title: Can I cancel touch programmatically?
body: <p>UIScrollView has a canceling mechanism, where it cancels the touch of subviews when it detects 'scrolling'.</p>
  
  <p>I wonder if I can cancel a touch event (which already has begun) programmatically.</p>
  
  <p>I have a draggable view inside a scroll view.<br>
  I can let the draggable view receive touches, but I'm wondering how to stop receiving touch events when I want and give touch events to the scroll view.</p>