PopupMenu Component

lib/flutter_sdk_util.dart

@@ -1,3 +1,4 @@
 library flutter_sdk_util;
 
 export 'src/pinch_zoom.dart';
+export 'src/popup_menu_bar.dart';

lib/src/popup_menu_bar.dart

@@ -0,0 +1,85 @@
+import 'package:flutter/material.dart';
+
+class MenuEntry {
+  const MenuEntry({
+    required this.child,
+    this.shortcut,
+    this.onPressed,
+    this.menuChildren,
+  }) : assert(
+          menuChildren == null || onPressed == null,
+          'onPressed is ignored if menuChildren are provided',
+        );
+
+  final Widget child;
+
+  final MenuSerializableShortcut? shortcut;
+  final VoidCallback? onPressed;
+  final List<MenuEntry>? menuChildren;
+
+  static List<Widget> build(List<MenuEntry> selections) {
+    Widget buildSelection(MenuEntry selection) {
+      if (selection.menuChildren != null) {
+        return SubmenuButton(
+          menuChildren: MenuEntry.build(selection.menuChildren!),
+          child: selection.child,
+        );
+      }
+
+      return MenuItemButton(
+        shortcut: selection.shortcut,
+        onPressed: selection.onPressed,
+        style: ButtonStyle(
+          alignment: Alignment.center,
+          backgroundColor: MaterialStateProperty.all(Colors.transparent),
+          padding: MaterialStateProperty.all(EdgeInsets.zero),
+        ),
+        child: selection.child,
+      );
+    }
+
+    return selections.map<Widget>(buildSelection).toList();
+  }
+
+  static Map<MenuSerializableShortcut, Intent> shortcuts(List<MenuEntry> selections) {
+    final Map<MenuSerializableShortcut, Intent> result = <MenuSerializableShortcut, Intent>{};
+    for (final MenuEntry selection in selections) {
+      if (selection.menuChildren != null) {
+        result.addAll(MenuEntry.shortcuts(selection.menuChildren!));
+      } else {
+        if (selection.shortcut != null && selection.onPressed != null) {
+          result[selection.shortcut!] = VoidCallbackIntent(selection.onPressed!);
+        }
+      }
+    }
+    return result;
+  }
+}
+
+class PopupMenuBar extends StatelessWidget {
+  const PopupMenuBar({
+    super.key,
+    required this.child,
+    required this.entries,
+  });
+
+  final Widget child;
+  final List<MenuEntry> entries;
+
+  @override
+  Widget build(BuildContext context) {
+    return MenuBar(
+      style: MenuStyle(
+        backgroundColor: MaterialStateProperty.all(Colors.transparent),
+        shadowColor: MaterialStateProperty.all(Colors.transparent),
+        surfaceTintColor: MaterialStateProperty.all(Colors.transparent),
+        padding: MaterialStateProperty.all(EdgeInsets.zero),
+      ),
+      children: MenuEntry.build(
+        [
+          MenuEntry(child: child, menuChildren: entries),
+        ],
+      ),
+    );
+  }
+}