How to implement animated transitions

To implement animated transitions in your app, you can leverage the information from the following sessions presented at WWDC:

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

Using SwiftUI for Custom Transitions

In the session Create custom visual effects with SwiftUI, you can learn how to create custom transitions by conforming to the Transition protocol. Here's a brief overview:

1. Define a Custom Transition:

   • Create a new struct that conforms to the Transition protocol.
   • Implement the transition body function, which takes content and phase parameters.
   • Use the phase value to conditionally style your view.

   struct Twirl: Transition {
       func body(content: Content, phase: TransitionPhase) -> some View {
           content
               .scaleEffect(phase == .active ? 1.0 : 0.5)
               .opacity(phase == .active ? 1.0 : 0.0)
               .rotationEffect(Angle(degrees: phase == .active ? 0 : -360))
               .brightness(phase == .active ? 0 : -0.5)
       }
   }
   

2. Apply the Custom Transition:

   • Attach your custom transition to your view.

   .transition(Twirl())
   

For more details, you can refer to the session Create custom visual effects with SwiftUI (10:13).

Using UIKit for Transitions

In the session Enhance your UI animations and transitions, you can learn about integrating SwiftUI animations with UIKit and AppKit views:

1. Zoom Transitions:

   • Use the new zoom transition to enhance visual continuity in your app.
   • Add the navigationTransitionStyle modifier to specify the zoom transition.

   .navigationTransitionStyle(.zoom)
   

2. Bridging Animations:

   • Use the new animate method on the context to bridge animations between SwiftUI and UIKit.

   context.animate {
       UIView.animate(withDuration: 0.3) {
           // Your UIKit animation code
       }
   }
   

For more details, you can refer to the session Enhance your UI animations and transitions (09:49).

Additional Tips

• Combining Transitions: You can chain multiple transitions using the combined method.
• Interactive Animations: Ensure your code is ready to handle transitions starting at any time, especially for continuously interactive transitions like the zoom transition.

For a comprehensive understanding, you can explore the chapters in the sessions mentioned above:

• Enhance your UI animations and transitions

  • Introduction
  • New transitions!
  • Zoom transitions in SwiftUI
  • Zoom transitions in UIKit
  • SwiftUI animation
  • Animating representables
  • Gesture-driven animations

• Create custom visual effects with SwiftUI

  • Introduction
  • View transitions
  • Text transitions

By following these guidelines and exploring the sessions, you can effectively implement animated transitions in your app.