fix autobug crash when primary channel is null

README.md

@@ -24,7 +24,7 @@ The app is also distributed for Amazon Fire devices via the Amazon appstore: [![
 If you would like to develop this application we'd love your help!  These build instructions are brief 
 and should be improved, please send a PR if you can.
 
-* Use Android Studio 4.0 RC 1 to build/debug (other versions might work but no promises)
+* Use Android Studio 4.1.2 to build/debug (other versions might work but no promises)
 * Use "git submodule update --init --recursive" to pull in the various submodules we depend on
 * There are a few config files which you'll need to copy from templates included in the project.
 Run the following commands to do so:

app/src/main/java/com/geeksville/mesh/MainActivity.kt

@@ -20,9 +20,7 @@ import android.os.Build
 import android.os.Bundle
 import android.os.Handler
 import android.os.RemoteException
-import android.text.SpannableString
 import android.text.method.LinkMovementMethod
-import android.text.util.Linkify
 import android.view.Menu
 import android.view.MenuItem
 import android.view.MotionEvent
@@ -44,7 +42,6 @@ import com.geeksville.android.Logging
 import com.geeksville.android.ServiceClient
 import com.geeksville.concurrent.handledLaunch
 import com.geeksville.mesh.databinding.ActivityMainBinding
-import com.geeksville.mesh.model.Channel
 import com.geeksville.mesh.model.ChannelSet
 import com.geeksville.mesh.model.DeviceVersion
 import com.geeksville.mesh.model.UIViewModel
@@ -307,11 +304,7 @@ class MainActivity : AppCompatActivity(), Logging,
 
         if (deniedPermissions.isNotEmpty()) {
             errormsg("Denied permissions: ${deniedPermissions.joinToString(",")}")
-            Toast.makeText(
-                this,
-                getString(R.string.permission_missing),
-                Toast.LENGTH_LONG
-            ).show()
+            showToast(R.string.permission_missing)
         }
     }
 
@@ -659,7 +652,7 @@ class MainActivity : AppCompatActivity(), Logging,
 
                         val curVer = DeviceVersion(info.firmwareVersion ?: "0.0.0")
                         val minVer = DeviceVersion("1.2.0")
-                        if(curVer < minVer)
+                        if (curVer < minVer)
                             showAlert(R.string.firmware_too_old, R.string.firmware_old)
                         else {
                             // If our app is too old/new, we probably don't understand the new radioconfig messages, so we don't read them until here
@@ -687,40 +680,52 @@ class MainActivity : AppCompatActivity(), Logging,
         }
     }
 
+    private fun showToast(msgId: Int) {
+        Toast.makeText(
+            this,
+            msgId,
+            Toast.LENGTH_LONG
+        ).show()
+    }
+
+    private fun showToast(msg: String) {
+        Toast.makeText(
+            this,
+            msg,
+            Toast.LENGTH_LONG
+        ).show()
+    }
+
     private fun perhapsChangeChannel() {
         // If the is opening a channel URL, handle it now
         requestedChannelUrl?.let { url ->
             try {
                 val channels = ChannelSet(url)
                 val primary = channels.primaryChannel
-                requestedChannelUrl = null
+                if (primary == null)
+                    showToast(R.string.channel_invalid)
+                else {
+                    requestedChannelUrl = null
 
-                MaterialAlertDialogBuilder(this)
-                    .setTitle(R.string.new_channel_rcvd)
-                    .setMessage(getString(R.string.do_you_want_switch).format(primary.name))
-                    .setNeutralButton(R.string.cancel) { _, _ ->
-                        // Do nothing
-                    }
-                    .setPositiveButton(R.string.accept) { _, _ ->
-                        debug("Setting channel from URL")
-                        try {
-                            model.setChannels(channels)
-                        } catch (ex: RemoteException) {
-                            errormsg("Couldn't change channel ${ex.message}")
-                            Toast.makeText(
-                                this,
-                                "Couldn't change channel, because radio is not yet connected. Please try again.",
-                                Toast.LENGTH_SHORT
-                            ).show()
+                    MaterialAlertDialogBuilder(this)
+                        .setTitle(R.string.new_channel_rcvd)
+                        .setMessage(getString(R.string.do_you_want_switch).format(primary.name))
+                        .setNeutralButton(R.string.cancel) { _, _ ->
+                            // Do nothing
                         }
-                    }
-                    .show()
+                        .setPositiveButton(R.string.accept) { _, _ ->
+                            debug("Setting channel from URL")
+                            try {
+                                model.setChannels(channels)
+                            } catch (ex: RemoteException) {
+                                errormsg("Couldn't change channel ${ex.message}")
+                                showToast(R.string.cant_change_no_radio)
+                            }
+                        }
+                        .show()
+                }
             } catch (ex: InvalidProtocolBufferException) {
-                Toast.makeText(
-                    this,
-                    R.string.channel_invalid,
-                    Toast.LENGTH_LONG
-                ).show()
+                showToast(R.string.channel_invalid)
             }
         }
     }
@@ -869,8 +874,7 @@ class MainActivity : AppCompatActivity(), Logging,
                     errormsg("Device error during init ${ex.message}")
                     model.isConnected.value =
                         MeshService.ConnectionState.valueOf(service.connectionState())
-                }
-                finally {
+                } finally {
                     connectionJob = null
                 }
 
@@ -1037,7 +1041,7 @@ class MainActivity : AppCompatActivity(), Logging,
         try {
             val packageInfo: PackageInfo = packageManager.getPackageInfo(packageName, 0)
             val versionName = packageInfo.versionName
-            Toast.makeText(applicationContext, versionName, Toast.LENGTH_LONG).show()
+            showToast(versionName)
         } catch (e: PackageManager.NameNotFoundException) {
             errormsg("Can not find the version: ${e.message}")
         }

app/src/main/java/com/geeksville/mesh/model/ChannelSet.kt

@@ -47,9 +47,11 @@ data class ChannelSet(
     /**
      * Return the primary channel info
      */
-    val primaryChannel: Channel get() {
-        return Channel(protobuf.getSettings(0))
-    }
+    val primaryChannel: Channel? get() =
+        if(protobuf.settingsCount > 0)
+            Channel(protobuf.getSettings(0))
+        else
+            null
 
     /// Return an URL that represents the current channel values
     /// @param upperCasePrefix - portions of the URL can be upper case to make for more efficient QR codes

app/src/main/java/com/geeksville/mesh/ui/ChannelFragment.kt

@@ -79,11 +79,10 @@ class ChannelFragment : ScreenFragment("Channel"), Logging {
     /// Pull the latest data from the model (discarding any user edits)
     private fun setGUIfromModel() {
         val channels = model.channels.value
+        val channel = channels?.primaryChannel
 
         binding.editableCheckbox.isChecked = false // start locked
-        if (channels != null) {
-            val channel = channels.primaryChannel
-
+        if (channel != null) {
             binding.qrView.visibility = View.VISIBLE
             binding.channelNameEdit.visibility = View.VISIBLE
             binding.channelNameEdit.setText(channel.humanName)
@@ -156,8 +155,8 @@ class ChannelFragment : ScreenFragment("Channel"), Logging {
             val checked = binding.editableCheckbox.isChecked
             if (checked) {
                 // User just unlocked for editing - remove the # goo around the channel name
-                model.channels.value?.let { channels ->
-                    binding.channelNameEdit.setText(channels.primaryChannel.name)
+                model.channels.value?.primaryChannel?.let { ch ->
+                    binding.channelNameEdit.setText(ch.name)
                 }
             } else {
                 // User just locked it, we should warn and then apply changes to radio
@@ -169,8 +168,7 @@ class ChannelFragment : ScreenFragment("Channel"), Logging {
                     }
                     .setPositiveButton(getString(R.string.accept)) { _, _ ->
                         // Generate a new channel with only the changes the user can change in the GUI
-                        model.channels.value?.let { old ->
-                            val oldPrimary = old.primaryChannel
+                        model.channels.value?.primaryChannel?.let { oldPrimary ->
                             val newSettings = oldPrimary.settings.toBuilder()
                             newSettings.name = binding.channelNameEdit.text.toString().trim()
 

app/src/main/res/values/strings.xml

@@ -94,4 +94,5 @@
     <string name="okay">Okay</string>
     <string name="must_set_region">You must set a region!</string>
     <string name="region">Region</string>
+    <string name="cant_change_no_radio">Couldn\'t change channel, because radio is not yet connected. Please try again.</string>
 </resources>