What's new in SwiftUI in Xcode 16?

In Xcode 16, there are several new features and improvements for SwiftUI:

1. Previews: Xcode Previews now have a new dynamic linking architecture that uses the same build artifacts for both previews and when you build and run. This change avoids the need to rebuild your project when switching between the two, resulting in a smoother workflow. Additionally, a new previewable macro allows you to use dynamic properties like state directly in an Xcode preview, reducing the amount of code you need to write.

2. Customizations: SwiftUI has gained new customization options to fine-tune the look and feel of your apps. This includes custom hover effects for visionOS, new options to customize window behavior and styling in macOS, and a new text renderer API for advanced visual effects and animations.

3. Graphics Capabilities: SwiftUI introduces new graphics capabilities, such as a mix modifier on colors to blend them by a given amount. The custom shader feature has been extended to allow precompiling shaders, avoiding frame drops caused by lazy shader compilation.

4. Scroll Views: There are new APIs for scroll views, providing fine-grained control over their behavior. You can now react to changes in content offsets and sizes, detect when a view's visibility changes due to scrolling, and programmatically control scroll positions and content alignment.

5. Interoperability: SwiftUI has improved interoperability with UIKit and AppKit. Gesture recognition has been factored out of UIKit, allowing you to use any built-in or custom UI gesture recognizer in your SwiftUI view hierarchy. Animations have also been factored out, enabling you to set up animations on UIKit or AppKit views and drive them with SwiftUI.

6. Swift 6 Language Mode: SwiftUI has improved its APIs to make it easier to adopt the new Swift 6 language mode, which provides compile-time data race safety.

For more detailed information, you can refer to the sessions Platforms State of the Union and What’s new in SwiftUI.