title: How to pass the touch event to superview when userInteractionEnabled = YES?
body: <p>I have the following setup. </p>
  
  <pre><code>+- XXXCustomControl : UIControl -------+
  | A                                    |
  |   +- ContentView -------------------+|
  |   |                                 ||
  |   |  B                              ||
  |   |                                 ||
  |   +---------------------------------+|
  +--------------------------------------+ 
  </code></pre>
  
  <p>A XXXCustomControl that is a subclass of UIControl. It contains one subview called contentView of type UIView with size that is smaller than the Control's area..
  That view has <code>.userInteractionEnabled = YES</code>;</p>
  
  <p>I need that property to have set to YES, because horizontal scrollviews are put inside this once in a while and they need to be scrollable. If the superview (in our case content view would not allow user interaction, this is inherited y the subviews.)
  But at the same time this <code>XXXCustomControl</code> need to be tappable when it contains no scrollview in its content view not only in area A but also in area B.</p>
  
  <p>So I have a "conflict of interests" here because I either</p>
  
  <p>1) set the content view to <code>userInteractionEnabled = NO</code>, then I can tap the empty control in the content view area both in A and B, but the scrollviews I will put there won't be scrollable..</p>
  
  <p>2) set the content view to <code>userInteractionEnabled = YES</code> but then, if the Control s empty, I can only tap area A to trigger a touch event.</p>
  
  <p>One idea I came up with is that I set the property to NO by default and when I populate the contentView I set it to yes. when I clear the contentView I set the property back to no. 
  Basically I want this to have set to yes all the time, and when it is empty ,force the contentView to pass the touchUpInside event up to its superview.</p>
  
  <p>Is this possible? </p>