Secondpage (#97)

isolate_example/lib/page_two.dart

@@ -19,9 +19,9 @@ import 'dart:math';
 
 class InfiniteProcessPageStarter extends StatelessWidget {
   @override
-  Widget build(BuildContext context) {
+  Widget build(context) {
     return ChangeNotifierProvider(
-      builder: (context) => IsolateController(),
+      builder: (context) => InfiniteProcessIsolateController(),
       child: InfiniteProcessPage(),
     );
   }
@@ -29,7 +29,9 @@ class InfiniteProcessPageStarter extends StatelessWidget {
 
 class InfiniteProcessPage extends StatelessWidget {
   @override
-  Widget build(BuildContext context) {
+  Widget build(context) {
+    final controller = Provider.of<InfiniteProcessIsolateController>(context);
+
     return Column(
       mainAxisSize: MainAxisSize.min,
       children: [
@@ -40,21 +42,15 @@ class InfiniteProcessPage extends StatelessWidget {
             children: [
               Row(
                 mainAxisAlignment: MainAxisAlignment.center,
-                children: [
-                  newButtons(context),
-                ],
+                children: [newButtons(context)],
               ),
               Row(
                 mainAxisAlignment: MainAxisAlignment.center,
                 crossAxisAlignment: CrossAxisAlignment.center,
-                children: <Widget>[
+                children: [
                   Switch(
-                    value:
-                        !(Provider.of<IsolateController>(context, listen: true)
-                            .paused),
-                    onChanged: (_) =>
-                        Provider.of<IsolateController>(context, listen: false)
-                            .pausedSwitch(),
+                    value: !controller.paused,
+                    onChanged: (_) => controller.pausedSwitch(),
                     activeTrackColor: Colors.lightGreenAccent,
                     activeColor: Colors.black,
                     inactiveTrackColor: Colors.deepOrangeAccent,
@@ -72,7 +68,7 @@ class InfiniteProcessPage extends StatelessWidget {
   }
 }
 
-class IsolateController extends ChangeNotifier {
+class InfiniteProcessIsolateController extends ChangeNotifier {
   Isolate newIsolate;
   ReceivePort mIceRP;
   SendPort newIceSP;
@@ -83,30 +79,30 @@ class IsolateController extends ChangeNotifier {
   bool _running = false;
   bool _paused = false;
 
-  IsolateController() {
+  InfiniteProcessIsolateController() {
     start();
     _running = true;
   }
 
-  void createIsolate() async {
+  Future<void> createIsolate() async {
     mIceRP = ReceivePort();
     newIsolate = await Isolate.spawn(_secondIsolateEntryPoint, mIceRP.sendPort);
   }
 
-  void listen() async {
+  void listen() {
     mIceRP.listen((message) {
       if (message is SendPort) {
         newIceSP = message;
-        newIceSP.send(_currentMultiplier.toString());
+        newIceSP.send(_currentMultiplier);
       } else if (message is int) {
         setCurrentResults(message);
       }
     });
   }
 
-  Future start() async {
+  Future<void> start() async {
     if (_running == false && _paused == false) {
-      createIsolate();
+      await createIsolate();
       listen();
       _running = true;
       notifyListeners();
@@ -144,20 +140,24 @@ class IsolateController extends ChangeNotifier {
   bool get running => _running;
 
   List<int> get currentResults => _currentResults;
+
+  void dispose() {
+    super.dispose();
+    newIsolate?.kill(priority: Isolate.immediate);
+    newIsolate = null;
+  }
 }
 
 class RunningList extends StatelessWidget {
   @override
-  Widget build(BuildContext context) {
-    List<int> sums =
-        Provider.of<IsolateController>(context, listen: true).currentResults;
+  Widget build(context) {
+    final controller = Provider.of<InfiniteProcessIsolateController>(context);
+
+    List<int> sums = controller.currentResults;
 
     return DecoratedBox(
       decoration: BoxDecoration(
-        color: (Provider.of<IsolateController>(context, listen: true).running ==
-                    true &&
-                Provider.of<IsolateController>(context, listen: true).paused ==
-                    false)
+        color: (controller.running == true && controller.paused == false)
             ? Colors.lightGreenAccent
             : Colors.deepOrangeAccent,
       ),
@@ -212,51 +212,48 @@ Future<int> brokenUpComputation(int num) {
 }
 
 Widget newButtons(context) {
+  final controller =
+      Provider.of<InfiniteProcessIsolateController>(context, listen: false);
+
   return ButtonBar(
     alignment: MainAxisAlignment.center,
     children: [
       RaisedButton(
         child: const Text('Start'),
         elevation: 8.0,
-        onPressed: () =>
-            Provider.of<IsolateController>(context, listen: false).start(),
+        onPressed: () => controller.start(),
       ),
       RaisedButton(
         child: const Text('Terminate'),
         elevation: 8.0,
-        onPressed: () =>
-            Provider.of<IsolateController>(context, listen: false).terminate(),
+        onPressed: () => controller.terminate(),
       ),
     ],
   );
 }
 
 Widget radioButtonWidget(context) {
+  final controller = Provider.of<InfiniteProcessIsolateController>(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),
+        groupValue: controller.multiplier,
+        onChanged: (_) => controller.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),
+        groupValue: controller.multiplier,
+        onChanged: (_) => controller.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),
+        groupValue: controller.multiplier,
+        onChanged: (_) => controller.setMultiplier(3),
       ),
       new Text('3x'),
     ],