title: AnimationDrawable: how to catch animation end event
body: <p>I have an <code>AnimationDrawable</code> that starts and I need to start a tween animation right after the first animation is ended.
  I've seen <code>AnimationDrawable</code> doesn't have an <code>AnimationListener</code> setter, so how can I know when it is finished?</p>
  
  <p>I've seen some solutions that compute the animation length and use an Handler, but they are not so accurate. In fact there is a (short) lag between the two animations.</p>
  
  <p>Thank you in advance.</p>