how to transition a view controller

To transition a view controller, you can follow the guidance provided in the session "Enhance your UI animations and transitions" from WWDC 2024. Here are some key points:

1. Zoom Transitions in UIKit:

   • To adopt a zoom transition in UIKit, you need to specify on the pushViewController that it would like to zoom and provide the view to use as a source of the zoom transition. This involves capturing a stable identifier, such as a model object, to fetch a view rather than capturing a view directly. This is particularly important in cases where the source view may get reused, such as in a collection view.
   • Example:

     // Specify the zoom transition
     viewController.transitioningDelegate = self
     navigationController?.pushViewController(viewController, animated: true)
     

2. Handling View Controller Lifecycle and Callbacks:

   • Ensure your code works perfectly in the new world where push and pop transitions can begin at any time. Be ready for a new transition to start at any time and don't try to handle being in a transition differently from not being in a transition.
   • Keep temporary transition state to a minimum. If you need to keep track of state during a transition, reset it by viewDidAppear or viewDidDisappear. These are guaranteed to be called at the end of the transition if you're using the navigation controller delegate methods willShow and didShow for the view controller.

3. SwiftUI Integration:

   • SwiftUI can be incorporated into your app to handle transitions more functionally. SwiftUI's new lower-level APIs for animating UIKit and AppKit views with SwiftUI animations can be used to build custom UI transitions.

For more detailed information, you can refer to the session Enhance your UI animations and transitions (00:04:15) which covers UIKit view controller lifecycle and callbacks.

Relevant Sessions

1. Enhance your UI animations and transitions
2. Create custom visual effects with SwiftUI