Fix ForEach Collection change rendered View correctness

Examples/Bundler.toml

@@ -64,3 +64,8 @@ version = '0.1.0'
 identifier = 'dev.swiftcrossui.HoverExample'
 product = 'HoverExample'
 version = '0.1.0'
+
+[apps.ForEachExample]
+identifier = 'dev.swiftcrossui.ForEachExample'
+product = 'ForEachExample'
+version = '0.1.0'

Examples/Package.swift

@@ -76,6 +76,10 @@ let package = Package(
         .executableTarget(
             name: "HoverExample",
             dependencies: exampleDependencies
-        )
+		),
+		.executableTarget(
+            name: "ForEachExample",
+            dependencies: exampleDependencies
+		)
     ]
 )

Examples/Sources/ForEachExample/ForEachApp.swift

@@ -0,0 +1,105 @@
+import DefaultBackend
+import Foundation
+import SwiftCrossUI
+
+#if canImport(SwiftBundlerRuntime)
+    import SwiftBundlerRuntime
+#endif
+
+@main
+@HotReloadable
+struct ForEachApp: App {
+    @State var items = {
+        var items = [Item]()
+        for i in 0..<20 {
+            items.append(.init("\(i)"))
+        }
+        return items
+    }()
+    @State var biggestValue = 19
+    @State var insertionPosition = 10
+
+    var body: some Scene {
+        WindowGroup("ForEach") {
+            #hotReloadable {
+                ScrollView {
+                    VStack {
+                        Button("Append") {
+                            biggestValue += 1
+                            items.append(.init("\(biggestValue)"))
+                        }
+
+                        #if !os(tvOS)
+                            Button(
+                                "Insert in front of current item at position \(insertionPosition)"
+                            ) {
+                                biggestValue += 1
+                                items.insert(.init("\(biggestValue)"), at: insertionPosition)
+                            }
+
+                            Slider($insertionPosition, minimum: 0, maximum: items.count - 1)
+                                .onChange(of: items.count) {
+                                    guard insertionPosition > items.count - 1 else {
+                                        return
+                                    }
+                                    insertionPosition = max(items.count - 1, 0)
+                                }
+                        #endif
+
+                        ForEach(items) { item in
+                            ItemRow(
+                                item: item, isFirst: Optional(item.id) == items.first?.id,
+                                isLast: Optional(item.id) == items.last?.id
+                            ) {
+                                items.removeAll(where: { $0.id == item.id })
+                            } moveUp: {
+                                guard
+                                    let ownIndex = items.firstIndex(where: { $0.id == item.id }),
+                                    ownIndex != items.startIndex
+                                else { return }
+                                items.swapAt(ownIndex, ownIndex - 1)
+                            } moveDown: {
+                                guard
+                                    let ownIndex = items.firstIndex(where: { $0.id == item.id }),
+                                    ownIndex != items.endIndex
+                                else { return }
+                                items.swapAt(ownIndex, ownIndex + 1)
+                            }
+                        }
+                    }
+                    .padding(10)
+                }
+            }
+        }
+        .defaultSize(width: 400, height: 800)
+    }
+}
+
+struct ItemRow: View {
+    @State var item: Item
+    let isFirst: Bool
+    let isLast: Bool
+    var remove: () -> Void
+    var moveUp: () -> Void
+    var moveDown: () -> Void
+
+    var body: some View {
+        HStack {
+            Text(item.value)
+            Button("Delete") { remove() }
+            Button("⌃") { moveUp() }
+                .disabled(isFirst)
+            Button("⌄") { moveDown() }
+                .disabled(isLast)
+        }
+    }
+}
+
+class Item: Identifiable, SwiftCrossUI.ObservableObject {
+    let id = UUID()
+    @SwiftCrossUI.Published var value: String
+
+    init(_ value: String) {
+        self.value = value
+    }
+}

Examples/Sources/GreetingGeneratorExample/GreetingGeneratorApp.swift

@@ -38,7 +38,7 @@
                                 .padding(.top, 20)
 
                             ScrollView {
-                                ForEach(greetings.reversed()[1...]) { greeting in
+                                ForEach(items: greetings.reversed()[1...]) { greeting in
                                     Text(greeting)
                                 }
                             }

Examples/Sources/StressTestExample/StressTestApp.swift

@@ -43,12 +43,11 @@ struct StressTestApp: App {
                             for _ in 0..<1000 {
                                 values.append(Self.options.randomElement()!)
                             }
-
                             self.values[tab!] = values
                         }
                         if let values = values[tab!] {
                             ScrollView {
-                                ForEach(values) { value in
+                                ForEach(values, id: \.self) { value in
                                     Text(value)
                                 }
                             }.frame(minWidth: 300)

Examples/Sources/WebViewExample/WebViewApp.swift

@@ -29,10 +29,12 @@ struct WebViewApp: App {
                     }
                     .padding()
 
-                    WebView($url)
-                        .onChange(of: url) {
-                            urlInput = url.absoluteString
-                        }
+                    #if !os(tvOS)
+                        WebView($url)
+                            .onChange(of: url) {
+                                urlInput = url.absoluteString
+                            }
+                    #endif
                 }
             }
         }

Package.swift

@@ -110,6 +110,10 @@ let package = Package(
             url: "https://github.com/stackotter/swift-winui",
             revision: "1695ee3ea2b7a249f6504c7f1759e7ec7a38eb86"
         ),
+        .package(
+            url: "https://github.com/apple/swift-collections.git",
+            exact: "1.2.1"
+        ),
         // .package(
         //     url: "https://github.com/stackotter/TermKit",
         //     revision: "163afa64f1257a0c026cc83ed8bc47a5f8fc9704"
@@ -129,6 +133,7 @@ let package = Package(
             dependencies: [
                 "HotReloadingMacrosPlugin",
                 .product(name: "ImageFormats", package: "swift-image-formats"),
+                .product(name: "OrderedCollections", package: "swift-collections")
             ],
             exclude: [
                 "Builders/ViewBuilder.swift.gyb",

Sources/SwiftCrossUI/Builders/MenuItemsBuilder.swift

@@ -17,8 +17,8 @@ public struct MenuItemsBuilder {
         first.items
     }
 
-    public static func buildPartialBlock<Items: Collection>(
-        first: ForEach<Items, [MenuItem]>
+    public static func buildPartialBlock<Items: Collection, ID: Hashable>(
+        first: ForEach<Items, ID, [MenuItem]>
     ) -> [MenuItem] {
         first.elements.map(first.child).flatMap { $0 }
     }
@@ -51,9 +51,9 @@ public struct MenuItemsBuilder {
         accumulated + buildPartialBlock(first: next)
     }
 
-    public static func buildPartialBlock<Items: Collection>(
+    public static func buildPartialBlock<Items: Collection, ID: Hashable>(
         accumulated: [MenuItem],
-        next: ForEach<Items, [MenuItem]>
+        next: ForEach<Items, ID, [MenuItem]>
     ) -> [MenuItem] {
         accumulated + buildPartialBlock(first: next)
     }

Sources/SwiftCrossUI/Views/Button.swift

@@ -21,8 +21,7 @@ public struct Button: Sendable {
     }
 }
 
-extension Button: View {
-}
+extension Button: View {}
 
 extension Button: ElementaryView {
     public func asWidget<Backend: AppBackend>(backend: Backend) -> Backend.Widget {