Add DisclosureGroup

AndroidSwiftUICore/Sources/AndroidSwiftUICore/Primitives/DisclosureGroup.swift

@@ -0,0 +1,67 @@
+//
+//  DisclosureGroup.swift
+//  AndroidSwiftUICore
+//
+//  A label that expands to reveal its content. Expansion can be left to the
+//  interpreter (it remembers the open/closed state) or driven by a binding —
+//  when bound, the header's tap round-trips through a callback so Swift stays
+//  the source of truth, exactly like a Toggle.
+//
+
+public struct DisclosureGroup<Label: View, Content: View>: View {
+
+    internal let label: Label
+    internal let content: Content
+    internal let isExpanded: Binding<Bool>?
+
+    public init(
+        isExpanded: Binding<Bool>? = nil,
+        @ViewBuilder content: () -> Content,
+        @ViewBuilder label: () -> Label
+    ) {
+        self.isExpanded = isExpanded
+        self.content = content()
+        self.label = label()
+    }
+
+    public typealias Body = Never
+}
+
+public extension DisclosureGroup where Label == Text {
+
+    init<S: StringProtocol>(_ title: S, @ViewBuilder content: () -> Content) {
+        self.init(content: content) { Text(title) }
+    }
+
+    init<S: StringProtocol>(
+        _ title: S,
+        isExpanded: Binding<Bool>,
+        @ViewBuilder content: () -> Content
+    ) {
+        self.init(isExpanded: isExpanded, content: content) { Text(title) }
+    }
+}
+
+extension DisclosureGroup: PrimitiveView {
+
+    public func _render(in context: ResolveContext) -> RenderNode {
+        // label first, then content; `labelCount` tells the interpreter where the
+        // header ends and the body begins
+        let labelNodes = Evaluator.resolveChildren(label, context.descending("label"))
+        let contentNodes = Evaluator.resolveChildren(content, context.descending("content"))
+
+        var props: [String: PropValue] = ["labelCount": .int(labelNodes.count)]
+        if let isExpanded {
+            props["isExpanded"] = .bool(isExpanded.wrappedValue)
+            let binding = isExpanded
+            let id = context.callbacks.register(.bool { binding.wrappedValue = $0 })
+            props["onToggle"] = .int(Int(id))
+        }
+        return RenderNode(
+            type: "DisclosureGroup",
+            id: context.path,
+            props: props,
+            children: labelNodes + contentNodes
+        )
+    }
+}

AndroidSwiftUICore/Tests/AndroidSwiftUICoreTests/EvaluatorTests.swift

@@ -854,3 +854,55 @@ struct AccessibilityTests {
         #expect(firstTextString(plain) == firstTextString(described))
     }
 }
+
+@Suite("DisclosureGroup")
+struct DisclosureGroupTests {
+
+    @Test("Emits its label then its content, marking the boundary")
+    func labelThenContent() {
+        let node = ViewHost(
+            DisclosureGroup("Advanced") {
+                Text("row one")
+                Text("row two")
+            }
+        ).evaluate()
+        #expect(node.type == "DisclosureGroup")
+        #expect(node.props["labelCount"] == .int(1))
+        #expect(node.children.count == 3)           // 1 label + 2 content
+        #expect(firstTextString(node.children[0]) == "Advanced")
+        #expect(firstTextString(node.children[1]) == "row one")
+        // unbound: the interpreter owns expansion, so no state crosses
+        #expect(node.props["isExpanded"] == nil)
+        #expect(node.props["onToggle"] == nil)
+    }
+
+    @Test("A bound group round-trips its expansion")
+    func boundExpansion() {
+        struct Screen: View {
+            @State var open = false
+            var body: some View {
+                DisclosureGroup("Details", isExpanded: $open) { Text("hidden") }
+            }
+        }
+        let host = ViewHost(Screen())
+        var node = host.evaluate()
+        #expect(node.props["isExpanded"] == .bool(false))
+        guard case .int(let id)? = node.props["onToggle"] else {
+            Issue.record("missing toggle callback"); return
+        }
+        host.callbacks.invokeBool(Int64(id), true)
+        node = host.evaluate()
+        #expect(node.props["isExpanded"] == .bool(true))
+    }
+
+    @Test("Accepts a view label, not only a title")
+    func viewLabel() {
+        let node = ViewHost(
+            DisclosureGroup(content: { Text("body") }, label: {
+                Label("Section", systemImage: "star")
+            })
+        ).evaluate()
+        #expect(node.props["labelCount"] == .int(1))
+        #expect(node.children[0].type == "Label")
+    }
+}

Demo/App.swiftpm/Sources/Catalog.swift

@@ -51,6 +51,7 @@ struct CatalogEntry: Identifiable {
         CatalogEntry(id: "list", title: "List", screen: AnyCatalogScreen(ListPlayground())),
         CatalogEntry(id: "lazystack", title: "Lazy Stacks", screen: AnyCatalogScreen(LazyStackPlayground())),
         CatalogEntry(id: "grid", title: "Grid", screen: AnyCatalogScreen(GridPlayground())),
+        CatalogEntry(id: "disclosure", title: "DisclosureGroup", screen: AnyCatalogScreen(DisclosurePlayground())),
         CatalogEntry(id: "form", title: "Form", screen: AnyCatalogScreen(FormPlayground())),
         CatalogEntry(id: "modifier", title: "Modifiers", screen: AnyCatalogScreen(ModifierPlayground())),
         CatalogEntry(id: "representable", title: "Custom Views", screen: AnyCatalogScreen(RepresentablePlayground())),

Demo/App.swiftpm/Sources/DisclosurePlaygrounds.swift

@@ -0,0 +1,43 @@
+#if canImport(AndroidSwiftUI)
+import AndroidSwiftUI
+#else
+import SwiftUI
+#endif
+
+struct DisclosurePlayground: View {
+
+    @State private var advancedOpen = false
+
+    var body: some View {
+        ScrollView {
+            VStack(alignment: .leading, spacing: 0) {
+                Example("Self-managed expansion") {
+                    DisclosureGroup("What's included") {
+                        Text("• Unlimited projects")
+                        Text("• Priority support")
+                        Text("• Early access")
+                    }
+                }
+                Example("Bound expansion") {
+                    VStack(alignment: .leading, spacing: 8) {
+                        DisclosureGroup("Advanced settings", isExpanded: $advancedOpen) {
+                            Text("Experimental features live here.")
+                            Toggle("Beta channel", isOn: .constant(true))
+                        }
+                        Button(advancedOpen ? "Collapse from outside" : "Expand from outside") {
+                            advancedOpen.toggle()
+                        }
+                    }
+                }
+                Example("With a Label header") {
+                    DisclosureGroup(content: {
+                        Text("Grouped under a labeled header.")
+                    }, label: {
+                        Label("Notifications", systemImage: "star.fill")
+                    })
+                }
+            }
+        }
+        .navigationTitle("DisclosureGroup")
+    }
+}

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

@@ -103,6 +103,8 @@ import androidx.compose.material3.TextButton
 import androidx.compose.material3.TopAppBar
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.automirrored.filled.ArrowBack
+import androidx.compose.material.icons.filled.KeyboardArrowDown
+import androidx.compose.material.icons.filled.KeyboardArrowUp
 import androidx.compose.material.icons.filled.Add
 import androidx.compose.material.icons.filled.Check
 import androidx.compose.material.icons.filled.Close
@@ -351,6 +353,8 @@ private fun RenderResolved(node: ViewNode) {
                 }
             }
 
+            "DisclosureGroup" -> RenderDisclosureGroup(node)
+
             "Label" -> RenderLabel(node)
 
             "Link" -> RenderLink(node)
@@ -629,6 +633,42 @@ private fun RenderLabel(node: ViewNode) {
     }
 }
 
+// A tappable header (label + chevron) over collapsible content. Expansion is
+// interpreter-local unless a binding is present, in which case the tap
+// round-trips through Swift like any other control.
+@Composable
+private fun RenderDisclosureGroup(node: ViewNode) {
+    val labelCount = node.long("labelCount")?.toInt() ?: 0
+    val onToggle = node.long("onToggle")
+    val bound = node.props.containsKey("isExpanded")
+
+    var localExpanded by remember(node.id) { mutableStateOf(false) }
+    val expanded = if (bound) node.string("isExpanded") == "true" else localExpanded
+
+    Column(modifier = node.composeModifiers().fillMaxWidth()) {
+        Row(
+            verticalAlignment = Alignment.CenterVertically,
+            modifier = Modifier.fillMaxWidth().clickable {
+                if (bound) onToggle?.let { SwiftBridge.sink.invokeBool(it, !expanded) }
+                else localExpanded = !localExpanded
+            }.padding(vertical = 6.dp),
+        ) {
+            Row(modifier = Modifier.weight(1f)) {
+                node.children.take(labelCount).forEach { RenderChild(it) }
+            }
+            Icon(
+                imageVector = if (expanded) Icons.Filled.KeyboardArrowUp else Icons.Filled.KeyboardArrowDown,
+                contentDescription = if (expanded) "Collapse" else "Expand",
+            )
+        }
+        if (expanded) {
+            Column(modifier = Modifier.fillMaxWidth().padding(start = 12.dp)) {
+                node.children.drop(labelCount).forEach { RenderChild(it) }
+            }
+        }
+    }
+}
+
 private fun ViewNode.isPresentation(): Boolean =
     type == "Sheet" || type == "Alert" || type == "ConfirmationDialog" || type == "ToolbarItem"