iOS 7, corrupt UINavigationBar when swiping back fast using the default interactivePopGestureRecognizer

Question

I have an issue that I\'m stuck on, but I have no idea why it even happens; If I push a detail controller on the stack, and I swipe back very quickly using the default left edge

Answer 1

Key Concept

Disable gesture recognizer when pushing view controller, and enable it when view appeared.

A Common Solution: Subclassing

You can subclass UINavigationController and UIViewController to prevent corruption.

MyNavigationController : UINavigationController

- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    [super pushViewController:viewController animated:animated];
    self.interactivePopGestureRecognizer.enabled = NO; // disable
}

MyViewController : UIViewController

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
    self.navigationController.interactivePopGestureRecognizer.enabled = YES; // enable
}

Problem: Too annoying

• Need to use MyNavigationController and MyViewController instead of UINavigationController and UIViewController.
• Need to subclass for UITableViewController, UICollectionViewController, and more.

A Better Solution: Method Swizzling

It could be done by swizzling UINavigationController and UIViewController methods. Want to know about method swizzling, visit here.

Example below uses JRSwizzle that makes method swizzling easy.

UINavigationController

+ (void)load
{
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        [self jr_swizzleMethod:@selector(viewDidLoad)
                    withMethod:@selector(hack_viewDidLoad)
                         error:nil];
        [self jr_swizzleMethod:@selector(pushViewController:animated:)
                    withMethod:@selector(hack_pushViewController:animated:)
                         error:nil];
    });
}

- (void)hack_viewDidLoad
{
    [self hack_viewDidLoad];
    self.interactivePopGestureRecognizer.delegate = (id)self;
}

- (void)hack_pushViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    [self hack_pushViewController:viewController animated:animated];
    self.interactivePopGestureRecognizer.enabled = NO;
}

UIViewController

+ (void)load
{
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        [self jr_swizzleMethod:@selector(viewDidAppear:)
                    withMethod:@selector(hack_viewDidAppear:)
                         error:nil];
    });
}

- (void)hack_viewDidAppear:(BOOL)animated
{
    [self hack_viewDidAppear:animated];
    self.navigationController.interactivePopGestureRecognizer.enabled = YES;
}

Being Simple: Use Open Source

SwipeBack

SwipeBack does it automatically without any code.

With CocoaPods, just add a line below into your Podfile. You don't need to write any code. CocoaPods automatically import SwipeBack globally.

pod 'SwipeBack'

Install pod, and it's done!