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Swift/Win32

AdaptivePresentationControllerDelegate

A set of methods that, in conjunction with a presentation controller, determine how to respond to trait changes in your application.

public protocol AdaptivePresentationControllerDelegate: AnyObject

Inheritance

AnyObject

Default Implementations

adaptivePresentationStyle(for:traitCollection:) 

public func adaptivePresentationStyle(for controller: PresentationController,
                                        traitCollection: TraitCollection)
      -> ModalPresentationStyle

adaptivePresentationStyle(for:) 

public func adaptivePresentationStyle(for controller: PresentationController)
      -> ModalPresentationStyle

presentationController(controller:viewControllerForAdaptivePresentationStyle:) 

public func presentationController(controller: PresentationController,
                                     viewControllerForAdaptivePresentationStyle style: ModalPresentationStyle)
      -> ViewController?

presentationController(_:willPresentWithAdaptiveStyle:transitionCoordinator:) 

public func presentationController(_ controller: PresentationController,
                                     willPresentWithAdaptiveStyle style: ModalPresentationStyle,
                                     transitionCoordinator: ViewControllerTransitionCoordinator?)

presentationControllerDidAttemptToDismiss(_:) 

public func presentationControllerDidAttemptToDismiss(_ presentationController: PresentationController)

presentationControllerShouldDismiss(_:) 

public func presentationControllerShouldDismiss(_ presentationController: PresentationController) -> Bool

presentationControllerDidDismiss(_:) 

public func presentationControllerDidDismiss(_ presentationController: PresentationController)

presentationControllerWillDismiss(_:) 

public func presentationControllerWillDismiss(_ presentationController: PresentationController)

presentationController(_:prepare:) 

public func presentationController(_ presentationController: PresentationController,
                                     prepare adaptivePresentationController: PresentationController)

Requirements

adaptivePresentationStyle(for:​traitCollection:​)

Asks the delegate for the presentation style to use when the specified set of traits are active.

func adaptivePresentationStyle(for controller: PresentationController,
                                 traitCollection: TraitCollection)
      -> ModalPresentationStyle

The presentation controller calls this method when the traits of the current environment are about to change. Your implementation of this method can return the preferred presentation style to use for the specified traits. If you do not return one of the allowed styles, the presentation controller uses its preferred default style.

If you do not implement this method in your delegate, the framework calls the adaptivePresentationStyle(for:) method instead.

adaptivePresentationStyle(for:​)

Asks the delegate for the new presentation style to use.

func adaptivePresentationStyle(for controller: PresentationController)
      -> ModalPresentationStyle

Use the adaptivePresentationStyle(for:traitCollection:) method to handle all trait changes instead of this method. If you do not implement that method, you can use this method to change the presentation style when transitioning to a horizontally compact environment.

If you do not implement this method or if you return an invalid style, the current presentation controller returns its preferred default style.

presentationController(_:​viewControllerForAdaptivePresentationStyle:​)

Asks the delegate for the view controller to display when adapting to the specified presentation style.

func presentationController(_ controller: PresentationController,
                              viewControllerForAdaptivePresentationStyle style: ModalPresentationStyle)
      -> ViewController?

When a size class change causes a change to the underlying presentation style, the presentation controller calls this method to ask for the view controller to display in that new style. This method is your opportunity to replace the current view controller with one that is better suited for the new presentation style. For example, you might use this method to insert a navigation controller into your view hierarchy to facilitate pushing new view controllers more easily in the compact environment. In that instance, you would return a navigation controller whose root view controller is the currently presented view controller. You could also return an entirely different view controller if you prefer.

If you do not implement this method or your implementation returns nil, the presentation controller uses its existing presented view controller.

presentationController(_:​willPresentWithAdaptiveStyle:​transitionCoordinator:​)

Notifies the delegate that an adaptivity-related transition is about to occur.

func presentationController(_ presentationController: PresentationController,
                              willPresentWithAdaptiveStyle style: ModalPresentationStyle,
                              transitionCoordinator: ViewControllerTransitionCoordinator?)

When a size class change occurs, the framework calls this method to let you know how the presentation controller will adapt. Use this method to make any additional changes. For example, you might use the transition coordinator object to create additional animations for the transition.

presentationControllerDidAttemptToDismiss(_:​)

Notifies the delegate that a user-initiated attempt to dismiss a view was prevented.

func presentationControllerDidAttemptToDismiss(_ presentationController: PresentationController)

The framework supports refusing to dismiss a presentation when the presentationController.isModalInPresentation returns true or presentationControllerShouldDismiss(_:) returns false.

Use this method to inform the user why the presentation can’t be dismissed, for example, by presenting an instance of AlertController.

presentationControllerShouldDismiss(_:​)

Asks the delegate for permission to dismiss the presentation.

func presentationControllerShouldDismiss(_ presentationController: PresentationController)
      -> Bool

The system may call this method at any time. This method isn’t guaranteed to be followed by a call to presentationControllerWillDismiss(_:) or presentationControllerDidDismiss(_:). Make sure that your implementation of this method returns quickly.

presentationControllerDidDismiss(_:​)

Notifies the delegate after a presentation is dismissed.

func presentationControllerDidDismiss(_ presentationController: PresentationController)

This method is not called if the presentation is dismissed programmatically.

presentationControllerWillDismiss(_:​)

Notifies the delegate before a presentation is dismissed.

func presentationControllerWillDismiss(_ presentationController: PresentationController)

You can use this method to set up animations or interaction notifications with the presentationController’s transitionCoordinator.

This method is not called if the presentation is dismissed programmatically.

presentationController(_:​prepare:​)

Provides an opportunity to configure the adaptive presentation controller after an adaptivity change.

func presentationController(_ presentationController: PresentationController,
                              prepare adaptivePresentationController: PresentationController)

The system calls this method during adaptation so the delegate can configure properties of the adaptive presentation controller before it presents.

For example, the system automatically adapts a view controller that presents as a popover in standard size classes to a sheet in compact size classes. You can implement this method to customize the sheet’s properties before it presents.