Open Radar

 
Summary:
In iOS 7 the navigation controller has a UIScreenEdgePanGestureRecognizer, swiping from the left of the screen pops the current view controller. Very nice.

However, using a custom leftBarButtonItem breaks this functionality:

self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Custom" style:UIBarButtonItemStylePlain target:self action:@selector(back)];

One simple fix is to include this code as well:

self.navigationController.interactivePopGestureRecognizer.delegate = self;

This works fine, except when you include an UICollectionView (or use an UICollectionViewController). It seems like it's impossible to have a working combination of collection view, custom leftBarButtonItem and the screen edge pan gesture.

Steps to Reproduce:
1. Create a stack of UINavigationController, UIViewController and push a UIViewController.

2. See that the UIScreenEdgePanGestureRecognizer works as expected.

3. Set a custom left bar button on the child controller:
self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Custom" style:UIBarButtonItemStylePlain target:self action:@selector(back)];

4. See that the UIScreenEdgePanGestureRecognizer no longer works.

5. Include this fix:
self.navigationController.interactivePopGestureRecognizer.delegate = self;

6. See that the UIScreenEdgePanGestureRecognizer again works as expected.

7. Now add a UICollectionView to the child view controller

8. See that the UIScreenEdgePanGestureRecognizer no longer works.

Expected Results:
The UIScreenEdgePanGestureRecognizer should still work.

Actual Results:
It doesn't and the interactivePopGestureRecognizer.delegate doesn't work.