title: Overlay view on top of list view?
body: <p>I have an app with a full screen list view. I'd like to add a new view hierarchy on top (it would partially block the list view and float above).  Sort of like Tweetbot, it will serve as a drop down message box that layers over the list view.  </p>
  
  <p>I can't figure out the right render code to achieve this. I was able to set position to absolute on both ListView and the floating view to layer them, but can't figure out how to expand the ListView to full screen (<code>flex: 1</code>) and have the floating box on top.</p>