title: How to create a "reveal" effect that's not circular?
body: <p>Android has a nice reveal animation (called "CircularReveal") that has a circle shape (link <a href="https://developer.android.com/training/material/animations.html#Reveal" rel="nofollow noreferrer"><strong>here</strong></a> and <a href="https://developer.android.com/reference/android/view/ViewAnimationUtils.html#createCircularReveal(android.view.View,%20int,%20int,%20float,%20float)" rel="nofollow noreferrer"><strong>here</strong></a>) .</p>
  
  <p>I was wondering: is it possible to do it in other shapes too?</p>
  
  <p>For example, reveal a view from top to bottom, in a rectangle shape, as such:</p>
  
  <pre><code>XXX     XXX    XXX
  ...  =&gt; XXX =&gt; XXX
  ...     ...    XXX
  </code></pre>
  
  <p>A video of how it looks like can be found <a href="https://www.youtube.com/watch?v=x-GUMQGnHvs&amp;feature=youtu.be&amp;t=30s" rel="nofollow noreferrer"><strong>here</strong></a>. </p>
  
  <p>In the previous way to do it, I've used a customized ObjectAnimator (link <a href="https://stackoverflow.com/questions/19519921/how-to-animate-imageview-from-center-crop-to-fill-the-screen-and-vice-versa-fac/19616416#19616416"><strong>here</strong></a>) that changes the layout params (which works, but it's a workaround and it's not quite customizable, and it will probably not work on this case), but I wonder if there's a new way to do it, something easier and more customizable.</p>
  
  <p>Also, is it possible to make this kind of animation work on previous Android versions, and not just Lollipop?</p>
  
  <p>It's just that I've seen "Google Now Launcher"'s search-history appear this way, and I wonder how to make a similar thing.</p>