title: Swift : Pull down to dismiss `UITableViewController`
body: <p>I want to pull down to dismiss <code>UITableViewController</code> so I used <code>scrollViewDidScroll</code> method but it didn't works!</p>
  
  <pre><code>    class CommentViewController: PFQueryTableViewController {
  
          private let tableHeaderHeight: CGFloat = 350.0
  
  
  
  extension CommentViewController
  {
      override func scrollViewDidScroll(scrollView: UIScrollView)
      {
  
  
  
              // Pull down to dismiss TVC 
              let offsetY = scrollView.contentOffset.y
              let adjustment: CGFloat = 130.0
  
              // for later use
              if (-offsetY) &gt; (tableHeaderHeight+adjustment) {
                  self.dismissViewControllerAnimated(true, completion: nil)
                  }
   }
      }
  </code></pre>