// 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 DropdownButton.selectedItemBuilder

import 'package:flutter/material.dart';

Map<String, String> cities = <String, String>{
  'New York': 'NYC',
  'Los Angeles': 'LA',
  'San Francisco': 'SF',
  'Chicago': 'CH',
  'Miami': 'MI',
};

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

class DropdownButtonApp extends StatelessWidget {
  const DropdownButtonApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: const Text('DropdownButton Sample')),
        body: const Center(child: DropdownButtonExample()),
      ),
    );
  }
}

class DropdownButtonExample extends StatefulWidget {
  const DropdownButtonExample({Key? key}) : super(key: key);

  @override
  State<DropdownButtonExample> createState() => _DropdownButtonExampleState();
}

class _DropdownButtonExampleState extends State<DropdownButtonExample> {
  String? selectedItem;

  @override
  Widget build(BuildContext context) {
    return Center(
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: <Widget>[
          DropdownButton<String>(
            value: selectedItem,
            alignment: Alignment.centerRight,
            hint: const Text('Hint'),
            onChanged: (String? string) {
              // This is called when the user selects an item.
              setState(() => selectedItem = string);
            },
            items: cities.keys.map<DropdownMenuItem<String>>((String item) {
              return DropdownMenuItem<String>(
                value: item,
                child: Text(item),
              );
            }).toList(),
          ),
          const SizedBox(height: 20),
          DropdownButton<String>(
            value: selectedItem,
            isExpanded: true,
            alignment: Alignment.centerRight,
            hint: const Text('Hint'),
            onChanged: (String? string) {
              // This is called when the user selects an item.
              setState(() => selectedItem = string);
            },
            items: cities.keys.map<DropdownMenuItem<String>>((String item) {
              return DropdownMenuItem<String>(
                value: item,
                child: Text(item),
              );
            }).toList(),
          ),
        ],
      ),
    );
  }
}