title: how to place an image over another image in android by onclick?
body: <p>i have an imageview in my xml file and i want to put another image over it where user clicks.
  i have used a canvas to place an image where user clicks but i am stuck when it comes to putting the canvas over my imageview.
  Or is there any way around when we want to put another image over an imageview while detecting user clicks?
  Thanks</p>