RadioMenuButton<T> class

A menu item that combines a Radio widget with a MenuItemButton.

To style the radio button separately from the overall button, add a RadioTheme ancestor.

This example shows a menu with three radio buttons with shortcuts that changes the background color of the body when the buttons are selected.

To see it in action, copy and run this code snippet on DartPad.

import 'package:flutter/services.dart';
import 'package:material_ui/material_ui.dart';

/// Flutter code sample for [RadioMenuButton].

void main() => runApp(const MenuApp());

class MyRadioMenu extends StatefulWidget {
  const MyRadioMenu({super.key});

  @override
  State<MyRadioMenu> createState() => _MyRadioMenuState();
}

class _MyRadioMenuState extends State<MyRadioMenu> {
  final FocusNode _buttonFocusNode = FocusNode(debugLabel: 'Menu Button');
  Color _backgroundColor = Colors.red;
  late ShortcutRegistryEntry _entry;

  static const SingleActivator _redShortcut = SingleActivator(
    LogicalKeyboardKey.keyR,
    control: true,
  );
  static const SingleActivator _greenShortcut = SingleActivator(
    LogicalKeyboardKey.keyG,
    control: true,
  );
  static const SingleActivator _blueShortcut = SingleActivator(
    LogicalKeyboardKey.keyB,
    control: true,
  );

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
    _entry = ShortcutRegistry.of(context).addAll(<
      ShortcutActivator,
      VoidCallbackIntent
    >{
      _redShortcut: VoidCallbackIntent(() => _setBackgroundColor(Colors.red)),
      _greenShortcut: VoidCallbackIntent(
        () => _setBackgroundColor(Colors.green),
      ),
      _blueShortcut: VoidCallbackIntent(() => _setBackgroundColor(Colors.blue)),
    });
  }

  @override
  void dispose() {
    _buttonFocusNode.dispose();
    _entry.dispose();
    super.dispose();
  }

  void _setBackgroundColor(Color? color) {
    setState(() {
      _backgroundColor = color!;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      crossAxisAlignment: .start,
      children: <Widget>[
        MenuAnchor(
          childFocusNode: _buttonFocusNode,
          menuChildren: <Widget>[
            RadioMenuButton<Color>(
              value: Colors.red,
              shortcut: _redShortcut,
              groupValue: _backgroundColor,
              onChanged: _setBackgroundColor,
              child: const Text('Red Background'),
            ),
            RadioMenuButton<Color>(
              value: Colors.green,
              shortcut: _greenShortcut,
              groupValue: _backgroundColor,
              onChanged: _setBackgroundColor,
              child: const Text('Green Background'),
            ),
            RadioMenuButton<Color>(
              value: Colors.blue,
              shortcut: _blueShortcut,
              groupValue: _backgroundColor,
              onChanged: _setBackgroundColor,
              child: const Text('Blue Background'),
            ),
          ],
          builder:
              (BuildContext context, MenuController controller, Widget? child) {
                return TextButton(
                  focusNode: _buttonFocusNode,
                  onPressed: () {
                    if (controller.isOpen) {
                      controller.close();
                    } else {
                      controller.open();
                    }
                  },
                  child: const Text('OPEN MENU'),
                );
              },
        ),
        Expanded(child: Container(color: _backgroundColor)),
      ],
    );
  }
}

class MenuApp extends StatelessWidget {
  const MenuApp({super.key});

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      home: Scaffold(body: SafeArea(child: MyRadioMenu())),
    );
  }
}

Constructors

RadioMenuButton({Key? key, required T value, required T? groupValue, required ValueChanged<T?>? onChanged, bool toggleable = false, ValueChanged<bool>? onHover, ValueChanged<bool>? onFocusChange, FocusNode? focusNode, MenuSerializableShortcut? shortcut, ButtonStyle? style, MaterialStatesController? statesController, Clip clipBehavior = Clip.none, Widget? trailingIcon, bool closeOnActivate = true, required Widget? child}): Creates a const RadioMenuButton.
const

Properties

child → Widget?: The widget displayed in the center of this button.
final
clipBehavior → Clip: The content will be clipped (or not) according to this option.
final
closeOnActivate → bool: Determines if the menu will be closed when a MenuItemButton is pressed.
final
enabled → bool: Whether the button is enabled or disabled.
no setter
focusNode → FocusNode?: An optional focus node to use as the focus node for this widget.
final
groupValue → T?: The currently selected value for a group of radio buttons.
final
hashCode → int: The hash code for this object.
no setterinherited
key → Key?: Controls how one widget replaces another widget in the tree.
finalinherited
onChanged → ValueChanged<T?>?: Called when the user selects this radio button.
final
onFocusChange → ValueChanged<bool>?: Handler called when the focus changes.
final
onHover → ValueChanged<bool>?: Called when a pointer enters or exits the button response area.
final
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited
shortcut → MenuSerializableShortcut?: The optional shortcut that selects this MenuItemButton.
final
statesController → MaterialStatesController?: Represents the interactive "state" of this widget in terms of a set of WidgetStates, like WidgetState.pressed and WidgetState.focused.
final
style → ButtonStyle?: Customizes this button's appearance.
final
toggleable → bool: Set to true if this radio button is allowed to be returned to an indeterminate state by selecting it again when selected.
final
trailingIcon → Widget?: An optional icon to display after the child label.
final
value → T: The value represented by this radio button.
final

Methods

build(BuildContext context) → Widget: Describes the part of the user interface represented by this widget.
override
createElement() → StatelessElement: Creates a StatelessElement to manage this widget's location in the tree.
inherited
debugDescribeChildren() → List<DiagnosticsNode>: Returns a list of DiagnosticsNode objects describing this node's children.
inherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void: Add additional properties associated with the node.
inherited
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
toDiagnosticsNode({String? name, DiagnosticsTreeStyle? style}) → DiagnosticsNode: Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep.
inherited
toString({DiagnosticLevel minLevel = DiagnosticLevel.info}) → String: A string representation of this object.
inherited
toStringDeep({String prefixLineOne = '', String? prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug, int wrapWidth = 65}) → String: Returns a string representation of this node and its descendants.
inherited
toStringShallow({String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) → String: Returns a one-line detailed description of the object.
inherited
toStringShort() → String: A short, textual description of this widget.
inherited

Operators

operator ==(Object other) → bool: The equality operator.
inherited

RadioMenuButton<T> class

Constructors

Properties

Methods

Operators

material_ui library