title: Animating Child View Controller's views during transition
body: <p>I have a Master custom container view controller, whose purpose is to swap between two different view controllers that each manage a form with text fields. We'll call these FormVC1 and FormVC2. Both of these controllers's views are managed by a XIB.</p>
  
  <p>I can successfully swap between FormVC1 and FormVC2 using:</p>
  
  <p><code>transitionFromViewController:toViewController:duration:options:animations:completion:</code> while passing <code>UIViewAnimationOptionTransitionCrossDissolve</code> for the <code>options</code> argument.</p>
  
  <p>Now I want to sweeten the transition a little, and when FormVC1 is being dismissed, I want the individual text fields to fly off to the left (one at a time), and when FormVC2 is being presented, I want the individual text fields to fly in from the right, one at a time.</p>
  
  <p>I'm a little confused as to how to set this all up, and where exactly to place the specific text field animation code. Do I put that in the animation block within Master? Do I put it in each FormVC's appearance callbacks?</p>