Custom modal presentation and interface orientations

Question

mindz_eye OP

Created Jul ’15

Replies 2

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Views 4.1k

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My app has the following configuration:

- root view controller only supports portrait orientation

- presented view controller supports both portrait and landscape

When presenting VC using default presentation all works as expected - user may rotate the device and presented VC rotates accordingly. After dismissal root VC still shows up in portrait without any unnecessary animations.

However, after switching to custom full screen presentation using UIPresentationController this behavior breaks.

First, the controller being presented completely ignores device rotation. As it turns out, -[UIPresentationController shouldRemovePresentersView] should return YES to make things work. Documentation states this method should be overriden for non-full screen presentations, so it's completely unclear why it affects the rotation in my case.

Second, after dismissing presented VC, presenting VC stays in current device orientation no matter what preferredInterfaceOrientationForPresentation return value is. The only "workaround" I have found so far is using -[UIDevice setOrientation:], but I would like to avoid using private API as much as possible.

Answered by Frameworks Engineer in 34477022

First, the controller being presented completely ignores device rotation. As it turns out, -[UIPresentationController shouldRemovePresentersView] should return YES to make things work. Documentation states this method should be overridden for non-full screen presentations, so it's completely unclear why it affects the rotation in my case.

Your presentation controller should override -shouldRemovePresentersView to return YES if your custom presentation completely cover's the presenter's view. When the presenter's view is removed, queries from the window about supported interface orientations are forwarded to the presented view controller.

Second, after dismissing presented VC, presenting VC stays in current device orientation no matter what preferredInterfaceOrientationForPresentation return value is.

I believe this is currently to be expected. The logic for preserving the presenter's orientation is implemented by the private UIPresentationController subclasses used for the built-in presentation styles (e.g. UIModalPresentationStyleFullscreen), not in the UIPresentationController base class. If you need this behavior, you must specify one of the built-in modal presentation styles for your presented view controller. With some exceptions, you can still specify your own transition delegate, and thus can implement your own animations, when using the built-in presentation styles.

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Answer 1

Frameworks Engineer OP

Apple

Jul ’15

Accepted Answer

First, the controller being presented completely ignores device rotation. As it turns out, -[UIPresentationController shouldRemovePresentersView] should return YES to make things work. Documentation states this method should be overridden for non-full screen presentations, so it's completely unclear why it affects the rotation in my case.

Your presentation controller should override -shouldRemovePresentersView to return YES if your custom presentation completely cover's the presenter's view. When the presenter's view is removed, queries from the window about supported interface orientations are forwarded to the presented view controller.

Second, after dismissing presented VC, presenting VC stays in current device orientation no matter what preferredInterfaceOrientationForPresentation return value is.

I believe this is currently to be expected. The logic for preserving the presenter's orientation is implemented by the private UIPresentationController subclasses used for the built-in presentation styles (e.g. UIModalPresentationStyleFullscreen), not in the UIPresentationController base class. If you need this behavior, you must specify one of the built-in modal presentation styles for your presented view controller. With some exceptions, you can still specify your own transition delegate, and thus can implement your own animations, when using the built-in presentation styles.

1

Answer 2

joe_lucid OP

May ’18

Can you elaborate on your answer? Are you saying that the only way to get the desired behavior is to *not* use modal presentation style `.custom`? If it is an option to use a custom presentation style, how do you convince the device to respect the orientation from within your `UIPresentationController` subclass. I've checked and the preferred orientation is being checked on presentation, but there doesn't appear to be a way to use it.

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