Allow multiple listeners for media state updates (#1693)

* Allow multiple listeners for media state updates

* Fix PR review issues

* Instance the correct class

Author: keianhzo

app/src/common/shared/org/mozilla/vrbrowser/browser/Media.java

@@ -1,9 +1,10 @@
 package org.mozilla.vrbrowser.browser;
 
+import androidx.annotation.NonNull;
+
 import org.mozilla.geckoview.MediaElement;
 
-import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
+import java.util.concurrent.CopyOnWriteArrayList;
 
 public class Media implements MediaElement.Delegate {
     private static final String LOGTAG = "VRB";
@@ -17,17 +18,22 @@ public class Media implements MediaElement.Delegate {
     private double mVolume = 1.0f;
     private boolean mIsMuted = false;
     private boolean mIsUnloaded = false;
-    private org.mozilla.geckoview.MediaElement mMedia;
-    private MediaElement.Delegate mDelegate;
+    private MediaElement mMedia;
+    private CopyOnWriteArrayList<MediaElement.Delegate> mMediaListeners;
     private ResizeDelegate mResizeDelegate;
 
     public Media(@NonNull MediaElement aMediaElement) {
         mMedia = aMediaElement;
+        mMediaListeners = new CopyOnWriteArrayList<>();
         aMediaElement.setDelegate(this);
     }
 
-    public void setDelegate(@Nullable MediaElement.Delegate aDelegate) {
-        mDelegate = aDelegate;
+    public void addMediaListener(MediaElement.Delegate aListener) {
+        mMediaListeners.add(aListener);
+    }
+
+    public void removeMediaListener(MediaElement.Delegate aListener) {
+        mMediaListeners.remove(aListener);
     }
 
     public double getDuration() {
@@ -103,7 +109,7 @@ public void setMuted(boolean aIsMuted) {
 
     public void unload() {
         mIsUnloaded = true;
-        mDelegate = null;
+        mMediaListeners.clear();
     }
 
     public int getWidth() {
@@ -132,27 +138,21 @@ public void onPlaybackStateChange(MediaElement mediaElement, int playbackState)
         } else if (playbackState == MediaElement.MEDIA_STATE_ENDED) {
             mEnded = true;
         }
-        if (mDelegate != null) {
-            mDelegate.onPlaybackStateChange(mediaElement, playbackState);
-        }
+        mMediaListeners.forEach(listener -> listener.onPlaybackStateChange(mediaElement, playbackState));
     }
 
     @Override
     public void onReadyStateChange(MediaElement mediaElement, int readyState) {
         mReadyState = readyState;
-        if (mDelegate != null) {
-            mDelegate.onReadyStateChange(mediaElement, readyState);
-        }
+        mMediaListeners.forEach(listener -> listener.onReadyStateChange(mediaElement, readyState));
     }
 
     @Override
     public void onMetadataChange(MediaElement mediaElement, MediaElement.Metadata metaData) {
         final int oldWidth = getWidth();
         final int oldHeight = getHeight();
         mMetaData = metaData;
-        if (mDelegate != null) {
-            mDelegate.onMetadataChange(mediaElement, metaData);
-        }
+        mMediaListeners.forEach(listener -> listener.onMetadataChange(mediaElement, metaData));
 
         if (mResizeDelegate!= null && metaData != null) {
             final int w = getWidth();
@@ -165,18 +165,14 @@ public void onMetadataChange(MediaElement mediaElement, MediaElement.Metadata me
 
     @Override
     public void onLoadProgress(MediaElement mediaElement, MediaElement.LoadProgressInfo progressInfo) {
-        if (mDelegate != null) {
-            mDelegate.onLoadProgress(mediaElement, progressInfo);
-        }
+        mMediaListeners.forEach(listener -> listener.onLoadProgress(mediaElement, progressInfo));
     }
 
     @Override
     public void onVolumeChange(MediaElement mediaElement, double volume, boolean muted) {
         mVolume = volume;
         mIsMuted = muted;
-        if (mDelegate != null) {
-            mDelegate.onVolumeChange(mediaElement, volume, muted);
-        }
+        mMediaListeners.forEach(listener -> listener.onVolumeChange(mediaElement, volume, muted));
     }
 
     @Override
@@ -186,31 +182,23 @@ public void onTimeChange(MediaElement mediaElement, double time) {
         if (duration <= 0 || mCurrentTime < getDuration()) {
             mEnded = false;
         }
-        if (mDelegate != null) {
-            mDelegate.onTimeChange(mediaElement, time);
-        }
+        mMediaListeners.forEach(listener -> listener.onTimeChange(mediaElement, time));
     }
 
     @Override
     public void onPlaybackRateChange(MediaElement mediaElement, double rate) {
         mPlaybackRate = rate;
-        if (mDelegate != null) {
-            mDelegate.onPlaybackRateChange(mediaElement, rate);
-        }
+        mMediaListeners.forEach(listener -> listener.onPlaybackRateChange(mediaElement, rate));
     }
 
     @Override
     public void onFullscreenChange(MediaElement mediaElement, boolean fullscreen) {
         mIsFullscreen = fullscreen;
-        if (mDelegate != null) {
-            mDelegate.onFullscreenChange(mediaElement, fullscreen);
-        }
+        mMediaListeners.forEach(listener -> listener.onFullscreenChange(mediaElement, fullscreen));
     }
 
     @Override
     public void onError(MediaElement mediaElement, int code) {
-        if (mDelegate != null) {
-            mDelegate.onError(mediaElement, code);
-        }
+        mMediaListeners.forEach(listener -> listener.onError(mediaElement, code));
     }
 }

app/src/common/shared/org/mozilla/vrbrowser/ui/widgets/MediaControlsWidget.java

@@ -244,7 +244,7 @@ public void setMedia(Media aMedia) {
             return;
         }
         if (mMedia != null) {
-            mMedia.setDelegate(null);
+            mMedia.removeMediaListener(this);
         }
         mMedia = aMedia;
         boolean enabled = mMedia != null;
@@ -266,7 +266,7 @@ public void setMedia(Media aMedia) {
             onPlaybackStateChange(mMedia.getMediaElement(), MediaElement.MEDIA_STATE_PLAY);
         }
 
-        mMedia.setDelegate(this);
+        mMedia.addMediaListener(this);
     }
 
     public void setProjectionSelectorEnabled(boolean aEnabled) {

app/src/common/shared/org/mozilla/vrbrowser/ui/widgets/TitleBarWidget.java

@@ -181,7 +181,8 @@ public void mediaAvailabilityChanged(boolean available) {
             mMedia = mAttachedWindow.getSessionStack().getFullScreenVideo();
             if (mMedia != null) {
                 mBinding.setIsMediaPlaying(mMedia.isPlaying());
-                mMedia.setDelegate(mMediaDelegate);
+                mMedia.removeMediaListener(mMediaDelegate);
+                mMedia.addMediaListener(mMediaDelegate);
             }
         }
     }