| // Copyright 2015 The Chromium 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 'dart:async'; |
| import 'dart:io'; |
| import 'dart:typed_data'; |
| import 'package:flutter/material.dart'; |
| import 'package:flutter/services.dart' show rootBundle; |
| import 'package:flutter/services.dart'; |
| |
| /// An example that sets up local http server for serving single |
| /// image, creates single flutter widget with five copies of requested |
| /// image and prints how long the loading took. |
| /// |
| /// This is used in [$FH/flutter/devicelab/bin/tasks/image_list_reported_duration.dart] test. |
| Future<void> main() async { |
| final HttpServer httpServer = |
| await HttpServer.bind(InternetAddress.anyIPv6, 0); |
| final int port = httpServer.port; |
| print('Listening on port $port.'); |
| |
| // Initializes bindings before using any platform channels. |
| WidgetsFlutterBinding.ensureInitialized(); |
| final ByteData byteData = await rootBundle.load('images/coast.jpg'); |
| final Uint8List bytes = byteData.buffer |
| .asUint8List(byteData.offsetInBytes, byteData.lengthInBytes); |
| httpServer.listen((HttpRequest request) async { |
| request.response.add(bytes); |
| request.response.close(); |
| }); |
| |
| runApp(MyApp(port)); |
| } |
| |
| const int IMAGES = 50; |
| |
| @immutable |
| class MyApp extends StatelessWidget { |
| const MyApp(this.port); |
| |
| final int port; |
| |
| @override |
| Widget build(BuildContext context) { |
| return MaterialApp( |
| title: 'Flutter Demo', |
| theme: ThemeData( |
| primarySwatch: Colors.blue, |
| ), |
| home: MyHomePage(title: 'Flutter Demo Home Page', port: port), |
| ); |
| } |
| } |
| |
| class MyHomePage extends StatefulWidget { |
| const MyHomePage({Key key, this.title, this.port}) : super(key: key); |
| final String title; |
| final int port; |
| |
| @override |
| _MyHomePageState createState() => _MyHomePageState(); |
| } |
| |
| class _MyHomePageState extends State<MyHomePage> with TickerProviderStateMixin { |
| int _counter = 0; |
| |
| void _incrementCounter() { |
| setState(() { |
| _counter++; |
| }); |
| } |
| |
| Widget createImage(final int index, final Completer<bool> completer) { |
| return Image.network( |
| 'http://localhost:${widget.port}/${_counter * IMAGES + index}', |
| frameBuilder: ( |
| BuildContext context, |
| Widget child, |
| int frame, |
| bool wasSynchronouslyLoaded, |
| ) { |
| if (frame == 0 && !completer.isCompleted) { |
| completer.complete(true); |
| } |
| return child; |
| }, |
| ); |
| } |
| |
| @override |
| Widget build(BuildContext context) { |
| final List<AnimationController> controllers = List<AnimationController>(IMAGES); |
| for (int i = 0; i < IMAGES; i++) { |
| controllers[i] = AnimationController( |
| duration: const Duration(milliseconds: 3600), |
| vsync: this, |
| )..repeat(); |
| } |
| final List<Completer<bool>> completers = List<Completer<bool>>(IMAGES); |
| for (int i = 0; i < IMAGES; i++) { |
| completers[i] = Completer<bool>(); |
| } |
| final List<Future<bool>> futures = completers.map( |
| (Completer<bool> completer) => completer.future).toList(); |
| final DateTime started = DateTime.now(); |
| Future.wait(futures).then((_) { |
| print( |
| '===image_list=== all loaded in ${DateTime.now().difference(started).inMilliseconds}ms.'); |
| }); |
| return Scaffold( |
| appBar: AppBar( |
| title: Text(widget.title), |
| ), |
| body: Center( |
| child: Column( |
| mainAxisAlignment: MainAxisAlignment.center, |
| children: <Widget>[ |
| Row(children: createImageList(IMAGES, completers, controllers)), |
| const Text( |
| 'You have pushed the button this many times:', |
| ), |
| Text( |
| '$_counter', |
| style: Theme.of(context).textTheme.display1, |
| ), |
| ], |
| ), |
| ), |
| floatingActionButton: FloatingActionButton( |
| onPressed: _incrementCounter, |
| tooltip: 'Increment', |
| child: Icon(Icons.add), |
| ), |
| ); |
| } |
| |
| List<Widget> createImageList(int count, List<Completer<bool>> completers, |
| List<AnimationController> controllers) { |
| final List<Widget> list = <Widget>[]; |
| for (int i = 0; i < count; i++) { |
| list.add(Flexible( |
| fit: FlexFit.tight, |
| flex: i + 1, |
| child: RotationTransition( |
| turns: controllers[i], |
| child: createImage(i + 1, completers[i])))); |
| } |
| return list; |
| } |
| } |