title: android-set onTouchListener on Service
body: <p>I have a <code>Service</code> in my app which detects whether the user has touched the screen or not. The problem is where should I set the <code>onTouchListener</code> to listen for the touch whenever/wherever the user touches the screen? </p>
  
  <p>I know how to set this listener for a layout. But what about <code>Service</code>?</p>