Add media controls in media notification

chrome/android/java/src/org/chromium/chrome/browser/media/ui/MediaNotificationManager.java

Index: chrome/android/java/src/org/chromium/chrome/browser/media/ui/MediaNotificationManager.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/media/ui/MediaNotificationManager.java b/chrome/android/java/src/org/chromium/chrome/browser/media/ui/MediaNotificationManager.java
index 2333b372437919ea28a81ec40974ce068fdd0fe0..83b25a9660349565195f53c79cc79fe77eaeb4a4 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/media/ui/MediaNotificationManager.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/media/ui/MediaNotificationManager.java
@@ -76,6 +76,10 @@ public class MediaNotificationManager {
                 "MediaNotificationManager.ListenerService.SWIPE";
         private static final String ACTION_CANCEL =
                 "MediaNotificationManager.ListenerService.CANCEL";
+        private static final String ACTION_PREVIOUS_TRACK =
+                "MediaNotificationManager.ListenerService.PREVIOUS_TRACK";
+        private static final String ACTION_NEXT_TRACK =
+                "MediaNotificationManager.ListenerService.NEXT_TRACK";
 
         @Override
         public IBinder onBind(Intent intent) {
@@ -159,6 +163,10 @@ public class MediaNotificationManager {
                 manager.onPause(MediaNotificationListener.ACTION_SOURCE_MEDIA_NOTIFICATION);
             } else if (AudioManager.ACTION_AUDIO_BECOMING_NOISY.equals(action)) {
                 manager.onPause(MediaNotificationListener.ACTION_SOURCE_HEADSET_UNPLUG);
+            } else if (ACTION_PREVIOUS_TRACK.equals(action)) {
+                manager.onMediaSessionAction(MediaSessionAction.ACTION_PREVIOUS_TRACK);
+            } else if (ACTION_NEXT_TRACK.equals(action)) {
+                manager.onMediaSessionAction(MediaSessionAction.ACTION_NEXT_TRACK);
             }
         }
     }
@@ -430,6 +438,8 @@ public class MediaNotificationManager {
     private final String mPlayDescription;
     private final String mPauseDescription;
     private final String mStopDescription;
+    private final String mPreviousTrackDescription;
+    private final String mNextTrackDescription;
 
     private NotificationCompat.Builder mNotificationBuilder;
 
@@ -461,6 +471,9 @@ public class MediaNotificationManager {
         mPlayDescription = context.getResources().getString(R.string.accessibility_play);
         mPauseDescription = context.getResources().getString(R.string.accessibility_pause);
         mStopDescription = context.getResources().getString(R.string.accessibility_stop);
+        mPreviousTrackDescription = context.getResources().getString(
+            R.string.accessibility_previous_track);
+        mNextTrackDescription = context.getResources().getString(R.string.accessibility_next_track);
     }
 
     /**
@@ -502,6 +515,10 @@ public class MediaNotificationManager {
         mMediaNotificationInfo.listener.onStop(actionSource);
     }
 
+    private void onMediaSessionAction(int action) {
+        mMediaNotificationInfo.listener.onMediaSessionAction(action);
+    }
+
     private void showNotification(MediaNotificationInfo mediaNotificationInfo) {
         if (mediaNotificationInfo.equals(mMediaNotificationInfo)) return;
 
@@ -685,11 +702,24 @@ public class MediaNotificationManager {
         // removing the time.
         builder.setShowWhen(false).setWhen(0);
 
+        addNotificationButtons(builder);
+    }
+
+    private void addNotificationButtons(NotificationCompat.Builder builder) {
         // Only apply MediaStyle when NotificationInfo supports play/pause.
         if (mMediaNotificationInfo.supportsPlayPause()) {
             NotificationCompat.MediaStyle style = new NotificationCompat.MediaStyle();
             style.setMediaSession(mMediaSession.getSessionToken());
 
+            int numActions = 0;

[whywhat, 2016/10/28 16:38:02]

nit: I wonder if numActions could be just mediaSessionActions.size() + 1 or
something?

[Zhiqiang Zhang (Slow), 2016/11/01 14:55:25]

No, we are actually ignoring actions except for PREVIOUS/NEXT track

+
+            if (mMediaNotificationInfo.mediaSessionActions.contains(
+                        MediaSessionAction.ACTION_PREVIOUS_TRACK)) {
+                builder.addAction(R.drawable.ic_media_control_skip_previous,
+                        mPreviousTrackDescription,
+                        createPendingIntent(ListenerService.ACTION_PREVIOUS_TRACK));
+                ++numActions;
+            }
             if (mMediaNotificationInfo.isPaused) {
                 builder.addAction(R.drawable.ic_media_control_play, mPlayDescription,
                         createPendingIntent(ListenerService.ACTION_PLAY));
@@ -698,7 +728,17 @@ public class MediaNotificationManager {
                 builder.addAction(R.drawable.ic_media_control_pause, mPauseDescription,
                         createPendingIntent(ListenerService.ACTION_PAUSE));
             }
-            style.setShowActionsInCompactView(0);
+            ++numActions;
+            if (mMediaNotificationInfo.mediaSessionActions.contains(
+                        MediaSessionAction.ACTION_NEXT_TRACK)) {
+                builder.addAction(R.drawable.ic_media_control_skip_next, mNextTrackDescription,
+                        createPendingIntent(ListenerService.ACTION_NEXT_TRACK));
+                ++numActions;
+            }
+            numActions = Math.min(numActions, 3);

[whywhat, 2016/10/28 16:38:02]

nit: 3 is a magic number - give it a name.

[Zhiqiang Zhang (Slow), 2016/11/01 14:55:25]

Done.

+            int[] compactViewActions = new int[numActions];
+            for (int i = 0; i < numActions; ++i) compactViewActions[i] = i;
+            style.setShowActionsInCompactView(compactViewActions);
             style.setCancelButtonIntent(createPendingIntent(ListenerService.ACTION_CANCEL));
             style.setShowCancelButton(true);
             builder.setStyle(style);