examples/api/lib/material/expansion_panel/expansion_panel_list.expansion_panel_list_radio.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 [ExpansionPanelList.radio].

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

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: const Text('ExpansionPanelList.radio Sample')),
        body: const ExpansionPanelListRadioExample(),
      ),
    );
  }
}

// stores ExpansionPanel state information
class Item {
  Item({
    required this.id,
    required this.expandedValue,
    required this.headerValue,
  });

  int id;
  String expandedValue;
  String headerValue;
}

List<Item> generateItems(int numberOfItems) {
  return List<Item>.generate(numberOfItems, (int index) {
    return Item(
      id: index,
      headerValue: 'Panel $index',
      expandedValue: 'This is item number $index',
    );
  });
}

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

  @override
  State<ExpansionPanelListRadioExample> createState() => _ExpansionPanelListRadioExampleState();
}

class _ExpansionPanelListRadioExampleState extends State<ExpansionPanelListRadioExample> {
  final List<Item> _data = generateItems(8);

  @override
  Widget build(BuildContext context) {
    return SingleChildScrollView(
      child: Container(
        child: _buildPanel(),
      ),
    );
  }

  Widget _buildPanel() {
    return ExpansionPanelList.radio(
      initialOpenPanelValue: 2,
      children: _data.map<ExpansionPanelRadio>((Item item) {
        return ExpansionPanelRadio(
            value: item.id,
            headerBuilder: (BuildContext context, bool isExpanded) {
              return ListTile(
                title: Text(item.headerValue),
              );
            },
            body: ListTile(
                title: Text(item.expandedValue),
                subtitle: const Text('To delete this panel, tap the trash can icon'),
                trailing: const Icon(Icons.delete),
                onTap: () {
                  setState(() {
                    _data.removeWhere((Item currentItem) => item == currentItem);
                  });
                }));
      }).toList(),
    );
  }
}