Update notification when play queue is edited

app/src/main/java/org/schabi/newpipe/player/VideoPlayerImpl.java

@@ -642,6 +642,12 @@ public class VideoPlayerImpl extends VideoPlayer
                 duration);
     }
 
+    @Override
+    public void onPlayQueueEdited() {
+        updatePlayback();
+        NotificationUtil.getInstance().createNotificationIfNeededAndUpdate(this, false);
+    }
+
     @Override
     @Nullable
     public MediaSource sourceOf(final PlayQueueItem item, final StreamInfo info) {

app/src/main/java/org/schabi/newpipe/player/playback/MediaSourceManager.java

@@ -255,21 +255,21 @@ public class MediaSourceManager {
 
         // Loading and Syncing
         switch (event.type()) {
-            case INIT:
+            case INIT: case REORDER: case ERROR: case SELECT:
-            case REORDER:
-            case ERROR:
-            case SELECT:
                 loadImmediate(); // low frequency, critical events
                 break;
-            case APPEND:
+            case APPEND: case REMOVE: case MOVE: case RECOVERY:
-            case REMOVE:
-            case MOVE:
-            case RECOVERY:
             default:
                 loadDebounced(); // high frequency or noncritical events
                 break;
         }
 
+        // update ui and notification
+        switch (event.type()) {
+            case APPEND: case REMOVE: case MOVE: case REORDER:
+                playbackListener.onPlayQueueEdited();
+        }
+
         if (!isPlayQueueReady()) {
             maybeBlock();
             playQueue.fetch();

app/src/main/java/org/schabi/newpipe/player/playback/PlaybackListener.java

@@ -69,7 +69,7 @@ public interface PlaybackListener {
     MediaSource sourceOf(PlayQueueItem item, StreamInfo info);
 
     /**
-     * Called when the play queue can no longer to played or used.
+     * Called when the play queue can no longer be played or used.
      * Currently, this means the play queue is empty and complete.
      * Signals to the listener that it should shutdown.
      * <p>
@@ -77,4 +77,13 @@ public interface PlaybackListener {
      * </p>
      */
     void onPlaybackShutdown();
+
+    /**
+     * Called whenever the play queue was edited (items were added, deleted or moved),
+     * use this to e.g. update notification buttons or fragment ui.
+     * <p>
+     * May be called at any time.
+     * </p>
+     */
+    void onPlayQueueEdited();
 }