title: Test all pixels by changing color on screen touch
body: <p>I'm developing a code in which I have to test if all pixels are working fine by changing the color of every pixel. Currently, I'm able to successfully change the color by painting the screen on touch event when the user touches the screen, but I'm not able to keep track of pixels being painted. </p>
  
  <p>The problem is on <strong>onTouchEvent</strong> if we use <strong>event.getX() and event.getY()</strong> it doesn't give the values of all pixels touched by the finger. </p>
  
  <p><strong>My requirement is to check all pixels by changing the color and once the whole screen is painted pass or fail the test depending upon whether all pixels were colored by the user.</strong></p>