This solution is for iOS 8+.
Problem description
- Application key window have UINavigationController's subclass as its rootViewController.
- This NC subclass prohibits some of the interface orientations.
- Some View Controller (VC1) in the NC stack is presenting another View Controller (VC2) modally and fullscreen.
- This presented VC2 allows more interface orientations than NC do.
- User rotates device to orientation that is prohibited by NC, but allowed by presented VC2.
- User dismisses the presented VC2.
- View of VC1 has incorrect frame.
Setup and illustration
UINavigationController's subclass:
- (NSUInteger)supportedInterfaceOrientations
{
return UIInterfaceOrientationMaskPortrait;
}
- (BOOL)shouldAutorotate
{
return YES;
}
VC1 initial appearance and UI view stack:
Presenting VC2 (QLPreviewController in that example) from VC1:
QLPreviewController *pc = [[QLPreviewController alloc] init];
pc.dataSource = self;
pc.delegate = self;
pc.modalPresentationStyle = UIModalPresentationFullScreen;
[self.navigationController presentViewController:pc animated:YES completion:nil];
VC2 is presented and device rotated to landscape:
VC2 dismissed, device is back in portrait mode, but NC stack remains in landscape:
Cause
Apple documentation states:
When you present a view controller using the presentViewController:animated:completion: method, UIKit always manages the presentation process. Part of that process involves creating the presentation controller that is appropriate for the given presentation style.
Apparently there is a bug in handling UINavigationController stack.
Solution
This bug can be bypassed by providing our own transitioning delegate.
BTTransitioningDelegate.h
#import <UIKit/UIKit.h>
@interface BTTransitioningDelegate : NSObject <UIViewControllerTransitioningDelegate>
@end
BTTransitioningDelegate.m
#import "BTTransitioningDelegate.h"
static NSTimeInterval kDuration = 0.5;
// This class handles presentation phase.
@interface BTPresentedAC : NSObject <UIViewControllerAnimatedTransitioning>
@end
@implementation BTPresentedAC
- (NSTimeInterval)transitionDuration:(id <UIViewControllerContextTransitioning>)transitionContext
{
return kDuration;
}
- (void)animateTransition:(id<UIViewControllerContextTransitioning>)context
{
// presented VC
UIViewController *toVC = [context viewControllerForKey:UITransitionContextToViewControllerKey];
// presented controller ought to be fullscreen
CGRect frame = [[[UIApplication sharedApplication] keyWindow] bounds];
// we will slide view of the presended VC from the bottom of the screen,
// so here we set the initial frame
toVC.view.frame = CGRectMake(frame.origin.x, frame.origin.y + frame.size.height, frame.size.width, frame.size.height);
// [context containerView] acts as the superview for the views involved in the transition
[[context containerView] addSubview:toVC.view];
UIViewAnimationOptions options = (UIViewAnimationOptionCurveEaseOut);
[UIView animateWithDuration:kDuration delay:0 options:options animations:^{
// slide view to position
toVC.view.frame = frame;
} completion:^(BOOL finished) {
// required to notify the system that the transition animation is done
[context completeTransition:finished];
}];
}
@end
// This class handles dismission phase.
@interface BTDismissedAC : NSObject <UIViewControllerAnimatedTransitioning>
@end
@implementation BTDismissedAC
- (NSTimeInterval)transitionDuration:(id <UIViewControllerContextTransitioning>)transitionContext
{
return kDuration;
}
- (void)animateTransition:(id<UIViewControllerContextTransitioning>)context
{
// presented VC
UIViewController *fromVC = [context viewControllerForKey:UITransitionContextFromViewControllerKey];
// presenting VC
UIViewController *toVC = [context viewControllerForKey:UITransitionContextToViewControllerKey];
// inserting presenting VC's view under presented VC's view
toVC.view.frame = [[[UIApplication sharedApplication] keyWindow] bounds];
[[context containerView] insertSubview:toVC.view belowSubview:fromVC.view];
// current frame and transform of presented VC
CGRect frame = fromVC.view.frame;
CGAffineTransform transform = fromVC.view.transform;
// determine current presented VC's view rotation and assemble
// target frame to provide naturally-looking dismissal animation
if (transform.b == -1) {
// -pi/2
frame = CGRectMake(frame.origin.x + frame.size.width, frame.origin.y, frame.size.width, frame.size.height);
} else if (transform.b == 1) {
// pi/2
frame = CGRectMake(frame.origin.x - frame.size.width, frame.origin.y, frame.size.width, frame.size.height);
} else if (transform.a == -1) {
// pi
frame = CGRectMake(frame.origin.x, frame.origin.y - frame.size.height, frame.size.width, frame.size.height);
} else {
// 0
frame = CGRectMake(frame.origin.x, frame.origin.y + frame.size.height, frame.size.width, frame.size.height);
}
UIViewAnimationOptions options = (UIViewAnimationOptionCurveEaseOut);
[UIView animateWithDuration:kDuration delay:0 options:options animations:^{
// slide view off-screen
fromVC.view.frame = frame;
} completion:^(BOOL finished) {
// required to notify the system that the transition animation is done
[context completeTransition:finished];
}];
}
@end
@implementation BTTransitioningDelegate
- (id <UIViewControllerAnimatedTransitioning>)animationControllerForPresentedController:(UIViewController *)presented presentingController:(UIViewController *)presenting sourceController:(UIViewController *)source
{
return [[BTPresentedAC alloc] init];
}
- (id <UIViewControllerAnimatedTransitioning>)animationControllerForDismissedController:(UIViewController *)dismissed
{
return [[BTDismissedAC alloc] init];
}
@end
Import that transitioning delegate in presenting VC:
#import "BTTransitioningDelegate.h"
Store a strong reference to an instance:
@property (nonatomic, strong) BTTransitioningDelegate *transitioningDelegate;
Instantiate in -viewDidLoad:
self.transitioningDelegate = [[BTTransitioningDelegate alloc] init];
Call when appropriate:
QLPreviewController *pc = [[QLPreviewController alloc] init];
pc.dataSource = self;
pc.delegate = self;
pc.transitioningDelegate = self.transitioningDelegate;
pc.modalPresentationStyle = UIModalPresentationFullScreen;
[self.navigationController presentViewController:pc animated:YES completion:nil];
