| // 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 [SearchAnchor]. |
| |
| const Duration fakeAPIDuration = Duration(seconds: 1); |
| |
| void main() => runApp(const SearchAnchorAsyncExampleApp()); |
| |
| class SearchAnchorAsyncExampleApp extends StatelessWidget { |
| const SearchAnchorAsyncExampleApp({super.key}); |
| |
| @override |
| Widget build(BuildContext context) { |
| return MaterialApp( |
| home: Scaffold( |
| appBar: AppBar( |
| title: const Text('SearchAnchor - async'), |
| ), |
| body: const Center( |
| child: _AsyncSearchAnchor(), |
| ), |
| ), |
| ); |
| } |
| } |
| |
| class _AsyncSearchAnchor extends StatefulWidget { |
| const _AsyncSearchAnchor(); |
| |
| @override |
| State<_AsyncSearchAnchor > createState() => _AsyncSearchAnchorState(); |
| } |
| |
| class _AsyncSearchAnchorState extends State<_AsyncSearchAnchor > { |
| // The query currently being searched for. If null, there is no pending |
| // request. |
| String? _searchingWithQuery; |
| |
| // The most recent options received from the API. |
| late Iterable<Widget> _lastOptions = <Widget>[]; |
| |
| @override |
| Widget build(BuildContext context) { |
| return SearchAnchor( |
| builder: (BuildContext context, SearchController controller) { |
| return IconButton( |
| icon: const Icon(Icons.search), |
| onPressed: () { |
| controller.openView(); |
| }, |
| ); |
| }, |
| suggestionsBuilder: (BuildContext context, SearchController controller) async { |
| _searchingWithQuery = controller.text; |
| final List<String> options = (await _FakeAPI.search(_searchingWithQuery!)).toList(); |
| |
| // If another search happened after this one, throw away these options. |
| // Use the previous options instead and wait for the newer request to |
| // finish. |
| if (_searchingWithQuery != controller.text) { |
| return _lastOptions; |
| } |
| |
| _lastOptions = List<ListTile>.generate(options.length, (int index) { |
| final String item = options[index]; |
| return ListTile( |
| title: Text(item), |
| ); |
| }); |
| |
| return _lastOptions; |
| }); |
| } |
| } |
| |
| // Mimics a remote API. |
| class _FakeAPI { |
| static const List<String> _kOptions = <String>[ |
| 'aardvark', |
| 'bobcat', |
| 'chameleon', |
| ]; |
| |
| // Searches the options, but injects a fake "network" delay. |
| static Future<Iterable<String>> search(String query) async { |
| await Future<void>.delayed(fakeAPIDuration); // Fake 1 second delay. |
| if (query == '') { |
| return const Iterable<String>.empty(); |
| } |
| return _kOptions.where((String option) { |
| return option.contains(query.toLowerCase()); |
| }); |
| } |
| } |