// 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';

/// Flutter code sample for [UndoHistoryController].

void main() {
  runApp(const UndoHistoryControllerExampleApp());
}

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

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(home: MyHomePage());
  }
}

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

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  final TextEditingController _controller = TextEditingController();
  final FocusNode _focusNode = FocusNode();
  final UndoHistoryController _undoController = UndoHistoryController();

  TextStyle? get enabledStyle => Theme.of(context).textTheme.bodyMedium;
  TextStyle? get disabledStyle =>
      Theme.of(context).textTheme.bodyMedium?.copyWith(color: Colors.grey);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            TextField(
              maxLines: 4,
              controller: _controller,
              focusNode: _focusNode,
              undoController: _undoController,
            ),
            ValueListenableBuilder<UndoHistoryValue>(
              valueListenable: _undoController,
              builder:
                  (
                    BuildContext context,
                    UndoHistoryValue value,
                    Widget? child,
                  ) {
                    return Row(
                      children: <Widget>[
                        TextButton(
                          child: Text(
                            'Undo',
                            style: value.canUndo ? enabledStyle : disabledStyle,
                          ),
                          onPressed: () {
                            _undoController.undo();
                          },
                        ),
                        TextButton(
                          child: Text(
                            'Redo',
                            style: value.canRedo ? enabledStyle : disabledStyle,
                          ),
                          onPressed: () {
                            _undoController.redo();
                          },
                        ),
                      ],
                    );
                  },
            ),
          ],
        ),
      ),
    );
  }
}