isolate demo

dependencies:
flutter:
sdk: flutter # The following adds the Cupertino Icons font to your application.
# Use with the CupertinoIcons class for iOS style icons.
cupertino_icons: ^0.1.2

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter_isolates_example/demo_isolates.dart';void main() => runApp(MyApp());class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(),
);
}
}class MyHomePage extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Isolates'),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
DartIsolateWidget(),
FlutterIsolateWidget(),
],
),
),
floatingActionButton: FloatingActionButton(
child: Icon(Icons.home),
onPressed: (){
Navigator.of(context).push(MaterialPageRoute(builder: (context){
return Test();
}));
},
),
);
}
}class Test extends StatelessWidget { @override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: Text('test'),),
body: Container(child: Text('just test'),),
);
}
}class DartIsolateWidget extends StatefulWidget {
@override
_DartIsolateWidgetState createState() => _DartIsolateWidgetState();
}class _DartIsolateWidgetState extends State<DartIsolateWidget> {
StoppableIsolate isolate; @override
Widget build(BuildContext context) => Padding(
padding: const EdgeInsets.all(16.0),
child: Row(
children: <Widget>[
Expanded(
child: Text(
'Dart Isolates',
),
),
Switch(
value: isolate != null,
onChanged: (bool checked) async {
if (checked) {
StoppableIsolate isolate = await spawnIsolate();
setState(() {
this.isolate = isolate;
});
} else {
isolate.stop();
setState(() {
isolate = null;
});
}
},
),
],
),
);
}class FlutterIsolateWidget extends StatelessWidget {
@override
Widget build(BuildContext context) {
return FlatButton(
colorBrightness: Brightness.dark,
color: Colors.blue,
onPressed: () async {
String result = await compute(flutterIsolateComputation, null);
print('RECEIVED: ' + result);
},
child: Text(
'Flutter Isolates',
),
);
}
}

import 'dart:async';
import 'dart:io';
import 'dart:isolate';Future<StoppableIsolate> spawnIsolate() async {
ReceivePort receivePort = new ReceivePort();
Isolate isolate = await Isolate.spawn(dartIsolateLongRunningOperation, receivePort.sendPort);
receivePort.listen((data) {
print('RECEIVED: ' + data);
});
return StoppableIsolate(isolate, receivePort);
}// Isolate code
void dartIsolateLongRunningOperation(SendPort sendPort) async {
while (true) {
sleep(Duration(seconds: 3));
sendPort.send('Dart: Worked for 3 seconds');
}
}class StoppableIsolate {
final Isolate isolate;
final ReceivePort receivePort; StoppableIsolate(this.isolate, this.receivePort); void stop() {
receivePort.close();
isolate.kill(priority: Isolate.immediate);
}
}// Isolate code
String flutterIsolateComputation(Null unused) {
sleep(Duration(seconds: 3));
return 'Flutter: Worked for 3 seconds';
}