onSkipToNext() and onSkipToPrevious() of MediaSessionCompat.Callback does not get triggered

Question

I'm trying to implement a notification player in Android. I followed this guide to achieve this. However as my requirement I need to implement "skip to next" and "skip to previous" in the background notification player.

So far onPlay() and onPause() of MediaSessionCompact.Callback get triggered. However while debugging I noticed onSkipToNext() and onSkipToPrevious() callback methods does not get triggered when next and previous buttons are pressed in notification player.

Appreciate your input. I have added relevant code below.

BackgroundAudioService

private void showPlayingNotification() {
    NotificationCompat.Builder builder = MediaStyleHelper.from(BackgroundAudioService.this, mMediaSessionCompat);
    if (builder == null) {
        return;
    }

    builder.addAction(new NotificationCompat.Action(android.R.drawable.ic_media_previous, "Previous", MediaButtonReceiver.buildMediaButtonPendingIntent(this, PlaybackStateCompat.ACTION_SKIP_TO_PREVIOUS)));
    builder.addAction(new NotificationCompat.Action(android.R.drawable.ic_media_pause, "Pause", MediaButtonReceiver.buildMediaButtonPendingIntent(this, PlaybackStateCompat.ACTION_PLAY_PAUSE)));
    builder.addAction(new NotificationCompat.Action(android.R.drawable.ic_media_next, "Next", MediaButtonReceiver.buildMediaButtonPendingIntent(this, PlaybackStateCompat.ACTION_SKIP_TO_NEXT)));

    builder.setStyle(new NotificationCompat.MediaStyle().setShowActionsInCompactView(0).setMediaSession(mMediaSessionCompat.getSessionToken()));
    builder.setSmallIcon(R.mipmap.ic_launcher);
    NotificationManagerCompat.from(BackgroundAudioService.this).notify(1, builder.build());
}

private void showPausedNotification() {
    NotificationCompat.Builder builder = MediaStyleHelper.from(this, mMediaSessionCompat);
    if (builder == null) {
        return;
    }

    builder.addAction(new NotificationCompat.Action(android.R.drawable.ic_media_previous, "Previous", MediaButtonReceiver.buildMediaButtonPendingIntent(this, PlaybackStateCompat.ACTION_SKIP_TO_PREVIOUS)));
    builder.addAction(new NotificationCompat.Action(android.R.drawable.ic_media_play, "Play", MediaButtonReceiver.buildMediaButtonPendingIntent(this, PlaybackStateCompat.ACTION_PLAY_PAUSE)));
    builder.addAction(new NotificationCompat.Action(android.R.drawable.ic_media_next, "Next", MediaButtonReceiver.buildMediaButtonPendingIntent(this, PlaybackStateCompat.ACTION_SKIP_TO_NEXT)));


    builder.setStyle(new NotificationCompat.MediaStyle().setShowActionsInCompactView(0).setMediaSession(mMediaSessionCompat.getSessionToken()));
    builder.setSmallIcon(R.mipmap.ic_launcher);
    NotificationManagerCompat.from(this).notify(1, builder.build());
}

private MediaSessionCompat.Callback mMediaSessionCallback = new MediaSessionCompat.Callback() {

    @Override
    public void onPlay() {
        super.onPlay();
        if (!successfullyRetrievedAudioFocus()) {
            return;
        }

        mMediaSessionCompat.setActive(true);
        setMediaPlaybackState(PlaybackStateCompat.STATE_PLAYING);
        Log.d("MyLog", "STATE_PLAYING");
        showPlayingNotification();
        mMediaPlayer.start();
    }

    @Override
    public void onPause() {
        super.onPause();

        if (mMediaPlayer.isPlaying()) {
            mMediaPlayer.pause();
            setMediaPlaybackState(PlaybackStateCompat.STATE_PAUSED);
            Log.d("MyLog", "STATE_PAUSED");
            showPausedNotification();
        }
    }

    @Override
    public void onSkipToNext() {
        super.onSkipToNext();
        setMediaPlaybackState(PlaybackStateCompat.STATE_SKIPPING_TO_NEXT);
        Log.d("MyLog", "STATE_SKIPPING_TO_NEXT");
    }

    @Override
    public void onSkipToPrevious() {
        super.onSkipToPrevious();
        setMediaPlaybackState(PlaybackStateCompat.STATE_SKIPPING_TO_PREVIOUS);
        Log.d("MyLog", "STATE_SKIPPING_TO_PREVIOUS");
    }
}

MediaStyleHelper

public static NotificationCompat.Builder from(
        Context context, MediaSessionCompat mediaSession) {
    MediaControllerCompat controller = mediaSession.getController();
    MediaMetadataCompat mediaMetadata = controller.getMetadata();
    MediaDescriptionCompat description = mediaMetadata.getDescription();

    NotificationCompat.Builder builder = new NotificationCompat.Builder(context);
    builder
            .setContentTitle(description.getTitle())
            .setContentText(description.getSubtitle())
            .setSubText(description.getDescription())
            .setLargeIcon(description.getIconBitmap())
            .setContentIntent(controller.getSessionActivity())
            .setDeleteIntent(
                    MediaButtonReceiver.buildMediaButtonPendingIntent(context, PlaybackStateCompat.ACTION_STOP))
            .setVisibility(NotificationCompat.VISIBILITY_PUBLIC);
    return builder;
}

MainActivity's onCreate

    mMediaBrowserCompat = new MediaBrowserCompat(this, new ComponentName(this, BackgroundAudioService.class),
            mMediaBrowserCompatConnectionCallback, getIntent().getExtras());

MainActivity

private MediaBrowserCompat.ConnectionCallback mMediaBrowserCompatConnectionCallback = new MediaBrowserCompat.ConnectionCallback() {

    @Override
    public void onConnected() {
        super.onConnected();
        try {
            mMediaControllerCompat = new MediaControllerCompat(MainActivity.this, mMediaBrowserCompat.getSessionToken());
            mMediaControllerCompat.registerCallback(mMediaControllerCompatCallback);
            setSupportMediaController(mMediaControllerCompat);
            getSupportMediaController().getTransportControls().playFromMediaId(String.valueOf(R.raw.warner_tautz_off_broadway), null);

        } catch( RemoteException e ) {

        }
    }
};

private MediaControllerCompat.Callback mMediaControllerCompatCallback = new MediaControllerCompat.Callback() {

    @Override
    public void onPlaybackStateChanged(PlaybackStateCompat state) {
        super.onPlaybackStateChanged(state);
        if( state == null ) {
            return;
        }

        switch( state.getState() ) {
            case PlaybackStateCompat.STATE_PLAYING: {
                mCurrentState = STATE_PLAYING;
                break;
            }
            case PlaybackStateCompat.STATE_PAUSED: {
                mCurrentState = STATE_PAUSED;
                break;
            }
            case PlaybackStateCompat.STATE_SKIPPING_TO_NEXT: {
                mCurrentState = STATE_SKIPPING_TO_NEXT;
                break;
            }
            case PlaybackStateCompat.STATE_SKIPPING_TO_PREVIOUS: {
                mCurrentState = STATE_SKIPPING_TO_PREVIOUS;
            }
        }
    }
};

Update

Seems like onMediaButtonEvent() gets triggered for next and previous in notification player with action name "android.intent.action.MEDIA_BUTTON" for both buttons.

    @Override
    public boolean onMediaButtonEvent(Intent mediaButtonEvent) {
        Log.d("MyLog", "executing onMediaButtonEvent: " + mediaButtonEvent.getAction());
        return super.onMediaButtonEvent(mediaButtonEvent);
    }

Answer 1

Just ran into this issue after following the same guide.

Look for a method called setMediaPlaybackState(int state) inside your BackgroundAudioService class. This is where you define a PlaybackStateCompat.Builder and define the current capabilities available on the session using setActions.

OnSkipToNext and onSkipToPrevious won't be called unless ACTION_SKIP_TO_NEXT and ACTION_SKIP_TO_PREVIOUS are passed in as supported actions. I managed to get it working after updating setActions to the following...

private void setMediaPlaybackState(int state) {
    PlaybackStateCompat.Builder playbackstateBuilder = new PlaybackStateCompat.Builder();
    switch (state) {
        case PlaybackStateCompat.STATE_PLAYING: {
            playbackstateBuilder.setActions(PlaybackStateCompat.ACTION_PLAY_PAUSE | PlaybackStateCompat.ACTION_PAUSE
                    | PlaybackStateCompat.ACTION_SKIP_TO_NEXT | PlaybackStateCompat.ACTION_SKIP_TO_PREVIOUS);
            break;
        }
        default: {
            playbackstateBuilder.setActions(PlaybackStateCompat.ACTION_PLAY_PAUSE | PlaybackStateCompat.ACTION_PLAY
                    | PlaybackStateCompat.ACTION_SKIP_TO_NEXT | PlaybackStateCompat.ACTION_SKIP_TO_PREVIOUS);
            break;
        }
    }

    playbackstateBuilder.setState(state, PlaybackStateCompat.PLAYBACK_POSITION_UNKNOWN, 0);
    mMediaSessionCompat.setPlaybackState(playbackstateBuilder.build());
}

Be nice if there was a slightly cleaner way to do this but it seems that all actions need to be set in one hit and can't be split across multiple calls.