MediaBrowserCompat.ConnectionCallback.onConnected() is not being called after connect()

Question

I'm creating a player app for android and want to access MediaControllerCompat from any UI class. For this purpose I use MediaBrowserCompat class, I'm trying to connect it to my MediaBrowserServiceCompat and get MediaControllerCompat with MediaSessionCompat.Token, already set in my Service.

I tried MediaBrowserCompat.connect() never calls onConnected or any MediaBrowserCompat.ConnectionCallback method solution, but it didn't help.

TortoiseActivity.java

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_tortoise);

        mediaBrowser = new MediaBrowserCompat(
                TortoiseActivity.this,
                new ComponentName(TortoiseActivity.this, Service.class),
                new MediaBrowserCompat.ConnectionCallback() {
                    @Override
                    public void onConnected() {
                        try {
                            MediaSessionCompat.Token token = mediaBrowser.getSessionToken();
                            MediaControllerCompat controller = new MediaControllerCompat(TortoiseActivity.this, token);
                            MediaControllerCompat.setMediaController(TortoiseActivity.this, controller);
                        } catch (RemoteException e) {
                            e.printStackTrace();
                        }
                    }

                    @Override
                    public void onConnectionFailed() {
                        Log.e("TAG", "onConnectionFailed");
                    }

                    @Override
                    public void onConnectionSuspended() {
                        Log.e("TAG", "onConnectionSuspended");
                    }
                },
                null);
        mediaBrowser.connect();
    }

Service.java

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return mBinder;
    }

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

        mediaSession = new MediaSessionCompat(this, Service.class.getSimpleName());
        setSessionToken(mediaSession.getSessionToken());

        mediaSession.setFlags(MediaSessionCompat.FLAG_HANDLES_MEDIA_BUTTONS | MediaSessionCompat.FLAG_HANDLES_TRANSPORT_CONTROLS);
        mediaSession.setActive(true);

        mediaSession.setCallback(callback);
    }

SmallPlayerFragment.java

void initControls(Activity context) {
        MediaControllerCompat mediaController = MediaControllerCompat.getMediaController(context);
        this.transportControls = mediaController.getTransportControls();
    }

As a result, I get NullPointer

java.lang.NullPointerException: Attempt to invoke virtual method 'android.support.v4.media.session.MediaControllerCompat$TransportControls android.support.v4.media.session.MediaControllerCompat.getTransportControls()' on a null object reference
        at ru.krivocraft.kbmp.SmallPlayerFragment.initControls(SmallPlayerFragment.java:49)
        at ru.krivocraft.kbmp.TortoiseActivity.getSmallPlayerFragment(TortoiseActivity.java:122)
        at ru.krivocraft.kbmp.TortoiseActivity.showSmallPlayerFragment(TortoiseActivity.java:248)
        at ru.krivocraft.kbmp.TortoiseActivity.access$200(TortoiseActivity.java:31)
        at ru.krivocraft.kbmp.TortoiseActivity$4.onItemClick(TortoiseActivity.java:109)

when trying to get MediaControllerCompat.TrasportControls. MediaControllerCompat is, definitely, null. I set breakpoint in Callback's onConnected(), but thread doesn't suspend on it. So, i can conclude, that callback is not being called.

score 5 · Accepted Answer · answered Jun 13 '19 at 09:11

https://stackoverflow.com/a/43676925/11485632 - this answer helped me to solve the problem. It turned out you can't even have your own Binder implemented. After removing overridden onBind(Intent intent) in Service.java callback started being invoked.

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return mBinder; //remove this custom binder
    }

MediaBrowserCompat.ConnectionCallback.onConnected() is not being called after connect()

1 Answers1