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// Copyright 2014 The Flutter Authors. 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/foundation.dart';
import 'package:flutter/widgets.dart';
import 'menu_anchor.dart';
import 'menu_style.dart';
import 'theme.dart';
// Examples can assume:
// late Widget child;
/// Defines the configuration of the submenus created by the [SubmenuButton],
/// [MenuBar], or [MenuAnchor] widgets.
/// Descendant widgets obtain the current [MenuThemeData] object using
/// `MenuTheme.of(context)`.
/// Typically, a [MenuThemeData] is specified as part of the overall [Theme]
/// with [ThemeData.menuTheme]. Otherwise, [MenuTheme] can be used to configure
/// its own widget subtree.
/// All [MenuThemeData] properties are `null` by default. If any of these
/// properties are null, the menu bar will provide its own defaults.
/// See also:
/// * [ThemeData], which describes the overall theme for the application.
/// * [MenuBarThemeData], which describes the theme for the menu bar itself in a
/// [MenuBar] widget.
class MenuThemeData with Diagnosticable {
/// Creates a const set of properties used to configure [MenuTheme].
const MenuThemeData({});
/// The [MenuStyle] of a [SubmenuButton] menu.
/// Any values not set in the [MenuStyle] will use the menu default for that
/// property.
final MenuStyle? style;
/// Linearly interpolate between two menu button themes.
static MenuThemeData? lerp(MenuThemeData? a, MenuThemeData? b, double t) {
if (identical(a, b)) {
return a;
return MenuThemeData(style: MenuStyle.lerp(a?.style, b?.style, t));
int get hashCode => style.hashCode;
bool operator ==(Object other) {
if (identical(this, other)) {
return true;
if (other.runtimeType != runtimeType) {
return false;
return other is MenuThemeData && == style;
void debugFillProperties(DiagnosticPropertiesBuilder properties) {
properties.add(DiagnosticsProperty<MenuStyle>('style', style, defaultValue: null));
/// An inherited widget that defines the configuration in this widget's
/// descendants for menus created by the [SubmenuButton], [MenuBar], or
/// [MenuAnchor] widgets.
/// Values specified here are used for [SubmenuButton]'s menu properties that
/// are not given an explicit non-null value.
/// See also:
/// * [MenuThemeData], a configuration object that holds attributes of a menu
/// used by this theme.
/// * [MenuBarTheme], which does the same thing for the [MenuBar] widget.
/// * [MenuBar], a widget that manages [MenuItemButton]s.
/// * [MenuAnchor], a widget that creates a region that has a submenu.
/// * [MenuItemButton], a widget that is a selectable item in a menu bar menu.
/// * [SubmenuButton], a widget that specifies an item with a cascading submenu
/// in a [MenuBar] menu.
class MenuTheme extends InheritedTheme {
/// Creates a const theme that controls the configurations for the menus
/// created by the [SubmenuButton] or [MenuAnchor] widgets.
const MenuTheme({
required super.child,
/// The properties for [MenuBar] and [MenuItemButton] in this widget's
/// descendants.
final MenuThemeData data;
/// Returns the closest instance of this class's [data] value that encloses
/// the given context. If there is no ancestor, it returns
/// [ThemeData.menuTheme].
/// Typical usage is as follows:
/// ```dart
/// Widget build(BuildContext context) {
/// return MenuTheme(
/// data: const MenuThemeData(
/// style: MenuStyle(
/// backgroundColor: MaterialStatePropertyAll<Color>(,
/// ),
/// ),
/// child: child,
/// );
/// }
/// ```
static MenuThemeData of(BuildContext context) {
final MenuTheme? menuTheme = context.dependOnInheritedWidgetOfExactType<MenuTheme>();
return menuTheme?.data ?? Theme.of(context).menuTheme;
Widget wrap(BuildContext context, Widget child) {
return MenuTheme(data: data, child: child);
bool updateShouldNotify(MenuTheme oldWidget) => data !=;