title: How to "transfer" an ongoing gesture from a subview to the superview without interruption?
body: <p>This is what I'm trying to do:</p>
  
  <p>I want to start recognizing a gesture in a subview and then, when the finger leaves the subview, let the superview take over and handle the gesture. Is that possible? </p>
  
  <p><img src="https://i.stack.imgur.com/MxAn5.png" alt="enter image description here"></p>
  
  <p>At the moment, the view in which the gesture started "wins". Is there any way to "hand over" a gesture from one view to another "on the fly", without lifting the finger off the screen?</p>
  
  <p>This is the code for a simple demo:</p>
  
  <pre><code>@implementation SPWKViewController {
      UIView *_innerView;
      UIPanGestureRecognizer *_outerGestureRecognizer;
      UIPanGestureRecognizer *_innerGestureRecognizer;
  
      UILabel *_label;
  }
  
  - (void)loadView
  {
      [super loadView];
  
      self.view.backgroundColor = [UIColor yellowColor];
  
      _innerView = [[UIView alloc] initWithFrame:CGRectMake(50, 50, self.view.frame.size.width - 100, 200)];
      _innerView.autoresizingMask = UIViewAutoresizingFlexibleWidth;
      _innerView.backgroundColor = [UIColor greenColor];
  
      _label = [[UILabel alloc] initWithFrame:CGRectMake(0, 300, self.view.frame.size.width, 40)];
      _label.autoresizingMask = UIViewAutoresizingFlexibleWidth;
      _label.textAlignment = NSTextAlignmentCenter;
      _label.backgroundColor = [UIColor clearColor];
  
      [self.view addSubview:_innerView];
      [self.view addSubview:_label];
  }
  
  - (void)viewDidLoad
  {
      [super viewDidLoad];
  
      _outerGestureRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handleGesture:)];
      [self.view addGestureRecognizer:_outerGestureRecognizer];
  
      _innerGestureRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handleGesture:)];
      [_innerView addGestureRecognizer:_innerGestureRecognizer];
  }
  
  - (void)handleGesture:(UIGestureRecognizer *)gestureRecognizer
  {
      if (gestureRecognizer.state == UIGestureRecognizerStateChanged) {
          if (gestureRecognizer == _outerGestureRecognizer) {
              _label.text = @"outer";
          } else {
              _label.text = @"inner";
          }
      } else {
          _label.text = @"";
      }
  }
  
  @end
  </code></pre>
  
  <p>Some background information: The actual problem I'd like to solve is this: I'd like to put a UIWebView inside of a UIScrollView. When I scroll to the bottom of the UIWebView, I want the parent UIScrollView to "take over" and keep scrolling without having to lift the finger off the screen first. I figured that in order to achieve that, I'd need to "hand over" the gesture from the UIWebView to the parent UIScrollView.</p>
  
  <p>Thank you!</p>