PlaybackInfoListener.java

public interface PlaybackInfoListener {

   @IntDef({State.INVALID, State.PLAYING, State.PAUSED, State.RESET, State.COMPLETED})
   @Retention(RetentionPolicy.SOURCE)
   @interface State {

       int INVALID = -1;
       int PLAYING = 0;
       int PAUSED = 1;
       int RESET = 2;
       int COMPLETED = 3;
   }

   void onLogUpdated(String formattedMessage);

   void onDurationChanged(int duration);

   void onPositionChanged(int position);

   void onStateChanged(@State int state);

   void onPlaybackCompleted();
}