title: On iOS, if a superview's userInteractionEnabled is NO, then all subviews are disabled as well?
body: <p>I thought when a view is touched or tapped on, its handler get called first, and then its superview's handler is called (propagate upward).</p>
  
  <p>But is it true that if the superview's <code>userInteractionEnabled</code> is set to NO, then all subviews and offspring is also disabled for user interaction?  What if we want to disable for just the main view but don't want to disable for the subviews?</p>