How to use UIViewControllerAnimatedTransitioning with UINavigationController? - ios

Question

How can I get custom transitions (iOS7) when pushing a view controller onto UINavigationController? I tried setting the TransitioningDelegate both in the UINavigationController and also on the controller I'm pushing
The methods never get called.
All examples I find use custom transitions when presenting modally.

Answer 1

#rounak has the right idea, but sometimes it helps to have code ready without having to download from github.
Here are the steps that I took:
Make your FromViewController.m conform to UINavigationControllerDelegate. Other sample code out there tells you to conform to UIViewControllerTransitioningDelegate, but that's only if you're presenting the ToViewController.
#interface ViewController : UIViewController
Return your custom transition animator object in the delegate callback method in FromViewController:
- (id <UIViewControllerAnimatedTransitioning>)navigationController:(UINavigationController *)navigationController
animationControllerForOperation:(UINavigationControllerOperation)operation
fromViewController:(UIViewController *)fromVC
toViewController:(UIViewController *)toVC {
TransitionAnimator *animator = [TransitionAnimator new];
animator.presenting = (operation == UINavigationControllerOperationPush);
return animator;
}
Create your custom animator class and paste these sample methods:
- (NSTimeInterval)transitionDuration:(id <UIViewControllerContextTransitioning>)transitionContext {
return 0.5f;
}
- (void)animateTransition:(id <UIViewControllerContextTransitioning>)transitionContext {
// Grab the from and to view controllers from the context
UIViewController *fromViewController = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
UIViewController *toViewController = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
// Set our ending frame. We'll modify this later if we have to
CGRect endFrame = CGRectMake(80, 280, 160, 100);
if (self.presenting) {
fromViewController.view.userInteractionEnabled = NO;
[transitionContext.containerView addSubview:fromViewController.view];
[transitionContext.containerView addSubview:toViewController.view];
CGRect startFrame = endFrame;
startFrame.origin.x += 320;
toViewController.view.frame = startFrame;
[UIView animateWithDuration:[self transitionDuration:transitionContext] animations:^{
fromViewController.view.tintAdjustmentMode = UIViewTintAdjustmentModeDimmed;
toViewController.view.frame = endFrame;
} completion:^(BOOL finished) {
[transitionContext completeTransition:YES];
}];
}
else {
toViewController.view.userInteractionEnabled = YES;
[transitionContext.containerView addSubview:toViewController.view];
[transitionContext.containerView addSubview:fromViewController.view];
endFrame.origin.x += 320;
[UIView animateWithDuration:[self transitionDuration:transitionContext] animations:^{
toViewController.view.tintAdjustmentMode = UIViewTintAdjustmentModeAutomatic;
fromViewController.view.frame = endFrame;
} completion:^(BOOL finished) {
[transitionContext completeTransition:YES];
}];
}
}
Essentially, the animator is the object doing the heavy lifting. Of course, you can make your UINavigationControllerDelegate be a separate object, but that depends on how your architect your app.

Answer 2

objc.io's post on view controller transitions are specifically for pushing and popping view controllers. http://objc.io/issue-5/view-controller-transitions.html
I've done this animation (http://i.imgur.com/1qEyMu3.gif) solely based on the objc.io post.
In short you have to have a class(es) implementing UINavigationControllerDelegate, and UIViewControllerAnimatedTransitioning with the required methods for returning the correct animator, and performing the animations.

Answer 3

You can look at my demo project which demonstrates using custom transitions in UINavigationController. Look at https://github.com/Vaberer/BlurTransition.

Answer 4

EDIT: Just realised this might not answer your question. But it is an alternative.
If you're using a storyboard you can do a custom transition by creating a custom segue.
In the attributes inspector change the segue class name to your custom transition class e.g. MySegue. Then create the MySegue class and implement the -(void)perform method to perform your transition.
- (void) perform{
UIViewController *source = self.sourceViewController;
UIViewController *destination = self.destinationViewController;
[UIView transitionFromView:source.view
toView:destination.view
duration:0.50f
options:UIViewAnimationOptionTransitionFlipFromTop
completion:nil];
}