Restore the List and Grid gallery screens

Author: colemancda

Demo/App.swiftpm/Sources/ContentView.swift

@@ -16,6 +16,8 @@ struct ContentView: View {
                     NavigationLink("Text", destination: TextScreen())
                     NavigationLink("Buttons", destination: ButtonScreen())
                     NavigationLink("Stacks", destination: StacksScreen())
+                    NavigationLink("List", destination: ListScreen())
+                    NavigationLink("Grid", destination: GridScreen())
                     NavigationLink("State", destination: StateScreen())
                     NavigationLink("Controls", destination: ControlsScreen())
                     NavigationLink("Modifiers", destination: ModifierScreen())

Demo/App.swiftpm/Sources/GridScreen.swift

@@ -0,0 +1,41 @@
+#if canImport(AndroidSwiftUI)
+import AndroidSwiftUI
+#else
+import SwiftUI
+#endif
+
+/// Lazy grids.
+struct GridScreen: View {
+
+    var body: some View {
+        VStack(spacing: 16) {
+            Text("Three fixed columns")
+            LazyVGrid(columns: [GridItem(.flexible()), GridItem(.flexible()), GridItem(.flexible())]) {
+                ForEach(1...9, id: \.self) { number in
+                    Text("\(number)")
+                        .padding()
+                        .background(Color.blue)
+                }
+            }
+            Divider()
+            Text("Adaptive columns")
+            LazyVGrid(columns: [GridItem(.adaptive(minimum: 80))]) {
+                ForEach(1...8, id: \.self) { number in
+                    Text("Item \(number)")
+                        .padding()
+                        .background(Color.orange)
+                }
+            }
+            Divider()
+            Text("Two rows, horizontal")
+            LazyHGrid(rows: [GridItem(.flexible()), GridItem(.flexible())]) {
+                ForEach(1...8, id: \.self) { number in
+                    Text("Cell \(number)")
+                        .padding()
+                        .background(Color.green)
+                }
+            }
+            .frame(height: 160)
+        }
+    }
+}

Demo/App.swiftpm/Sources/ListScreen.swift

@@ -0,0 +1,36 @@
+#if canImport(AndroidSwiftUI)
+import AndroidSwiftUI
+#else
+import SwiftUI
+#endif
+
+/// A lazy list with pull to refresh. Rows are evaluated on demand, so the
+/// large-list variant scrolls without materializing every row up front.
+struct ListScreen: View {
+
+    @State
+    private var items = (1...30).map(ListItem.init)
+
+    var body: some View {
+        List(items) { item in
+            Text(item.title)
+        }
+        .refreshable {
+            await addItem()
+        }
+    }
+
+    private func addItem() async {
+        try? await Task.sleep(for: .seconds(1))
+        items.insert(ListItem(id: items.count + 1), at: 0)
+    }
+}
+
+struct ListItem: Identifiable {
+
+    let id: Int
+
+    var title: String {
+        "Row \(id)"
+    }
+}