Request the user to ignore the battery optimizations which avoid running Delta Chat properly.

MessengerProj/src/main/java/com/b44t/messenger/ApplicationLoader.java

@@ -203,20 +203,7 @@ public class ApplicationLoader extends Application {
         UserConfig.loadConfig();
 
         // create a timer that wakes up the CPU from time to time
-        try
-        {
-            Intent intent = new Intent(applicationContext, TimerReceiver.class);
-            PendingIntent alarmIntent = PendingIntent.getBroadcast(applicationContext, 0, intent, 0);
-
-            AlarmManager alarmManager = (AlarmManager)applicationContext.getSystemService(Activity.ALARM_SERVICE);
-            alarmManager.setInexactRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP,
-                    SystemClock.elapsedRealtime()+60*1000,
-                    60*1000,
-                    alarmIntent);
-        }
-        catch( Exception e) {
-            Log.e("DeltaChat", "Cannot create alarm.");
-        }
+        TimerReceiver.scheduleNextAlarm();
 
         // make sure, the notifications for the "deaddrop" dialog are muted by default
         SharedPreferences notificationPreferences = ApplicationLoader.applicationContext.getSharedPreferences("Notifications", Activity.MODE_PRIVATE);
@@ -273,6 +260,6 @@ public class ApplicationLoader extends Application {
 
     public static void stayAwakeForAMoment()
     {
-        stayAwakeWakeLock.acquire(10*60*1000); // 10 Minutes to wait for "after chat" messages, after that, we sleep most time, see wakeupWakeLock
+        stayAwakeWakeLock.acquire(1*60*1000); // 1 Minute to wait for "after chat" messages, after that, we sleep most time, see wakeupWakeLock
     }
 }

MessengerProj/src/main/java/com/b44t/messenger/TimerReceiver.java

@@ -22,18 +22,49 @@
 
 package com.b44t.messenger;
 
+import android.app.Activity;
+import android.app.AlarmManager;
+import android.app.PendingIntent;
 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
+import android.os.Build;
 import android.util.Log;
 
 
 public class TimerReceiver extends BroadcastReceiver {
     public void onReceive(Context context, Intent intent) {
+
+        // acquire for 3 seconds, this should wake up the threads,
+        // _if_ there is more to do, the backend acquires an additional wakelock using MR_EVENT_WAKE_LOCK
+        ApplicationLoader.wakeupWakeLock.acquire(3*1000); // do this first!
         Log.i("DeltaChat", "*** TimerReceiver.onReceive()");
 
-        // acquire for 5 seconds, this should wake un the threads,
-        // _if_ there is more to do, the backend acquires an additional wakelock using MR_EVENT_WAKE_LOCK
-        ApplicationLoader.wakeupWakeLock.acquire(5*1000);
+        // we assume, the IMAP thread is alive. I cannot imagine, the thread was killed with the App being running.
+        // (if the whole App was killed, the IMAP thread is already started by MrMailbox.connect() if we're here)
+        // (the thread itself will reconnect to the IMAP server as needed)
+
+        // create the next alarm in about a minute
+        scheduleNextAlarm();
+    }
+
+    public static void scheduleNextAlarm()
+    {
+        try {
+            Intent intent = new Intent(ApplicationLoader.applicationContext, TimerReceiver.class);
+            PendingIntent alarmIntent = PendingIntent.getBroadcast(ApplicationLoader.applicationContext, 0, intent, 0);
+
+            long triggerAtMillis = System.currentTimeMillis() + 60 * 1000;
+
+            AlarmManager alarmManager = (AlarmManager) ApplicationLoader.applicationContext.getSystemService(Activity.ALARM_SERVICE);
+            if( Build.VERSION.SDK_INT >= 23 ) {
+                // a simple AlarmManager.set() is no longer send in the new DOZE mode
+                alarmManager.setAndAllowWhileIdle(AlarmManager.RTC_WAKEUP, triggerAtMillis, alarmIntent);
+            }
+            else {
+                alarmManager.set(AlarmManager.RTC_WAKEUP, triggerAtMillis, alarmIntent);
+            }
+        }
+        catch(Exception e) { Log.e("DeltaChat", "Cannot create alarm.", e); }
     }
 }

MessengerProj/src/main/java/com/b44t/ui/ActionBar/BaseFragment.java

@@ -60,7 +60,8 @@ public class BaseFragment {
             RC13_AVATAR_IMAGE_CAPTURE          = 13,
             RC14_AVATAR_GET_CONTENT            = 14,
             RC21_CHAT_PICK_WO_COMPR            = 21,
-            RC500_PHOTO_VIEW                   = 500;
+            RC500_PHOTO_VIEW                   = 500,
+            RC600_BATTERY_REQUEST_DONE         = 600;
 
     public BaseFragment() {
         classGuid = ApplicationLoader.generateClassGuid();

MessengerProj/src/main/java/com/b44t/ui/DialogsActivity.java

@@ -32,11 +32,16 @@ import android.app.Activity;
 import android.app.AlertDialog;
 import android.content.Context;
 import android.content.DialogInterface;
+import android.content.Intent;
 import android.content.pm.PackageManager;
 import android.content.res.Configuration;
 import android.graphics.Outline;
+import android.net.Uri;
 import android.os.Build;
 import android.os.Bundle;
+import android.os.PowerManager;
+import android.provider.Settings;
+import android.util.Log;
 import android.util.TypedValue;
 import android.view.Gravity;
 import android.view.MotionEvent;
@@ -53,6 +58,7 @@ import android.widget.TextView;
 
 import com.b44t.messenger.AndroidUtilities;
 import com.b44t.messenger.ApplicationLoader;
+import com.b44t.messenger.FileLog;
 import com.b44t.messenger.ImageLoader;
 import com.b44t.messenger.LocaleController;
 import com.b44t.messenger.MrChat;
@@ -516,30 +522,107 @@ public class DialogsActivity extends BaseFragment implements NotificationCenter.
             dialogsSearchAdapter.notifyDataSetChanged();
         }
         if (checkPermission && !onlySelect && Build.VERSION.SDK_INT >= 23) {
-            Activity activity = getParentActivity();
-            if (activity != null) {
-                checkPermission = false;
-                if (activity.checkSelfPermission(Manifest.permission.READ_CONTACTS) != PackageManager.PERMISSION_GRANTED || activity.checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
-                    askForPermissons();
+            checkPermission = false;
+            askForIgnoreBatteryOptimization(); // after that, requestForOtherPermissions() is called
+        }
+    }
+
+    @TargetApi(Build.VERSION_CODES.M)
+    private void askForIgnoreBatteryOptimization() {
+        boolean requestIgnoreActivityStarted = false;
+
+        try {
+            String packageName = ApplicationLoader.applicationContext.getPackageName();
+            PowerManager pm = (PowerManager) ApplicationLoader.applicationContext.getSystemService(Context.POWER_SERVICE);
+            if (!pm.isIgnoringBatteryOptimizations(packageName)) {
+
+                // As FCM (was: GCM) does not support IMAP servers and there are other server involved,
+                // the only possibility for us to get notified about new messages, is to keep the connection to the server alive.
+                // This is done by ACTION_REQUEST_IGNORE_BATTERY_OPTIMIZATIONS.
+                //
+                // This is an "Acceptable Use Cases for Whitelisting", see
+                // https://developer.android.com/training/monitoring-device-state/doze-standby.html#whitelisting-cases
+                // "Instant messaging, chat, or calling app; enterprise VOIP apps |
+                //  No, can't use FCM because of technical dependency on another messaging service or Doze and App Standby break the core function of the app |
+                //  Acceptable"
+                Intent intent = new Intent();
+                intent.setAction(Settings.ACTION_REQUEST_IGNORE_BATTERY_OPTIMIZATIONS);
+                intent.setData(Uri.parse("package:" + packageName));
+                getParentActivity().startActivityForResult(intent, BaseFragment.RC600_BATTERY_REQUEST_DONE);
+                requestIgnoreActivityStarted = true;
+            }
+        } catch (Exception e) {
+            Log.e("DeltaChat", "cannot ignore battery optimizations.", e);
+        }
+
+        if( !requestIgnoreActivityStarted ) {
+            askForOtherPermissons(); // otherwise, it gets started on RC600_BATTERY_REQUEST_DONE
+        }
+    }
+
+    @Override
+    public void onActivityResultFragment(int requestCode, int resultCode, Intent data) {
+        if (requestCode == BaseFragment.RC600_BATTERY_REQUEST_DONE) {
+            boolean requestIgnoreActivityMaybeRestarted = false;
+
+            if( Build.VERSION.SDK_INT >= 23 ) {
+                PowerManager pm = (PowerManager) ApplicationLoader.applicationContext.getSystemService(Context.POWER_SERVICE);
+                if (!pm.isIgnoringBatteryOptimizations(ApplicationLoader.applicationContext.getPackageName())) {
+                    AlertDialog.Builder builder = new AlertDialog.Builder(getParentActivity());
+                    builder.setMessage(AndroidUtilities.replaceTags(ApplicationLoader.applicationContext.getString(R.string.PermissionBattery)));
+                    builder.setPositiveButton(ApplicationLoader.applicationContext.getString(R.string.OK), new DialogInterface.OnClickListener() {
+                        @Override
+                        public void onClick(DialogInterface dialog, int which) {
+                            askForIgnoreBatteryOptimization();
+                        }
+                    });
+                    builder.setCancelable(false);
+                    builder.setNegativeButton(ApplicationLoader.applicationContext.getString(R.string.Cancel), new DialogInterface.OnClickListener() {
+                        @Override
+                        public void onClick(DialogInterface dialog, int which) {
+                            askForOtherPermissons();
+                        }
+                    });
+                    builder.show();
+                    requestIgnoreActivityMaybeRestarted  = true;
+
+                    /*-- this is an alternative implementation to the alert above
+                    IF we use this, we should handle the situation, ACTION_REQUEST_IGNORE_BATTERY_OPTIMIZATIONS cannot be started due to a missing REQUEST_IGNORE_BATTERY_OPTIMIZATIONS permission
+                    checkPermission = true;
+                    getParentActivity().finish();
+                    return;
+                    */
                 }
             }
+
+            if( !requestIgnoreActivityMaybeRestarted ) {
+                askForOtherPermissons();
+            }
         }
     }
 
     @TargetApi(Build.VERSION_CODES.M)
-    private void askForPermissons() {
+    private void askForOtherPermissons() {
         Activity activity = getParentActivity();
         if (activity == null) {
             return;
         }
+
+        if (activity.checkSelfPermission(Manifest.permission.READ_CONTACTS) == PackageManager.PERMISSION_GRANTED
+         && activity.checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
+            return; // everything is fine
+        }
+
         ArrayList<String> permissons = new ArrayList<>();
         if (activity.checkSelfPermission(Manifest.permission.READ_CONTACTS) != PackageManager.PERMISSION_GRANTED) {
             permissons.add(Manifest.permission.READ_CONTACTS);
         }
+
         if (activity.checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
             permissons.add(Manifest.permission.READ_EXTERNAL_STORAGE);
             permissons.add(Manifest.permission.WRITE_EXTERNAL_STORAGE);
         }
+
         String[] items = permissons.toArray(new String[permissons.size()]);
         activity.requestPermissions(items, LaunchActivity.REQ_CONTACT_N_STORAGE_PERMISON_ID);
     }

MessengerProj/src/main/java/com/b44t/ui/SettingsActivity.java

@@ -31,6 +31,7 @@ import android.content.Context;
 import android.content.DialogInterface;
 import android.content.pm.PackageInfo;
 import android.os.Build;
+import android.os.PowerManager;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.AdapterView;
@@ -177,7 +178,7 @@ public class SettingsActivity extends BaseFragment {
     private String getAndroidInfo()
     {
         String abi = "ErrAbi";
-        int versionCode = 0;
+        int versionCode = 0, ignoreBatteryOptimizations = -1;
         try {
             PackageInfo pInfo = ApplicationLoader.applicationContext.getPackageManager().getPackageInfo(ApplicationLoader.applicationContext.getPackageName(), 0);
             versionCode = pInfo.versionCode;
@@ -195,6 +196,10 @@ public class SettingsActivity extends BaseFragment {
                     abi = "universal";
                     break;
             }
+            if( Build.VERSION.SDK_INT >= 23 ) {
+                PowerManager pm = (PowerManager) ApplicationLoader.applicationContext.getSystemService(Context.POWER_SERVICE);
+                ignoreBatteryOptimizations = pm.isIgnoringBatteryOptimizations(ApplicationLoader.applicationContext.getPackageName())? 1 : 0;
+            }
         } catch (Exception e) {}
 
         return      "SDK_INT="       + Build.VERSION.SDK_INT
@@ -202,6 +207,7 @@ public class SettingsActivity extends BaseFragment {
                 + "\nMODEL="         + Build.MODEL
                 + "\nDEBUG_VERSION=" + BuildVars.DEBUG_VERSION
                 + "\nABI="           + abi // ABI = Application Binary Interface
+                + "\nignoreBatteryOptimizations=" + ignoreBatteryOptimizations
                 + "\nversionCode="   + versionCode;
     }