UINavigationController animation issues fix

gistfile1.m

@interface NavigationController : UINavigationController <UINavigationControllerDelegate> {
    NSMutableArray *animatingControllers;
}

@end

@implementation NavigationController
- (id)init
{
    self = [super init];
    if (self) {
        animatingControllers = [NSMutableArray array];
    }
    return self;
}

- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    if (animated) {
        [animatingControllers addObject:viewController];
    }
}

- (void)navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    if (animated) {
        [animatingControllers removeObject:viewController];
    }
}

- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    if ([animatingControllers count] == 0) {
        return [super pushViewController:viewController animated:animated];
    }
    
    dispatch_async(dispatch_get_main_queue(), ^{
        [self pushViewController:viewController animated:animated];
    });
}

- (UIViewController *)popViewControllerAnimated:(BOOL)animated
{
    if ([animatingControllers count] == 0) {
        return [super popViewControllerAnimated:animated];
    }
    
    dispatch_async(dispatch_get_main_queue(), ^{
       [self popViewControllerAnimated:animated];
    });
    
    return [self topViewController];
}

- (NSArray *)popToRootViewControllerAnimated:(BOOL)animated
{
    if ([animatingControllers count] == 0) {
        return [super popToRootViewControllerAnimated:animated];
    }
    
    dispatch_async(dispatch_get_main_queue(), ^{
        [self popToRootViewControllerAnimated:animated];
    });
    
    NSArray *vcs = [self viewControllers];
    return [vcs subarrayWithRange:NSMakeRange(1, [vcs count] - 1)];
}

- (NSArray *)popToViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    if ([animatingControllers count] == 0) {
        return [super popToViewController:viewController animated:animated];
    }
    
    dispatch_async(dispatch_get_main_queue(), ^{
        [self popToViewController:viewController animated:animated];
    });
    
    NSArray *vcs = [self viewControllers];
    NSUInteger index = [vcs indexOfObject:viewController];
    index = index == NSNotFound ? [vcs count] : index;
    return [vcs subarrayWithRange:NSMakeRange(index + 1, [vcs count] - index - 1)];
}
@end