title: Restricting a ScrollView to scroll only when a specific button is pressed in iOS
body: <p>I have a scrollView in my app and I have 9 buttons on each I want when the last button (9th button) is tapped only then the scrollView scrolls else it shouldn't even scroll. Where should I apply the checks from the below methods:</p>
  
  <pre><code>1.scrollViewDidScroll
  2.scrollViewWillBeginDragging
  3.scrollViewDidEndDecelerating
  </code></pre>
  
  <p>Or if you can tell any other way to do that?</p>