implicit-casts:false in examples (#45805)

examples/catalog/lib/animated_list.dart

@@ -122,7 +122,7 @@ class ListModel<E> {
        _items = initialItems?.toList() ?? <E>[];
 
   final GlobalKey<AnimatedListState> listKey;
-  final dynamic removedItemBuilder;
+  final Widget Function(E item, BuildContext context, Animation<double> animation) removedItemBuilder;
   final List<E> _items;
 
   AnimatedListState get _animatedList => listKey.currentState;

examples/flutter_gallery/lib/demo/animation/home.dart

@@ -64,7 +64,7 @@ class _RenderStatusBarPaddingSliver extends RenderSliver {
 
   @override
   void performLayout() {
-    final double height = (maxHeight - constraints.scrollOffset / scrollFactor).clamp(0.0, maxHeight);
+    final double height = (maxHeight - constraints.scrollOffset / scrollFactor).clamp(0.0, maxHeight) as double;
     geometry = SliverGeometry(
       paintExtent: math.min(height, constraints.remainingPaintExtent),
       scrollExtent: maxHeight,
@@ -285,7 +285,7 @@ class _AllSectionsView extends AnimatedWidget {
   final List<Widget> sectionCards;
 
   double _selectedIndexDelta(int index) {
-    return (index.toDouble() - selectedIndex.value).abs().clamp(0.0, 1.0);
+    return (index.toDouble() - selectedIndex.value).abs().clamp(0.0, 1.0) as double;
   }
 
   Widget _build(BuildContext context, BoxConstraints constraints) {
@@ -498,7 +498,7 @@ class _AnimationDemoHomeState extends State<AnimationDemoHome> {
     return ListTile.divideTiles(context: context, tiles: detailItems);
   }
 
-  Iterable<Widget> _allHeadingItems(double maxHeight, double midScrollOffset) {
+  List<Widget> _allHeadingItems(double maxHeight, double midScrollOffset) {
     final List<Widget> sectionCards = <Widget>[];
     for (int index = 0; index < allSections.length; index++) {
       sectionCards.add(LayoutId(

examples/flutter_gallery/lib/demo/animation/sections.dart

@@ -44,10 +44,8 @@ class Section {
 
   @override
   bool operator==(Object other) {
-    if (other is! Section)
+    return other is Section
-      return false;
+        && other.title == title;
-    final Section otherSection = other;
-    return title == otherSection.title;
   }
 
   @override

examples/flutter_gallery/lib/demo/calculator/logic.dart

@@ -287,7 +287,7 @@ class CalcExpression {
     // multiplication or division symbols.
     num currentTermValue = removeNextTerm(list);
     while (list.isNotEmpty) {
-      final OperationToken opToken = list.removeAt(0);
+      final OperationToken opToken = list.removeAt(0) as OperationToken;
       final num nextTermValue = removeNextTerm(list);
       switch (opToken.operation) {
         case Operation.Addition:
@@ -313,11 +313,11 @@ class CalcExpression {
   /// and division symbols.
   static num removeNextTerm(List<ExpressionToken> list) {
     assert(list != null && list.isNotEmpty);
-    final NumberToken firstNumToken = list.removeAt(0);
+    final NumberToken firstNumToken = list.removeAt(0) as NumberToken;
     num currentValue = firstNumToken.number;
     while (list.isNotEmpty) {
       bool isDivision = false;
-      final OperationToken nextOpToken = list.first;
+      final OperationToken nextOpToken = list.first as OperationToken;
       switch (nextOpToken.operation) {
         case Operation.Addition:
         case Operation.Subtraction:
@@ -331,7 +331,7 @@ class CalcExpression {
       // Remove the operation token.
       list.removeAt(0);
       // Remove the next number token.
-      final NumberToken nextNumToken = list.removeAt(0);
+      final NumberToken nextNumToken = list.removeAt(0) as NumberToken;
       final num nextNumber = nextNumToken.number;
       if (isDivision)
         currentValue /= nextNumber;

examples/flutter_gallery/lib/demo/cupertino/cupertino_navigation_demo.dart

@@ -293,9 +293,9 @@ class Tab1ItemPageState extends State<Tab1ItemPage> {
       final math.Random random = math.Random();
       return Color.fromARGB(
         255,
-      (widget.color.red + random.nextInt(100) - 50).clamp(0, 255),
+        (widget.color.red + random.nextInt(100) - 50).clamp(0, 255) as int,
-        (widget.color.green + random.nextInt(100) - 50).clamp(0, 255),
+        (widget.color.green + random.nextInt(100) - 50).clamp(0, 255) as int,
-        (widget.color.blue + random.nextInt(100) - 50).clamp(0, 255),
+        (widget.color.blue + random.nextInt(100) - 50).clamp(0, 255) as int,
       );
     });
   }
@@ -635,9 +635,9 @@ class Tab2ConversationAvatar extends StatelessWidget {
             color,
             Color.fromARGB(
               color.alpha,
-              (color.red - 60).clamp(0, 255),
+              (color.red - 60).clamp(0, 255) as int,
-              (color.green - 60).clamp(0, 255),
+              (color.green - 60).clamp(0, 255) as int,
-              (color.blue - 60).clamp(0, 255),
+              (color.blue - 60).clamp(0, 255) as int,
             ),
           ],
         ),

examples/flutter_gallery/lib/demo/material/backdrop_demo.dart

@@ -205,12 +205,12 @@ class BackdropPanel extends StatelessWidget {
 class BackdropTitle extends AnimatedWidget {
   const BackdropTitle({
     Key key,
-    Listenable listenable,
+    Animation<double> listenable,
   }) : super(key: key, listenable: listenable);
 
   @override
   Widget build(BuildContext context) {
-    final Animation<double> animation = listenable;
+    final Animation<double> animation = listenable as Animation<double>;
     return DefaultTextStyle(
       style: Theme.of(context).primaryTextTheme.title,
       softWrap: false,
@@ -283,7 +283,7 @@ class _BackdropDemoState extends State<BackdropDemo> with SingleTickerProviderSt
   }
 
   double get _backdropHeight {
-    final RenderBox renderBox = _backdropKey.currentContext.findRenderObject();
+    final RenderBox renderBox = _backdropKey.currentContext.findRenderObject() as RenderBox;
     return renderBox.size.height;
   }
 

examples/flutter_gallery/lib/demo/material/grid_list_demo.dart

@@ -87,7 +87,10 @@ class _GridPhotoViewerState extends State<GridPhotoViewer> with SingleTickerProv
   Offset _clampOffset(Offset offset) {
     final Size size = context.size;
     final Offset minOffset = Offset(size.width, size.height) * (1.0 - _scale);
-    return Offset(offset.dx.clamp(minOffset.dx, 0.0), offset.dy.clamp(minOffset.dy, 0.0));
+    return Offset(
+      offset.dx.clamp(minOffset.dx, 0.0) as double,
+      offset.dy.clamp(minOffset.dy, 0.0) as double,
+    );
   }
 
   void _handleFlingAnimation() {
@@ -107,7 +110,7 @@ class _GridPhotoViewerState extends State<GridPhotoViewer> with SingleTickerProv
 
   void _handleOnScaleUpdate(ScaleUpdateDetails details) {
     setState(() {
-      _scale = (_previousScale * details.scale).clamp(1.0, 4.0);
+      _scale = (_previousScale * details.scale).clamp(1.0, 4.0) as double;
       // Ensure that image location under the focal point stays in the same place despite scaling.
       _offset = _clampOffset(details.focalPoint - _normalizedOffset * _scale);
     });

examples/flutter_gallery/lib/demo/material/page_selector_demo.dart

@@ -14,7 +14,7 @@ class _PageSelector extends StatelessWidget {
   void _handleArrowButtonPress(BuildContext context, int delta) {
     final TabController controller = DefaultTabController.of(context);
     if (!controller.indexIsChanging)
-      controller.animateTo((controller.index + delta).clamp(0, icons.length - 1));
+      controller.animateTo((controller.index + delta).clamp(0, icons.length - 1) as int);
   }
 
   @override

examples/flutter_gallery/lib/demo/material/slider_demo.dart

@@ -257,7 +257,7 @@ class _SlidersState extends State<_Sliders> {
                       final double newValue = double.tryParse(value);
                       if (newValue != null && newValue != _continuousValue) {
                         setState(() {
-                          _continuousValue = newValue.clamp(0, 100);
+                          _continuousValue = newValue.clamp(0.0, 100.0) as double;
                         });
                       }
                     },

examples/flutter_gallery/lib/demo/pesto_demo.dart

@@ -129,7 +129,7 @@ class _RecipeGridPageState extends State<RecipeGridPage> {
               bottom: extraPadding,
             ),
             child: Center(
-              child: PestoLogo(height: logoHeight, t: t.clamp(0.0, 1.0)),
+              child: PestoLogo(height: logoHeight, t: t.clamp(0.0, 1.0) as double),
             ),
           );
         },

examples/flutter_gallery/lib/demo/shrine/backdrop.dart

@@ -111,7 +111,7 @@ class _FrontLayer extends StatelessWidget {
 class _BackdropTitle extends AnimatedWidget {
   const _BackdropTitle({
     Key key,
-    Listenable listenable,
+    Animation<double> listenable,
     this.onPress,
     @required this.frontTitle,
     @required this.backTitle,
@@ -119,14 +119,14 @@ class _BackdropTitle extends AnimatedWidget {
        assert(backTitle != null),
        super(key: key, listenable: listenable);
 
-  final Function onPress;
+  final void Function() onPress;
   final Widget frontTitle;
   final Widget backTitle;
 
   @override
   Widget build(BuildContext context) {
     final Animation<double> animation = CurvedAnimation(
-      parent: listenable,
+      parent: listenable as Animation<double>,
       curve: const Interval(0.0, 0.78),
     );
 

examples/flutter_gallery/lib/demo/shrine/expanding_bottom_sheet.dart

@@ -604,7 +604,7 @@ class _ListModel {
        _items = initialItems?.toList() ?? <int>[];
 
   final GlobalKey<AnimatedListState> listKey;
-  final dynamic removedItemBuilder;
+  final Widget Function(int item, BuildContext context, Animation<double> animation) removedItemBuilder;
   final List<int> _items;
 
   AnimatedListState get _animatedList => listKey.currentState;

examples/flutter_gallery/lib/demo/transformations/transformations_demo_board.dart

@@ -270,8 +270,9 @@ class BoardPoint {
     if (other.runtimeType != runtimeType) {
       return false;
     }
-    final BoardPoint boardPoint = other;
+    return other is BoardPoint
-    return boardPoint.q == q && boardPoint.r == r;
+        && other.q == q
+        && other.r == r;
   }
 
   @override

examples/flutter_gallery/lib/demo/transformations/transformations_demo_gesture_transformable.dart

@@ -183,7 +183,7 @@ class _GestureTransformableState extends State<GestureTransformable> with Ticker
   // Get the offset of the current widget from the global screen coordinates.
   // TODO(justinmc): Protect against calling this during first build.
   static Offset getOffset(BuildContext context) {
-    final RenderBox renderObject = context.findRenderObject();
+    final RenderBox renderObject = context.findRenderObject() as RenderBox;
     return renderObject.localToGlobal(Offset.zero);
   }
 
@@ -377,7 +377,7 @@ class _GestureTransformableState extends State<GestureTransformable> with Ticker
     final double clampedTotalScale = totalScale.clamp(
       widget.minScale,
       widget.maxScale,
-    );
+    ) as double;
     final double clampedScale = clampedTotalScale / currentScale;
     return matrix..scale(clampedScale);
   }

examples/flutter_gallery/lib/demo/video_demo.dart

@@ -280,7 +280,7 @@ class _ConnectivityOverlayState extends State<ConnectivityOverlay> {
   StreamSubscription<ConnectivityResult> connectivitySubscription;
   bool connected = true;
 
-  static const Widget errorSnackBar = SnackBar(
+  static const SnackBar errorSnackBar = SnackBar(
     backgroundColor: Colors.red,
     content: ListTile(
       title: Text('No network'),

examples/flutter_gallery/lib/gallery/app.dart

@@ -53,8 +53,8 @@ class _GalleryAppState extends State<GalleryApp> {
     // https://docs.flutter.io/flutter/widgets/Navigator-class.html
     return Map<String, WidgetBuilder>.fromIterable(
       kAllGalleryDemos,
-      key: (dynamic demo) => '${demo.routeName}',
+      key: (dynamic demo) => '${(demo as GalleryDemo).routeName}',
-      value: (dynamic demo) => demo.buildRoute,
+      value: (dynamic demo) => (demo as GalleryDemo).buildRoute,
     );
   }
 

examples/flutter_gallery/lib/gallery/backdrop.dart

@@ -97,7 +97,7 @@ class _CrossFadeTransition extends AnimatedWidget {
 
   @override
   Widget build(BuildContext context) {
-    final Animation<double> progress = listenable;
+    final Animation<double> progress = listenable as Animation<double>;
 
     final double opacity1 = CurvedAnimation(
       parent: ReverseAnimation(progress),
@@ -227,7 +227,7 @@ class _BackdropState extends State<Backdrop> with SingleTickerProviderStateMixin
   double get _backdropHeight {
     // Warning: this can be safely called from the event handlers but it may
     // not be called at build time.
-    final RenderBox renderBox = _backdropKey.currentContext.findRenderObject();
+    final RenderBox renderBox = _backdropKey.currentContext.findRenderObject() as RenderBox;
     return math.max(0.0, renderBox.size.height - _kBackAppBarHeight - _kFrontClosedHeight);
   }
 

examples/flutter_gallery/lib/gallery/demo.dart

@@ -31,10 +31,10 @@ class ComponentDemoTabData {
   bool operator==(Object other) {
     if (other.runtimeType != runtimeType)
       return false;
-    final ComponentDemoTabData typedOther = other;
+    return other is ComponentDemoTabData
-    return typedOther.tabName == tabName
+        && other.tabName == tabName
-        && typedOther.description == description
+        && other.description == description
-        && typedOther.documentationUrl == documentationUrl;
+        && other.documentationUrl == documentationUrl;
   }
 
   @override

examples/flutter_gallery/lib/gallery/demos.dart

@@ -22,8 +22,8 @@ class GalleryDemoCategory {
       return true;
     if (runtimeType != other.runtimeType)
       return false;
-    final GalleryDemoCategory typedOther = other;
+    return other is GalleryDemoCategory
-    return typedOther.name == name && typedOther.icon == icon;
+        && other.name == name && other.icon == icon;
   }
 
   @override
@@ -582,6 +582,6 @@ final Map<GalleryDemoCategory, List<GalleryDemo>> kGalleryCategoryToDemos =
 final Map<String, String> kDemoDocumentationUrl =
     Map<String, String>.fromIterable(
       kAllGalleryDemos.where((GalleryDemo demo) => demo.documentationUrl != null),
-      key: (dynamic demo) => demo.routeName,
+      key: (dynamic demo) => (demo as GalleryDemo).routeName,
-      value: (dynamic demo) => demo.documentationUrl,
+      value: (dynamic demo) => (demo as GalleryDemo).documentationUrl,
     );

examples/flutter_gallery/lib/gallery/home.dart

@@ -134,7 +134,7 @@ class _CategoriesPage extends StatelessWidget {
                 crossAxisAlignment: CrossAxisAlignment.stretch,
                 children: List<Widget>.generate(rowCount, (int rowIndex) {
                   final int columnCountForRow = rowIndex == rowCount - 1
-                    ? categories.length - columnCount * math.max(0, rowCount - 1)
+                    ? categories.length - columnCount * math.max<int>(0, rowCount - 1)
                     : columnCount;
 
                   return Row(

examples/flutter_gallery/lib/gallery/options.dart

@@ -54,14 +54,14 @@ class GalleryOptions {
   bool operator ==(dynamic other) {
     if (runtimeType != other.runtimeType)
       return false;
-    final GalleryOptions typedOther = other;
+    return other is GalleryOptions
-    return themeMode == typedOther.themeMode
+        && other.themeMode == themeMode
-        && textScaleFactor == typedOther.textScaleFactor
+        && other.textScaleFactor == textScaleFactor
-        && textDirection == typedOther.textDirection
+        && other.textDirection == textDirection
-        && platform == typedOther.platform
+        && other.platform == platform
-        && showPerformanceOverlay == typedOther.showPerformanceOverlay
+        && other.showPerformanceOverlay == showPerformanceOverlay
-        && showRasterCacheImagesCheckerboard == typedOther.showRasterCacheImagesCheckerboard
+        && other.showRasterCacheImagesCheckerboard == showRasterCacheImagesCheckerboard
-        && showOffscreenLayersCheckerboard == typedOther.showRasterCacheImagesCheckerboard;
+        && other.showOffscreenLayersCheckerboard == showRasterCacheImagesCheckerboard;
   }
 
   @override

examples/flutter_gallery/lib/gallery/scales.dart

@@ -14,8 +14,9 @@ class GalleryTextScaleValue {
   bool operator ==(dynamic other) {
     if (runtimeType != other.runtimeType)
       return false;
-    final GalleryTextScaleValue typedOther = other;
+    return other is GalleryTextScaleValue
-    return scale == typedOther.scale && label == typedOther.label;
+        && other.scale == scale
+        && other.label == label;
   }
 
   @override

examples/flutter_gallery/test/calculator/smoke_test.dart

@@ -7,7 +7,7 @@ import 'package:flutter_gallery/demo/calculator_demo.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 void main() {
-  final TestWidgetsFlutterBinding binding = TestWidgetsFlutterBinding.ensureInitialized();
+  final TestWidgetsFlutterBinding binding = TestWidgetsFlutterBinding.ensureInitialized() as TestWidgetsFlutterBinding;
   if (binding is LiveTestWidgetsFlutterBinding)
     binding.framePolicy = LiveTestWidgetsFlutterBindingFramePolicy.fullyLive;
 

examples/flutter_gallery/test/drawer_test.dart

@@ -8,7 +8,7 @@ import 'package:flutter_test/flutter_test.dart';
 import 'package:flutter_gallery/gallery/app.dart';
 
 void main() {
-  final TestWidgetsFlutterBinding binding = TestWidgetsFlutterBinding.ensureInitialized();
+  final TestWidgetsFlutterBinding binding = TestWidgetsFlutterBinding.ensureInitialized() as TestWidgetsFlutterBinding;
   if (binding is LiveTestWidgetsFlutterBinding)
     binding.framePolicy = LiveTestWidgetsFlutterBindingFramePolicy.fullyLive;
 
@@ -31,7 +31,7 @@ void main() {
     await tester.pumpAndSettle();
 
     // Verify theme settings
-    MaterialApp app = find.byType(MaterialApp).evaluate().first.widget;
+    MaterialApp app = find.byType(MaterialApp).evaluate().first.widget as MaterialApp;
     expect(app.theme.brightness, equals(Brightness.light));
     expect(app.darkTheme.brightness, equals(Brightness.dark));
 
@@ -40,7 +40,7 @@ void main() {
     await tester.pumpAndSettle();
     await tester.tap(find.text('Dark'));
     await tester.pumpAndSettle();
-    app = find.byType(MaterialApp).evaluate().first.widget;
+    app = find.byType(MaterialApp).evaluate().first.widget as MaterialApp;
     expect(app.themeMode, ThemeMode.dark);
 
     // Switch to the light theme: first menu button, choose 'Light'
@@ -48,7 +48,7 @@ void main() {
     await tester.pumpAndSettle();
     await tester.tap(find.text('Light'));
     await tester.pumpAndSettle();
-    app = find.byType(MaterialApp).evaluate().first.widget;
+    app = find.byType(MaterialApp).evaluate().first.widget as MaterialApp;
     expect(app.themeMode, ThemeMode.light);
 
     // Switch back to system theme setting: first menu button, choose 'System Default'
@@ -56,7 +56,7 @@ void main() {
     await tester.pumpAndSettle();
     await tester.tap(find.text('System Default').at(1));
     await tester.pumpAndSettle();
-    app = find.byType(MaterialApp).evaluate().first.widget;
+    app = find.byType(MaterialApp).evaluate().first.widget as MaterialApp;
     expect(app.themeMode, ThemeMode.system);
 
     // Verify platform settings
@@ -67,7 +67,7 @@ void main() {
     await tester.pumpAndSettle();
     await tester.tap(find.text('Cupertino').at(1));
     await tester.pumpAndSettle();
-    app = find.byType(MaterialApp).evaluate().first.widget;
+    app = find.byType(MaterialApp).evaluate().first.widget as MaterialApp;
     expect(app.theme.platform, equals(TargetPlatform.iOS));
 
     // Verify the font scale.

examples/flutter_gallery/test/example_code_display_test.dart

@@ -7,7 +7,7 @@ import 'package:flutter_gallery/gallery/app.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 void main() {
-  final TestWidgetsFlutterBinding binding = TestWidgetsFlutterBinding.ensureInitialized();
+  final TestWidgetsFlutterBinding binding = TestWidgetsFlutterBinding.ensureInitialized() as TestWidgetsFlutterBinding;
   if (binding is LiveTestWidgetsFlutterBinding)
     binding.framePolicy = LiveTestWidgetsFlutterBindingFramePolicy.fullyLive;
 

examples/flutter_gallery/test/pesto_test.dart

@@ -7,7 +7,7 @@ import 'package:flutter_test/flutter_test.dart';
 import 'package:flutter_gallery/gallery/app.dart';
 
 void main() {
-  final TestWidgetsFlutterBinding binding = TestWidgetsFlutterBinding.ensureInitialized();
+  final TestWidgetsFlutterBinding binding = TestWidgetsFlutterBinding.ensureInitialized() as TestWidgetsFlutterBinding;
   if (binding is LiveTestWidgetsFlutterBinding)
     binding.framePolicy = LiveTestWidgetsFlutterBindingFramePolicy.fullyLive;
 

examples/flutter_gallery/test/simple_smoke_test.dart

@@ -7,7 +7,7 @@ import 'package:flutter_test/flutter_test.dart';
 import 'package:flutter_gallery/gallery/app.dart' show GalleryApp;
 
 void main() {
-  final TestWidgetsFlutterBinding binding = TestWidgetsFlutterBinding.ensureInitialized();
+  final TestWidgetsFlutterBinding binding = TestWidgetsFlutterBinding.ensureInitialized() as TestWidgetsFlutterBinding;
   if (binding is LiveTestWidgetsFlutterBinding)
     binding.framePolicy = LiveTestWidgetsFlutterBindingFramePolicy.fullyLive;
 

examples/flutter_gallery/test/update_test.dart

@@ -11,7 +11,7 @@ Future<String> mockUpdateUrlFetcher() {
 }
 
 void main() {
-  final TestWidgetsFlutterBinding binding = TestWidgetsFlutterBinding.ensureInitialized();
+  final TestWidgetsFlutterBinding binding = TestWidgetsFlutterBinding.ensureInitialized() as TestWidgetsFlutterBinding;
   if (binding is LiveTestWidgetsFlutterBinding)
     binding.framePolicy = LiveTestWidgetsFlutterBindingFramePolicy.fullyLive;
 

examples/flutter_gallery/test_driver/transitions_perf_test.dart

@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 import 'dart:async';
-import 'dart:convert' show JsonEncoder, JsonDecoder;
+import 'dart:convert' show JsonEncoder, json;
 
 import 'package:file/file.dart';
 import 'package:file/local.dart';
@@ -69,14 +69,14 @@ Future<void> saveDurationsHistogram(List<Map<String, dynamic>> events, String ou
 
   // Save the duration of the first frame after each 'Start Transition' event.
   for (Map<String, dynamic> event in events) {
-    final String eventName = event['name'];
+    final String eventName = event['name'] as String;
     if (eventName == 'Start Transition') {
       assert(startEvent == null);
       startEvent = event;
     } else if (startEvent != null && eventName == 'Frame') {
-      final String routeName = startEvent['args']['to'];
+      final String routeName = startEvent['args']['to'] as String;
       durations[routeName] ??= <int>[];
-      durations[routeName].add(event['dur']);
+      durations[routeName].add(event['dur'] as int);
       startEvent = null;
     }
   }
@@ -101,13 +101,13 @@ Future<void> saveDurationsHistogram(List<Map<String, dynamic>> events, String ou
     String lastEventName = '';
     String lastRouteName = '';
     while (eventIter.moveNext()) {
-      final String eventName = eventIter.current['name'];
+      final String eventName = eventIter.current['name'] as String;
 
       if (!<String>['Start Transition', 'Frame'].contains(eventName))
         continue;
 
       final String routeName = eventName == 'Start Transition'
-        ? eventIter.current['args']['to']
+        ? eventIter.current['args']['to'] as String
         : '';
 
       if (eventName == lastEventName && routeName == lastRouteName) {
@@ -192,7 +192,7 @@ void main([List<String> args = const <String>[]]) {
       }
 
       // See _handleMessages() in transitions_perf.dart.
-      _allDemos = List<String>.from(const JsonDecoder().convert(await driver.requestData('demoNames')));
+      _allDemos = List<String>.from(json.decode(await driver.requestData('demoNames')) as List<dynamic>);
       if (_allDemos.isEmpty)
         throw 'no demo names found';
     });
@@ -221,7 +221,7 @@ void main([List<String> args = const <String>[]]) {
       await summary.writeSummaryToFile('transitions', pretty: true);
       final String histogramPath = path.join(testOutputsDirectory, 'transition_durations.timeline.json');
       await saveDurationsHistogram(
-          List<Map<String, dynamic>>.from(timeline.json['traceEvents']),
+          List<Map<String, dynamic>>.from(timeline.json['traceEvents'] as List<dynamic>),
           histogramPath);
 
       // Execute the remaining tests.

examples/layers/rendering/flex_layout.dart

@@ -48,7 +48,7 @@ void main() {
     subrow.add(RenderSolidColorBox(const Color(0x7FCCFFFF), desiredSize: const Size(30.0, 40.0)));
     row.add(subrow);
     table.add(row);
-    final FlexParentData rowParentData = row.parentData;
+    final FlexParentData rowParentData = row.parentData as FlexParentData;
     rowParentData.flex = 1;
   }
 
@@ -71,7 +71,7 @@ void main() {
     row.add(RenderSolidColorBox(const Color(0xFFCCCCFF), desiredSize: const Size(160.0, 60.0)));
     row.mainAxisAlignment = justify;
     table.add(row);
-    final FlexParentData rowParentData = row.parentData;
+    final FlexParentData rowParentData = row.parentData as FlexParentData;
     rowParentData.flex = 1;
   }
 

examples/layers/rendering/src/sector_layout.dart

@@ -31,11 +31,11 @@ class SectorConstraints extends Constraints {
   final double maxDeltaTheta;
 
   double constrainDeltaRadius(double deltaRadius) {
-    return deltaRadius.clamp(minDeltaRadius, maxDeltaRadius);
+    return deltaRadius.clamp(minDeltaRadius, maxDeltaRadius) as double;
   }
 
   double constrainDeltaTheta(double deltaTheta) {
-    return deltaTheta.clamp(minDeltaTheta, maxDeltaTheta);
+    return deltaTheta.clamp(minDeltaTheta, maxDeltaTheta) as double;
   }
 
   @override
@@ -100,14 +100,14 @@ abstract class RenderSector extends RenderObject {
   // RenderSectors always use SectorParentData subclasses, as they need to be
   // able to read their position information for painting and hit testing.
   @override
-  SectorParentData get parentData => super.parentData;
+  SectorParentData get parentData => super.parentData as SectorParentData;
 
   SectorDimensions getIntrinsicDimensions(SectorConstraints constraints, double radius) {
     return SectorDimensions.withConstraints(constraints);
   }
 
   @override
-  SectorConstraints get constraints => super.constraints;
+  SectorConstraints get constraints => super.constraints as SectorConstraints;
 
   @override
   void debugAssertDoesMeetConstraints() {
@@ -208,7 +208,7 @@ class RenderSectorWithChildren extends RenderDecoratedSector with ContainerRende
     while (child != null) {
       if (child.hitTest(result, radius: radius, theta: theta))
         return;
-      final SectorChildListParentData childParentData = child.parentData;
+      final SectorChildListParentData childParentData = child.parentData as SectorChildListParentData;
       child = childParentData.previousSibling;
     }
   }
@@ -218,7 +218,7 @@ class RenderSectorWithChildren extends RenderDecoratedSector with ContainerRende
     RenderSector child = lastChild;
     while (child != null) {
       visitor(child);
-      final SectorChildListParentData childParentData = child.parentData;
+      final SectorChildListParentData childParentData = child.parentData as SectorChildListParentData;
       child = childParentData.previousSibling;
     }
   }
@@ -282,7 +282,7 @@ class RenderSectorRing extends RenderSectorWithChildren {
       final SectorDimensions childDimensions = child.getIntrinsicDimensions(innerConstraints, childRadius);
       innerTheta += childDimensions.deltaTheta;
       remainingDeltaTheta -= childDimensions.deltaTheta;
-      final SectorChildListParentData childParentData = child.parentData;
+      final SectorChildListParentData childParentData = child.parentData as SectorChildListParentData;
       child = childParentData.nextSibling;
       if (child != null) {
         innerTheta += paddingTheta;
@@ -316,7 +316,7 @@ class RenderSectorRing extends RenderSectorWithChildren {
       child.layout(innerConstraints, parentUsesSize: true);
       innerTheta += child.deltaTheta;
       remainingDeltaTheta -= child.deltaTheta;
-      final SectorChildListParentData childParentData = child.parentData;
+      final SectorChildListParentData childParentData = child.parentData as SectorChildListParentData;
       child = childParentData.nextSibling;
       if (child != null) {
         innerTheta += paddingTheta;
@@ -335,7 +335,7 @@ class RenderSectorRing extends RenderSectorWithChildren {
     RenderSector child = firstChild;
     while (child != null) {
       context.paintChild(child, offset);
-      final SectorChildListParentData childParentData = child.parentData;
+      final SectorChildListParentData childParentData = child.parentData as SectorChildListParentData;
       child = childParentData.nextSibling;
     }
   }
@@ -396,7 +396,7 @@ class RenderSectorSlice extends RenderSectorWithChildren {
       final SectorDimensions childDimensions = child.getIntrinsicDimensions(innerConstraints, childRadius);
       childRadius += childDimensions.deltaRadius;
       remainingDeltaRadius -= childDimensions.deltaRadius;
-      final SectorChildListParentData childParentData = child.parentData;
+      final SectorChildListParentData childParentData = child.parentData as SectorChildListParentData;
       child = childParentData.nextSibling;
       childRadius += padding;
       remainingDeltaRadius -= padding;
@@ -427,7 +427,7 @@ class RenderSectorSlice extends RenderSectorWithChildren {
       child.layout(innerConstraints, parentUsesSize: true);
       childRadius += child.deltaRadius;
       remainingDeltaRadius -= child.deltaRadius;
-      final SectorChildListParentData childParentData = child.parentData;
+      final SectorChildListParentData childParentData = child.parentData as SectorChildListParentData;
       child = childParentData.nextSibling;
       childRadius += padding;
       remainingDeltaRadius -= padding;
@@ -445,7 +445,7 @@ class RenderSectorSlice extends RenderSectorWithChildren {
     while (child != null) {
       assert(child.parentData is SectorChildListParentData);
       context.paintChild(child, offset);
-      final SectorChildListParentData childParentData = child.parentData;
+      final SectorChildListParentData childParentData = child.parentData as SectorChildListParentData;
       child = childParentData.nextSibling;
     }
   }
@@ -638,7 +638,7 @@ class SectorHitTestEntry extends HitTestEntry {
         super(target);
 
   @override
-  RenderSector get target => super.target;
+  RenderSector get target => super.target as RenderSector;
 
   /// The radius component of the hit test position in the local coordinates of
   /// [target].

examples/layers/rendering/touch_input.dart

@@ -65,7 +65,7 @@ class RenderDots extends RenderBox {
   @override
   void handleEvent(PointerEvent event, BoxHitTestEntry entry) {
     if (event is PointerDownEvent) {
-      final Color color = _kColors[event.pointer.remainder(_kColors.length)];
+      final Color color = _kColors[event.pointer.remainder(_kColors.length) as int];
       _dots[event.pointer] = Dot(color: color)..update(event);
       // We call markNeedsPaint to indicate that our painting commands have
       // changed and that paint needs to be called before displaying a new frame
@@ -126,7 +126,7 @@ void main() {
   //
   // We use the StackParentData of the paragraph to position the text in the top
   // left corner of the screen.
-  final StackParentData paragraphParentData = paragraph.parentData;
+  final StackParentData paragraphParentData = paragraph.parentData as StackParentData;
   paragraphParentData
     ..top = 40.0
     ..left = 20.0;

examples/layers/services/isolate.dart

@@ -44,7 +44,7 @@ class Calculator {
       }
     );
     try {
-      final List<dynamic> result = decoder.convert(_data);
+      final List<dynamic> result = decoder.convert(_data) as List<dynamic>;
       final int n = result.length;
       onResultListener('Decoded $n results');
     } catch (e, stack) {

examples/layers/widgets/sectors.dart

@@ -9,7 +9,7 @@ import 'package:flutter/rendering.dart';
 
 import '../rendering/src/sector_layout.dart';
 
-RenderBox initCircle() {
+RenderBoxToRenderSectorAdapter initCircle() {
   return RenderBoxToRenderSectorAdapter(
     innerRadius: 25.0,
     child: RenderSectorRing(padding: 0.0),
@@ -54,7 +54,7 @@ class SectorAppState extends State<SectorApp> {
     int index = 0;
     while (index < actualSectorSizes.length && index < wantedSectorSizes.length && actualSectorSizes[index] == wantedSectorSizes[index])
       index += 1;
-    final RenderSectorRing ring = sectors.child;
+    final RenderSectorRing ring = sectors.child as RenderSectorRing;
     while (index < actualSectorSizes.length) {
       ring.remove(ring.lastChild);
       actualSectorSizes.removeLast();
@@ -67,7 +67,7 @@ class SectorAppState extends State<SectorApp> {
     }
   }
 
-  static RenderBox initSector(Color color) {
+  static RenderBoxToRenderSectorAdapter initSector(Color color) {
     final RenderSectorRing ring = RenderSectorRing(padding: 1.0);
     ring.add(RenderSolidColor(const Color(0xFF909090), desiredDeltaTheta: kTwoPi * 0.15));
     ring.add(RenderSolidColor(const Color(0xFF909090), desiredDeltaTheta: kTwoPi * 0.15));

examples/layers/widgets/spinning_mixed.dart

@@ -11,7 +11,7 @@ import '../rendering/src/solid_color_box.dart';
 void addFlexChildSolidColor(RenderFlex parent, Color backgroundColor, { int flex = 0 }) {
   final RenderSolidColorBox child = RenderSolidColorBox(backgroundColor);
   parent.add(child);
-  final FlexParentData childParentData = child.parentData;
+  final FlexParentData childParentData = child.parentData as FlexParentData;
   childParentData.flex = flex;
 }
 

examples/stocks/lib/main.dart

@@ -71,7 +71,7 @@ class StocksAppState extends State<StocksApp> {
 
   Route<dynamic> _getRoute(RouteSettings settings) {
     if (settings.name == '/stock') {
-      final String symbol = settings.arguments;
+      final String symbol = settings.arguments as String;
       return MaterialPageRoute<void>(
         settings: settings,
         builder: (BuildContext context) => StockSymbolPage(symbol: symbol, stocks: stocks),

examples/stocks/lib/stock_data.dart

@@ -49,14 +49,14 @@ class StockData extends ChangeNotifier {
   final List<String> _symbols = <String>[];
   final Map<String, Stock> _stocks = <String, Stock>{};
 
-  Iterable<String> get allSymbols => _symbols;
+  List<String> get allSymbols => _symbols;
 
   Stock operator [](String symbol) => _stocks[symbol];
 
   bool get loading => _httpClient != null;
 
   void add(List<dynamic> data) {
-    for (List<dynamic> fields in data) {
+    for (List<dynamic> fields in data.cast<List<dynamic>>()) {
       final Stock stock = Stock.fromFields(fields.cast<String>());
       _symbols.add(stock.symbol);
       _stocks[stock.symbol] = stock;
@@ -85,7 +85,7 @@ class StockData extends ChangeNotifier {
         return;
       }
       const JsonDecoder decoder = JsonDecoder();
-      add(decoder.convert(json));
+      add(decoder.convert(json) as List<dynamic>);
       if (_nextChunk < _chunkCount) {
         _fetchNextChunk();
       } else {

examples/stocks/lib/stock_home.dart

@@ -188,7 +188,7 @@ class StockHomeState extends State<StockHome> {
     showAboutDialog(context: context);
   }
 
-  Widget buildAppBar() {
+  AppBar buildAppBar() {
     return AppBar(
       elevation: 0.0,
       title: Text(StockStrings.of(context).title),
@@ -283,7 +283,7 @@ class StockHomeState extends State<StockHome> {
 
   static const List<String> portfolioSymbols = <String>['AAPL','FIZZ', 'FIVE', 'FLAT', 'ZINC', 'ZNGA'];
 
-  Widget buildSearchBar() {
+  AppBar buildSearchBar() {
     return AppBar(
       leading: BackButton(
         color: Theme.of(context).accentColor,

examples/stocks/lib/stock_settings.dart

@@ -97,7 +97,7 @@ class StockSettingsState extends State<StockSettings> {
       widget.updater(value);
   }
 
-  Widget buildAppBar(BuildContext context) {
+  AppBar buildAppBar(BuildContext context) {
     return AppBar(
       title: const Text('Settings'),
     );

examples/stocks/test/icon_color_test.dart

@@ -41,7 +41,7 @@ void checkIconColor(WidgetTester tester, String label, Color color) {
   final Element listTile = findElementOfExactWidgetTypeGoingUp(tester.element(find.text(label)), ListTile);
   expect(listTile, isNotNull);
   final Element asset = findElementOfExactWidgetTypeGoingDown(listTile, RichText);
-  final RichText richText = asset.widget;
+  final RichText richText = asset.widget as RichText;
   expect(richText.text.style.color, equals(color));
 }