Custom UIViewController Transitions Mike Zornek • January 8, 2015

More Info • WWDC 2013 Session 218 • Sample Code:
 https://github.com/soleares/SOLPresentingFun • My Demo:
 https://github.com/zorn/ CustomViewControllerTransitionsDemo

Transitions are found inside… • Presentation
 presentViewController:animated:completion: • UINavigationController • UITabBarController • UICollectionViewController

A B .modalPresentationStyle .modalTransitionStyle

.modalPresentationStyle The presentation style determines how a modally presented view controller is displayed onscreen. In a horizontally compact environment, modal view controllers are always presented full-screen. In a horizontally regular environment, there are several different presentation options. For a list of possible presentation styles, and their compatibility with the available transition styles, see the Modal Presentation Styles constant descriptions.

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.modalTransitionStyle This property determines how the view controller's is animated onscreen when it is presented using the presentViewController:animated:completion: method. To change the transition type, you must set this property before presenting the view controller. The default value for this property is UIModalTransitionStyleCoverVertical. Others include: • UIModalTransitionStyleFlipHorizontal • UIModalTransitionStyleCrossDissolve • UIModalTransitionStylePartialCurl

Doing it custom…

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender { if ([segue.identifier isEqualToString:@"launchModal"]) { UIViewController *vc = segue.destinationViewController; vc.modalPresentationStyle = UIModalPresentationCustom; vc.transitioningDelegate = self; } }

@protocol UIViewControllerTransitioningDelegate @optional - (id ) animationControllerForPresentedController:(UIViewController *)presented presentingController:(UIViewController *)presenting sourceController:(UIViewController *)source; - (id ) animationControllerForDismissedController:(UIViewController *)dismissed; // 2 more for interaction, 1 more for presentation controller @end

#pragma mark - UIViewControllerTransitioningDelegate - (id ) animationControllerForPresentedController:(UIViewController *)presented presentingController:(UIViewController *)presenting sourceController:(UIViewController *)source { GrowAndFadeTransitionAnimator *animator = [[GrowAndFadeTransitionAnimator alloc] init]; animator.appearing = YES; return animator; } - (id ) animationControllerForDismissedController:(UIViewController *)dismissed;{ GrowAndFadeTransitionAnimator *animator = [[GrowAndFadeTransitionAnimator alloc] init]; animator.appearing = NO; return animator; }

@protocol UIViewControllerAnimatedTransitioning - (NSTimeInterval)transitionDuration:(id )transitionContext; - (void)animateTransition:(id )transitionContext; @optional - (void)animationEnded:(BOOL) transitionCompleted; @end

Demo