title: UIScrollView prevent scrolling in one direction regardless of contentSize/Offset
body: <p>I have a UIScrollView with paging enabled but I would like to be able to prevent the user to swipe to the next page or back to the previous page in some cases.</p>
  
  <p>For instance someone could be passing a test with ten questions (one question per page) but scrolling won't work unless the person has answered the question at the current page.</p>
  
  <p>It could also be to prevent them to swipe back to the previous page. So basically I cannot use directional lock or temporarily disable user interaction because the reader could be allowed to swipe left but not to swipe right.</p>
  
  <p>I noticed a few people play around with the content offset but I find that solution ugly because the user can still swipe, it's just that the app automatically readjusts the content offset. I would like it to be as if the view had reached the end of the content or if user interaction was disabled. </p>
  
  <p>I guess I could maybe "play" with the content size/offset and refresh it on each page but I am not sure how to do that properly as I also have "links" that can allow someone to jump from one page to another (that could at the time be outside the defined content).</p>
  
  <p>I have tried using a custom view for pages where swipe in a specific direction is locked but it doesn't work as I could not find a way to prevent the scroll view from detecting the swipe without affecting pages were swipe should work in a normal way. I saw that I could set that custom view exclusiveTouch property to YES and assumed that since it was going to get all the events I could handle swipes via custom gesture recognizers and forward the events if swipe was allowed or ignore them if not. It did not work, the ScrollView always catches swipe events.</p>
  
  <p>I feel I have exhausted every possibility and I cannot find anyone who had similar needs.</p>
  
  <p>So I am wondering, is this even possible? If yes, will it require bad hacks or to make a new custom scroll view? </p>
  
  <p>Any help/idea would be greatly appreciated. </p>