1import 'package:flutter/material.dart';
 2
 3/// A [ListTile] that allows choosing from a dropdown.
 4class DropDownListTile<T> extends StatefulWidget {
 5  /// Creates a list tile that allows choosing an item from a dropdown.
 6  ///
 7  /// Using this is equivalent to using a [ListTile] with a trailing [DropdownButton]. Please refer to those classes for
 8  /// argument definitions.
 9  const DropDownListTile({
10    required this.title,
11    required this.value,
12    required this.onChanged,
13    required this.items,
14    this.leading,
15    this.subtitle,
16    super.key,});
17
18  /// Primary description of the tile.
19  final Widget title;
20
21  /// Secondary description below the title.
22  final Widget? subtitle;
23
24  /// A widget to display before the title.
25  final Widget? leading;
26
27  /// The value of the currently selected [DropdownMenuItem].
28  final T? value;
29
30  /// A list of items the user can select.
31  final List<DropdownMenuItem<T>> items;
32
33  /// Called when the selection changes.
34  final void Function(T? value) onChanged;
35
36  @override
37  State<DropDownListTile<T>> createState() => _DropDownListTileState<T>();
38}
39
40class _DropDownListTileState<T> extends State<DropDownListTile<T>> {
41  final focusNode = FocusNode();
42
43
44  @override
45  void dispose() {
46    focusNode.dispose();
47    super.dispose();
48  }
49
50  @override
51  Widget build(BuildContext context) => ListTile(
52      title: widget.title,
53      subtitle: widget.subtitle,
54      leading: widget.leading,
55      onTap: focusNode.requestFocus,
56      trailing: DropdownButton<T>(
57        focusNode: focusNode,
58        value: widget.value,
59        items: widget.items,
60        onChanged: widget.onChanged,
61      ),
62    );
63}