SwiftUI performance

SwiftUI has introduced several new features and improvements aimed at enhancing performance and providing more control over animations and visual effects. Here are some key points related to SwiftUI performance from the WWDC 2024 sessions:

1. Custom Shaders and Metal Integration:

   • SwiftUI now allows the use of custom Metal shaders directly within SwiftUI views, enabling high-performance imperative drawing and more complex visual effects. This can be particularly useful for creating unique experiences, such as a classic flipboard animation using Metal shaders (SwiftUI essentials).

2. Precompiled Shaders:

   • To avoid frame drops caused by lazy shader compilation, SwiftUI now supports precompiling shaders before their first use. This ensures smoother performance when using custom shaders (What’s new in SwiftUI).

3. Enhanced Scroll View Control:

   • SwiftUI has introduced new APIs for fine-grained control over scroll views. These include the ability to react to changes in content offsets and sizes, detect view visibility changes due to scrolling, and programmatically control scroll positions. These enhancements help in creating more performant and responsive scrolling experiences (What’s new in SwiftUI).

4. Swift 6 Language Mode:

   • The new Swift 6 language mode includes compile-time data race safety, which improves the reliability and performance of SwiftUI apps. Views in SwiftUI are now evaluated on the main actor, ensuring that all types conforming to the view protocol are implicitly isolated to the main actor by default (What’s new in SwiftUI).

5. Declarative Structure and State Management:

   • SwiftUI's declarative structure and state-driven updates automatically keep the UI up to date, reducing boilerplate code and minimizing update bugs. This approach ensures that the UI remains performant as data changes (SwiftUI essentials).

6. Interactive Previews:

   • Xcode previews in SwiftUI allow developers to see how their views look and behave in different contexts without needing to run the app repeatedly. This feature helps in quickly iterating and optimizing the performance of the UI (SwiftUI essentials).

For more detailed information, you can refer to the following sessions:

• Create custom visual effects with SwiftUI
• SwiftUI essentials
• What’s new in SwiftUI
• Platforms State of the Union