Lockscreen Remote Controls for Media Player

gistfile1.java

	private Song mSong;
	private RemoteControlClient remoteControlClient;
	private AudioManager audioManager;
	
	// ...
	
	private void broadcastTrackInfoToLockscreen(){
	    MetadataEditor editor = remoteControlClient.editMetadata(false);
	
	    editor.putString(MediaMetadataRetriever.METADATA_KEY_ALBUM, mSong.getFullAlbumTitle());
	    editor.putString(MediaMetadataRetriever.METADATA_KEY_ARTIST, mSong.getArtistName());
	    editor.putString(MediaMetadataRetriever.METADATA_KEY_TITLE, mSong.getFullTitle());
	    editor.putLong(MediaMetadataRetriever.METADATA_KEY_CD_TRACK_NUMBER, Long.parseLong(mSong.getTrackNumber()));
	
	    editor.apply();
	}
	
	@SuppressLint("NewApi")
	private void setUpRemoteControlClient() {
		
		ComponentName myEventReceiver = new ComponentName(getPackageName(), MediaControlReceiver.class.getName());
		audioManager.registerMediaButtonEventReceiver(myEventReceiver);
		
		if (remoteControlClient == null) {
			Intent mediaButtonIntent = new Intent(Intent.ACTION_MEDIA_BUTTON);
			mediaButtonIntent.setComponent(myEventReceiver);
			PendingIntent mediaPendingIntent = PendingIntent.getBroadcast(this, 0, mediaButtonIntent, 0);

			// create and register the remote control client
			remoteControlClient = new RemoteControlClient(mediaPendingIntent);
		}

		remoteControlClient.setTransportControlFlags(
				RemoteControlClient.FLAG_KEY_MEDIA_PLAY |
				RemoteControlClient.FLAG_KEY_MEDIA_PAUSE |
				RemoteControlClient.FLAG_KEY_MEDIA_PREVIOUS |
				RemoteControlClient.FLAG_KEY_MEDIA_NEXT |
				RemoteControlClient.FLAG_KEY_MEDIA_STOP);
		
		if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) {
			remoteControlClient.setPlaybackPositionUpdateListener(new OnPlaybackPositionUpdateListener() {
				@Override
				public void onPlaybackPositionUpdate(long newPositionMs) {
					mPlayer.seekTo((int) newPositionMs);				
				}
			});
			
			remoteControlClient.setOnGetPlaybackPositionListener(new OnGetPlaybackPositionListener() {
				
				@Override
				public long onGetPlaybackPosition() {
					return mPlayer.getCurrentPosition();
				}
			});
		}
		
		audioManager.registerRemoteControlClient(remoteControlClient);
	}
	
	public void updateState(boolean isPlaying) {
		if (remoteControlClient != null) {
			if (isPlaying) {
				remoteControlClient
				.setPlaybackState(RemoteControlClient.PLAYSTATE_PLAYING);
			} else {
				remoteControlClient
				.setPlaybackState(RemoteControlClient.PLAYSTATE_PAUSED);
			}
		}
	}