27.5 Implementing the onTouchEvent() Method
If the application were to be compiled and run at this point, nothing would happen if gestures were performed on the device display. This is because no code has been added to intercept touch events and to pass them through to the GestureDetectorCompat instance. In order to achieve this, it is necessary to override the onTouchEvent() method within the activity class and implement it such that it calls the onTouchEvent() method of the GestureDetectorCompat instance. Remaining in the MainActivity.java file, therefore, implement this method so that it reads as follows:
@Override
public boolean onTouchEvent(MotionEvent event) {
this.gDetector.onTouchEvent(event);
// Be sure to call the superclass implementation
return super.onTouchEvent(event);
}