Use UIPanGestureRecognizer instead of UIScreenEdgePanGestureRecognizer

1.m

// it's just a proof of concept; there are known problems with this solution
- (void)addPanGestureForPopTransitioning
{
    UINavigationController *navigationController = self.navigationController;
    NSArray *targets = [navigationController.interactivePopGestureRecognizer valueForKey:@"_targets"];
    if ([targets isKindOfClass:[NSArray class]]) {
        @try {
            id interactivePanTarget = [[targets firstObject] valueForKey:@"target"];
            UIPanGestureRecognizer *panRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:interactivePanTarget action:NSSelectorFromString(@"handleNavigationTransition:")];
            [navigationController.view addGestureRecognizer:panRecognizer];

            navigationController.interactivePopGestureRecognizer.enabled = NO;
        }
        @catch (NSException *exception) {
            NSLog(@"%@", exception);
        }
    }
}

http://web.archive.org/web/20140827064005/http://blommegard.se/blog/2014/01/31/a-take-on-custom-transitions-with-uinavigationcontroller/

Hm, maybe we could modify the edges property of UIScreenEdgePanGestureRecognizer instead.