MainActivity.java

mVideoView = (UserAwareVideoView) findViewById(R.id.video_view);
mVideoView.setUserAwarenessListener(new UserAwarenessListener() {
            @Override
            public void onErrorOccurred(int errorCode) {
                //Handle errors.
                 switch (errorCode) {
                            case Errors.UNDEFINED:
                                //Unknown error occured. 
                                //This will stop eye tracking, but video will keep playing.
                                break;
                            case Errors.FRONT_CAMERA_NOT_AVAILABLE:
                                //This indicates that device doesnot have the front camera
                                //This will stop eye tracking, but video will keep playing.
                                break;
                            case Errors.CAMERA_PERMISSION_NOT_AVAILABLE:
                                //This indicates that camera permission is not available.
                                //Ask for the runtime camera permission.
                                break;
                            case Errors.LOW_LIGHT:
                                //This indicates that there is dark out side. We cannot detect user's face.
                                //This will stop eye tracking, but video will keep playing.
                                break;
                        }
            }

            @Override
            public void onEyeTrackingStarted() {
                //Eye detection started
            }

            @Override
            public void onEyeTrackingStop() {
                //Eye detection is stopped.
            }
        });
//Atatch your media controller, provide video to play and start the video
//......
//......