[Gallery] Add Material Menu demo (#212)

* Add Material Menu demo

gallery/gallery/lib/data/demos.dart

@@ -24,6 +24,7 @@ import 'package:gallery/demos/material/chip_demo.dart';
 import 'package:gallery/demos/material/dialog_demo.dart';
 import 'package:gallery/demos/material/grid_list_demo.dart';
 import 'package:gallery/demos/material/list_demo.dart';
+import 'package:gallery/demos/material/menu_demo.dart';
 import 'package:gallery/demos/material/progress_indicator_demo.dart';
 import 'package:gallery/demos/material/selection_controls_demo.dart';
 import 'package:gallery/demos/material/sliders_demo.dart';
@@ -337,6 +338,53 @@ List<GalleryDemo> materialDemos(BuildContext context) {
         ),
       ],
     ),
+    GalleryDemo(
+      title: GalleryLocalizations.of(context).demoMenuTitle,
+      icon: GalleryIcons.moreVert,
+      subtitle: GalleryLocalizations.of(context).demoMenuSubtitle,
+      configurations: [
+        GalleryDemoConfiguration(
+          title: GalleryLocalizations.of(context).demoContextMenuTitle,
+          description: GalleryLocalizations.of(context).demoMenuDescription,
+          documentationUrl:
+              'https://api.flutter.dev/flutter/material/PopupMenuItem-class.html',
+          buildRoute: (context) => MenuDemo(
+            type: MenuDemoType.contextMenu,
+          ),
+          code: CodeSegments.menuDemoContext,
+        ),
+        GalleryDemoConfiguration(
+          title: GalleryLocalizations.of(context).demoSectionedMenuTitle,
+          description: GalleryLocalizations.of(context).demoMenuDescription,
+          documentationUrl:
+              'https://api.flutter.dev/flutter/material/PopupMenuItem-class.html',
+          buildRoute: (context) => MenuDemo(
+            type: MenuDemoType.sectionedMenu,
+          ),
+          code: CodeSegments.menuDemoSectioned,
+        ),
+        GalleryDemoConfiguration(
+          title: GalleryLocalizations.of(context).demoChecklistMenuTitle,
+          description: GalleryLocalizations.of(context).demoMenuDescription,
+          documentationUrl:
+              'https://api.flutter.dev/flutter/material/CheckedPopupMenuItem-class.html',
+          buildRoute: (context) => MenuDemo(
+            type: MenuDemoType.checklistMenu,
+          ),
+          code: CodeSegments.menuDemoChecklist,
+        ),
+        GalleryDemoConfiguration(
+          title: GalleryLocalizations.of(context).demoSimpleMenuTitle,
+          description: GalleryLocalizations.of(context).demoMenuDescription,
+          documentationUrl:
+              'https://api.flutter.dev/flutter/material/PopupMenuItem-class.html',
+          buildRoute: (context) => MenuDemo(
+            type: MenuDemoType.simpleMenu,
+          ),
+          code: CodeSegments.menuDemoSimple,
+        ),
+      ],
+    ),
     GalleryDemo(
       title: GalleryLocalizations.of(context).demoProgressIndicatorTitle,
       icon: GalleryIcons.progressActivity,

gallery/gallery/lib/demos/material/menu_demo.dart

@@ -0,0 +1,367 @@
+// Copyright 2019 The Flutter team. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:flutter/material.dart';
+
+import 'package:gallery/l10n/gallery_localizations.dart';
+
+enum MenuDemoType {
+  contextMenu,
+  sectionedMenu,
+  simpleMenu,
+  checklistMenu,
+}
+
+enum SimpleValue {
+  one,
+  two,
+  three,
+}
+
+enum CheckedValue {
+  one,
+  two,
+  three,
+  four,
+}
+
+class MenuDemo extends StatefulWidget {
+  const MenuDemo({Key key, this.type}) : super(key: key);
+
+  final MenuDemoType type;
+
+  @override
+  _MenuDemoState createState() => _MenuDemoState();
+}
+
+class _MenuDemoState extends State<MenuDemo> {
+  final GlobalKey<ScaffoldState> _scaffoldKey = GlobalKey<ScaffoldState>();
+
+  void showInSnackBar(String value) {
+    _scaffoldKey.currentState.showSnackBar(SnackBar(
+      content: Text(value),
+    ));
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    Widget demo;
+    switch (widget.type) {
+      case MenuDemoType.contextMenu:
+        demo = _ContextMenuDemo(showInSnackBar: showInSnackBar);
+        break;
+      case MenuDemoType.sectionedMenu:
+        demo = _SectionedMenuDemo(showInSnackBar: showInSnackBar);
+        break;
+      case MenuDemoType.simpleMenu:
+        demo = _SimpleMenuDemo(showInSnackBar: showInSnackBar);
+        break;
+      case MenuDemoType.checklistMenu:
+        demo = _ChecklistMenuDemo(showInSnackBar: showInSnackBar);
+        break;
+    }
+
+    return Scaffold(
+      key: _scaffoldKey,
+      appBar: AppBar(
+        title: Text(GalleryLocalizations.of(context).demoMenuTitle),
+        automaticallyImplyLeading: false,
+      ),
+      body: Padding(
+        padding: EdgeInsets.symmetric(horizontal: 20),
+        child: Center(
+          child: demo,
+        ),
+      ),
+    );
+  }
+}
+
+// BEGIN menuDemoContext
+
+// Pressing the PopupMenuButton on the right of this item shows
+// a simple menu with one disabled item. Typically the contents
+// of this "contextual menu" would reflect the app's state.
+class _ContextMenuDemo extends StatelessWidget {
+  const _ContextMenuDemo({Key key, this.showInSnackBar}) : super(key: key);
+
+  final void Function(String value) showInSnackBar;
+
+  @override
+  Widget build(BuildContext context) {
+    return ListTile(
+      title: Text(GalleryLocalizations.of(context)
+          .demoMenuAnItemWithAContextMenuButton),
+      trailing: PopupMenuButton<String>(
+        padding: EdgeInsets.zero,
+        onSelected: (value) => showInSnackBar(
+          GalleryLocalizations.of(context).demoMenuSelected(value),
+        ),
+        itemBuilder: (context) => <PopupMenuItem<String>>[
+          PopupMenuItem<String>(
+            value: GalleryLocalizations.of(context).demoMenuContextMenuItemOne,
+            child: Text(
+              GalleryLocalizations.of(context).demoMenuContextMenuItemOne,
+            ),
+          ),
+          PopupMenuItem<String>(
+            enabled: false,
+            child: Text(
+              GalleryLocalizations.of(context).demoMenuADisabledMenuItem,
+            ),
+          ),
+          PopupMenuItem<String>(
+            value:
+                GalleryLocalizations.of(context).demoMenuContextMenuItemThree,
+            child: Text(
+              GalleryLocalizations.of(context).demoMenuContextMenuItemThree,
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+// END
+
+// BEGIN menuDemoSectioned
+
+// Pressing the PopupMenuButton on the right of this item shows
+// a menu whose items have text labels and icons and a divider
+// That separates the first three items from the last one.
+class _SectionedMenuDemo extends StatelessWidget {
+  const _SectionedMenuDemo({Key key, this.showInSnackBar}) : super(key: key);
+
+  final void Function(String value) showInSnackBar;
+
+  @override
+  Widget build(BuildContext context) {
+    return ListTile(
+      title: Text(
+          GalleryLocalizations.of(context).demoMenuAnItemWithASectionedMenu),
+      trailing: PopupMenuButton<String>(
+        padding: EdgeInsets.zero,
+        onSelected: (value) => showInSnackBar(
+            GalleryLocalizations.of(context).demoMenuSelected(value)),
+        itemBuilder: (context) => <PopupMenuEntry<String>>[
+          PopupMenuItem<String>(
+            value: GalleryLocalizations.of(context).demoMenuPreview,
+            child: ListTile(
+              leading: Icon(Icons.visibility),
+              title: Text(
+                GalleryLocalizations.of(context).demoMenuPreview,
+              ),
+            ),
+          ),
+          PopupMenuItem<String>(
+            value: GalleryLocalizations.of(context).demoMenuShare,
+            child: ListTile(
+              leading: Icon(Icons.person_add),
+              title: Text(
+                GalleryLocalizations.of(context).demoMenuShare,
+              ),
+            ),
+          ),
+          PopupMenuItem<String>(
+            value: GalleryLocalizations.of(context).demoMenuGetLink,
+            child: ListTile(
+              leading: Icon(Icons.link),
+              title: Text(
+                GalleryLocalizations.of(context).demoMenuGetLink,
+              ),
+            ),
+          ),
+          const PopupMenuDivider(),
+          PopupMenuItem<String>(
+            value: GalleryLocalizations.of(context).demoMenuRemove,
+            child: ListTile(
+              leading: Icon(Icons.delete),
+              title: Text(
+                GalleryLocalizations.of(context).demoMenuRemove,
+              ),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+// END
+
+// BEGIN menuDemoSimple
+
+// This entire list item is a PopupMenuButton. Tapping anywhere shows
+// a menu whose current value is highlighted and aligned over the
+// list item's center line.
+class _SimpleMenuDemo extends StatefulWidget {
+  const _SimpleMenuDemo({Key key, this.showInSnackBar}) : super(key: key);
+
+  final void Function(String value) showInSnackBar;
+
+  @override
+  _SimpleMenuDemoState createState() => _SimpleMenuDemoState();
+}
+
+class _SimpleMenuDemoState extends State<_SimpleMenuDemo> {
+  SimpleValue _simpleValue;
+
+  void showAndSetMenuSelection(BuildContext context, SimpleValue value) {
+    setState(() {
+      _simpleValue = value;
+    });
+    widget.showInSnackBar(
+      GalleryLocalizations.of(context)
+          .demoMenuSelected(simpleValueToString(context, value)),
+    );
+  }
+
+  String simpleValueToString(BuildContext context, SimpleValue value) => {
+        SimpleValue.one: GalleryLocalizations.of(context).demoMenuItemValueOne,
+        SimpleValue.two: GalleryLocalizations.of(context).demoMenuItemValueTwo,
+        SimpleValue.three:
+            GalleryLocalizations.of(context).demoMenuItemValueThree,
+      }[value];
+
+  @override
+  void initState() {
+    super.initState();
+    _simpleValue = SimpleValue.two;
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return PopupMenuButton<SimpleValue>(
+      padding: EdgeInsets.zero,
+      initialValue: _simpleValue,
+      onSelected: (value) => showAndSetMenuSelection(context, value),
+      child: ListTile(
+        title: Text(
+            GalleryLocalizations.of(context).demoMenuAnItemWithASimpleMenu),
+        subtitle: Text(simpleValueToString(context, _simpleValue)),
+      ),
+      itemBuilder: (context) => <PopupMenuItem<SimpleValue>>[
+        PopupMenuItem<SimpleValue>(
+          value: SimpleValue.one,
+          child: Text(simpleValueToString(
+            context,
+            SimpleValue.one,
+          )),
+        ),
+        PopupMenuItem<SimpleValue>(
+          value: SimpleValue.two,
+          child: Text(simpleValueToString(
+            context,
+            SimpleValue.two,
+          )),
+        ),
+        PopupMenuItem<SimpleValue>(
+          value: SimpleValue.three,
+          child: Text(simpleValueToString(
+            context,
+            SimpleValue.three,
+          )),
+        ),
+      ],
+    );
+  }
+}
+
+// END
+
+// BEGIN menuDemoChecklist
+
+// Pressing the PopupMenuButton on the right of this item shows a menu
+// whose items have checked icons that reflect this app's state.
+class _ChecklistMenuDemo extends StatefulWidget {
+  const _ChecklistMenuDemo({Key key, this.showInSnackBar}) : super(key: key);
+
+  final void Function(String value) showInSnackBar;
+
+  @override
+  _ChecklistMenuDemoState createState() => _ChecklistMenuDemoState();
+}
+
+class _ChecklistMenuDemoState extends State<_ChecklistMenuDemo> {
+  List<CheckedValue> _checkedValues;
+
+  @override
+  void initState() {
+    super.initState();
+    _checkedValues = [CheckedValue.three];
+  }
+
+  void showCheckedMenuSelections(BuildContext context, CheckedValue value) {
+    if (_checkedValues.contains(value)) {
+      setState(() {
+        _checkedValues.remove(value);
+      });
+    } else {
+      setState(() {
+        _checkedValues.add(value);
+      });
+    }
+
+    widget.showInSnackBar(
+      GalleryLocalizations.of(context).demoMenuChecked(
+        _checkedValues.map((value) => checkedValueToString(context, value)),
+      ),
+    );
+  }
+
+  String checkedValueToString(BuildContext context, CheckedValue value) => {
+        CheckedValue.one: GalleryLocalizations.of(context).demoMenuOne,
+        CheckedValue.two: GalleryLocalizations.of(context).demoMenuTwo,
+        CheckedValue.three: GalleryLocalizations.of(context).demoMenuThree,
+        CheckedValue.four: GalleryLocalizations.of(context).demoMenuFour,
+      }[value];
+
+  bool isChecked(CheckedValue value) => _checkedValues.contains(value);
+
+  @override
+  Widget build(BuildContext context) {
+    return ListTile(
+      title: Text(
+          GalleryLocalizations.of(context).demoMenuAnItemWithAChecklistMenu),
+      trailing: PopupMenuButton<CheckedValue>(
+        padding: EdgeInsets.zero,
+        onSelected: (value) => showCheckedMenuSelections(context, value),
+        itemBuilder: (context) => <PopupMenuItem<CheckedValue>>[
+          CheckedPopupMenuItem<CheckedValue>(
+            value: CheckedValue.one,
+            checked: isChecked(CheckedValue.one),
+            child: Text(
+              checkedValueToString(context, CheckedValue.one),
+            ),
+          ),
+          CheckedPopupMenuItem<CheckedValue>(
+            value: CheckedValue.two,
+            enabled: false,
+            checked: isChecked(CheckedValue.two),
+            child: Text(
+              checkedValueToString(context, CheckedValue.two),
+            ),
+          ),
+          CheckedPopupMenuItem<CheckedValue>(
+            value: CheckedValue.three,
+            checked: isChecked(CheckedValue.three),
+            child: Text(
+              checkedValueToString(context, CheckedValue.three),
+            ),
+          ),
+          CheckedPopupMenuItem<CheckedValue>(
+            value: CheckedValue.four,
+            checked: isChecked(CheckedValue.four),
+            child: Text(
+              checkedValueToString(context, CheckedValue.four),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+// END

gallery/gallery/lib/l10n/gallery_localizations.dart

@@ -1434,6 +1434,13 @@ class GalleryLocalizations {
         desc: r'Title for the material buttons component demo.');
   }
 
+  String get demoChecklistMenuTitle {
+    return Intl.message(r'Checklist menu',
+        locale: _localeName,
+        name: 'demoChecklistMenuTitle',
+        desc: r'Title for the checklist menu component demo.');
+  }
+
   String get demoChipSubtitle {
     return Intl.message(
         r'Compact elements that represent an input, attribute, or action',
@@ -1535,6 +1542,13 @@ class GalleryLocalizations {
         desc: r'Title for the colors demo.');
   }
 
+  String get demoContextMenuTitle {
+    return Intl.message(r'Context menu',
+        locale: _localeName,
+        name: 'demoContextMenuTitle',
+        desc: r'Title for the context menu component demo.');
+  }
+
   String get demoCupertinoActionSheetDescription {
     return Intl.message(
         r'An action sheet is a specific style of alert that presents the user with a set of two or more choices related to the current context. An action sheet can have a title, an additional message, and a list of actions.',
@@ -1989,6 +2003,169 @@ class GalleryLocalizations {
         desc: r'Title for lists demo.');
   }
 
+  String get demoMenuADisabledMenuItem {
+    return Intl.message(r'Disabled menu item',
+        locale: _localeName,
+        name: 'demoMenuADisabledMenuItem',
+        desc:
+            r'Text label for a disabled menu item. A menu displays a list of choices on a temporary surface. Used as an example in a demo.');
+  }
+
+  String get demoMenuAnItemWithAChecklistMenu {
+    return Intl.message(r'An item with a checklist menu',
+        locale: _localeName,
+        name: 'demoMenuAnItemWithAChecklistMenu',
+        desc:
+            r'Label next to a button that opens a checklist menu. A menu displays a list of choices on a temporary surface. Used as an example in a demo.');
+  }
+
+  String get demoMenuAnItemWithAContextMenuButton {
+    return Intl.message(r'An item with a context menu',
+        locale: _localeName,
+        name: 'demoMenuAnItemWithAContextMenuButton',
+        desc:
+            r'Label next to a button that opens a menu. A menu displays a list of choices on a temporary surface. Used as an example in a demo.');
+  }
+
+  String get demoMenuAnItemWithASectionedMenu {
+    return Intl.message(r'An item with a sectioned menu',
+        locale: _localeName,
+        name: 'demoMenuAnItemWithASectionedMenu',
+        desc:
+            r'Label next to a button that opens a sectioned menu . A menu displays a list of choices on a temporary surface. Used as an example in a demo.');
+  }
+
+  String get demoMenuAnItemWithASimpleMenu {
+    return Intl.message(r'An item with a simple menu',
+        locale: _localeName,
+        name: 'demoMenuAnItemWithASimpleMenu',
+        desc:
+            r'Label next to a button that opens a simple menu. A menu displays a list of choices on a temporary surface. Used as an example in a demo.');
+  }
+
+  String demoMenuChecked(Object value) {
+    return Intl.message(r'Checked: $value',
+        locale: _localeName,
+        name: 'demoMenuChecked',
+        desc: r'A text to show what value was checked.',
+        args: <Object>[value]);
+  }
+
+  String get demoMenuContextMenuItemOne {
+    return Intl.message(r'Context menu item one',
+        locale: _localeName,
+        name: 'demoMenuContextMenuItemOne',
+        desc:
+            r'Text label for a context menu item. A menu displays a list of choices on a temporary surface. Used as an example in a demo.');
+  }
+
+  String get demoMenuContextMenuItemThree {
+    return Intl.message(r'Context menu item three',
+        locale: _localeName,
+        name: 'demoMenuContextMenuItemThree',
+        desc:
+            r'Text label for a context menu item three. A menu displays a list of choices on a temporary surface. Used as an example in a demo.');
+  }
+
+  String get demoMenuDescription {
+    return Intl.message(
+        r'A menu displays a list of choices on a temporary surface. They appear when users interact with a button, action, or other control.',
+        locale: _localeName,
+        name: 'demoMenuDescription',
+        desc: r'Description for the menu demo.');
+  }
+
+  String get demoMenuFour {
+    return Intl.message(r'Four',
+        locale: _localeName, name: 'demoMenuFour', desc: r'The number four.');
+  }
+
+  String get demoMenuGetLink {
+    return Intl.message(r'Get link',
+        locale: _localeName,
+        name: 'demoMenuGetLink',
+        desc: r'Button to get link for content.');
+  }
+
+  String get demoMenuItemValueOne {
+    return Intl.message(r'Menu item one',
+        locale: _localeName,
+        name: 'demoMenuItemValueOne',
+        desc: r'The first item in a menu.');
+  }
+
+  String get demoMenuItemValueThree {
+    return Intl.message(r'Menu item three',
+        locale: _localeName,
+        name: 'demoMenuItemValueThree',
+        desc: r'The third item in a menu.');
+  }
+
+  String get demoMenuItemValueTwo {
+    return Intl.message(r'Menu item two',
+        locale: _localeName,
+        name: 'demoMenuItemValueTwo',
+        desc: r'The second item in a menu.');
+  }
+
+  String get demoMenuOne {
+    return Intl.message(r'One',
+        locale: _localeName, name: 'demoMenuOne', desc: r'The number one.');
+  }
+
+  String get demoMenuPreview {
+    return Intl.message(r'Preview',
+        locale: _localeName,
+        name: 'demoMenuPreview',
+        desc: r'Button to preview content.');
+  }
+
+  String get demoMenuRemove {
+    return Intl.message(r'Remove',
+        locale: _localeName,
+        name: 'demoMenuRemove',
+        desc: r'Button to remove content.');
+  }
+
+  String demoMenuSelected(Object value) {
+    return Intl.message(r'Selected: $value',
+        locale: _localeName,
+        name: 'demoMenuSelected',
+        desc: r'A text to show what value was selected.',
+        args: <Object>[value]);
+  }
+
+  String get demoMenuShare {
+    return Intl.message(r'Share',
+        locale: _localeName,
+        name: 'demoMenuShare',
+        desc: r'Button to share content.');
+  }
+
+  String get demoMenuSubtitle {
+    return Intl.message(r'Menu buttons and simple menus',
+        locale: _localeName,
+        name: 'demoMenuSubtitle',
+        desc: r'Short description for the menu component demo.');
+  }
+
+  String get demoMenuThree {
+    return Intl.message(r'Three',
+        locale: _localeName, name: 'demoMenuThree', desc: r'The number three.');
+  }
+
+  String get demoMenuTitle {
+    return Intl.message(r'Menu',
+        locale: _localeName,
+        name: 'demoMenuTitle',
+        desc: r'Title for the menu component demo.');
+  }
+
+  String get demoMenuTwo {
+    return Intl.message(r'Two',
+        locale: _localeName, name: 'demoMenuTwo', desc: r'The number two.');
+  }
+
   String get demoOneLineListsTitle {
     return Intl.message(r'One Line',
         locale: _localeName,
@@ -2078,6 +2255,13 @@ class GalleryLocalizations {
         desc: r'Title for the range sliders component demo.');
   }
 
+  String get demoSectionedMenuTitle {
+    return Intl.message(r'Sectioned menu',
+        locale: _localeName,
+        name: 'demoSectionedMenuTitle',
+        desc: r'Title for the sectioned menu component demo.');
+  }
+
   String get demoSelectionControlsCheckboxDescription {
     return Intl.message(
         r'Checkboxes allow the user to select multiple options from a set. A normal checkbox'
@@ -2156,6 +2340,13 @@ class GalleryLocalizations {
         desc: r'Title for the simple dialog component demo.');
   }
 
+  String get demoSimpleMenuTitle {
+    return Intl.message(r'Simple menu',
+        locale: _localeName,
+        name: 'demoSimpleMenuTitle',
+        desc: r'Title for the simple menu component demo.');
+  }
+
   String get demoSlidersContinuous {
     return Intl.message(r'Continuous',
         locale: _localeName,

gallery/gallery/lib/l10n/intl_en_US.arb

@@ -689,6 +689,124 @@
   "@demoSlidersEditableNumericalValue": {
     "description": "Label for input field that has an editable numerical value."
   },
+  "demoMenuTitle": "Menu",
+  "@demoMenuTitle": {
+    "description": "Title for the menu component demo."
+  },
+  "demoContextMenuTitle": "Context menu",
+  "@demoContextMenuTitle": {
+    "description": "Title for the context menu component demo."
+  },
+  "demoSectionedMenuTitle": "Sectioned menu",
+  "@demoSectionedMenuTitle": {
+    "description": "Title for the sectioned menu component demo."
+  },
+  "demoSimpleMenuTitle": "Simple menu",
+  "@demoSimpleMenuTitle": {
+    "description": "Title for the simple menu component demo."
+  },
+  "demoChecklistMenuTitle": "Checklist menu",
+  "@demoChecklistMenuTitle": {
+    "description": "Title for the checklist menu component demo."
+  },
+  "demoMenuSubtitle": "Menu buttons and simple menus",
+  "@demoMenuSubtitle": {
+    "description": "Short description for the menu component demo."
+  },
+  "demoMenuDescription": "A menu displays a list of choices on a temporary surface. They appear when users interact with a button, action, or other control.",
+  "@demoMenuDescription": {
+    "description": "Description for the menu demo."
+  },
+  "demoMenuItemValueOne": "Menu item one",
+  "@demoMenuItemValueOne": {
+    "description": "The first item in a menu."
+  },
+  "demoMenuItemValueTwo": "Menu item two",
+  "@demoMenuItemValueTwo": {
+    "description": "The second item in a menu."
+  },
+  "demoMenuItemValueThree": "Menu item three",
+  "@demoMenuItemValueThree": {
+    "description": "The third item in a menu."
+  },
+  "demoMenuOne": "One",
+  "@demoMenuOne": {
+    "description": "The number one."
+  },
+  "demoMenuTwo": "Two",
+  "@demoMenuTwo": {
+    "description": "The number two."
+  },
+  "demoMenuThree": "Three",
+  "@demoMenuThree": {
+    "description": "The number three."
+  },
+  "demoMenuFour": "Four",
+  "@demoMenuFour": {
+    "description": "The number four."
+  },
+  "demoMenuAnItemWithAContextMenuButton": "An item with a context menu",
+  "@demoMenuAnItemWithAContextMenuButton": {
+    "description": "Label next to a button that opens a menu. A menu displays a list of choices on a temporary surface. Used as an example in a demo."
+  },
+  "demoMenuContextMenuItemOne": "Context menu item one",
+  "@demoMenuContextMenuItemOne": {
+    "description": "Text label for a context menu item. A menu displays a list of choices on a temporary surface. Used as an example in a demo."
+  },
+  "demoMenuADisabledMenuItem": "Disabled menu item",
+  "@demoMenuADisabledMenuItem": {
+    "description": "Text label for a disabled menu item. A menu displays a list of choices on a temporary surface. Used as an example in a demo."
+  },
+  "demoMenuContextMenuItemThree": "Context menu item three",
+  "@demoMenuContextMenuItemThree": {
+    "description": "Text label for a context menu item three. A menu displays a list of choices on a temporary surface. Used as an example in a demo."
+  },
+  "demoMenuAnItemWithASectionedMenu": "An item with a sectioned menu",
+  "@demoMenuAnItemWithASectionedMenu": {
+    "description": "Label next to a button that opens a sectioned menu . A menu displays a list of choices on a temporary surface. Used as an example in a demo."
+  },
+  "demoMenuPreview": "Preview",
+  "@demoMenuPreview": {
+    "description": "Button to preview content."
+  },
+  "demoMenuShare": "Share",
+  "@demoMenuShare": {
+    "description": "Button to share content."
+  },
+  "demoMenuGetLink": "Get link",
+  "@demoMenuGetLink": {
+    "description": "Button to get link for content."
+  },
+  "demoMenuRemove": "Remove",
+  "@demoMenuRemove": {
+    "description": "Button to remove content."
+  },
+  "demoMenuSelected": "Selected: {value}",
+  "@demoMenuSelected": {
+    "description": "A text to show what value was selected.",
+    "placeholders": {
+      "value": {
+        "example": "1"
+      }
+    }
+  },
+  "demoMenuChecked": "Checked: {value}",
+  "@demoMenuChecked": {
+    "description": "A text to show what value was checked.",
+    "placeholders": {
+      "value": {
+        "example": "1"
+      }
+    }
+  },
+  "demoMenuAnItemWithASimpleMenu": "An item with a simple menu",
+  "@demoMenuAnItemWithASimpleMenu": {
+    "description": "Label next to a button that opens a simple menu. A menu displays a list of choices on a temporary surface. Used as an example in a demo."
+  },
+  "demoMenuAnItemWithAChecklistMenu": "An item with a checklist menu",
+  "@demoMenuAnItemWithAChecklistMenu": {
+    "description": "Label next to a button that opens a checklist menu. A menu displays a list of choices on a temporary surface. Used as an example in a demo."
+  },
   "demoFullscreenDialogTitle": "Fullscreen",
   "@demoFullscreenDialogTitle": {
     "description": "Title for the fullscreen dialog component demo."

gallery/gallery/lib/l10n/intl_en_US.xml

@@ -653,6 +653,114 @@
     name="demoSlidersEditableNumericalValue"
     description="Label for input field that has an editable numerical value."
     >Editable numerical value</string>
+  <string
+    name="demoMenuTitle"
+    description="Title for the menu component demo."
+    >Menu</string>
+  <string
+    name="demoContextMenuTitle"
+    description="Title for the context menu component demo."
+    >Context menu</string>
+  <string
+    name="demoSectionedMenuTitle"
+    description="Title for the sectioned menu component demo."
+    >Sectioned menu</string>
+  <string
+    name="demoSimpleMenuTitle"
+    description="Title for the simple menu component demo."
+    >Simple menu</string>
+  <string
+    name="demoChecklistMenuTitle"
+    description="Title for the checklist menu component demo."
+    >Checklist menu</string>
+  <string
+    name="demoMenuSubtitle"
+    description="Short description for the menu component demo."
+    >Menu buttons and simple menus</string>
+  <string
+    name="demoMenuDescription"
+    description="Description for the menu demo."
+    >A menu displays a list of choices on a temporary surface. They appear when users interact with a button, action, or other control.</string>
+  <string
+    name="demoMenuItemValueOne"
+    description="The first item in a menu."
+    >Menu item one</string>
+  <string
+    name="demoMenuItemValueTwo"
+    description="The second item in a menu."
+    >Menu item two</string>
+  <string
+    name="demoMenuItemValueThree"
+    description="The third item in a menu."
+    >Menu item three</string>
+  <string
+    name="demoMenuOne"
+    description="The number one."
+    >One</string>
+  <string
+    name="demoMenuTwo"
+    description="The number two."
+    >Two</string>
+  <string
+    name="demoMenuThree"
+    description="The number three."
+    >Three</string>
+  <string
+    name="demoMenuFour"
+    description="The number four."
+    >Four</string>
+  <string
+    name="demoMenuAnItemWithAContextMenuButton"
+    description="Label next to a button that opens a menu. A menu displays a list of choices on a temporary surface. Used as an example in a demo."
+    >An item with a context menu</string>
+  <string
+    name="demoMenuContextMenuItemOne"
+    description="Text label for a context menu item. A menu displays a list of choices on a temporary surface. Used as an example in a demo."
+    >Context menu item one</string>
+  <string
+    name="demoMenuADisabledMenuItem"
+    description="Text label for a disabled menu item. A menu displays a list of choices on a temporary surface. Used as an example in a demo."
+    >Disabled menu item</string>
+  <string
+    name="demoMenuContextMenuItemThree"
+    description="Text label for a context menu item three. A menu displays a list of choices on a temporary surface. Used as an example in a demo."
+    >Context menu item three</string>
+  <string
+    name="demoMenuAnItemWithASectionedMenu"
+    description="Label next to a button that opens a sectioned menu . A menu displays a list of choices on a temporary surface. Used as an example in a demo."
+    >An item with a sectioned menu</string>
+  <string
+    name="demoMenuPreview"
+    description="Button to preview content."
+    >Preview</string>
+  <string
+    name="demoMenuShare"
+    description="Button to share content."
+    >Share</string>
+  <string
+    name="demoMenuGetLink"
+    description="Button to get link for content."
+    >Get link</string>
+  <string
+    name="demoMenuRemove"
+    description="Button to remove content."
+    >Remove</string>
+  <string
+    name="demoMenuSelected"
+    description="A text to show what value was selected."
+    >Selected: {value}</string>
+  <string
+    name="demoMenuChecked"
+    description="A text to show what value was checked."
+    >Checked: {value}</string>
+  <string
+    name="demoMenuAnItemWithASimpleMenu"
+    description="Label next to a button that opens a simple menu. A menu displays a list of choices on a temporary surface. Used as an example in a demo."
+    >An item with a simple menu</string>
+  <string
+    name="demoMenuAnItemWithAChecklistMenu"
+    description="Label next to a button that opens a checklist menu. A menu displays a list of choices on a temporary surface. Used as an example in a demo."
+    >An item with a checklist menu</string>
   <string
     name="demoFullscreenDialogTitle"
     description="Title for the fullscreen dialog component demo."

gallery/gallery/lib/l10n/messages_en_US.dart

@@ -41,6 +41,10 @@ class MessageLookup extends MessageLookupByLibrary {
 
   static m8(value) => "Discrete: ${value}";
 
+  static m25(value) => "Checked: ${value}";
+
+  static m26(value) => "Selected: ${value}";
+
   static m9(name, phoneNumber) => "${name} phone number is ${phoneNumber}";
 
   static m10(value) => "You selected: \"${value}\"";
@@ -372,6 +376,8 @@ class MessageLookup extends MessageLookupByLibrary {
         "demoButtonSubtitle": MessageLookupByLibrary.simpleMessage(
             "Flat, raised, outline, and more"),
         "demoButtonTitle": MessageLookupByLibrary.simpleMessage("Buttons"),
+        "demoChecklistMenuTitle":
+            MessageLookupByLibrary.simpleMessage("Checklist menu"),
         "demoChipSubtitle": MessageLookupByLibrary.simpleMessage(
             "Compact elements that represent an input, attribute, or action"),
         "demoChipTitle": MessageLookupByLibrary.simpleMessage("Chips"),
@@ -395,6 +401,8 @@ class MessageLookup extends MessageLookupByLibrary {
         "demoColorsSubtitle": MessageLookupByLibrary.simpleMessage(
             "All of the predefined colors"),
         "demoColorsTitle": MessageLookupByLibrary.simpleMessage("Colors"),
+        "demoContextMenuTitle":
+            MessageLookupByLibrary.simpleMessage("Context menu"),
         "demoCupertinoActionSheetDescription": MessageLookupByLibrary.simpleMessage(
             "An action sheet is a specific style of alert that presents the user with a set of two or more choices related to the current context. An action sheet can have a title, an additional message, and a list of actions."),
         "demoCupertinoActionSheetTitle":
@@ -517,6 +525,43 @@ class MessageLookup extends MessageLookupByLibrary {
         "demoListsSubtitle":
             MessageLookupByLibrary.simpleMessage("Scrolling list layouts"),
         "demoListsTitle": MessageLookupByLibrary.simpleMessage("Lists"),
+        "demoMenuADisabledMenuItem":
+            MessageLookupByLibrary.simpleMessage("Disabled menu item"),
+        "demoMenuAnItemWithAChecklistMenu":
+            MessageLookupByLibrary.simpleMessage(
+                "An item with a checklist menu"),
+        "demoMenuAnItemWithAContextMenuButton":
+            MessageLookupByLibrary.simpleMessage("An item with a context menu"),
+        "demoMenuAnItemWithASectionedMenu":
+            MessageLookupByLibrary.simpleMessage(
+                "An item with a sectioned menu"),
+        "demoMenuAnItemWithASimpleMenu":
+            MessageLookupByLibrary.simpleMessage("An item with a simple menu"),
+        "demoMenuChecked": m25,
+        "demoMenuContextMenuItemOne":
+            MessageLookupByLibrary.simpleMessage("Context menu item one"),
+        "demoMenuContextMenuItemThree":
+            MessageLookupByLibrary.simpleMessage("Context menu item three"),
+        "demoMenuDescription": MessageLookupByLibrary.simpleMessage(
+            "A menu displays a list of choices on a temporary surface. They appear when users interact with a button, action, or other control."),
+        "demoMenuFour": MessageLookupByLibrary.simpleMessage("Four"),
+        "demoMenuGetLink": MessageLookupByLibrary.simpleMessage("Get link"),
+        "demoMenuItemValueOne":
+            MessageLookupByLibrary.simpleMessage("Menu item one"),
+        "demoMenuItemValueThree":
+            MessageLookupByLibrary.simpleMessage("Menu item three"),
+        "demoMenuItemValueTwo":
+            MessageLookupByLibrary.simpleMessage("Menu item two"),
+        "demoMenuOne": MessageLookupByLibrary.simpleMessage("One"),
+        "demoMenuPreview": MessageLookupByLibrary.simpleMessage("Preview"),
+        "demoMenuRemove": MessageLookupByLibrary.simpleMessage("Remove"),
+        "demoMenuSelected": m26,
+        "demoMenuShare": MessageLookupByLibrary.simpleMessage("Share"),
+        "demoMenuSubtitle": MessageLookupByLibrary.simpleMessage(
+            "Menu buttons and simple menus"),
+        "demoMenuThree": MessageLookupByLibrary.simpleMessage("Three"),
+        "demoMenuTitle": MessageLookupByLibrary.simpleMessage("Menu"),
+        "demoMenuTwo": MessageLookupByLibrary.simpleMessage("Two"),
         "demoOneLineListsTitle":
             MessageLookupByLibrary.simpleMessage("One Line"),
         "demoOptionsFeatureDescription": MessageLookupByLibrary.simpleMessage(
@@ -540,6 +585,8 @@ class MessageLookup extends MessageLookupByLibrary {
             "Sliders reflect a range of values along a bar. They can have icons on both ends of the bar that reflect a range of values. They are ideal for adjusting settings such as volume, brightness, or applying image filters."),
         "demoRangeSlidersTitle":
             MessageLookupByLibrary.simpleMessage("Range Sliders"),
+        "demoSectionedMenuTitle":
+            MessageLookupByLibrary.simpleMessage("Sectioned menu"),
         "demoSelectionControlsCheckboxDescription":
             MessageLookupByLibrary.simpleMessage(
                 "Checkboxes allow the user to select multiple options from a set. A normal checkbox\'s value is true or false and a tristate checkbox\'s value can also be null."),
@@ -562,6 +609,8 @@ class MessageLookup extends MessageLookupByLibrary {
         "demoSimpleDialogDescription": MessageLookupByLibrary.simpleMessage(
             "A simple dialog offers the user a choice between several options. A simple dialog has an optional title that is displayed above the choices."),
         "demoSimpleDialogTitle": MessageLookupByLibrary.simpleMessage("Simple"),
+        "demoSimpleMenuTitle":
+            MessageLookupByLibrary.simpleMessage("Simple menu"),
         "demoSlidersContinuous":
             MessageLookupByLibrary.simpleMessage("Continuous"),
         "demoSlidersContinuousRangeSliderWithCustomTheme":