How do I do a carrousel in SwiftUI?

To create a carousel effect in SwiftUI, you can use the scrollTransition modifier to transform a standard collection of elements into a custom scroll view. Here's a brief overview of how you can achieve this:

1. Use a Horizontal Scroll View: Start with a horizontal scroll view containing your items, such as photos.

2. Apply the scrollTransition Modifier: This modifier allows you to change the rotation and offset of each item based on its position in the scroll view. As you scroll, items on the leading and trailing edges can be rotated to create a circular carousel effect.

3. Adjust Rotation and Offset: Use the value property to determine how far off-screen an item is and apply rotation accordingly. If an item is fully on-screen, the isIdentity property will be true.

Here is a simplified example based on the context provided:

import SwiftUI

struct CarouselView: View {
    let photos: [String] // Array of photo names

    var body: some View {
        ScrollView(.horizontal, showsIndicators: false) {
            HStack {
                ForEach(photos, id: \.self) { photo in
                    Image(photo)
                        .resizable()
                        .scaledToFit()
                        .frame(width: 200, height: 200)
                        .scrollTransition { content, phase in
                            content
                                .rotation3DEffect(
                                    .degrees(phase.isIdentity ? 0 : -30),
                                    axis: (x: 0, y: 1, z: 0)
                                )
                                .offset(x: phase.isIdentity ? 0 : -50)
                        }
                }
            }
        }
    }
}

For more detailed information and examples, you can refer to the session Create custom visual effects with SwiftUI at WWDC 2024. This session covers how to use the scrollTransition modifier to create unique scroll effects, including a carousel.