Imitation of the Photos app browse mode. Horizontally scrolling thumbnails, with detail view above the scrollview. SwiftUI and Bindings exercise. Tested on macOS, iOS, visionOS.
Follows the concepts of https://developer.apple.com/tutorials/swiftui-concepts/driving-changes-in-your-ui-with-state-and-bindings, but this is a vertical layout, not a horizontal layout. Imagine a NavigationSplitViewController that’s laid out vertically instead of horizontally.
The thumbnail and detail views are quite primitive. They're meant as simple examples. This is a Bindings exercise, not a pretty UI exercise.
For the detail view: we have a detail wrapper that accepts a binding to an item (a notional City). The detail wrapper performs a lookup of the item binding ID, and shows a detail view that accepts an actual item/City).
