ASTableNode swipe-to-delete cell gesture can leave delete action in a partially visible state

[rewcraig]

When using UITableView's native swipe to delete table cell gesture, a partial swipe gesture either fully shows or hides the actions below the cell's content view.

The same gesture using ASTableNode/ASTableView leaves the cell's content view in a partially open state.

It appears that this functionality is implemented in UITableView's own (private)
implementation of:
-(void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset;

ASTableView overrides this method, which breaks the show/hide functionality. Removing ASTableView's implementation restores the functionality; obviously this is not the solution.

As an ugly solution I have tried creating a category on UITableView to expose the private method and calling [super scrollViewWillEndDragging] at the top of ASTableView's implementation.
This resolves the show/hide problem, but it doesn't seem ideal and I'm not sure of it's impact on other code.

Sample project:
ASTableSwipe.zip

[Adlai-Holler]

Hmm great catch!

I think the thing to do is:

• At the top of ASTableView.mm, add the @interface UITableView (ScrollViewDelegate) category you described.
• Inside each of the scroll view delegate methods, add something like:

static BOOL superResponds;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
  superResponds = [UITableView instancesRespondToSelector:_cmd];
});
if (superResponds && scrollView != self) {
  [super scrollViewDid……]; 
  return;
}

To keep the code cleaner, you could make a macro that contains the top portion and returns the BOOL superResponds.

This way we only message UITableView with UIScrollViewDelegate methods that it implements, and we only ever message it for other scroll views – UITableView doesn't listen for self-events on the public protocol, it uses private methods like _scrollViewDid… for that.

Would you be willing to implement it?

[rewcraig]

I'll certainly give it a shot! Thanks for the quick response :)

[Labun]

Hi, I use version 2.3.2 and this bug still appears. Any suggestions?

[rewcraig]

This was not integrated into the release until 2.3.3. Here is the commit:
e18d139
Hopefully you are able to upgrade from 2.3.2.