title: Custom UIViewController Transition Not Happening Interactively
body: <p>I've a custom UIViewController transition which basically stacks the coming ViewController to the right of the current one on the screen and slides them to the left(push) or right(pop).</p>
  
  <p>I've implemented the transition to be interactive:</p>
  
  <pre><code>@objc private func addPanGestureRecognizer(_ gestureRecognizer: UIScreenEdgePanGestureRecognizer) {
      guard let view = gestureRecognizer.view else { return }
      let progress = gestureRecognizer.translation(in: view).x / view.frame.size.width
  
      switch gestureRecognizer.state {
      case .began:
          interactionController = UIPercentDrivenInteractiveTransition()
          navigationController.popViewController(animated: true)
      case .changed:
          interactionController.update(progress)
      default:
          if progress &gt;= 0.5 {
              interactionController.finish()
          } else {
              interactionController.cancel()
          }
  
          interactionController = nil
      }
  }
  </code></pre>
  
  <p>The above gesture action initiates my custom transition when I apply a swipe gesture from the left edge of the screen although it doesn't happen interactively but just runs my custom animation completely.</p>
  
  <p>What's causing it not to act interactively?</p>
  
  <p>p.s. The above gesture actions gets added as the action of a <code>UIScreenEdgePanGestureRecognizer</code> to the pushed view controller's view.</p>