flutter/examples/api/lib/widgets/layout_builder/layout_builder.0.dart

// 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.

/// Flutter code sample for [LayoutBuilder].

import 'package:flutter/material.dart';

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

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

  static const String _title = 'Flutter Code Sample';

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      title: _title,
      home: MyStatelessWidget(),
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('LayoutBuilder Example')),
      body: LayoutBuilder(
        builder: (BuildContext context, BoxConstraints constraints) {
          if (constraints.maxWidth > 600) {
            return _buildWideContainers();
          } else {
            return _buildNormalContainer();
          }
        },
      ),
    );
  }

  Widget _buildNormalContainer() {
    return Center(
      child: Container(
        height: 100.0,
        width: 100.0,
        color: Colors.red,
      ),
    );
  }

  Widget _buildWideContainers() {
    return Center(
      child: Row(
        mainAxisAlignment: MainAxisAlignment.spaceEvenly,
        children: <Widget>[
          Container(
            height: 100.0,
            width: 100.0,
            color: Colors.red,
          ),
          Container(
            height: 100.0,
            width: 100.0,
            color: Colors.yellow,
          ),
        ],
      ),
    );
  }
}