The Garage SDKs, in the open

garage_auth, garage_entitlements, garage_iap and garage_ui, moved out of
Garage-Services and Metro-Map-Maker into one public repo. MIT, one readme,
docs under docs/.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013F4NWNvYcdeSgqbWMT1VQ7

garage_ui/lib/app_menu_notifier.dart

@@ -0,0 +1,67 @@
+import "package:flutter/foundation.dart";
+import "package:flutter/widgets.dart";
+
+class AppMenuNotifier extends ChangeNotifier {
+  List<PlatformMenuItem> _menus = const [];
+
+  List<PlatformMenuItem> get menus => _menus;
+
+  void update(List<PlatformMenuItem> menus) {
+    _menus = menus;
+    notifyListeners();
+  }
+}
+
+/// Keeps one native platform menu host above an application's provider tree.
+class PlatformMenuHost extends StatefulWidget {
+  const PlatformMenuHost({
+    super.key,
+    required this.notifier,
+    required this.child,
+  });
+
+  final AppMenuNotifier notifier;
+  final Widget child;
+
+  @override
+  State<PlatformMenuHost> createState() => _PlatformMenuHostState();
+}
+
+class _PlatformMenuHostState extends State<PlatformMenuHost> {
+  List<PlatformMenuItem> _menus = const [];
+
+  static bool get _supported =>
+      !kIsWeb && defaultTargetPlatform == TargetPlatform.macOS;
+
+  @override
+  void initState() {
+    super.initState();
+    _menus = widget.notifier.menus;
+    widget.notifier.addListener(_onMenusChanged);
+  }
+
+  @override
+  void didUpdateWidget(PlatformMenuHost oldWidget) {
+    super.didUpdateWidget(oldWidget);
+    if (widget.notifier == oldWidget.notifier) return;
+    oldWidget.notifier.removeListener(_onMenusChanged);
+    widget.notifier.addListener(_onMenusChanged);
+    _menus = widget.notifier.menus;
+  }
+
+  @override
+  void dispose() {
+    widget.notifier.removeListener(_onMenusChanged);
+    super.dispose();
+  }
+
+  void _onMenusChanged() {
+    if (mounted) setState(() => _menus = widget.notifier.menus);
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    if (!_supported) return widget.child;
+    return PlatformMenuBar(menus: _menus, child: widget.child);
+  }
+}