Question

I need to create a window that the user can tap. I need to know when the user starts tapping, stops tapping, if the user moves his finger keeping it down, and the exact coordinates of where he taps, and where he is moving his finger, in real time.
I cannot understand which widget is the best for this kind of activity: can someone give me a hint, please?
Thanks.

Answer 1

Any View (including any ViewGroup) with an attached OnTouchListener can do what you’re looking for. In the ACTION_DOWN event, you can record where the tap occurred; in the ACTION_MOVE event, you can get the coordinate of the current pointer location.

Simply attach an OnTouchListener to your view and handle it accordingly:

View view = findViewById(R.id.my_view);
view.setOnTouchListener(new View.OnTouchListener() {
    @Override
    public boolean onTouch(View view, MotionEvent event) {
        switch(event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                float xTap = event.getX();
                float yTap = event.getY();
                break;
            case MotionEvent.ACTION_MOVE:
                float xMovement = event.getX();
                float yMovement = event.getY();
                break;
        }
    }
}