The rest of page one for isolate_example

2025-11-08 22:09:06 +00:00 · 2019-06-25 11:28:13 -07:00
parent 599c865629
commit e4b4b35182
5 changed files with 363 additions and 21 deletions
--- a/isolate_example/lib/main.dart
+++ b/isolate_example/lib/main.dart
@@ -18,9 +18,7 @@ import 'page_one.dart';
 import 'page_two.dart';
 import 'page_three.dart';

-void main() {
-  runApp(StartApp());
-}
+void main() => runApp(new MaterialApp(home: new StartApp()));

 class StartApp extends StatelessWidget {
  @override
@@ -42,7 +40,7 @@ class StartApp extends StatelessWidget {
          body: TabBarView(
            children: [
              PerformancePage(),
-              InfiniteProcessPage(),
+              InfiniteProcessPageStarter(),
              DataTransferPage(),
            ],
          ),
--- a/isolate_example/lib/page_one.dart
+++ b/isolate_example/lib/page_one.dart
@@ -12,20 +12,117 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.

+import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';

-class PerformancePage extends StatelessWidget {
+class PerformancePage extends StatefulWidget {
+  @override
+  _PerformancePageState createState() => _PerformancePageState();
+}
+
+class _PerformancePageState extends State<PerformancePage> {
+  Future<void> computeFuture = Future.value();
+
  @override
  Widget build(BuildContext context) {
    return Center(
      child: Column(
        mainAxisSize: MainAxisSize.min,
-        children: <Widget>[
+        children: [
          SmoothAnimationWidget(),
+          Container(
+            alignment: Alignment.bottomCenter,
+            padding: EdgeInsets.only(top: 150),
+            child: Column(
+              children: [
+                FutureBuilder<void>(
+                  future: computeFuture,
+                  builder: (BuildContext context, AsyncSnapshot snapshot) {
+                    return RaisedButton(
+                      child: const Text('Compute on Main'),
+                      elevation: 8.0,
+                      onPressed: createMainIsolateCallBack(context, snapshot),
+                    );
+                  },
+                ),
+                FutureBuilder<void>(
+                  future: computeFuture,
+                  builder: (BuildContext context, AsyncSnapshot snapshot) {
+                    return RaisedButton(
+                      child: const Text('Compute on Secondary'),
+                      elevation: 8.0,
+                      onPressed:
+                          createSecondaryIsolateCallBack(context, snapshot),
+                    );
+                  },
+                ),
+              ],
+            ),
+          ),
        ],
      ),
    );
  }
+
+  VoidCallback createMainIsolateCallBack(
+      BuildContext context, AsyncSnapshot snapshot) {
+    if (snapshot.connectionState == ConnectionState.done) {
+      return () {
+        setState(() {
+          computeFuture = computeOnMainIsolate()
+            ..then((_) {
+              final snackBar = SnackBar(
+                content: Text('Main Isolate Done!'),
+              );
+              Scaffold.of(context).showSnackBar(snackBar);
+            });
+        });
+      };
+    } else {
+      return null;
+    }
+  }
+
+  VoidCallback createSecondaryIsolateCallBack(
+      BuildContext context, AsyncSnapshot snapshot) {
+    if (snapshot.connectionState == ConnectionState.done) {
+      return () {
+        setState(() {
+          computeFuture = computeOnSecondaryIsolate()
+            ..then((_) {
+              final snackBar = SnackBar(
+                content: Text('Secondary Isolate Done!'),
+              );
+              Scaffold.of(context).showSnackBar(snackBar);
+            });
+        });
+      };
+    } else {
+      return null;
+    }
+  }
+}
+
+Future<void> computeOnMainIsolate() async {
+  // The isolate will need a little time to disable the buttons before the performance hit.
+  await Future.delayed(Duration(milliseconds: 100), () => fib(45));
+}
+
+Future<void> computeOnSecondaryIsolate() async {
+  await compute(fib, 45);
+}
+
+int fib(int n) {
+  int number1 = n - 1;
+  int number2 = n - 2;
+
+  if (n == 1) {
+    return 0;
+  } else if (n == 0) {
+    return 1;
+  } else {
+    return (fib(number1) + fib(number2));
+  }
 }

 class SmoothAnimationWidget extends StatefulWidget {
@@ -42,10 +139,9 @@ class SmoothAnimationWidgetState extends State<SmoothAnimationWidget>
  void initState() {
    super.initState();

-    _controller = AnimationController(
-      duration: const Duration(seconds: 1),
-      vsync: this,
-    )..addStatusListener(
+    _controller =
+        AnimationController(duration: const Duration(seconds: 1), vsync: this)
+          ..addStatusListener(
            (status) {
              if (status == AnimationStatus.completed) {
                _controller.reverse();
@@ -72,7 +168,7 @@ class SmoothAnimationWidgetState extends State<SmoothAnimationWidget>
  Widget build(BuildContext context) {
    return AnimatedBuilder(
      animation: borderRadius,
-      builder: (context, child) {
+      builder: (BuildContext context, Widget child) {
        return Center(
          child: Container(
            child: new FlutterLogo(
--- a/isolate_example/lib/page_two.dart
+++ b/isolate_example/lib/page_two.dart
@@ -13,12 +13,252 @@
 // limitations under the License.

 import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+import 'dart:isolate';
+import 'dart:math';
+
+class InfiniteProcessPageStarter extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return ChangeNotifierProvider(
+      builder: (context) => IsolateController(),
+      child: InfiniteProcessPage(),
+    );
+  }
+}

 class InfiniteProcessPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
-    return Center(
-      child: Text('Welcome to the Infinite Process Page'),
+    return Column(
+      mainAxisSize: MainAxisSize.min,
+      children: [
+        Expanded(child: RunningList()),
+        SafeArea(
+          child: Column(
+            mainAxisSize: MainAxisSize.min,
+            children: [
+              Row(
+                mainAxisAlignment: MainAxisAlignment.center,
+                children: [
+                  newButtons(context),
+                ],
+              ),
+              Row(
+                mainAxisAlignment: MainAxisAlignment.center,
+                crossAxisAlignment: CrossAxisAlignment.center,
+                children: <Widget>[
+                  Switch(
+                    value:
+                        !(Provider.of<IsolateController>(context, listen: true)
+                            .paused),
+                    onChanged: (_) =>
+                        Provider.of<IsolateController>(context, listen: false)
+                            .pausedSwitch(),
+                    activeTrackColor: Colors.lightGreenAccent,
+                    activeColor: Colors.black,
+                    inactiveTrackColor: Colors.deepOrangeAccent,
+                    inactiveThumbColor: Colors.black,
+                  ),
+                  Text('Pause/Resume'),
+                ],
+              ),
+              radioButtonWidget(context),
+            ],
+          ),
+        ),
+      ],
    );
  }
 }
+
+class IsolateController extends ChangeNotifier {
+  Isolate newIsolate;
+  ReceivePort mIceRP;
+  SendPort newIceSP;
+  Capability capability;
+
+  int _currentMultiplier = 1;
+  List<int> _currentResults = [];
+  bool _running = false;
+  bool _paused = false;
+
+  IsolateController() {
+    start();
+    _running = true;
+  }
+
+  void createIsolate() async {
+    mIceRP = ReceivePort();
+    newIsolate = await Isolate.spawn(_secondIsolateEntryPoint, mIceRP.sendPort);
+  }
+
+  void listen() async {
+    mIceRP.listen((message) {
+      if (message is SendPort) {
+        newIceSP = message;
+        newIceSP.send(_currentMultiplier.toString());
+      } else if (message is int) {
+        setCurrentResults(message);
+      }
+    });
+  }
+
+  Future start() async {
+    if (_running == false && _paused == false) {
+      createIsolate();
+      listen();
+      _running = true;
+      notifyListeners();
+    }
+  }
+
+  void terminate() {
+    newIsolate.kill();
+    _running = false;
+    _currentResults.clear();
+    notifyListeners();
+  }
+
+  void pausedSwitch() {
+    (_paused) ? newIsolate.resume(capability) : capability = newIsolate.pause();
+    _paused = !_paused;
+    notifyListeners();
+  }
+
+  void setMultiplier(int newMultiplier) {
+    _currentMultiplier = newMultiplier;
+    newIceSP.send(_currentMultiplier);
+    notifyListeners();
+  }
+
+  void setCurrentResults(int newNum) {
+    _currentResults.insert(0, newNum);
+    notifyListeners();
+  }
+
+  int get multiplier => _currentMultiplier;
+
+  bool get paused => _paused;
+
+  bool get running => _running;
+
+  List<int> get currentResults => _currentResults;
+}
+
+class RunningList extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    List<int> sums =
+        Provider.of<IsolateController>(context, listen: true).currentResults;
+
+    return DecoratedBox(
+      decoration: BoxDecoration(
+        color: (Provider.of<IsolateController>(context, listen: true).running ==
+                    true &&
+                Provider.of<IsolateController>(context, listen: true).paused ==
+                    false)
+            ? Colors.lightGreenAccent
+            : Colors.deepOrangeAccent,
+      ),
+      child: new ListView.builder(
+        itemCount: sums.length,
+        itemBuilder: (context, index) {
+          return ListTile(
+            title: Text((sums.length - index).toString() +
+                '. ' +
+                sums[index].toString()),
+          );
+        },
+      ),
+    );
+  }
+}
+
+Future<void> _secondIsolateEntryPoint(SendPort callerSP) async {
+  int multiplyValue = 1;
+
+  ReceivePort newIceRP = ReceivePort();
+  callerSP.send(newIceRP.sendPort);
+
+  newIceRP.listen((message) {
+    if (message is int) multiplyValue = message;
+  });
+
+  int forEnd = 10000;
+  while (true) {
+    int sum = 0;
+
+    for (int i = 0; i < forEnd; i++) {
+      sum += await brokenUpComputation(1000);
+    }
+
+    forEnd += 10;
+    callerSP.send(sum * multiplyValue);
+  }
+}
+
+Future<int> brokenUpComputation(int num) {
+  Random rng = new Random();
+
+  return Future(() {
+    int sum = 0;
+
+    for (int i = 0; i < num; i++) {
+      sum += rng.nextInt(100);
+    }
+    return sum;
+  });
+}
+
+Widget newButtons(context) {
+  return ButtonBar(
+    alignment: MainAxisAlignment.center,
+    children: [
+      RaisedButton(
+        child: const Text('Start'),
+        elevation: 8.0,
+        onPressed: () =>
+            Provider.of<IsolateController>(context, listen: false).start(),
+      ),
+      RaisedButton(
+        child: const Text('Terminate'),
+        elevation: 8.0,
+        onPressed: () =>
+            Provider.of<IsolateController>(context, listen: false).terminate(),
+      ),
+    ],
+  );
+}
+
+Widget radioButtonWidget(context) {
+  return new Row(
+    mainAxisAlignment: MainAxisAlignment.center,
+    children: [
+      new Radio(
+        value: 1,
+        groupValue:
+            Provider.of<IsolateController>(context, listen: true).multiplier,
+        onChanged: (_) => Provider.of<IsolateController>(context, listen: false)
+            .setMultiplier(1),
+      ),
+      new Text('1x'),
+      new Radio(
+        value: 2,
+        groupValue:
+            Provider.of<IsolateController>(context, listen: true).multiplier,
+        onChanged: (_) => Provider.of<IsolateController>(context, listen: false)
+            .setMultiplier(2),
+      ),
+      new Text('2x'),
+      new Radio(
+        value: 3,
+        groupValue:
+            Provider.of<IsolateController>(context, listen: true).multiplier,
+        onChanged: (_) => Provider.of<IsolateController>(context, listen: false)
+            .setMultiplier(3),
+      ),
+      new Text('3x'),
+    ],
+  );
+}
--- a/isolate_example/pubspec.lock
+++ b/isolate_example/pubspec.lock
@@ -74,6 +74,13 @@ packages:
      url: "https://pub.dartlang.org"
    source: hosted
    version: "1.5.0"
+  provider:
+    dependency: "direct main"
+    description:
+      name: provider
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "3.0.0+1"
  quiver:
    dependency: transitive
    description:
--- a/isolate_example/pubspec.yaml
+++ b/isolate_example/pubspec.yaml
@@ -9,6 +9,7 @@ dependencies:
  flutter:
    sdk: flutter
  cupertino_icons: ^0.1.2
+  provider: ^3.0.0

 dev_dependencies:
  flutter_test: