isolate_example: Update lints, rebuild runners (#825)

isolate_example/lib/data_transfer_page.dart

@@ -20,16 +20,20 @@ import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 
 class DataTransferPageStarter extends StatelessWidget {
+  const DataTransferPageStarter({Key? key}) : super(key: key);
+
   @override
   Widget build(BuildContext context) {
     return ChangeNotifierProvider(
       create: (context) => DataTransferIsolateController(),
-      child: DataTransferPage(),
+      child: const DataTransferPage(),
     );
   }
 }
 
 class DataTransferPage extends StatelessWidget {
+  const DataTransferPage({Key? key}) : super(key: key);
+
   @override
   Widget build(context) {
     final controller = Provider.of<DataTransferIsolateController>(context);
@@ -49,7 +53,7 @@ class DataTransferPage extends StatelessWidget {
             value: controller.progressPercent,
             backgroundColor: Colors.grey[200],
           ),
-          Expanded(
+          const Expanded(
             child: RunningList(),
           ),
           Column(
@@ -193,6 +197,8 @@ class DataTransferIsolateController extends ChangeNotifier {
 }
 
 class RunningList extends StatelessWidget {
+  const RunningList({Key? key}) : super(key: key);
+
   @override
   Widget build(BuildContext context) {
     final progress =

isolate_example/lib/infinite_process_page.dart

@@ -19,16 +19,20 @@ import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 
 class InfiniteProcessPageStarter extends StatelessWidget {
+  const InfiniteProcessPageStarter({Key? key}) : super(key: key);
+
   @override
   Widget build(context) {
     return ChangeNotifierProvider(
       create: (context) => InfiniteProcessIsolateController(),
-      child: InfiniteProcessPage(),
+      child: const InfiniteProcessPage(),
     );
   }
 }
 
 class InfiniteProcessPage extends StatelessWidget {
+  const InfiniteProcessPage({Key? key}) : super(key: key);
+
   @override
   Widget build(context) {
     final controller = Provider.of<InfiniteProcessIsolateController>(context);
@@ -44,7 +48,7 @@ class InfiniteProcessPage extends StatelessWidget {
               style: Theme.of(context).textTheme.headline6,
             ),
           ),
-          Expanded(
+          const Expanded(
             child: RunningList(),
           ),
           Column(
@@ -183,6 +187,8 @@ class InfiniteProcessIsolateController extends ChangeNotifier {
 }
 
 class RunningList extends StatelessWidget {
+  const RunningList({Key? key}) : super(key: key);
+
   @override
   Widget build(context) {
     final controller = Provider.of<InfiniteProcessIsolateController>(context);

isolate_example/lib/main.dart

@@ -20,13 +20,15 @@ import 'performance_page.dart';
 
 void main() {
   runApp(
-    MaterialApp(
+    const MaterialApp(
       home: HomePage(),
     ),
   );
 }
 
 class HomePage extends StatelessWidget {
+  const HomePage({Key? key}) : super(key: key);
+
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
@@ -52,7 +54,7 @@ class HomePage extends StatelessWidget {
             ),
             title: const Text('Isolate Example'),
           ),
-          body: TabBarView(
+          body: const TabBarView(
             children: [
               PerformancePage(),
               InfiniteProcessPageStarter(),

isolate_example/lib/performance_page.dart

@@ -30,6 +30,8 @@ int fib(int n) {
 }
 
 class PerformancePage extends StatefulWidget {
+  const PerformancePage({Key? key}) : super(key: key);
+
   @override
   _PerformancePageState createState() => _PerformancePageState();
 }
@@ -43,7 +45,7 @@ class _PerformancePageState extends State<PerformancePage> {
       child: Column(
         mainAxisSize: MainAxisSize.min,
         children: [
-          SmoothAnimationWidget(),
+          const SmoothAnimationWidget(),
           Container(
             alignment: Alignment.bottomCenter,
             padding: const EdgeInsets.only(top: 150),
@@ -125,6 +127,8 @@ class _PerformancePageState extends State<PerformancePage> {
 }
 
 class SmoothAnimationWidget extends StatefulWidget {
+  const SmoothAnimationWidget({Key? key}) : super(key: key);
+
   @override
   SmoothAnimationWidgetState createState() => SmoothAnimationWidgetState();
 }