title: UICollectionViewCell expanding animation
body: <p>I'm trying to get an expanding transition animation : I have a UICollectionView and when the user select a cell I want this cell to expand to the whole screen. The transition is a Push segue transition</p>
  
  <p>I tried getting the cell location and then animate but I don't think I'm doing it the right way. </p>
  
  <p>I have some class : </p>
  
  <ul>
  <li>CollectionViewController : subclass of <code>UICollectionViewController</code></li>
  <li>FinalViewController : subclass of <code>UIViewController</code></li>
  <li>NavigationControllerDelegate : <code>UINavigationControllerDelegate</code> Protocol implemented</li>
  <li>Animator : <code>UIViewControllerAnimatedTransitioning</code> protocol implemented</li>
  </ul>
  
  <p>First question : does anyone ever get this effect, have a sample code or know a proper way to achieve this ? This would be really great</p>
  
  <p>Otherwise : How should I get the concerned cell in the Animator class ? I need the frame of the cell, and the subviews. Actually I have a <code>selectedCell</code> property that I set in the <code>prepareForSegue</code> function if the CollectionViewController, but I'm not sure it's the right way</p>
  
  <p>Thanks for your help</p>