// 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. // Template: dev/snippets/config/templates/stateful_widget_scaffold_center.tmpl // // Comment lines marked with "▼▼▼" and "▲▲▲" are used for authoring // of samples, and may be ignored if you are just exploring the sample. // Flutter code sample for Radio // //*************************************************************************** //* ▼▼▼▼▼▼▼▼ description ▼▼▼▼▼▼▼▼ (do not modify or remove section marker) // Here is an example of Radio widgets wrapped in ListTiles, which is similar // to what you could get with the RadioListTile widget. // // The currently selected character is passed into `groupValue`, which is // maintained by the example's `State`. In this case, the first `Radio` // will start off selected because `_character` is initialized to // `SingingCharacter.lafayette`. // // If the second radio button is pressed, the example's state is updated // with `setState`, updating `_character` to `SingingCharacter.jefferson`. // This causes the buttons to rebuild with the updated `groupValue`, and // therefore the selection of the second button. // // Requires one of its ancestors to be a [Material] widget. //* ▲▲▲▲▲▲▲▲ description ▲▲▲▲▲▲▲▲ (do not modify or remove section marker) //*************************************************************************** import 'package:flutter/material.dart'; void main() => runApp(const MyApp()); /// This is the main application widget. class MyApp extends StatelessWidget { const MyApp({Key? key}) : super(key: key); static const String _title = 'Flutter Code Sample'; @override Widget build(BuildContext context) { return MaterialApp( title: _title, home: Scaffold( appBar: AppBar(title: const Text(_title)), body: const Center( child: MyStatefulWidget(), ), ), ); } } //***************************************************************************** //* ▼▼▼▼▼▼▼▼ code-preamble ▼▼▼▼▼▼▼▼ (do not modify or remove section marker) enum SingingCharacter { lafayette, jefferson } //* ▲▲▲▲▲▲▲▲ code-preamble ▲▲▲▲▲▲▲▲ (do not modify or remove section marker) //***************************************************************************** /// This is the stateful widget that the main application instantiates. class MyStatefulWidget extends StatefulWidget { const MyStatefulWidget({Key? key}) : super(key: key); @override State createState() => _MyStatefulWidgetState(); } /// This is the private State class that goes with MyStatefulWidget. class _MyStatefulWidgetState extends State { //******************************************************************** //* ▼▼▼▼▼▼▼▼ code ▼▼▼▼▼▼▼▼ (do not modify or remove section marker) SingingCharacter? _character = SingingCharacter.lafayette; @override Widget build(BuildContext context) { return Column( children: [ ListTile( title: const Text('Lafayette'), leading: Radio( value: SingingCharacter.lafayette, groupValue: _character, onChanged: (SingingCharacter? value) { setState(() { _character = value; }); }, ), ), ListTile( title: const Text('Thomas Jefferson'), leading: Radio( value: SingingCharacter.jefferson, groupValue: _character, onChanged: (SingingCharacter? value) { setState(() { _character = value; }); }, ), ), ], ); } //* ▲▲▲▲▲▲▲▲ code ▲▲▲▲▲▲▲▲ (do not modify or remove section marker) //******************************************************************** }