What performance improvements are there for SwiftUI?

Performance Improvements in SwiftUI

SwiftUI has received several performance improvements and new features this year, as highlighted in the sessions at WWDC 2024:

1. Precompiled Shaders: SwiftUI now allows for the precompilation of custom shaders before their first use, which helps avoid frame drops caused by lazy shader compilation. This ensures smoother graphics performance (What’s new in SwiftUI).

2. Dynamic Linking in Xcode Previews: Xcode Previews has a new dynamic linking architecture that uses the same build artifacts for previews and when you build and run. This avoids the need to rebuild your project when switching between the two, making for a dramatically smoother and more productive workflow (Platforms State of the Union).

3. Improved Scrolling Performance: SwiftUI has introduced new APIs for finer control over scroll views, including the ability to detect changes in view visibility due to scrolling. This allows for more performant reactions to content changes and better user experiences (What’s new in SwiftUI).

4. Main Actor Annotation: Views in SwiftUI are now marked with the main actor annotation, which means all types conforming to the view protocol are implicitly isolated to the main actor by default. This change helps in maintaining performance and thread safety (What’s new in SwiftUI).

5. Interoperability Enhancements: SwiftUI has improved its interoperability with UIKit and AppKit, allowing for better integration of gesture recognizers and animations. This includes the ability to set up animations on UIKit or AppKit views and drive them with SwiftUI, including fully custom animations (Platforms State of the Union).

Relevant Sessions

• Platforms State of the Union
• What’s new in SwiftUI
• SwiftUI essentials

These sessions provide a comprehensive overview of the new features and performance improvements in SwiftUI.