UIPanGestureRecognizer in Texture/AsyncDisplayKit's ASCellNode prevents the table from scrolling when implementing `swipe to perform action` type behaviour

[Pran]

I am using the Texture/AsyncDisplayKit library:

https://github.com/texturegroup/texture

I am trying to implement "swipe to perform action" in a ASCellNode. The problem is that the UIPanGestureRecognizer prevents the table from scrolling.

I am able to successfully get this to work in UIKit using UITableViewCell but for some reason it's not working when using Texture's ASCellNode. I can demonstrate the issue easily with the ASDKgram example provided with this library which has both a UIKit example in one tab and Texture example in another tab:

https://github.com/TextureGroup/Texture/tree/master/examples/ASDKgram

For the UIKit example, all I had to do was:

Add <UIGestureRecognizerDelegate> to PhotoTableViewCell.h

Add UIPanGestureRecognizer *_panGestureRecognizer; in the @implementation PhotoTableViewCell

Add following to the - (instancetype)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier:

_panGestureRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panned:)];
_panGestureRecognizer.delegate = self;
[self.contentView addGestureRecognizer:_panGestureRecognizer];

Add following:

- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer{
  if (gestureRecognizer == _panGestureRecognizer) {
    CGPoint v = [_panGestureRecognizer velocityInView:_panGestureRecognizer.view];
    return fabs(v.x) > fabs(v.y);
  }
  return false;
}

-(void)panned:(UIPanGestureRecognizer *)sender{
  NSLog(@"Panned!");
}

This was enough to get it to print Panned! when panning horizontally and also let the UITableView scroll when it's vertical direction.

The same does not work for the PhotoCellNode. I did the following:

Add <UIGestureRecognizerDelegate> to PhotoCellNode.h

Add UIPanGestureRecognizer *_panGestureRecognizer; in the @implementation PhotoCellNode

Add following to the PhotoCellNode.m:

- (void)didLoad {
  [super didLoad];
  _panGestureRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panned:)];
  _panGestureRecognizer.delegate = self;
  [self.view addGestureRecognizer:_panGestureRecognizer];
}

- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer{
  if (gestureRecognizer == _panGestureRecognizer) {
    CGPoint v = [_panGestureRecognizer velocityInView:_panGestureRecognizer.view];
    return fabs(v.x) > fabs(v.y);
  }
  return false;
}

-(void)panned:(UIPanGestureRecognizer *)sender{
  NSLog(@"Panned!");
}

This allows Panned! to print when panning horizontally but the table does not scroll at all. Why are they working differently? How can I make the table scroll when the touches are vertical?

[Pran]

I was able to solve it. Though I am not sure why the behavior is different between the UITableViewCell and ASCellNode. @appleguy can you help point out why the difference?

In the PhotoCellNode.m, I returned [super gestureRecognizerShouldBegin:gestureRecognizer] in gestureRecognizerShouldBegin and I also added the shouldRecognizeSimultaneouslyWithGestureRecognizer function:

- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer{
  if (gestureRecognizer == _panGestureRecognizer) {
    CGPoint v = [_panGestureRecognizer velocityInView:_panGestureRecognizer.view];
    return fabs(v.x) > fabs(v.y);
  }
  return [super gestureRecognizerShouldBegin:gestureRecognizer];
}

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer{
  return false;
}