Question

I’m relatively new to Android and very new to graphics. I can draw a circle on the screen and even drag it around and grow (radius continues to increase) while it’s moving, but when I just touch the screen, the circle does not increase in size. I presume this is because of the MotionEvent.

Essentially, what I want to do is have a circle increase in size whenever the screen is touched and move relative to the center of the circle when the user moves his finger, then reset to the original radius when the finger is lifted up. Any advice would be great or if someone knows of a tutorial that covers this that would be great too. Thanks.

Answer 1

In your onTouchEvent method, check the type of event using getActionMasked();

int eventType = event.getActionMasked();
if(eventType == MotionEvent.ACTION_DOWN)
   growCircle();
else if(eventType == MotionEvent.ACTION_UP)
  returnCircleToNormal();