF000000"
+        android:fillColor="#000000"
         android:pathData="M12,2C6.48,2 2,6.48 2,12s4.48,10 10,10 10,-4.48 10,-10S17.52,2 12,2zm1,17h-2v-2h2v2zm2.07,-7.75l-0.9,0.92C13.45,12.9 13,13.5 13,15h-2v-0.5c0,-1.1 0.45,-2.1 1.17,-2.83l1.24,-1.26c0.37,-0.36 0.59,-0.86 0.59,-1.41 0,-1.1 -0.9,-2 -2,-2s-2,0.9 -2,2H8c0,-2.21 1.79,-4 4,-4s4,1.79 4,4c0,0.88 -0.36,1.68 -0.93,2.25z"/>
 </vector>

app/src/main/res/drawable/ic_settings_action.xml

@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+        android:width="24dp"
+        android:height="24dp"
+        android:viewportHeight="24.0"
+        android:viewportWidth="24.0">
+    <path
+        android:fillColor="@color/actionBarButton"
+        android:pathData="M19.43,12.98c0.04,-0.32 0.07,-0.64 0.07,-0.98s-0.03,-0.66 -0.07,-0.98l2.11,-1.65c0.19,-0.15 0.24,-0.42 0.12,-0.64l-2,-3.46c-0.12,-0.22 -0.39,-0.3 -0.61,-0.22l-2.49,1c-0.52,-0.4 -1.08,-0.73 -1.69,-0.98l-0.38,-2.65C14.46,2.18 14.25,2 14,2h-4c-0.25,0 -0.46,0.18 -0.49,0.42l-0.38,2.65c-0.61,0.25 -1.17,0.59 -1.69,0.98l-2.49,-1c-0.23,-0.09 -0.49,0 -0.61,0.22l-2,3.46c-0.13,0.22 -0.07,0.49 0.12,0.64l2.11,1.65c-0.04,0.32 -0.07,0.65 -0.07,0.98s0.03,0.66 0.07,0.98l-2.11,1.65c-0.19,0.15 -0.24,0.42 -0.12,0.64l2,3.46c0.12,0.22 0.39,0.3 0.61,0.22l2.49,-1c0.52,0.4 1.08,0.73 1.69,0.98l0.38,2.65c0.03,0.24 0.24,0.42 0.49,0.42h4c0.25,0 0.46,-0.18 0.49,-0.42l0.38,-2.65c0.61,-0.25 1.17,-0.59 1.69,-0.98l2.49,1c0.23,0.09 0.49,0 0.61,-0.22l2,-3.46c0.12,-0.22 0.07,-0.49 -0.12,-0.64l-2.11,-1.65zM12,15.5c-1.93,0 -3.5,-1.57 -3.5,-3.5s1.57,-3.5 3.5,-3.5 3.5,1.57 3.5,3.5 -1.57,3.5 -3.5,3.5z"/>
+</vector>

app/src/main/res/drawable/ic_settings_dark.xml

@@ -1,5 +1,18 @@
-<vector android:alpha="0.54" android:height="24dp"
-    android:viewportHeight="24.0" android:viewportWidth="24.0"
-    android:width="24dp" xmlns:android="http://schemas.android.com/apk/res/android">
-    <path android:fillColor="#FF000000" android:pathData="M19.43,12.98c0.04,-0.32 0.07,-0.64 0.07,-0.98s-0.03,-0.66 -0.07,-0.98l2.11,-1.65c0.19,-0.15 0.24,-0.42 0.12,-0.64l-2,-3.46c-0.12,-0.22 -0.39,-0.3 -0.61,-0.22l-2.49,1c-0.52,-0.4 -1.08,-0.73 -1.69,-0.98l-0.38,-2.65C14.46,2.18 14.25,2 14,2h-4c-0.25,0 -0.46,0.18 -0.49,0.42l-0.38,2.65c-0.61,0.25 -1.17,0.59 -1.69,0.98l-2.49,-1c-0.23,-0.09 -0.49,0 -0.61,0.22l-2,3.46c-0.13,0.22 -0.07,0.49 0.12,0.64l2.11,1.65c-0.04,0.32 -0.07,0.65 -0.07,0.98s0.03,0.66 0.07,0.98l-2.11,1.65c-0.19,0.15 -0.24,0.42 -0.12,0.64l2,3.46c0.12,0.22 0.39,0.3 0.61,0.22l2.49,-1c0.52,0.4 1.08,0.73 1.69,0.98l0.38,2.65c0.03,0.24 0.24,0.42 0.49,0.42h4c0.25,0 0.46,-0.18 0.49,-0.42l0.38,-2.65c0.61,-0.25 1.17,-0.59 1.69,-0.98l2.49,1c0.23,0.09 0.49,0 0.61,-0.22l2,-3.46c0.12,-0.22 0.07,-0.49 -0.12,-0.64l-2.11,-1.65zM12,15.5c-1.93,0 -3.5,-1.57 -3.5,-3.5s1.57,-3.5 3.5,-3.5 3.5,1.57 3.5,3.5 -1.57,3.5 -3.5,3.5z"/>
+<!--
+  ~ 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
+  -->
+
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+        android:width="24dp"
+        android:height="24dp"
+        android:viewportHeight="24.0"
+        android:viewportWidth="24.0"
+        android:alpha=".54">
+    <path
+        android:fillColor="#000000"
+        android:pathData="M19.43,12.98c0.04,-0.32 0.07,-0.64 0.07,-0.98s-0.03,-0.66 -0.07,-0.98l2.11,-1.65c0.19,-0.15 0.24,-0.42 0.12,-0.64l-2,-3.46c-0.12,-0.22 -0.39,-0.3 -0.61,-0.22l-2.49,1c-0.52,-0.4 -1.08,-0.73 -1.69,-0.98l-0.38,-2.65C14.46,2.18 14.25,2 14,2h-4c-0.25,0 -0.46,0.18 -0.49,0.42l-0.38,2.65c-0.61,0.25 -1.17,0.59 -1.69,0.98l-2.49,-1c-0.23,-0.09 -0.49,0 -0.61,0.22l-2,3.46c-0.13,0.22 -0.07,0.49 0.12,0.64l2.11,1.65c-0.04,0.32 -0.07,0.65 -0.07,0.98s0.03,0.66 0.07,0.98l-2.11,1.65c-0.19,0.15 -0.24,0.42 -0.12,0.64l2,3.46c0.12,0.22 0.39,0.3 0.61,0.22l2.49,-1c0.52,0.4 1.08,0.73 1.69,0.98l0.38,2.65c0.03,0.24 0.24,0.42 0.49,0.42h4c0.25,0 0.46,-0.18 0.49,-0.42l0.38,-2.65c0.61,-0.25 1.17,-0.59 1.69,-0.98l2.49,1c0.23,0.09 0.49,0 0.61,-0.22l2,-3.46c0.12,-0.22 0.07,-0.49 -0.12,-0.64l-2.11,-1.65zM12,15.5c-1.93,0 -3.5,-1.57 -3.5,-3.5s1.57,-3.5 3.5,-3.5 3.5,1.57 3.5,3.5 -1.57,3.5 -3.5,3.5z"/>
 </vector>

app/src/main/res/drawable/ic_share_action.xml

@@ -0,0 +1,17 @@
+<!--
+  ~ 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
+  -->
+
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+        android:width="24dp"
+        android:height="24dp"
+        android:viewportHeight="24.0"
+        android:viewportWidth="24.0">
+    <path
+        android:fillColor="@color/actionBarButton"
+        android:pathData="M18,16.08c-0.76,0 -1.44,0.3 -1.96,0.77L8.91,12.7c0.05,-0.23 0.09,-0.46 0.09,-0.7s-0.04,-0.47 -0.09,-0.7l7.05,-4.11c0.54,0.5 1.25,0.81 2.04,0.81 1.66,0 3,-1.34 3,-3s-1.34,-3 -3,-3 -3,1.34 -3,3c0,0.24 0.04,0.47 0.09,0.7L8.04,9.81C7.5,9.31 6.79,9 6,9c-1.66,0 -3,1.34 -3,3s1.34,3 3,3c0.79,0 1.5,-0.31 2.04,-0.81l7.12,4.16c-0.05,0.21 -0.08,0.43 -0.08,0.65 0,1.61 1.31,2.92 2.92,2.92 1.61,0 2.92,-1.31 2.92,-2.92s-1.31,-2.92 -2.92,-2.92z"/>
+</vector>