InteractivePopGestureRecognizer causing app freezing

Question

In my app I have different controllers. When I push controller1 to navigation controller and swipe to back, all works good. But, if I push navigation controller1, and into controller1 push controller2 and try to swipe to back I get a frozen application. If go back through back button all works fine.

How can I catch the problem?

Answer 1

I had similar problem with freezing interface when using swipe-to-pop gesture. In my case the problem was in controller1.viewDidAppear I was disabling swipe gesture: self.navigationController.interactivePopGestureRecognizer.enabled = NO. So when user started to swipe back from contorller2, controller1.viewDidAppear was triggered and gesture was disabled, right during it's work.

I solved this by setting self.navigationController.interactivePopGestureRecognizer.delegate = self in controller1 and implementing gestureRecognizerShouldBegin:, instead of disabling gesture recognizer:

- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer {
    if ([self.navigationController respondsToSelector:@selector(interactivePopGestureRecognizer)] &&
            gestureRecognizer == self.navigationController.interactivePopGestureRecognizer) {
        return NO;
    }
    return YES;
}

Answer 2

My solution was to add a delegate to the navigation controller. Then disable the pop gesture recogniser in the root view controller only. YMMV.

#pragma mark - UINavigationControllerDelegate

- (void)navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    BOOL isRootVC = viewController == navigationController.viewControllers.firstObject;
    navigationController.interactivePopGestureRecognizer.enabled = !isRootVC;
}