Update app background state when starting/ending bg tasks

All tasks starting and ending should check the current background state
to make sure we are always in the correct state when deciding what to do
next.
We want to update the state on bg task expiry, too, to make sure the
expiry wasn't caused by a wrong state.

Author: tmolitor-stud-tu

Monal/Classes/MonalAppDelegate.m

@@ -1334,6 +1334,8 @@ -(void) checkIfBackgroundTaskIsStillNeeded
 -(void) addBackgroundTask
 {
     [HelperTools dispatchAsync:NO reentrantOnQueue:dispatch_get_main_queue() withBlock:^{
+        [self updateBackgroundState];       //make sure we are in the correct state
+        
         //don't start uikit bg task if it's already running
         if(self->_bgTask != UIBackgroundTaskInvalid)
             DDLogVerbose(@"Not starting UIKit background task, already running: %d", (int)self->_bgTask);
@@ -1344,6 +1346,7 @@ -(void) addBackgroundTask
             self->_bgTask = [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:^(void) {
                 DDLogWarn(@"BG WAKE EXPIRING");
                 [DDLog flushLog];
+                [self updateBackgroundState];       //make sure we are in the correct state
 
                 @synchronized(self) {
                     //ui background tasks expire at the same time as background processing/refreshing tasks
@@ -1398,6 +1401,7 @@ -(void) handleBackgroundProcessingTask:(BGTask*) task
         strongify(task);
         DDLogWarn(@"*** BGPROCESSING EXPIRED ***");
         [DDLog flushLog];
+        [self updateBackgroundState];       //make sure we are in the correct state
 
         DDLogVerbose(@"Dispatching to main queue...");
         [HelperTools dispatchAsync:NO reentrantOnQueue:dispatch_get_main_queue() withBlock:^{
@@ -1502,6 +1506,7 @@ -(void) handleBackgroundRefreshingTask:(BGTask*) task
         strongify(task);
         DDLogWarn(@"*** BGREFRESHING EXPIRED ***");
         [DDLog flushLog];
+        [self updateBackgroundState];       //make sure we are in the correct state
 
         DDLogVerbose(@"Dispatching to main queue...");
         [HelperTools dispatchAsync:NO reentrantOnQueue:dispatch_get_main_queue() withBlock:^{
@@ -1594,6 +1599,7 @@ -(void) configureBackgroundTasks
     [[BGTaskScheduler sharedScheduler] registerForTaskWithIdentifier:kBackgroundProcessingTask usingQueue:dispatch_get_main_queue() launchHandler:^(BGTask *task) {
         //resume logging and other core tasks
         [HelperTools signalResumption];
+        [self updateBackgroundState];       //make sure we are in the correct state
 
         DDLogDebug(@"RUNNING BGPROCESSING LAUNCH HANDLER");
         DDLogInfo(@"BG time available: %f", [UIApplication sharedApplication].backgroundTimeRemaining);
@@ -1617,6 +1623,7 @@ -(void) configureBackgroundTasks
     [[BGTaskScheduler sharedScheduler] registerForTaskWithIdentifier:kBackgroundRefreshingTask usingQueue:dispatch_get_main_queue() launchHandler:^(BGTask *task) {
         //resume logging and other core tasks
         [HelperTools signalResumption];
+        [self updateBackgroundState];       //make sure we are in the correct state
 
         DDLogDebug(@"RUNNING BGREFRESHING LAUNCH HANDLER");
         DDLogInfo(@"BG time available: %f", [UIApplication sharedApplication].backgroundTimeRemaining);
@@ -1697,6 +1704,7 @@ -(void) incomingWakeupWithCompletionHandler:(void (^)(UIBackgroundFetchResult re
 {
     //resume logging and other core tasks
     [HelperTools signalResumption];
+    [self updateBackgroundState];       //make sure we are in the correct state
 
     if(![HelperTools isInBackground])
     {
@@ -1732,6 +1740,7 @@ -(void) incomingWakeupWithCompletionHandler:(void (^)(UIBackgroundFetchResult re
             @"timer": createTimer(GRACEFUL_TIMEOUT, (^{
                 DDLogWarn(@"### Wakeup timer triggered for ID %@ ###", completionId);
                 dispatch_async(dispatch_get_main_queue(), ^{
+                    [self updateBackgroundState];       //make sure we are in the correct state
                     @synchronized(self) {
                         DDLogInfo(@"Handling wakeup completion %@", completionId);
                         BOOL background = [HelperTools isInBackground];
@@ -1786,6 +1795,16 @@ -(void) incomingWakeupWithCompletionHandler:(void (^)(UIBackgroundFetchResult re
     }
 }
 
+-(void) updateBackgroundState
+{
+    [HelperTools dispatchAsync:NO reentrantOnQueue:dispatch_get_main_queue() withBlock:^{
+        if([UIApplication sharedApplication].applicationState==UIApplicationStateBackground)
+            [[MLXMPPManager sharedInstance] nowBackgrounded];
+        else
+            [[MLXMPPManager sharedInstance] nowForegrounded];
+    }];
+}
+
 
 #pragma mark - share sheet added