UIModalTransitionStylePartialCurl with UITabBarController

Question

This question has been asked a lot e.g. here but as far as I can see is yet to be answered in full.

I have a UITabBarController with a UINavigatio

Answer 1

Tim Arnold's response worked great for me, thanks!

One trap to watch out for: your modal page-curl transition will take over the whole screen if your content view controller is added as a child of the container view controller. You could just not add it as a child, but then none of the view lifecycle methods will get called on your content controller (e.g. viewDidLoad, viewWillAppear), which could be a problem.

Fortunately, there is a way around this. In your container controller:

• Add your content controller as a child in viewDidLoad
• Remove it as a child in viewDidAppear
• Re-add it as a child in viewWillDisappear.

That way, your content controller gets its lifecycle methods called, while still being able to do a modal page-curl transition without taking up the whole screen.

Here is the entire code of a bare-bones solution:

@interface XXContainerController : UIViewController
@property (strong, nonatomic) UIViewController *contentController;
@property (nonatomic) BOOL curled;
@end

@implementation XXContainerController

@synthesize contentController = _contentController;
@synthesize curled = _curled;

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.contentController = [self.storyboard
        instantiateViewControllerWithIdentifier:@"SomeControllerInStoryboard"];

    // Add content controller as child view controller.
    // This way, it will receive all the view lifecycle events
    [self addChildViewController:self.contentController];
    self.contentController.view.frame = self.view.bounds;
    [self.view addSubview:self.contentController.view];
    [self.contentController didMoveToParentViewController:self];    
}

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];

    // Remove the content controller as child view controller.
    // This way, the modal page curl transition will
    // not take over the whole screen.
    // NOTE: need to wait until content controller has appeared
    // (which will happen later).
    // Achieve this by running the code at the end of the animation loop
    [UIView animateWithDuration:0 animations:nil completion:^(BOOL finished) {
        [self.contentController removeFromParentViewController];
    }];
}

- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];

    // Add the content controller as child view controller again
    // so it receives the view lifecycle events
    [self addChildViewController:self.contentController];
}

- (void)setCurled:(BOOL)curled
{
    if (curled == _curled) return;

    _curled = curled;

    // Curl up the content view and show underneath controller's view
    if (curled) {
        // Note you can specify any modal transition in storyboard
        // E.g. page curl, flip horizontal
        [self.contentController
            performSegueWithIdentifier:@"SomeModalSegueDefinedInStoryboard"
            sender:self];

    // Uncurl and show the content controller's view again
    } else {
        [self.contentController dismissModalViewControllerAnimated:YES];

        // Have to do this, otherwise the content controller's view
        // gets messed up for some reason 
        self.contentController.view.frame = self.view.bounds;
    }
}

@end