android process handling improvements

android/app/src/main/kotlin/im/cwtch/flwtch/FlwtchWorker.kt

@@ -55,8 +55,9 @@ class FlwtchWorker(context: Context, parameters: WorkerParameters) :
 
                 if (Cwtch.startCwtch(appDir, torPath) != 0.toLong()) return Result.failure()
 
-                // infinite coroutine :)
+                Log.i("FlwtchWorker.kt", "startCwtch success, starting coroutine AppbusEvent loop...")
                 while(true) {
+                    Log.i("FlwtchWorker.kt", "while(true)getAppbusEvent()")
                     val evt = MainActivity.AppbusEvent(Cwtch.getAppBusEvent())
                     if (evt.EventType == "NewMessageFromPeer" || evt.EventType == "NewMessageFromGroup") {
                         val data = JSONObject(evt.Data)
@@ -213,11 +214,20 @@ class FlwtchWorker(context: Context, parameters: WorkerParameters) :
         val id = "flwtch"
         val title = "Flwtch"
         val cancel = "Shut down"//todo: translate
+        val channelId =
+                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+                    createForegroundNotificationChannel(id, id)
+                } else {
+                    // If earlier version channel ID is not used
+                    // https://developer.android.com/reference/android/support/v4/app/NotificationCompat.Builder.html#NotificationCompat.Builder(android.content.Context)
+                    ""
+                }
+
         // This PendingIntent can be used to cancel the worker
         val intent = WorkManager.getInstance(applicationContext)
                 .createCancelPendingIntent(getId())
 
-        val notification = NotificationCompat.Builder(applicationContext, id)
+        val notification = NotificationCompat.Builder(applicationContext, channelId)
                 .setContentTitle(title)
                 .setTicker(title)
                 .setContentText(progress)
@@ -231,10 +241,18 @@ class FlwtchWorker(context: Context, parameters: WorkerParameters) :
         return ForegroundInfo(101, notification)
     }
 
+    @RequiresApi(Build.VERSION_CODES.O)
+    private fun createForegroundNotificationChannel(channelId: String, channelName: String): String{
+        val chan = NotificationChannel(channelId, channelName, NotificationManager.IMPORTANCE_NONE)
+        chan.lightColor = Color.MAGENTA
+        chan.lockscreenVisibility = Notification.VISIBILITY_PRIVATE
+        notificationManager.createNotificationChannel(chan)
+        return channelId
+    }
+
     @RequiresApi(Build.VERSION_CODES.O)
     private fun createMessageNotificationChannel(channelId: String, channelName: String): String{
-        val chan = NotificationChannel(channelId,
+        val chan = NotificationChannel(channelId, channelName, NotificationManager.IMPORTANCE_HIGH)
-                channelName, NotificationManager.IMPORTANCE_HIGH)
         chan.lightColor = Color.MAGENTA
         chan.lockscreenVisibility = Notification.VISIBILITY_PRIVATE
         notificationManager.createNotificationChannel(chan)

android/app/src/main/kotlin/im/cwtch/flwtch/MainActivity.kt

@@ -7,36 +7,20 @@ import android.content.Intent
 import android.content.IntentFilter
 import androidx.annotation.NonNull
 import android.content.pm.PackageManager
-import android.os.Build
-import android.os.Bundle
-import android.os.Looper
 import android.util.Log
 import android.view.Window
-import android.widget.Toast
-import androidx.annotation.RequiresApi
 import androidx.lifecycle.Observer
 import androidx.localbroadcastmanager.content.LocalBroadcastManager
 import androidx.work.*
 
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.GlobalScope
-import kotlinx.coroutines.launch
-
 import io.flutter.embedding.android.SplashScreen
 import io.flutter.embedding.android.FlutterActivity
 import io.flutter.embedding.engine.FlutterEngine
 import io.flutter.plugin.common.MethodChannel
 import io.flutter.plugin.common.MethodCall
-import io.flutter.plugin.common.MethodChannel.MethodCallHandler
 import io.flutter.plugin.common.MethodChannel.Result
 
-import cwtch.Cwtch
-import io.flutter.plugin.common.EventChannel
-import kotlin.concurrent.thread
-
 import org.json.JSONObject
-import java.io.File
-import java.time.Duration
 import java.util.concurrent.TimeUnit
 
 class MainActivity: FlutterActivity() {
@@ -55,6 +39,9 @@ class MainActivity: FlutterActivity() {
     // Channel to trigger contactview when an external notification is clicked
     private val CHANNEL_NOTIF_CLICK = "im.cwtch.flwtch/notificationClickHandler"
 
+    // WorkManager tag applied to all Start() infinite coroutines
+    val WORKER_TAG = "cwtchEventBusWorker"
+
     private var myReceiver: MyBroadcastReceiver? = null
     private var methodChan: MethodChannel? = null
 
@@ -106,24 +93,26 @@ class MainActivity: FlutterActivity() {
         // in case the ForegroundService is still running. in both cases, however, we *do* want to re-register
         // the eventbus listener.
         if (call.method == "Start") {
-            val workerTag = "cwtchEventBusWorker"
             val uniqueTag = argmap["torPath"] ?: "nullEventBus"
 
             // note: because the ForegroundService is specified as UniquePeriodicWork, it can't actually get
             // accidentally duplicated. however, we still need to manually check if it's running or not, so
             // that we can divert this method call to ReconnectCwtchForeground instead if so.
-            val works = WorkManager.getInstance(this).getWorkInfosByTag(workerTag).get()
+            val works = WorkManager.getInstance(this).getWorkInfosByTag(WORKER_TAG).get()
             for (workInfo in works) {
+                Log.i("handleCwtch:WorkManager", "$workInfo")
                 if (!workInfo.tags.contains(uniqueTag)) {
+                    Log.i("handleCwtch:WorkManager", "canceling ${workInfo.id} bc tags don't include $uniqueTag")
                     WorkManager.getInstance(this).cancelWorkById(workInfo.id)
                 }
             }
+            WorkManager.getInstance(this).pruneWork()
 
             Log.i("MainActivity.kt", "Start() launching foregroundservice")
             // this is where the eventbus ForegroundService gets launched. WorkManager should keep it alive after this
             val data: Data = Data.Builder().putString(FlwtchWorker.KEY_METHOD, call.method).putString(FlwtchWorker.KEY_ARGS, JSONObject(argmap).toString()).build()
             // 15 minutes is the shortest interval you can request
-            val workRequest = PeriodicWorkRequestBuilder<FlwtchWorker>(15, TimeUnit.MINUTES).setInputData(data).addTag(workerTag).addTag(uniqueTag).build()
+            val workRequest = PeriodicWorkRequestBuilder<FlwtchWorker>(15, TimeUnit.MINUTES).setInputData(data).addTag(WORKER_TAG).addTag(uniqueTag).build()
             WorkManager.getInstance(this).enqueueUniquePeriodicWork("req_$uniqueTag", ExistingPeriodicWorkPolicy.REPLACE, workRequest)
             return
         }
@@ -145,8 +134,9 @@ class MainActivity: FlutterActivity() {
     // using onresume/onstop for broadcastreceiver because of extended discussion on https://stackoverflow.com/questions/7439041/how-to-unregister-broadcastreceiver
     override fun onResume() {
         super.onResume()
-
+        Log.i("MainActivity.kt", "onResume")
         if (myReceiver == null) {
+            Log.i("MainActivity.kt", "onResume registering localbroadcastreceiver")
             val mc = MethodChannel(flutterEngine?.dartExecutor?.binaryMessenger, CWTCH_EVENTBUS)
             val filter = IntentFilter("im.cwtch.flwtch.broadcast.SERVICE_EVENT_BUS")
             myReceiver = MyBroadcastReceiver(mc)
@@ -156,12 +146,20 @@ class MainActivity: FlutterActivity() {
 
     override fun onStop() {
         super.onStop()
+        Log.i("MainActivity.kt", "onStop")
         if (myReceiver != null) {
             LocalBroadcastManager.getInstance(applicationContext).unregisterReceiver(myReceiver!!);
             myReceiver = null;
         }
     }
 
+    override fun onDestroy() {
+        super.onDestroy()
+        Log.i("MainActivity.kt", "onDestroy")
+        WorkManager.getInstance(this).cancelAllWorkByTag(WORKER_TAG)
+        WorkManager.getInstance(this).pruneWork()
+    }
+
 // source: https://web.archive.org/web/20210203022531/https://stackoverflow.com/questions/41928803/how-to-parse-json-in-kotlin/50468095
 // for reference:
 //

lib/main.dart

@@ -30,6 +30,7 @@ var globalAppState = AppState();
 void main() {
   print("main()");
   LicenseRegistry.addLicense(() => licenses());
+  WidgetsFlutterBinding.ensureInitialized();
   print("runApp()");
   runApp(Flwtch());
 }
@@ -55,11 +56,14 @@ class FlwtchState extends State<Flwtch> {
 
   @override
   initState() {
+    print("initState: running...");
     super.initState();
 
+    print("initState: registering notification, shutdown handlers...");
     profs = ProfileListState();
     notificationClickChannel.setMethodCallHandler(_externalNotificationClicked);
     shutdownMethodChannel.setMethodCallHandler(shutdown);
+    print("initState: creating cwtchnotifier, ffi");
     if (Platform.isAndroid) {
       var cwtchNotifier = new CwtchNotifier(profs, globalSettings, globalErrorHandler, globalTorStatus, NullNotificationsManager(), globalAppState);
       cwtch = CwtchGomobile(cwtchNotifier);
@@ -70,7 +74,9 @@ class FlwtchState extends State<Flwtch> {
       var cwtchNotifier = new CwtchNotifier(profs, globalSettings, globalErrorHandler, globalTorStatus, NullNotificationsManager(), globalAppState);
       cwtch = CwtchFfi(cwtchNotifier);
     }
+    print("initState: invoking cwtch.Start()");
     cwtch.Start();
+    print("initState: done!");
   }
 
   ChangeNotifierProvider<TorStatus> getTorStatusProvider() => ChangeNotifierProvider.value(value: globalTorStatus);