| // 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/material.dart'; |
| import '../utils.dart'; |
| import 'use_cases.dart'; |
| |
| class TextButtonUseCase extends UseCase { |
| @override |
| String get name => 'TextButton'; |
| |
| @override |
| String get route => '/text-button'; |
| |
| @override |
| Widget build(BuildContext context) => const MainWidget(); |
| } |
| |
| class MainWidget extends StatefulWidget { |
| const MainWidget({super.key}); |
| |
| @override |
| State<MainWidget> createState() => MainWidgetState(); |
| } |
| |
| class MainWidgetState extends State<MainWidget> { |
| String pageTitle = getUseCaseName(TextButtonUseCase()); |
| final GlobalKey<FormState> _formKey = GlobalKey<FormState>(); |
| |
| @override |
| Widget build(BuildContext context) { |
| return Scaffold( |
| appBar: AppBar( |
| backgroundColor: Theme.of(context).colorScheme.inversePrimary, |
| title: Semantics(headingLevel: 1, child: Text('$pageTitle Demo')), |
| ), |
| body: Form( |
| key: _formKey, |
| child: Column( |
| crossAxisAlignment: CrossAxisAlignment.start, |
| children: <Widget>[ |
| TextFormField( |
| // The validator receives the text that the user has entered. |
| validator: (String? value) { |
| if (value == null || value.isEmpty) { |
| return 'Please enter some text'; |
| } |
| return null; |
| }, |
| ), |
| Padding( |
| padding: const EdgeInsets.symmetric(vertical: 16), |
| child: ElevatedButton( |
| onPressed: () { |
| // Validate returns true if the form is valid, or false otherwise. |
| if (_formKey.currentState!.validate()) { |
| // If the form is valid, display a snackbar. In the real world, |
| // this might also send a request to a server. |
| ScaffoldMessenger.of(context).showSnackBar( |
| const SnackBar(content: Text('Form submitted')), |
| ); |
| } |
| }, |
| child: const Text('Submit'), |
| ), |
| ), |
| ], |
| ), |
| ), |
| ); |
| } |
| } |