Odtnhj

I am currently developing an app that uses audio.
When the device is locked, the user must be able to control the audio on the lock screen. This must work on API 19 (4.4 KitKat) until API28 (pie, with oreo notification channel) (and up). The app must be able to receive input (button listeners/clicks on the buttons) and the app must be able to hand over the right song to the service to play.

I am trying to make something like this or an album lock screen like Android 4.4 as a fallback.

I successfully managed to make a notification in the notification drawer with MediaPlayer controls.

Now, I try something similar, but this time, I want to control the audio on the lock screen.

I already managed to make this but it only works on API21 to API25.
It needs to work on API 19 until 26 (and newer/future proof).

And here is my code:
public class LockscreenService extends Service {

private MediaSession mSession;

public static final String ACTION_PLAY = "ACTION_PLAY";
public static final String ACTION_PAUSE = "ACTION_PAUSE";
public static final String ACTION_REWIND = "ACTION_REWIND";
public static final String ACTION_FAST_FORWARD = "ACTION_FAST_FORWARD";
public static final String ACTION_NEXT = "ACTION_NEXT";
public static final String ACTION_PREVIOUS = "ACTION_PREVIOUS";
public static final String ACTION_STOP = "ACTION_STOP";

private MediaPlayer mMediaplayer;
private MediaSessionManager mediaSessionManager;
private MediaController mController;

//region EXTENDS
@Override
public IBinder onBind(Intent intent) 
 return null;


@Override
public boolean onUnbind(Intent intent) 
 // mSession.release();
 return super.onUnbind(intent);



@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
@Override
public int onStartCommand(Intent intent, int flags, int startId) 
 if (mediaSessionManager == null) 
 initMediaSession();
 
 handleIntent(intent);
 return super.onStartCommand(intent, flags, startId);



//endregion

//region

@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
private void initMediaSession() 

 mSession = new MediaSession(getApplicationContext(), "example session");
 mController = new MediaController(getApplicationContext(), mSession.getSessionToken());

 mSession.setCallback(new MediaSession.Callback() 
 @Override
 public void onPlay() 
 super.onPlay();
 playMusic();
 buildNotification(generateAction(android.R.drawable.ic_media_pause, "pause", ACTION_PAUSE));
 

 @Override
 public void onPause() 
 super.onPause();
 pauseMusic();
 buildNotification(generateAction(android.R.drawable.ic_media_play, "pause", ACTION_PLAY));
 

 @Override
 public void onSkipToNext() 
 super.onSkipToNext();
 buildNotification(generateAction(android.R.drawable.ic_media_pause, "pause", ACTION_PAUSE));
 

 @Override
 public void onFastForward() 
 pauseMusic();
 super.onSkipToNext();
 

 @Override
 public void onRewind() 
 pauseMusic();
 super.onSkipToNext();
 

 @Override
 public void onSkipToPrevious() 
 super.onSkipToPrevious();
 pauseMusic();
 


 @Override
 public void onStop() 
 super.onStop();
 NotificationManager notificationManager = (NotificationManager) getApplicationContext().getSystemService(Context.NOTIFICATION_SERVICE);
 notificationManager.cancel(1);
 Intent intent = new Intent(getApplicationContext(), LockscreenService.class);
 stopService(intent);
 

 );



@TargetApi(Build.VERSION_CODES.LOLLIPOP)
private void handleIntent(Intent intent) intent.getAction() == null) 
 // STOP
 

 String action = Objects.requireNonNull(intent).getAction();
 assert action != null;
 if (action.equalsIgnoreCase(ACTION_PLAY)) 
 Toast.makeText(this, "Clicked Play", Toast.LENGTH_SHORT).show();
 mController.getTransportControls().play();
 else if (action.equalsIgnoreCase(ACTION_PAUSE)) 
 Toast.makeText(this, "Clicked pause", Toast.LENGTH_SHORT).show();
 mController.getTransportControls().pause();
 else if (action.equalsIgnoreCase(ACTION_FAST_FORWARD)) 
 Toast.makeText(this, "Clicked fast forward", Toast.LENGTH_SHORT).show();
 mController.getTransportControls().fastForward();
 else if (action.equalsIgnoreCase(ACTION_REWIND)) 
 Toast.makeText(this, "Clicked rewind", Toast.LENGTH_SHORT).show();
 mController.getTransportControls().rewind();
 else if (action.equalsIgnoreCase(ACTION_PREVIOUS)) 
 Toast.makeText(this, "Clicked previous", Toast.LENGTH_SHORT).show();
 pauseMusic();
 mController.getTransportControls().skipToPrevious();
 else if (action.equalsIgnoreCase(ACTION_NEXT)) 
 Toast.makeText(this, "Clicked next", Toast.LENGTH_SHORT).show();
 mController.getTransportControls().skipToNext();
 else if (action.equalsIgnoreCase(ACTION_STOP)) 
 Toast.makeText(this, "Clicked stop", Toast.LENGTH_SHORT).show();
 mController.getTransportControls().stop();
 



@TargetApi(Build.VERSION_CODES.KITKAT_WATCH)
private Notification.Action generateAction(int icon, String title, String intentAction) 
 Intent intent = new Intent(getApplicationContext(), LockscreenService.class);
 intent.setAction(intentAction);
 PendingIntent pendingIntent = PendingIntent.getService(getApplicationContext(), 1, intent, 0);
 return new Notification.Action.Builder(icon, title, pendingIntent).build();


@TargetApi(Build.VERSION_CODES.LOLLIPOP)
private void buildNotification(Notification.Action action) 
 Notification.MediaStyle style = new Notification.MediaStyle();
 Intent intent = new Intent(getApplicationContext(), LockscreenService.class);
 intent.setAction(ACTION_STOP);
 PendingIntent pendingIntent = PendingIntent.getService(getApplicationContext(), 1, intent, 0);
 Notification.Builder builder = new Notification.Builder(this)
 .setSmallIcon(R.mipmap.ic_launcher_round)
 .setContentTitle("Lockscreen Book Example")
 .setContentText("Title of the book")
 .setDeleteIntent(pendingIntent)
 .setStyle(style);

 builder.addAction(generateAction(android.R.drawable.ic_media_previous, "previous", ACTION_PREVIOUS));
 builder.addAction(generateAction(android.R.drawable.ic_media_rew, "previous", ACTION_PREVIOUS));
 builder.addAction(action);
 builder.addAction(generateAction(android.R.drawable.ic_media_previous, "fast forward", ACTION_FAST_FORWARD));
 builder.addAction(generateAction(android.R.drawable.ic_media_rew, "Next", ACTION_NEXT));
 style.setShowActionsInCompactView(0, 1, 2, 3, 4);

 NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
 notificationManager.notify(1, builder.build());




//region music controls
public void initMusic() 
 //getting systems default ringtone
 mMediaplayer = MediaPlayer.create(this,
 Settings.System.DEFAULT_RINGTONE_URI);


public void playMusic() 
 if (mMediaplayer != null) 
 mMediaplayer.start();
 else 
 initMusic();
 //staring the player
 mMediaplayer.start();
 


public void pauseMusic() 
 if (mMediaplayer != null)
 mMediaplayer.pause();



//endregion

//endregion

When I try to use NotificationCompat, I can't let MediaStyle work, so I unable to generate the controls.

Can someone please help me out how I can make audio controls on the lock screen that works on KitKat until Pie (and newer)?