Response to animated/interactive UIViewController transition.

gistfile1.m

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    
    [self.transitionCoordinator animateAlongsideTransition:nil completion:^(id<UIViewControllerTransitionCoordinatorContext> context) {
        if ( [context initiallyInteractive] ) return;
        [self _onTransitionEnd:context];
    }];
    [self.transitionCoordinator notifyWhenInteractionEndsUsingBlock:^(id<UIViewControllerTransitionCoordinatorContext> context) {
        [self _onTransitionEnd:context];
    }];
}

- (void)_onTransitionEnd:(id<UIViewControllerTransitionCoordinatorContext>)context
{
    if ( [context isCancelled] ) {
        
    }
    else {
        
    }
}