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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/widgets.dart';
import 'menu_anchor.dart';
import 'menu_style.dart';
import 'menu_theme.dart';
import 'theme.dart';
// Examples can assume:
// late Widget child;
/// A data class that [MenuBarTheme] uses to define the visual properties of
/// [MenuBar] widgets.
/// This class defines the visual properties of [MenuBar] widgets themselves,
/// but not their submenus. Those properties are defined by [MenuThemeData] or
/// [MenuButtonThemeData] instead.
/// Descendant widgets obtain the current [MenuBarThemeData] object using
/// `MenuBarTheme.of(context)`.
/// Typically, a [MenuBarThemeData] is specified as part of the overall [Theme]
/// with [ThemeData.menuBarTheme]. Otherwise, [MenuTheme] can be used to
/// configure its own widget subtree.
/// All [MenuBarThemeData] properties are `null` by default. If any of these
/// properties are null, the menu bar will provide its own defaults.
/// See also:
/// * [MenuThemeData], which describes the theme for the submenus of a
/// [MenuBar].
/// * [MenuButtonThemeData], which describes the theme for the [MenuItemButton]s
/// in a menu.
/// * [ThemeData], which describes the overall theme for the application.
class MenuBarThemeData extends MenuThemeData {
/// Creates a const set of properties used to configure [MenuTheme].
const MenuBarThemeData({});
/// Linearly interpolate between two [MenuBar] themes.
static MenuBarThemeData? lerp(MenuBarThemeData? a, MenuBarThemeData? b, double t) {
if (identical(a, b)) {
return a;
return MenuBarThemeData(style: MenuStyle.lerp(a?.style, b?.style, t));
/// An inherited widget that defines the configuration for the [MenuBar] widgets
/// in this widget's descendants.
/// This class defines the visual properties of [MenuBar] widgets themselves,
/// but not their submenus. Those properties are defined by [MenuTheme] or
/// [MenuButtonTheme] instead.
/// Values specified here are used for [MenuBar]'s properties that are not given
/// an explicit non-null value.
/// See also:
/// * [MenuStyle], a configuration object that holds attributes of a menu, and
/// is used by this theme to define those attributes.
/// * [MenuTheme], which does the same thing for the menus created by a
/// [SubmenuButton] or [MenuAnchor].
/// * [MenuButtonTheme], which does the same thing for the [MenuItemButton]s
/// inside of the menus.
/// * [SubmenuButton], a button that manages a submenu that uses these
/// properties.
/// * [MenuBar], a widget that creates a menu bar that can use [SubmenuButton]s.
class MenuBarTheme extends InheritedTheme {
/// Creates a theme that controls the configurations for [MenuBar] and
/// [MenuItemButton] in its widget subtree.
const MenuBarTheme({
required super.child,
/// The properties to set for [MenuBar] in this widget's descendants.
final MenuBarThemeData data;
/// Returns the closest instance of this class's [data] value that encloses
/// the given context. If there is no ancestor, it returns
/// [ThemeData.menuBarTheme].
/// Typical usage is as follows:
/// ```dart
/// Widget build(BuildContext context) {
/// return MenuTheme(
/// data: const MenuThemeData(
/// style: MenuStyle(
/// backgroundColor: MaterialStatePropertyAll<Color?>(,
/// ),
/// ),
/// child: child,
/// );
/// }
/// ```
static MenuBarThemeData of(BuildContext context) {
final MenuBarTheme? menuBarTheme = context.dependOnInheritedWidgetOfExactType<MenuBarTheme>();
return menuBarTheme?.data ?? Theme.of(context).menuBarTheme;
Widget wrap(BuildContext context, Widget child) {
return MenuBarTheme(data: data, child: child);
bool updateShouldNotify(MenuBarTheme oldWidget) => data !=;