Add searchable — a navigation search field

AndroidSwiftUICore/Sources/AndroidSwiftUICore/Evaluator.swift

@@ -112,6 +112,11 @@ public protocol _ResolutionEffectView {
 public final class TitleSink {
     public var title: String?
     public var detents: [PresentationDetent] = []
+    /// A `searchable` declared inside the screen: current text, the string
+    /// callback its field pushes to, and an optional placeholder prompt.
+    public var searchText: String?
+    public var searchCallbackID: Int64?
+    public var searchPrompt: String?
     public init() {}
 }
 

AndroidSwiftUICore/Sources/AndroidSwiftUICore/Navigation.swift

@@ -76,6 +76,7 @@ extension NavigationStack: PrimitiveView {
         // captures its navigationTitle
         var screens: [RenderNode] = []
         var titles: [PropValue] = []
+        var searches: [PropValue] = []
 
         func resolveScreen(_ view: any View, index: Int, canDismiss: Bool) {
             var childContext = context.descending("screen\(index)")
@@ -87,6 +88,17 @@ extension NavigationStack: PrimitiveView {
             childContext.titleSink = sink
             screens.append(Evaluator.resolve(view, childContext))
             titles.append(.string(sink.title ?? ""))
+            // Each screen carries its search field descriptor, or an empty array
+            // when it declared no `searchable`.
+            if let id = sink.searchCallbackID {
+                searches.append(.array([
+                    .string(sink.searchText ?? ""),
+                    .int(Int(id)),
+                    .string(sink.searchPrompt ?? ""),
+                ]))
+            } else {
+                searches.append(.array([]))
+            }
         }
 
         resolveScreen(root, index: 0, canDismiss: false)
@@ -99,7 +111,7 @@ extension NavigationStack: PrimitiveView {
         return RenderNode(
             type: "NavStack",
             id: context.path,
-            props: ["titles": .array(titles), "onPop": .int(Int(popID))],
+            props: ["titles": .array(titles), "searches": .array(searches), "onPop": .int(Int(popID))],
             children: screens
         )
     }
@@ -180,6 +192,31 @@ public extension View {
     }
 }
 
+/// Attaches a search field to the enclosing navigation stack, bound to `text`.
+public struct _SearchableView<Content: View>: View {
+    internal let text: Binding<String>
+    internal let prompt: String?
+    internal let content: Content
+    public typealias Body = Never
+}
+
+extension _SearchableView: _ResolutionEffectView {
+    public func _applyEffect(_ context: inout ResolveContext) -> any View {
+        let binding = text
+        let id = context.callbacks.register(.string { binding.wrappedValue = $0 })
+        context.titleSink?.searchText = text.wrappedValue
+        context.titleSink?.searchCallbackID = id
+        context.titleSink?.searchPrompt = prompt
+        return content
+    }
+}
+
+public extension View {
+    func searchable(text: Binding<String>, prompt: String? = nil) -> _SearchableView<Self> {
+        _SearchableView(text: text, prompt: prompt, content: self)
+    }
+}
+
 /// Registers a value-type destination builder with the enclosing stack.
 public struct _NavigationDestinationView<Content: View, D: Hashable>: View {
     internal let build: (D) -> any View

AndroidSwiftUICore/Tests/AndroidSwiftUICoreTests/NavigationTests.swift

@@ -151,6 +151,38 @@ struct NavigationTests {
         #expect(node.props["hasConfirmationDialog"] == nil)   // dismissed
     }
 
+    @Test("searchable surfaces a per-screen field whose input drives its binding")
+    func searchable() {
+        struct Screen: View {
+            @State var query = ""
+            var body: some View {
+                NavigationStack {
+                    Text("Results for \(query)")
+                        .searchable(text: $query, prompt: "Find")
+                }
+            }
+        }
+        let host = ViewHost(Screen())
+        let node = host.evaluate()
+        #expect(node.type == "NavStack")
+        guard case .array(let searches)? = node.props["searches"],
+              case .array(let entry) = searches[0], entry.count == 3 else {
+            Issue.record("expected a search descriptor for the root screen"); return
+        }
+        #expect(entry[0] == .string(""))          // current text
+        #expect(entry[2] == .string("Find"))      // prompt
+        guard case .int(let id) = entry[1] else {
+            Issue.record("missing search callback id"); return
+        }
+        host.callbacks.invokeString(Int64(id), "abc")
+        let updated = host.evaluate()
+        guard case .array(let searches2)? = updated.props["searches"],
+              case .array(let entry2) = searches2[0] else {
+            Issue.record("missing search descriptor after input"); return
+        }
+        #expect(entry2[0] == .string("abc"))       // binding round-tripped
+    }
+
     @Test("TabView emits tabs with their item labels and selection")
     func tabs() {
         struct Screen: View {

Demo/App.swiftpm/Sources/Catalog.swift

@@ -50,6 +50,7 @@ struct CatalogEntry: Identifiable {
         CatalogEntry(id: "animation", title: "Animation", screen: AnyCatalogScreen(AnimationPlayground())),
         CatalogEntry(id: "interaction", title: "Interaction", screen: AnyCatalogScreen(InteractionPlayground())),
         CatalogEntry(id: "navigation", title: "Navigation", screen: AnyCatalogScreen(NavigationPlayground())),
+        CatalogEntry(id: "searchable", title: "Searchable", screen: AnyCatalogScreen(SearchablePlayground())),
         CatalogEntry(id: "tab", title: "TabView", screen: AnyCatalogScreen(TabViewPlayground())),
         CatalogEntry(id: "sheet", title: "Sheet", screen: AnyCatalogScreen(SheetPlayground())),
         CatalogEntry(id: "alert", title: "Alert", screen: AnyCatalogScreen(AlertPlayground())),

Demo/App.swiftpm/Sources/SearchablePlaygrounds.swift

@@ -0,0 +1,34 @@
+#if canImport(AndroidSwiftUI)
+import AndroidSwiftUI
+#else
+import SwiftUI
+#endif
+
+struct SearchablePlayground: View {
+    @State private var query = ""
+
+    private let fruits = [
+        "Apple", "Apricot", "Banana", "Blueberry", "Cherry", "Grape",
+        "Lemon", "Lime", "Mango", "Orange", "Peach", "Pear", "Plum",
+    ]
+
+    private var filtered: [String] {
+        query.isEmpty ? fruits : fruits.filter { $0.lowercased().contains(query.lowercased()) }
+    }
+
+    var body: some View {
+        ScrollView {
+            VStack(alignment: .leading, spacing: 12) {
+                if filtered.isEmpty {
+                    Text("No matches").foregroundColor(.gray)
+                }
+                ForEach(filtered, id: \.self) { fruit in
+                    Text(fruit)
+                }
+            }
+            .padding()
+        }
+        .searchable(text: $query, prompt: "Search fruit")
+        .navigationTitle("Searchable")
+    }
+}

Demo/swiftui/src/commonMain/kotlin/com/pureswift/swiftui/Render.kt

@@ -1243,13 +1243,55 @@ private fun RenderNavStack(node: ViewNode) {
             label = "nav",
         ) { index ->
             LayoutColumn(modifier = Modifier.padding(padding)) {
+                node.searchField(index)?.let { RenderSearchField(it, index) }
                 node.children.getOrNull(index)?.let { Render(it) }
             }
         }
     }
     RenderSheetsAndAlerts(node.children.getOrNull(topIndex))
 }
 
+private class SearchFieldSpec(val text: String, val callbackId: Long, val prompt: String)
+
+// A screen's `searchable` descriptor: [text, callbackId, prompt], or an empty
+// array when that screen declared none.
+private fun ViewNode.searchField(index: Int): SearchFieldSpec? {
+    val searches = props["searches"] as? kotlinx.serialization.json.JsonArray ?: return null
+    val entry = searches.getOrNull(index) as? kotlinx.serialization.json.JsonArray ?: return null
+    if (entry.size < 3) return null
+    val text = (entry[0] as? kotlinx.serialization.json.JsonPrimitive)?.content ?: ""
+    val id = (entry[1] as? kotlinx.serialization.json.JsonPrimitive)?.content?.toLongOrNull() ?: return null
+    val prompt = (entry[2] as? kotlinx.serialization.json.JsonPrimitive)?.content ?: ""
+    return SearchFieldSpec(text, id, prompt)
+}
+
+// Same uncontrolled-with-reconciliation scheme as RenderTextField, keyed by the
+// stable screen index (the callback id churns each evaluation, so it can't key
+// the remembered cursor state).
+@Composable
+private fun RenderSearchField(spec: SearchFieldSpec, index: Int) {
+    var local by remember(index) { mutableStateOf(TextFieldValue(spec.text)) }
+    var lastSent by remember(index) { mutableStateOf(spec.text) }
+    if (spec.text != lastSent) {
+        local = TextFieldValue(spec.text, selection = androidx.compose.ui.text.TextRange(spec.text.length))
+        lastSent = spec.text
+    }
+    OutlinedTextField(
+        value = local,
+        onValueChange = { v ->
+            local = v
+            if (v.text != lastSent) {
+                lastSent = v.text
+                SwiftBridge.sink.invokeString(spec.callbackId, v.text)
+            }
+        },
+        placeholder = { Text(spec.prompt.ifEmpty { "Search" }) },
+        leadingIcon = { Icon(Icons.Filled.Search, contentDescription = null) },
+        singleLine = true,
+        modifier = Modifier.fillMaxWidth().padding(horizontal = 12.dp, vertical = 4.dp),
+    )
+}
+
 @Composable
 private fun RenderTabView(node: ViewNode) {
     val selection = node.long("selection")?.toInt() ?: 0