flutter/examples/api/lib/material/expansion_tile/expansion_tile.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.

import 'package:flutter/material.dart';

/// Flutter code sample for [ExpansionTile].

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

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData(useMaterial3: true),
      home: Scaffold(
        appBar: AppBar(title: const Text('ExpansionTile Sample')),
        body: const ExpansionTileExample(),
      ),
    );
  }
}

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

  @override
  State<ExpansionTileExample> createState() => _ExpansionTileExampleState();
}

class _ExpansionTileExampleState extends State<ExpansionTileExample> {
  bool _customTileExpanded = false;

  @override
  Widget build(BuildContext context) {
    return Column(
      children: <Widget>[
        const ExpansionTile(
          title: Text('ExpansionTile 1'),
          subtitle: Text('Trailing expansion arrow icon'),
          children: <Widget>[
            ListTile(title: Text('This is tile number 1')),
          ],
        ),
        ExpansionTile(
          title: const Text('ExpansionTile 2'),
          subtitle: const Text('Custom expansion arrow icon'),
          trailing: Icon(
            _customTileExpanded ? Icons.arrow_drop_down_circle : Icons.arrow_drop_down,
          ),
          children: const <Widget>[
            ListTile(title: Text('This is tile number 2')),
          ],
          onExpansionChanged: (bool expanded) {
            setState(() {
              _customTileExpanded = expanded;
            });
          },
        ),
        const ExpansionTile(
          title: Text('ExpansionTile 3'),
          subtitle: Text('Leading expansion arrow icon'),
          controlAffinity: ListTileControlAffinity.leading,
          children: <Widget>[
            ListTile(title: Text('This is tile number 3')),
          ],
        ),
      ],
    );
  }
}