Constants! Constants everywhere! (#9286)

Aggressively apply the const lint.

dev/automated_tests/flutter_test/test_async_utils_guarded_test.dart

@@ -14,7 +14,7 @@ class TestTestBinding extends AutomatedTestWidgetsFlutterBinding {
 
 Future<Null> guardedHelper(WidgetTester tester) {
   return TestAsyncUtils.guard(() async {
-    await tester.pumpWidget(new Text('Hello'));
+    await tester.pumpWidget(const Text('Hello'));
   });
 }
 

dev/benchmarks/complex_layout/lib/main.dart

@@ -57,7 +57,7 @@ class ComplexLayoutState extends State<ComplexLayout> {
   Widget build(BuildContext context) {
     return new Scaffold(
       appBar: new AppBar(
-        title: new Text('Advanced Layout'),
+        title: const Text('Advanced Layout'),
         actions: <Widget>[
           new IconButton(
             icon: new Icon(Icons.create),
@@ -356,9 +356,9 @@ class UserHeader extends StatelessWidget {
 class ItemDescription extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
-    return new Padding(
+    return const Padding(
       padding: const EdgeInsets.all(8.0),
-      child: new Text('Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.')
+      child: const Text('Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.')
     );
   }
 }
@@ -579,7 +579,7 @@ class GalleryDrawer extends StatelessWidget {
           new FancyDrawerHeader(),
           new ListTile(
             leading: new Icon(Icons.brightness_5),
-            title: new Text('Light'),
+            title: const Text('Light'),
             onTap: () { _changeTheme(context, true); },
             selected: ComplexLayoutApp.of(context).lightTheme,
             trailing: new Radio<bool>(
@@ -590,7 +590,7 @@ class GalleryDrawer extends StatelessWidget {
           ),
           new ListTile(
             leading: new Icon(Icons.brightness_7),
-            title: new Text('Dark'),
+            title: const Text('Dark'),
             onTap: () { _changeTheme(context, false); },
             selected: !ComplexLayoutApp.of(context).lightTheme,
             trailing: new Radio<bool>(
@@ -602,7 +602,7 @@ class GalleryDrawer extends StatelessWidget {
           new Divider(),
           new ListTile(
             leading: new Icon(Icons.hourglass_empty),
-            title: new Text('Animate Slowly'),
+            title: const Text('Animate Slowly'),
             selected: timeDilation != 1.0,
             onTap: () { ComplexLayoutApp.of(context).toggleAnimationSpeed(); },
             trailing: new Checkbox(

dev/devicelab/lib/framework/utils.dart

@@ -15,7 +15,7 @@ import 'package:stack_trace/stack_trace.dart';
 String cwd = Directory.current.path;
 
 List<ProcessInfo> _runningProcesses = <ProcessInfo>[];
-ProcessManager _processManager = new LocalProcessManager();
+ProcessManager _processManager = const LocalProcessManager();
 
 class ProcessInfo {
   ProcessInfo(this.command, this.process);

dev/devicelab/test/run_test.dart

@@ -10,7 +10,7 @@ import 'package:process/process.dart';
 import 'package:test/test.dart';
 
 void main() {
-  final ProcessManager processManager = new LocalProcessManager();
+  final ProcessManager processManager = const LocalProcessManager();
 
   group('run.dart script', () {
     Future<int> runScript(List<String> testNames) async {

dev/manual_tests/card_collection.dart

@@ -88,7 +88,7 @@ class CardCollectionState extends State<CardCollection> {
         data: const IconThemeData(color: Colors.black),
         child: new ListView(
           children: <Widget>[
-            new DrawerHeader(child: new Center(child: new Text('Options'))),
+            const DrawerHeader(child: const Center(child: const Text('Options'))),
             buildDrawerCheckbox("Make card labels editable", _editable, _toggleEditable),
             buildDrawerCheckbox("Fixed size cards", _fixedSizeCards, _toggleFixedSizeCards),
             buildDrawerCheckbox("Let the sun shine", _sunshine, _toggleSunshine),
@@ -110,7 +110,7 @@ class CardCollectionState extends State<CardCollection> {
             new ListTile(
               leading: new Icon(Icons.dvr),
               onTap: () { debugDumpApp(); debugDumpRenderTree(); },
-              title: new Text('Dump App to Console'),
+              title: const Text('Dump App to Console'),
             ),
           ],
         ),

dev/manual_tests/drag_and_drop.dart

@@ -42,7 +42,7 @@ class ExampleDragTargetState extends State<ExampleDragTarget> {
 }
 
 class Dot extends StatefulWidget {
-  Dot({ Key key, this.color, this.size, this.child, this.tappable: false }) : super(key: key);
+  const Dot({ Key key, this.color, this.size, this.child, this.tappable: false }) : super(key: key);
 
   final Color color;
   final double size;
@@ -193,13 +193,13 @@ class MovableBall extends StatelessWidget {
         color: Colors.blue.shade700,
         size: kBallSize,
         tappable: true,
-        child: new Center(child: new Text('BALL'))
+        child: const Center(child: const Text('BALL'))
       )
     );
     final Widget dashedBall = new Container(
       width: kBallSize,
       height: kBallSize,
-      child: new CustomPaint(
+      child: const CustomPaint(
         painter: const DashOutlineCirclePainter()
       )
     );
@@ -238,7 +238,7 @@ class DragAndDropAppState extends State<DragAndDropApp> {
   Widget build(BuildContext context) {
     return new Scaffold(
       appBar: new AppBar(
-        title: new Text('Drag and Drop Flutter Demo')
+        title: const Text('Drag and Drop Flutter Demo')
       ),
       body: new Column(
         children: <Widget>[
@@ -251,19 +251,19 @@ class DragAndDropAppState extends State<DragAndDropApp> {
                   color: Colors.yellow.shade300,
                   under: true,
                   heavy: false,
-                  child: new Text('under')
+                  child: const Text('under')
                 ),
                 new ExampleDragSource(
                   color: Colors.green.shade300,
                   under: false,
                   heavy: true,
-                  child: new Text('long-press above')
+                  child: const Text('long-press above')
                 ),
                 new ExampleDragSource(
                   color: Colors.indigo.shade300,
                   under: false,
                   heavy: false,
-                  child: new Text('above')
+                  child: const Text('above')
                 ),
               ],
             )

dev/manual_tests/material_arc.dart

@@ -444,7 +444,7 @@ class _AnimationDemoState extends State<AnimationDemo> with TickerProviderStateM
       length: _allDemos.length,
       child: new Scaffold(
         appBar: new AppBar(
-          title: new Text('Animation'),
+          title: const Text('Animation'),
           bottom: new TabBar(
             tabs: _allDemos.map((_ArcDemo demo) => new Tab(text: demo.title)).toList(),
           ),

dev/manual_tests/overlay_geometry.dart

@@ -181,7 +181,7 @@ class OverlayGeometryAppState extends State<OverlayGeometryApp> {
   Widget build(BuildContext context) {
     final List<Widget> layers = <Widget>[
       new Scaffold(
-        appBar: new AppBar(title: new Text('Tap a Card')),
+        appBar: new AppBar(title: const Text('Tap a Card')),
         body: new Container(
           padding: const EdgeInsets.symmetric(vertical: 12.0, horizontal: 8.0),
           child: new NotificationListener<ScrollNotification>(

dev/manual_tests/page_view.dart

@@ -84,22 +84,22 @@ class PageViewAppState extends State<PageViewApp> {
     return new Drawer(
       child: new ListView(
         children: <Widget>[
-          new DrawerHeader(child: new Center(child: new Text('Options'))),
+          const DrawerHeader(child: const Center(child: const Text('Options'))),
           new ListTile(
             leading: new Icon(Icons.more_horiz),
             selected: scrollDirection == Axis.horizontal,
-            trailing: new Text('Horizontal Layout'),
+            trailing: const Text('Horizontal Layout'),
             onTap: switchScrollDirection,
           ),
           new ListTile(
             leading: new Icon(Icons.more_vert),
             selected: scrollDirection == Axis.vertical,
-            trailing: new Text('Vertical Layout'),
+            trailing: const Text('Vertical Layout'),
             onTap: switchScrollDirection,
           ),
           new ListTile(
             onTap: toggleItemsWrap,
-            title: new Text('Scrolling wraps around'),
+            title: const Text('Scrolling wraps around'),
             // TODO(abarth): Actually make this checkbox change this value.
             trailing: new Checkbox(value: itemsWrap, onChanged: null),
           ),
@@ -110,7 +110,7 @@ class PageViewAppState extends State<PageViewApp> {
 
   Widget _buildAppBar() {
     return new AppBar(
-      title: new Text('PageView'),
+      title: const Text('PageView'),
       actions: <Widget>[
         new Text(scrollDirection == Axis.horizontal ? "horizontal" : "vertical"),
       ],

dev/manual_tests/raw_keyboard.dart

@@ -10,7 +10,7 @@ void main() {
     title: 'Hardware Key Demo',
     home: new Scaffold(
       appBar: new AppBar(
-        title: new Text('Hardware Key Demo'),
+        title: const Text('Hardware Key Demo'),
       ),
       body: new Center(
         child: new RawKeyboardDemo(),

examples/flutter_gallery/lib/demo/colors_demo.dart

@@ -125,7 +125,7 @@ class ColorsDemo extends StatelessWidget {
       child: new Scaffold(
         appBar: new AppBar(
           elevation: 0,
-          title: new Text('Colors'),
+          title: const Text('Colors'),
           bottom: new TabBar(
             isScrollable: true,
             tabs: allPalettes.map((Palette swatch) => new Tab(text: swatch.name)).toList(),

examples/flutter_gallery/lib/demo/contacts_demo.dart

@@ -113,11 +113,11 @@ class ContactsDemoState extends State<ContactsDemo> {
               floating: _appBarBehavior == AppBarBehavior.floating,
               actions: <Widget>[
                 new IconButton(
-                  icon: new Icon(Icons.create),
+                  icon: const Icon(Icons.create),
                   tooltip: 'Edit',
                   onPressed: () {
                     _scaffoldKey.currentState.showSnackBar(new SnackBar(
-                      content: new Text('This is actually just a demo. Editing isn\'t supported.')
+                      content: const Text('This is actually just a demo. Editing isn\'t supported.')
                     ));
                   },
                 ),
@@ -130,21 +130,21 @@ class ContactsDemoState extends State<ContactsDemo> {
                   itemBuilder: (BuildContext context) => <PopupMenuItem<AppBarBehavior>>[
                     new PopupMenuItem<AppBarBehavior>(
                       value: AppBarBehavior.normal,
-                      child: new Text('App bar scrolls away')
+                      child: const Text('App bar scrolls away')
                     ),
                     new PopupMenuItem<AppBarBehavior>(
                       value: AppBarBehavior.pinned,
-                      child: new Text('App bar stays put')
+                      child: const Text('App bar stays put')
                     ),
                     new PopupMenuItem<AppBarBehavior>(
                       value: AppBarBehavior.floating,
-                      child: new Text('App bar floats')
+                      child: const Text('App bar floats')
                     ),
                   ],
                 ),
               ],
               flexibleSpace: new FlexibleSpaceBar(
-                title: new Text('Ali Connors'),
+                title: const Text('Ali Connors'),
                 background: new Stack(
                   children: <Widget>[
                     new Image.asset(
@@ -154,7 +154,7 @@ class ContactsDemoState extends State<ContactsDemo> {
                     ),
                     // This gradient ensures that the toolbar icons are distinct
                     // against the background image.
-                    new DecoratedBox(
+                    const DecoratedBox(
                       decoration: const BoxDecoration(
                         gradient: const LinearGradient(
                           begin: const FractionalOffset(0.5, 0.0),
@@ -177,7 +177,7 @@ class ContactsDemoState extends State<ContactsDemo> {
                       tooltip: 'Send message',
                       onPressed: () {
                         _scaffoldKey.currentState.showSnackBar(new SnackBar(
-                          content: new Text('Pretend that this opened your SMS application.')
+                          content: const Text('Pretend that this opened your SMS application.')
                         ));
                       },
                       lines: <String>[
@@ -190,7 +190,7 @@ class ContactsDemoState extends State<ContactsDemo> {
                       tooltip: 'Send message',
                       onPressed: () {
                         _scaffoldKey.currentState.showSnackBar(new SnackBar(
-                          content: new Text('In this demo, this button doesn\'t do anything.')
+                          content: const Text('In this demo, this button doesn\'t do anything.')
                         ));
                       },
                       lines: <String>[
@@ -203,7 +203,7 @@ class ContactsDemoState extends State<ContactsDemo> {
                       tooltip: 'Send message',
                       onPressed: () {
                         _scaffoldKey.currentState.showSnackBar(new SnackBar(
-                          content: new Text('Imagine if you will, a messaging application.')
+                          content: const Text('Imagine if you will, a messaging application.')
                         ));
                       },
                       lines: <String>[
@@ -221,7 +221,7 @@ class ContactsDemoState extends State<ContactsDemo> {
                       tooltip: 'Send personal e-mail',
                       onPressed: () {
                         _scaffoldKey.currentState.showSnackBar(new SnackBar(
-                          content: new Text('Here, your e-mail application would open.')
+                          content: const Text('Here, your e-mail application would open.')
                         ));
                       },
                       lines: <String>[
@@ -234,7 +234,7 @@ class ContactsDemoState extends State<ContactsDemo> {
                       tooltip: 'Send work e-mail',
                       onPressed: () {
                         _scaffoldKey.currentState.showSnackBar(new SnackBar(
-                          content: new Text('This is a demo, so this button does not actually work.')
+                          content: const Text('This is a demo, so this button does not actually work.')
                         ));
                       },
                       lines: <String>[
@@ -252,7 +252,7 @@ class ContactsDemoState extends State<ContactsDemo> {
                       tooltip: 'Open map',
                       onPressed: () {
                         _scaffoldKey.currentState.showSnackBar(new SnackBar(
-                          content: new Text('This would show a map of San Francisco.')
+                          content: const Text('This would show a map of San Francisco.')
                         ));
                       },
                       lines: <String>[
@@ -266,7 +266,7 @@ class ContactsDemoState extends State<ContactsDemo> {
                       tooltip: 'Open map',
                       onPressed: () {
                         _scaffoldKey.currentState.showSnackBar(new SnackBar(
-                          content: new Text('This would show a map of Mountain View.')
+                          content: const Text('This would show a map of Mountain View.')
                         ));
                       },
                       lines: <String>[
@@ -280,7 +280,7 @@ class ContactsDemoState extends State<ContactsDemo> {
                       tooltip: 'Open map',
                       onPressed: () {
                         _scaffoldKey.currentState.showSnackBar(new SnackBar(
-                          content: new Text('This would also show a map, if this was not a demo.')
+                          content: const Text('This would also show a map, if this was not a demo.')
                         ));
                       },
                       lines: <String>[

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

@@ -12,7 +12,7 @@ class CupertinoProgressIndicatorDemo extends StatelessWidget {
   Widget build(BuildContext context) {
     return new Scaffold(
       appBar: new AppBar(
-        title: new Text('Cupertino Activity Indicator'),
+        title: const Text('Cupertino Activity Indicator'),
       ),
       body: new Center(
         child: new CupertinoActivityIndicator(),

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

@@ -21,13 +21,13 @@ class _CupertinoButtonDemoState extends State<CupertinoButtonsDemo> {
   Widget build(BuildContext context) {
     return new Scaffold(
       appBar: new AppBar(
-        title: new Text('Cupertino Buttons'),
+        title: const Text('Cupertino Buttons'),
       ),
       body: new Column(
         children: <Widget> [
-          new Padding(
+          const Padding(
             padding: const EdgeInsets.all(16.0),
-            child: new Text('iOS themed buttons are flat. They can have borders or backgrounds but '
+            child: const Text('iOS themed buttons are flat. They can have borders or backgrounds but '
                 'only when necessary.'),
           ),
           new Expanded(
@@ -35,36 +35,36 @@ class _CupertinoButtonDemoState extends State<CupertinoButtonsDemo> {
               mainAxisAlignment: MainAxisAlignment.center,
               children: <Widget> [
                 new Text(_pressedCount > 0 ? "Button pressed $_pressedCount times" : " "),
-                new Padding(padding: const EdgeInsets.all(12.0)),
+                const Padding(padding: const EdgeInsets.all(12.0)),
                 new Align(
                   alignment: const FractionalOffset(0.5, 0.4),
                   child: new Row(
                     mainAxisSize: MainAxisSize.min,
                     children: <Widget>[
                       new CupertinoButton(
-                        child: new Text('Cupertino Button'),
+                        child: const Text('Cupertino Button'),
                         onPressed: () {
                           setState(() {_pressedCount++;});
                         }
                       ),
                       new CupertinoButton(
-                        child: new Text('Disabled'),
+                        child: const Text('Disabled'),
                         onPressed: null,
                       ),
                     ],
                   ),
                 ),
-                new Padding(padding: const EdgeInsets.all(12.0)),
+                const Padding(padding: const EdgeInsets.all(12.0)),
                 new CupertinoButton(
-                  child: new Text('With Background'),
+                  child: const Text('With Background'),
                   color: _kBlue,
                   onPressed: () {
                     setState(() {_pressedCount++;});
                   }
                 ),
-                new Padding(padding: const EdgeInsets.all(12.0)),
+                const Padding(padding: const EdgeInsets.all(12.0)),
                 new CupertinoButton(
-                  child: new Text('Disabled'),
+                  child: const Text('Disabled'),
                   color: _kBlue,
                   onPressed: null,
                 ),

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

@@ -37,27 +37,27 @@ class _CupertinoDialogDemoState extends State<CupertinoDialogDemo> {
     return new Scaffold(
       key: _scaffoldKey,
       appBar: new AppBar(
-        title: new Text('Cupertino Dialogs'),
+        title: const Text('Cupertino Dialogs'),
       ),
       body: new ListView(
         padding: const EdgeInsets.symmetric(vertical: 24.0, horizontal: 72.0),
         children: <Widget> [
           new CupertinoButton(
-            child: new Text('Alert'),
+            child: const Text('Alert'),
             color: _kBlue,
             onPressed: () {
               showDemoDialog<String>(
                 context: context,
                 child: new CupertinoAlertDialog(
-                  content: new Text('Discard draft?'),
+                  content: const Text('Discard draft?'),
                   actions: <Widget>[
                     new CupertinoDialogAction(
-                      child: new Text('Discard'),
+                      child: const Text('Discard'),
                       isDestructive: true,
                       onPressed: () { Navigator.pop(context, 'OK'); }
                     ),
                     new CupertinoDialogAction(
-                      child: new Text('Cancel', style: const TextStyle(fontWeight: FontWeight.w600)),
+                      child: const Text('Cancel', style: const TextStyle(fontWeight: FontWeight.w600)),
                       onPressed: () { Navigator.pop(context, 'Cancel'); }
                     ),
                   ]
@@ -65,27 +65,27 @@ class _CupertinoDialogDemoState extends State<CupertinoDialogDemo> {
               );
             },
           ),
-          new Padding(padding: const EdgeInsets.all(8.0)),
+          const Padding(padding: const EdgeInsets.all(8.0)),
           new CupertinoButton(
-            child: new Text('Alert with Title'),
+            child: const Text('Alert with Title'),
             color: _kBlue,
             padding: const EdgeInsets.symmetric(vertical: 16.0, horizontal: 36.0),
             onPressed: () {
               showDemoDialog<String>(
                 context: context,
                 child: new CupertinoAlertDialog(
-                  title: new Text('Allow "Maps" to access your location while you use the app?'),
-                  content: new Text(
+                  title: const Text('Allow "Maps" to access your location while you use the app?'),
+                  content: const Text(
                     'Your current location will be displayed on the map and used for directions, '
                     'nearby search results, and estimated travel times.'
                   ),
                   actions: <Widget>[
                     new CupertinoDialogAction(
-                      child: new Text('Don\'t Allow'),
+                      child: const Text('Don\'t Allow'),
                       onPressed: () { Navigator.pop(context, 'Disallow'); }
                     ),
                     new CupertinoDialogAction(
-                      child: new Text('Allow'),
+                      child: const Text('Allow'),
                       onPressed: () { Navigator.pop(context, 'Allow'); }
                     ),
                   ]

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

@@ -20,7 +20,7 @@ class _CupertinoSliderDemoState extends State<CupertinoSliderDemo> {
   Widget build(BuildContext context) {
     return new Scaffold(
       appBar: new AppBar(
-        title: new Text('Cupertino Sliders'),
+        title: const Text('Cupertino Sliders'),
       ),
       body: new Center(
         child: new Column(
@@ -39,7 +39,7 @@ class _CupertinoSliderDemoState extends State<CupertinoSliderDemo> {
                     });
                   }
                 ),
-                new Text('Cupertino Continuous'),
+                const Text('Cupertino Continuous'),
               ]
             ),
             new Column(
@@ -56,7 +56,7 @@ class _CupertinoSliderDemoState extends State<CupertinoSliderDemo> {
                     });
                   }
                 ),
-                new Text('Cupertino Discrete'),
+                const Text('Cupertino Discrete'),
               ]
             ),
           ],

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

@@ -20,7 +20,7 @@ class _CupertinoSwitchDemoState extends State<CupertinoSwitchDemo> {
   Widget build(BuildContext context) {
     return new Scaffold(
       appBar: new AppBar(
-        title: new Text('Cupertino Switch'),
+        title: const Text('Cupertino Switch'),
       ),
       body: new Center(
         child:  new CupertinoSwitch(

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

@@ -23,7 +23,7 @@ class NavigationIconView {
        ) {
     _animation = new CurvedAnimation(
       parent: controller,
-      curve: new Interval(0.5, 1.0, curve: Curves.fastOutSlowIn),
+      curve: const Interval(0.5, 1.0, curve: Curves.fastOutSlowIn),
     );
   }
 
@@ -96,32 +96,32 @@ class _BottomNavigationDemoState extends State<BottomNavigationDemo>
     super.initState();
     _navigationViews = <NavigationIconView>[
       new NavigationIconView(
-        icon: new Icon(Icons.access_alarm),
-        title: new Text('Alarm'),
+        icon: const Icon(Icons.access_alarm),
+        title: const Text('Alarm'),
         color: Colors.deepPurple,
         vsync: this,
       ),
       new NavigationIconView(
         icon: new CustomIcon(),
-        title: new Text('Box'),
+        title: const Text('Box'),
         color: Colors.deepOrange,
         vsync: this,
       ),
       new NavigationIconView(
-        icon: new Icon(Icons.cloud),
-        title: new Text('Cloud'),
+        icon: const Icon(Icons.cloud),
+        title: const Text('Cloud'),
         color: Colors.teal,
         vsync: this,
       ),
       new NavigationIconView(
-        icon: new Icon(Icons.favorite),
-        title: new Text('Favorites'),
+        icon: const Icon(Icons.favorite),
+        title: const Text('Favorites'),
         color: Colors.indigo,
         vsync: this,
       ),
       new NavigationIconView(
-        icon: new Icon(Icons.event_available),
-        title: new Text('Event'),
+        icon: const Icon(Icons.event_available),
+        title: const Text('Event'),
         color: Colors.pink,
         vsync: this,
       )
@@ -183,7 +183,7 @@ class _BottomNavigationDemoState extends State<BottomNavigationDemo>
 
     return new Scaffold(
       appBar: new AppBar(
-        title: new Text('Bottom navigation'),
+        title: const Text('Bottom navigation'),
         actions: <Widget>[
           new PopupMenuButton<BottomNavigationBarType>(
             onSelected: (BottomNavigationBarType value) {
@@ -194,11 +194,11 @@ class _BottomNavigationDemoState extends State<BottomNavigationDemo>
             itemBuilder: (BuildContext context) => <PopupMenuItem<BottomNavigationBarType>>[
               new PopupMenuItem<BottomNavigationBarType>(
                 value: BottomNavigationBarType.fixed,
-                child: new Text('Fixed'),
+                child: const Text('Fixed'),
               ),
               new PopupMenuItem<BottomNavigationBarType>(
                 value: BottomNavigationBarType.shifting,
-                child: new Text('Shifting'),
+                child: const Text('Shifting'),
               )
             ],
           )

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

@@ -95,13 +95,13 @@ class _ButtonsDemoState extends State<ButtonsDemo> {
         mainAxisSize: MainAxisSize.min,
         children: <Widget>[
           new RaisedButton(
-            child: new Text('RAISED BUTTON'),
+            child: const Text('RAISED BUTTON'),
             onPressed: () {
               // Perform some action
             },
           ),
           new RaisedButton(
-            child: new Text('DISABLED'),
+            child: const Text('DISABLED'),
             onPressed: null,
           )
         ],
@@ -116,13 +116,13 @@ class _ButtonsDemoState extends State<ButtonsDemo> {
         mainAxisSize: MainAxisSize.min,
         children: <Widget>[
           new FlatButton(
-            child: new Text('FLAT BUTTON'),
+            child: const Text('FLAT BUTTON'),
             onPressed: () {
               // Perform some action
             },
           ),
           new FlatButton(
-            child: new Text('DISABLED'),
+            child: const Text('DISABLED'),
             onPressed: null,
           )
         ],
@@ -142,7 +142,7 @@ class _ButtonsDemoState extends State<ButtonsDemo> {
         mainAxisAlignment: MainAxisAlignment.start,
         children: <Widget>[
           new ListTile(
-            title: new Text('Simple dropdown:'),
+            title: const Text('Simple dropdown:'),
             trailing: new DropdownButton<String>(
               value: dropdown1Value,
               onChanged: (String newValue) {
@@ -162,10 +162,10 @@ class _ButtonsDemoState extends State<ButtonsDemo> {
             height: 24.0,
           ),
           new ListTile(
-            title: new Text('Dropdown with a hint:'),
+            title: const Text('Dropdown with a hint:'),
             trailing: new DropdownButton<String>(
               value: dropdown2Value,
-              hint: new Text('Choose'),
+              hint: const Text('Choose'),
               onChanged: (String newValue) {
                 setState(() {
                   dropdown2Value = newValue;
@@ -183,7 +183,7 @@ class _ButtonsDemoState extends State<ButtonsDemo> {
             height: 24.0,
           ),
           new ListTile(
-            title: new Text('Scrollable dropdown:'),
+            title: const Text('Scrollable dropdown:'),
             trailing: new DropdownButton<String>(
               value: dropdown3Value,
               onChanged: (String newValue) {
@@ -218,14 +218,14 @@ class _ButtonsDemoState extends State<ButtonsDemo> {
         mainAxisSize: MainAxisSize.min,
         children: <Widget>[
           new IconButton(
-            icon: new Icon(Icons.thumb_up),
+            icon: const Icon(Icons.thumb_up),
             onPressed: () {
               setState(() => iconButtonToggle = !iconButtonToggle);
             },
             color: iconButtonToggle ? Theme.of(context).primaryColor : null,
           ),
-          new IconButton(
-            icon: new Icon(Icons.thumb_up),
+          const IconButton(
+            icon: const Icon(Icons.thumb_up),
             onPressed: null,
           )
         ]
@@ -239,7 +239,7 @@ class _ButtonsDemoState extends State<ButtonsDemo> {
     return new Align(
       alignment: const FractionalOffset(0.5, 0.4),
       child: new FloatingActionButton(
-        child: new Icon(Icons.add),
+        child: const Icon(Icons.add),
         onPressed: () {
           // Perform some action
         },

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

@@ -116,12 +116,12 @@ class TravelDestinationItem extends StatelessWidget {
                 alignment: MainAxisAlignment.start,
                 children: <Widget>[
                   new FlatButton(
-                    child: new Text('SHARE'),
+                    child: const Text('SHARE'),
                     textColor: Colors.amber.shade500,
                     onPressed: () { /* do nothing */ },
                   ),
                   new FlatButton(
-                    child: new Text('EXPLORE'),
+                    child: const Text('EXPLORE'),
                     textColor: Colors.amber.shade500,
                     onPressed: () { /* do nothing */ },
                   ),
@@ -142,7 +142,7 @@ class CardsDemo extends StatelessWidget {
   Widget build(BuildContext context) {
     return new Scaffold(
       appBar: new AppBar(
-        title: new Text('Travel stream')
+        title: const Text('Travel stream')
       ),
       body: new ListView(
         itemExtent: TravelDestinationItem.height,

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

@@ -23,24 +23,24 @@ class _ChipDemoState extends State<ChipDemo> {
   @override
   Widget build(BuildContext context) {
     final List<Widget> chips = <Widget>[
-      new Chip(
-        label: new Text('Apple')
+      const Chip(
+        label: const Text('Apple')
       ),
       new Chip(
-        avatar: new CircleAvatar(child: new Text('B')),
-        label: new Text('Blueberry')
+        avatar: new CircleAvatar(child: const Text('B')),
+        label: const Text('Blueberry')
       ),
     ];
 
     if (_showBananas) {
       chips.add(new Chip(
-        label: new Text('Bananas'),
+        label: const Text('Bananas'),
         onDeleted: _deleteBananas
       ));
     }
 
     return new Scaffold(
-      appBar: new AppBar(title: new Text('Chips')),
+      appBar: new AppBar(title: const Text('Chips')),
       body: new ListView(
         children: chips.map((Widget widget) {
           return new Container(

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

@@ -164,12 +164,12 @@ class _DataTableDemoState extends State<DataTableDemo> {
   @override
   Widget build(BuildContext context) {
     return new Scaffold(
-      appBar: new AppBar(title: new Text('Data tables')),
+      appBar: new AppBar(title: const Text('Data tables')),
       body: new ListView(
         padding: const EdgeInsets.all(20.0),
         children: <Widget>[
           new PaginatedDataTable(
-            header: new Text('Nutrition'),
+            header: const Text('Nutrition'),
             rowsPerPage: _rowsPerPage,
             onRowsPerPageChanged: (int value) { setState(() { _rowsPerPage = value; }); },
             sortColumnIndex: _sortColumnIndex,
@@ -177,43 +177,43 @@ class _DataTableDemoState extends State<DataTableDemo> {
             onSelectAll: _dessertsDataSource._selectAll,
             columns: <DataColumn>[
               new DataColumn(
-                label: new Text('Dessert (100g serving)'),
+                label: const Text('Dessert (100g serving)'),
                 onSort: (int columnIndex, bool ascending) => _sort<String>((Dessert d) => d.name, columnIndex, ascending)
               ),
               new DataColumn(
-                label: new Text('Calories'),
+                label: const Text('Calories'),
                 tooltip: 'The total amount of food energy in the given serving size.',
                 numeric: true,
                 onSort: (int columnIndex, bool ascending) => _sort<num>((Dessert d) => d.calories, columnIndex, ascending)
               ),
               new DataColumn(
-                label: new Text('Fat (g)'),
+                label: const Text('Fat (g)'),
                 numeric: true,
                 onSort: (int columnIndex, bool ascending) => _sort<num>((Dessert d) => d.fat, columnIndex, ascending)
               ),
               new DataColumn(
-                label: new Text('Carbs (g)'),
+                label: const Text('Carbs (g)'),
                 numeric: true,
                 onSort: (int columnIndex, bool ascending) => _sort<num>((Dessert d) => d.carbs, columnIndex, ascending)
               ),
               new DataColumn(
-                label: new Text('Protein (g)'),
+                label: const Text('Protein (g)'),
                 numeric: true,
                 onSort: (int columnIndex, bool ascending) => _sort<num>((Dessert d) => d.protein, columnIndex, ascending)
               ),
               new DataColumn(
-                label: new Text('Sodium (mg)'),
+                label: const Text('Sodium (mg)'),
                 numeric: true,
                 onSort: (int columnIndex, bool ascending) => _sort<num>((Dessert d) => d.sodium, columnIndex, ascending)
               ),
               new DataColumn(
-                label: new Text('Calcium (%)'),
+                label: const Text('Calcium (%)'),
                 tooltip: 'The amount of calcium as a percentage of the recommended daily amount.',
                 numeric: true,
                 onSort: (int columnIndex, bool ascending) => _sort<num>((Dessert d) => d.calcium, columnIndex, ascending)
               ),
               new DataColumn(
-                label: new Text('Iron (%)'),
+                label: const Text('Iron (%)'),
                 numeric: true,
                 onSort: (int columnIndex, bool ascending) => _sort<num>((Dessert d) => d.iron, columnIndex, ascending)
               ),

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

@@ -129,7 +129,7 @@ class _DateAndTimePickerDemoState extends State<DateAndTimePickerDemo> {
   @override
   Widget build(BuildContext context) {
     return new Scaffold(
-      appBar: new AppBar(title: new Text('Date and time pickers')),
+      appBar: new AppBar(title: const Text('Date and time pickers')),
       body: new DropdownButtonHideUnderline(
         child: new ListView(
           padding: const EdgeInsets.all(16.0),

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

@@ -87,13 +87,13 @@ class DialogDemoState extends State<DialogDemo> {
     return new Scaffold(
       key: _scaffoldKey,
       appBar: new AppBar(
-        title: new Text('Dialogs')
+        title: const Text('Dialogs')
       ),
       body: new ListView(
         padding: const EdgeInsets.symmetric(vertical: 24.0, horizontal: 72.0),
         children: <Widget>[
           new RaisedButton(
-            child: new Text('ALERT'),
+            child: const Text('ALERT'),
             onPressed: () {
               showDemoDialog<DialogDemoAction>(
                 context: context,
@@ -104,11 +104,11 @@ class DialogDemoState extends State<DialogDemo> {
                   ),
                   actions: <Widget>[
                     new FlatButton(
-                      child: new Text('CANCEL'),
+                      child: const Text('CANCEL'),
                       onPressed: () { Navigator.pop(context, DialogDemoAction.cancel); }
                     ),
                     new FlatButton(
-                      child: new Text('DISCARD'),
+                      child: const Text('DISCARD'),
                       onPressed: () { Navigator.pop(context, DialogDemoAction.discard); }
                     )
                   ]
@@ -117,23 +117,23 @@ class DialogDemoState extends State<DialogDemo> {
             }
           ),
           new RaisedButton(
-            child: new Text('ALERT WITH TITLE'),
+            child: const Text('ALERT WITH TITLE'),
             onPressed: () {
               showDemoDialog<DialogDemoAction>(
                 context: context,
                 child: new AlertDialog(
-                  title: new Text('Use Google\'s location service?'),
+                  title: const Text('Use Google\'s location service?'),
                   content: new Text(
                     _alertWithTitleText,
                     style: dialogTextStyle
                   ),
                   actions: <Widget>[
                     new FlatButton(
-                      child: new Text('DISAGREE'),
+                      child: const Text('DISAGREE'),
                       onPressed: () { Navigator.pop(context, DialogDemoAction.disagree); }
                     ),
                     new FlatButton(
-                      child: new Text('AGREE'),
+                      child: const Text('AGREE'),
                       onPressed: () { Navigator.pop(context, DialogDemoAction.agree); }
                     )
                   ]
@@ -142,12 +142,12 @@ class DialogDemoState extends State<DialogDemo> {
             }
           ),
           new RaisedButton(
-            child: new Text('SIMPLE'),
+            child: const Text('SIMPLE'),
             onPressed: () {
               showDemoDialog<String>(
                 context: context,
                 child: new SimpleDialog(
-                  title: new Text('Set backup account'),
+                  title: const Text('Set backup account'),
                   children: <Widget>[
                     new DialogDemoItem(
                       icon: Icons.account_circle,
@@ -172,7 +172,7 @@ class DialogDemoState extends State<DialogDemo> {
             }
           ),
           new RaisedButton(
-            child: new Text('CONFIRMATION'),
+            child: const Text('CONFIRMATION'),
             onPressed: () {
               showTimePicker(
                 context: context,
@@ -189,7 +189,7 @@ class DialogDemoState extends State<DialogDemo> {
             }
           ),
           new RaisedButton(
-            child: new Text('FULLSCREEN'),
+            child: const Text('FULLSCREEN'),
             onPressed: () {
               Navigator.push(context, new MaterialPageRoute<DismissDialogAction>(
                 builder: (BuildContext context) => new FullScreenDialogDemo(),

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

@@ -68,7 +68,7 @@ class _DrawerDemoState extends State<DrawerDemo> with TickerProviderStateMixin {
   void _showNotImplementedMessage() {
     Navigator.of(context).pop(); // Dismiss the drawer.
     _scaffoldKey.currentState.showSnackBar(new SnackBar(
-      content: new Text("The drawer's items don't do anything")
+      content: const Text("The drawer's items don't do anything")
     ));
   }
 
@@ -85,14 +85,14 @@ class _DrawerDemoState extends State<DrawerDemo> with TickerProviderStateMixin {
             Navigator.pop(context);
           },
         ),
-        title: new Text('Navigation drawer'),
+        title: const Text('Navigation drawer'),
       ),
       drawer: new Drawer(
         child: new ListView(
           children: <Widget>[
             new UserAccountsDrawerHeader(
-              accountName: new Text('Zach Widget'),
-              accountEmail: new Text('zach.widget@example.com'),
+              accountName: const Text('Zach Widget'),
+              accountEmail: const Text('zach.widget@example.com'),
               currentAccountPicture: new CircleAvatar(backgroundImage: new AssetImage(_kAsset0)),
               otherAccountsPictures: <Widget>[
                 new CircleAvatar(backgroundImage: new AssetImage(_kAsset1)),
@@ -134,13 +134,13 @@ class _DrawerDemoState extends State<DrawerDemo> with TickerProviderStateMixin {
                         crossAxisAlignment: CrossAxisAlignment.stretch,
                         children: <Widget>[
                           new ListTile(
-                            leading: new Icon(Icons.add),
-                            title: new Text('Add account'),
+                            leading: const Icon(Icons.add),
+                            title: const Text('Add account'),
                             onTap: _showNotImplementedMessage,
                           ),
                           new ListTile(
-                            leading: new Icon(Icons.settings),
-                            title: new Text('Manage accounts'),
+                            leading: const Icon(Icons.settings),
+                            title: const Text('Manage accounts'),
                             onTap: _showNotImplementedMessage,
                           ),
                         ],

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

@@ -30,8 +30,8 @@ class DualHeaderWithHint extends StatelessWidget {
     return new AnimatedCrossFade(
       firstChild: first,
       secondChild: second,
-      firstCurve: new Interval(0.0, 0.6, curve: Curves.fastOutSlowIn),
-      secondCurve: new Interval(0.4, 1.0, curve: Curves.fastOutSlowIn),
+      firstCurve: const Interval(0.0, 0.6, curve: Curves.fastOutSlowIn),
+      secondCurve: const Interval(0.4, 1.0, curve: Curves.fastOutSlowIn),
       sizeCurve: Curves.fastOutSlowIn,
       crossFadeState: isExpanded ? CrossFadeState.showSecond : CrossFadeState.showFirst,
       duration: const Duration(milliseconds: 200),
@@ -118,7 +118,7 @@ class CollapsibleBody extends StatelessWidget {
                 margin: const EdgeInsets.only(right: 8.0),
                 child: new FlatButton(
                   onPressed: onCancel,
-                  child: new Text('CANCEL', style: new TextStyle(
+                  child: const Text('CANCEL', style: const TextStyle(
                     color: Colors.black54,
                     fontSize: 15.0,
                     fontWeight: FontWeight.w500
@@ -130,7 +130,7 @@ class CollapsibleBody extends StatelessWidget {
                 child: new FlatButton(
                   onPressed: onSave,
                   textTheme: ButtonTextTheme.accent,
-                  child: new Text('SAVE')
+                  child: const Text('SAVE')
                 )
               )
             ]
@@ -254,7 +254,7 @@ class _ExpansionPanelsDemoState extends State<ExpasionPanelsDemo> {
                                 groupValue: field.value,
                                 onChanged: field.onChanged,
                               ),
-                              new Text('Bahamas')
+                              const Text('Bahamas')
                             ]
                           ),
                           new Row(
@@ -265,7 +265,7 @@ class _ExpansionPanelsDemoState extends State<ExpasionPanelsDemo> {
                                 groupValue: field.value,
                                 onChanged: field.onChanged,
                               ),
-                              new Text('Barbados')
+                              const Text('Barbados')
                             ]
                           ),
                           new Row(
@@ -276,7 +276,7 @@ class _ExpansionPanelsDemoState extends State<ExpasionPanelsDemo> {
                                 groupValue: field.value,
                                 onChanged: field.onChanged,
                               ),
-                              new Text('Bermuda')
+                              const Text('Bermuda')
                             ]
                           )
                         ]
@@ -334,7 +334,7 @@ class _ExpansionPanelsDemoState extends State<ExpasionPanelsDemo> {
   @override
   Widget build(BuildContext context) {
     return new Scaffold(
-      appBar: new AppBar(title: new Text('Expansion panels')),
+      appBar: new AppBar(title: const Text('Expansion panels')),
       body: new SingleChildScrollView(
         child: new Container(
           margin: const EdgeInsets.all(24.0),

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

@@ -57,7 +57,7 @@ class DateTimeItem extends StatelessWidget {
                   mainAxisAlignment: MainAxisAlignment.spaceBetween,
                   children: <Widget>[
                     new Text(new DateFormat('EEE, MMM d yyyy').format(date)),
-                    new Icon(Icons.arrow_drop_down, color: Colors.black54),
+                    const Icon(Icons.arrow_drop_down, color: Colors.black54),
                   ]
                 )
               )
@@ -82,7 +82,7 @@ class DateTimeItem extends StatelessWidget {
               child: new Row(
                 children: <Widget>[
                   new Text('$time'),
-                  new Icon(Icons.arrow_drop_down, color: Colors.black54),
+                  const Icon(Icons.arrow_drop_down, color: Colors.black54),
                 ]
               )
             )
@@ -122,11 +122,11 @@ class FullScreenDialogDemoState extends State<FullScreenDialogDemo> {
         ),
         actions: <Widget>[
           new FlatButton(
-            child: new Text('CANCEL'),
+            child: const Text('CANCEL'),
             onPressed: () { Navigator.pop(context, DismissDialogAction.cancel); }
           ),
           new FlatButton(
-            child: new Text('DISCARD'),
+            child: const Text('DISCARD'),
             onPressed: () {
               Navigator.of(context)
                 ..pop(DismissDialogAction.discard) // pop the cancel/discard dialog
@@ -145,10 +145,10 @@ class FullScreenDialogDemoState extends State<FullScreenDialogDemo> {
     return new Scaffold(
       appBar: new AppBar(
         leading: new IconButton(
-          icon: new Icon(Icons.clear),
+          icon: const Icon(Icons.clear),
           onPressed: () { handleDismissButton(context); }
         ),
-        title: new Text('New event'),
+        title: const Text('New event'),
         actions: <Widget> [
           new FlatButton(
             child: new Text('SAVE', style: theme.textTheme.body1.copyWith(color: Colors.white)),
@@ -222,7 +222,7 @@ class FullScreenDialogDemoState extends State<FullScreenDialogDemo> {
                     });
                   }
                 ),
-                new Text('All-day')
+                const Text('All-day')
               ]
             )
           )

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

@@ -316,22 +316,22 @@ class GridListDemoState extends State<GridListDemo> {
     final Orientation orientation = MediaQuery.of(context).orientation;
     return new Scaffold(
       appBar: new AppBar(
-        title: new Text('Grid list'),
+        title: const Text('Grid list'),
         actions: <Widget>[
           new PopupMenuButton<GridDemoTileStyle>(
             onSelected: changeTileStyle,
             itemBuilder: (BuildContext context) => <PopupMenuItem<GridDemoTileStyle>>[
               new PopupMenuItem<GridDemoTileStyle>(
                 value: GridDemoTileStyle.imageOnly,
-                child: new Text('Image only'),
+                child: const Text('Image only'),
               ),
               new PopupMenuItem<GridDemoTileStyle>(
                 value: GridDemoTileStyle.oneLine,
-                child: new Text('One line'),
+                child: const Text('One line'),
               ),
               new PopupMenuItem<GridDemoTileStyle>(
                 value: GridDemoTileStyle.twoLine,
-                child: new Text('Two line'),
+                child: const Text('Two line'),
               ),
             ],
           ),

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

@@ -71,7 +71,7 @@ class IconsDemoState extends State<IconsDemo> {
 
     return new Scaffold(
       appBar: new AppBar(
-        title: new Text('Icons')
+        title: const Text('Icons')
       ),
       body: new IconTheme(
         data: new IconThemeData(opacity: iconOpacity),

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

@@ -104,13 +104,13 @@ class LeaveBehindDemoState extends State<LeaveBehindDemo> {
       background: new Container(
         color: theme.primaryColor,
         child: new ListTile(
-          leading: new Icon(Icons.delete, color: Colors.white, size: 36.0)
+          leading: const Icon(Icons.delete, color: Colors.white, size: 36.0)
         )
       ),
       secondaryBackground: new Container(
         color: theme.primaryColor,
         child: new ListTile(
-          trailing: new Icon(Icons.archive, color: Colors.white, size: 36.0)
+          trailing: const Icon(Icons.archive, color: Colors.white, size: 36.0)
         )
       ),
       child: new Container(
@@ -132,30 +132,30 @@ class LeaveBehindDemoState extends State<LeaveBehindDemo> {
     return new Scaffold(
       key: _scaffoldKey,
       appBar: new AppBar(
-        title: new Text('Swipe to dismiss'),
+        title: const Text('Swipe to dismiss'),
         actions: <Widget>[
           new PopupMenuButton<LeaveBehindDemoAction>(
             onSelected: handleDemoAction,
             itemBuilder: (BuildContext context) => <PopupMenuEntry<LeaveBehindDemoAction>>[
               new PopupMenuItem<LeaveBehindDemoAction>(
                 value: LeaveBehindDemoAction.reset,
-                child: new Text('Reset the list')
+                child: const Text('Reset the list')
               ),
               new PopupMenuDivider(), // ignore: list_element_type_not_assignable, https://github.com/flutter/flutter/issues/5771
               new CheckedPopupMenuItem<LeaveBehindDemoAction>(
                 value: LeaveBehindDemoAction.horizontalSwipe,
                 checked: _dismissDirection == DismissDirection.horizontal,
-                child: new Text('Hoizontal swipe')
+                child: const Text('Hoizontal swipe')
               ),
               new CheckedPopupMenuItem<LeaveBehindDemoAction>(
                 value: LeaveBehindDemoAction.leftSwipe,
                 checked: _dismissDirection == DismissDirection.endToStart,
-                child: new Text('Only swipe left')
+                child: const Text('Only swipe left')
               ),
               new CheckedPopupMenuItem<LeaveBehindDemoAction>(
                 value: LeaveBehindDemoAction.rightSwipe,
                 checked: _dismissDirection == DismissDirection.startToEnd,
-                child: new Text('Only swipe right')
+                child: const Text('Only swipe right')
               )
             ]
           )

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

@@ -37,15 +37,15 @@ class _ListDemoState extends State<ListDemo> {
   void _showConfigurationSheet() {
     final PersistentBottomSheetController<Null> bottomSheet = scaffoldKey.currentState.showBottomSheet((BuildContext bottomSheetContext) {
       return new Container(
-        decoration: new BoxDecoration(
-          border: new Border(top: new BorderSide(color: Colors.black26)),
+        decoration: const BoxDecoration(
+          border: const Border(top: const BorderSide(color: Colors.black26)),
         ),
         child: new ListView(
           shrinkWrap: true,
           children: <Widget>[
             new ListTile(
               dense: true,
-              title: new Text('One-line'),
+              title: const Text('One-line'),
               trailing: new Radio<MaterialListType>(
                 value: _showAvatars ? MaterialListType.oneLineWithAvatar : MaterialListType.oneLine,
                 groupValue: _itemType,
@@ -54,7 +54,7 @@ class _ListDemoState extends State<ListDemo> {
             ),
             new ListTile(
               dense: true,
-              title: new Text('Two-line'),
+              title: const Text('Two-line'),
               trailing: new Radio<MaterialListType>(
                 value: MaterialListType.twoLine,
                 groupValue: _itemType,
@@ -63,7 +63,7 @@ class _ListDemoState extends State<ListDemo> {
             ),
             new ListTile(
               dense: true,
-              title: new Text('Three-line'),
+              title: const Text('Three-line'),
               trailing: new Radio<MaterialListType>(
                 value: MaterialListType.threeLine,
                 groupValue: _itemType,
@@ -72,7 +72,7 @@ class _ListDemoState extends State<ListDemo> {
             ),
             new ListTile(
               dense: true,
-              title: new Text('Show avatar'),
+              title: const Text('Show avatar'),
               trailing: new Checkbox(
                 value: _showAvatars,
                 onChanged: (bool value) {
@@ -85,7 +85,7 @@ class _ListDemoState extends State<ListDemo> {
             ),
             new ListTile(
               dense: true,
-              title: new Text('Show icon'),
+              title: const Text('Show icon'),
               trailing: new Checkbox(
                 value: _showIcons,
                 onChanged: (bool value) {
@@ -98,7 +98,7 @@ class _ListDemoState extends State<ListDemo> {
             ),
             new ListTile(
               dense: true,
-              title: new Text('Show dividers'),
+              title: const Text('Show dividers'),
               trailing: new Checkbox(
                 value: _showDividers,
                 onChanged: (bool value) {
@@ -111,7 +111,7 @@ class _ListDemoState extends State<ListDemo> {
             ),
             new ListTile(
               dense: true,
-              title: new Text('Dense layout'),
+              title: const Text('Dense layout'),
               trailing: new Checkbox(
                 value: _dense,
                 onChanged: (bool value) {
@@ -143,9 +143,9 @@ class _ListDemoState extends State<ListDemo> {
   Widget buildListTile(BuildContext context, String item) {
     Widget secondary;
     if (_itemType == MaterialListType.twoLine) {
-      secondary = new Text("Additional item information.");
+      secondary = const Text("Additional item information.");
     } else if (_itemType == MaterialListType.threeLine) {
-      secondary = new Text(
+      secondary = const Text(
         "Even more additional list item information appears on line three.",
       );
     }
@@ -186,7 +186,7 @@ class _ListDemoState extends State<ListDemo> {
         title: new Text('Scrolling list\n$itemTypeText$layoutText'),
         actions: <Widget>[
           new IconButton(
-            icon: new Icon(Icons.sort_by_alpha),
+            icon: const Icon(Icons.sort_by_alpha),
             tooltip: 'Sort',
             onPressed: () {
               setState(() {
@@ -196,7 +196,7 @@ class _ListDemoState extends State<ListDemo> {
             },
           ),
           new IconButton(
-            icon: new Icon(Icons.more_vert),
+            icon: const Icon(Icons.more_vert),
             tooltip: 'Show menu',
             onPressed: _bottomSheet == null ? _showConfigurationSheet : null,
           ),

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

@@ -62,22 +62,22 @@ class MenuDemoState extends State<MenuDemo> {
     return new Scaffold(
       key: _scaffoldKey,
       appBar: new AppBar(
-        title: new Text('Menus'),
+        title: const Text('Menus'),
         actions: <Widget>[
           new PopupMenuButton<String>(
             onSelected: showMenuSelection,
             itemBuilder: (BuildContext context) => <PopupMenuItem<String>>[
               new PopupMenuItem<String>(
                 value: 'Toolbar menu',
-                child: new Text('Toolbar menu')
+                child: const Text('Toolbar menu')
               ),
               new PopupMenuItem<String>(
                 value: 'Right here',
-                child: new Text('Right here')
+                child: const Text('Right here')
               ),
               new PopupMenuItem<String>(
                 value: 'Hooray!',
-                child: new Text('Hooray!')
+                child: const Text('Hooray!')
               ),
             ]
           )
@@ -90,22 +90,22 @@ class MenuDemoState extends State<MenuDemo> {
           // a simple menu with one disabled item. Typically the contents
           // of this "contextual menu" would reflect the app's state.
           new ListTile(
-            title: new Text('An item with a context menu button'),
+            title: const Text('An item with a context menu button'),
             trailing: new PopupMenuButton<String>(
               padding: EdgeInsets.zero,
               onSelected: showMenuSelection,
               itemBuilder: (BuildContext context) => <PopupMenuItem<String>>[
                 new PopupMenuItem<String>(
                   value: _simpleValue1,
-                  child: new Text('Context menu item one')
+                  child: const Text('Context menu item one')
                 ),
                 new PopupMenuItem<String>(
                   enabled: false,
-                  child: new Text('A disabled menu item')
+                  child: const Text('A disabled menu item')
                 ),
                 new PopupMenuItem<String>(
                   value: _simpleValue3,
-                  child: new Text('Context menu item three')
+                  child: const Text('Context menu item three')
                 ),
               ]
             )
@@ -114,7 +114,7 @@ class MenuDemoState extends State<MenuDemo> {
           // a menu whose items have text labels and icons and a divider
           // That separates the first three items from the last one.
           new ListTile(
-            title: new Text('An item with a sectioned menu'),
+            title: const Text('An item with a sectioned menu'),
             trailing: new PopupMenuButton<String>(
               padding: EdgeInsets.zero,
               onSelected: showMenuSelection,
@@ -122,30 +122,30 @@ class MenuDemoState extends State<MenuDemo> {
                 new PopupMenuItem<String>(
                   value: 'Preview',
                   child: new ListTile(
-                    leading: new Icon(Icons.visibility),
-                    title: new Text('Preview')
+                    leading: const Icon(Icons.visibility),
+                    title: const Text('Preview')
                   )
                 ),
                 new PopupMenuItem<String>(
                   value: 'Share',
                   child: new ListTile(
-                    leading: new Icon(Icons.person_add),
-                    title: new Text('Share')
+                    leading: const Icon(Icons.person_add),
+                    title: const Text('Share')
                   )
                 ),
                 new PopupMenuItem<String>(
                   value: 'Get Link',
                   child: new ListTile(
-                    leading: new Icon(Icons.link),
-                    title: new Text('Get link')
+                    leading: const Icon(Icons.link),
+                    title: const Text('Get link')
                   )
                 ),
                 new PopupMenuDivider(), // ignore: list_element_type_not_assignable, https://github.com/flutter/flutter/issues/5771
                 new PopupMenuItem<String>(
                   value: 'Remove',
                   child: new ListTile(
-                    leading: new Icon(Icons.delete),
-                    title: new Text('Remove')
+                    leading: const Icon(Icons.delete),
+                    title: const Text('Remove')
                   )
                 )
               ]
@@ -159,7 +159,7 @@ class MenuDemoState extends State<MenuDemo> {
             initialValue: _simpleValue,
             onSelected: showMenuSelection,
             child: new ListTile(
-              title: new Text('An item with a simple menu'),
+              title: const Text('An item with a simple menu'),
               subtitle: new Text(_simpleValue)
             ),
             itemBuilder: (BuildContext context) => <PopupMenuItem<String>>[
@@ -180,7 +180,7 @@ class MenuDemoState extends State<MenuDemo> {
           // Pressing the PopupMenuButton on the right of this item shows a menu
           // whose items have checked icons that reflect this app's state.
           new ListTile(
-            title: new Text('An item with a checklist menu'),
+            title: const Text('An item with a checklist menu'),
             trailing: new PopupMenuButton<String>(
               padding: EdgeInsets.zero,
               onSelected: showCheckedMenuSelections,

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

@@ -10,10 +10,10 @@ class ModalBottomSheetDemo extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return new Scaffold(
-      appBar: new AppBar(title: new Text('Modal bottom sheet')),
+      appBar: new AppBar(title: const Text('Modal bottom sheet')),
       body: new Center(
         child: new RaisedButton(
-          child: new Text('SHOW BOTTOM SHEET'),
+          child: const Text('SHOW BOTTOM SHEET'),
           onPressed: () {
             showModalBottomSheet<Null>(context: context, builder: (BuildContext context) {
               return new Container(

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

@@ -29,7 +29,7 @@ class OverscrollDemoState extends State<OverscrollDemo> {
     new Timer(const Duration(seconds: 3), () { completer.complete(null); });
     return completer.future.then((_) {
        _scaffoldKey.currentState?.showSnackBar(new SnackBar(
-         content: new Text("Refresh complete"),
+         content: const Text("Refresh complete"),
          action: new SnackBarAction(
            label: 'RETRY',
            onPressed: () {
@@ -45,10 +45,10 @@ class OverscrollDemoState extends State<OverscrollDemo> {
     return new Scaffold(
       key: _scaffoldKey,
       appBar: new AppBar(
-        title: new Text('Pull to refresh'),
+        title: const Text('Pull to refresh'),
         actions: <Widget>[
           new IconButton(
-            icon: new Icon(Icons.refresh),
+            icon: const Icon(Icons.refresh),
             tooltip: 'Refresh',
             onPressed: () {
               _refreshIndicatorKey.currentState.show();
@@ -68,7 +68,7 @@ class OverscrollDemoState extends State<OverscrollDemo> {
               isThreeLine: true,
               leading: new CircleAvatar(child: new Text(item)),
               title: new Text('This item represents $item.'),
-              subtitle: new Text('Even more additional list item information appears on line three.'),
+              subtitle: const Text('Even more additional list item information appears on line three.'),
             );
           },
         ),

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

@@ -26,14 +26,14 @@ class _PageSelector extends StatelessWidget {
           child: new Row(
             children: <Widget>[
               new IconButton(
-                icon: new Icon(Icons.chevron_left),
+                icon: const Icon(Icons.chevron_left),
                 color: color,
                 onPressed: () { _handleArrowButtonPress(context, -1); },
                 tooltip: 'Page back'
               ),
               new TabPageSelector(controller: controller),
               new IconButton(
-                icon: new Icon(Icons.chevron_right),
+                icon: const Icon(Icons.chevron_right),
                 color: color,
                 onPressed: () { _handleArrowButtonPress(context, 1); },
                 tooltip: 'Page forward'
@@ -76,7 +76,7 @@ class PageSelectorDemo extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return new Scaffold(
-      appBar: new AppBar(title: new Text('Page selector')),
+      appBar: new AppBar(title: const Text('Page selector')),
       body: new DefaultTabController(
         length: icons.length,
         child: new _PageSelector(icons: icons),

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

@@ -57,11 +57,11 @@ class _PersistentBottomSheetDemoState extends State<PersistentBottomSheetDemo> {
     showDialog<Null>(
       context: context,
       child: new AlertDialog(
-        content: new Text('You tapped the floating action button.'),
+        content: const Text('You tapped the floating action button.'),
         actions: <Widget>[
           new FlatButton(
             onPressed: () { Navigator.pop(context); },
-            child: new Text('OK')
+            child: const Text('OK')
           )
         ]
       )
@@ -72,16 +72,16 @@ class _PersistentBottomSheetDemoState extends State<PersistentBottomSheetDemo> {
   Widget build(BuildContext context) {
     return new Scaffold(
       key: _scaffoldKey,
-      appBar: new AppBar(title: new Text('Persistent bottom sheet')),
+      appBar: new AppBar(title: const Text('Persistent bottom sheet')),
       floatingActionButton: new FloatingActionButton(
         onPressed: _showMessage,
         backgroundColor: Colors.redAccent,
-        child: new Icon(Icons.add)
+        child: const Icon(Icons.add)
       ),
       body: new Center(
         child: new RaisedButton(
           onPressed: _showBottomSheetCallback,
-          child: new Text('SHOW BOTTOM SHEET')
+          child: const Text('SHOW BOTTOM SHEET')
         )
       )
     );

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

@@ -25,7 +25,7 @@ class _ProgressIndicatorDemoState extends State<ProgressIndicatorDemo> with Sing
 
     _animation = new CurvedAnimation(
       parent: _controller,
-      curve: new Interval(0.0, 0.9, curve: Curves.fastOutSlowIn),
+      curve: const Interval(0.0, 0.9, curve: Curves.fastOutSlowIn),
       reverseCurve: Curves.fastOutSlowIn
     )..addStatusListener((AnimationStatus status) {
       if (status == AnimationStatus.dismissed)
@@ -99,7 +99,7 @@ class _ProgressIndicatorDemoState extends State<ProgressIndicatorDemo> with Sing
   @override
   Widget build(BuildContext context) {
     return new Scaffold(
-      appBar: new AppBar(title: new Text('Progress indicators')),
+      appBar: new AppBar(title: const Text('Progress indicators')),
       body: new Center(
         child: new SingleChildScrollView(
           child: new DefaultTextStyle(

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

@@ -59,22 +59,22 @@ class ScrollableTabsDemoState extends State<ScrollableTabsDemo> with SingleTicke
     final Color iconColor = Theme.of(context).accentColor;
     return new Scaffold(
       appBar: new AppBar(
-        title: new Text('Scrollable tabs'),
+        title: const Text('Scrollable tabs'),
         actions: <Widget>[
           new PopupMenuButton<TabsDemoStyle>(
             onSelected: changeDemoStyle,
             itemBuilder: (BuildContext context) => <PopupMenuItem<TabsDemoStyle>>[
               new PopupMenuItem<TabsDemoStyle>(
                 value: TabsDemoStyle.iconsAndText,
-                child: new Text('Icons and text')
+                child: const Text('Icons and text')
               ),
               new PopupMenuItem<TabsDemoStyle>(
                 value: TabsDemoStyle.iconsOnly,
-                child: new Text('Icons only')
+                child: const Text('Icons only')
               ),
               new PopupMenuItem<TabsDemoStyle>(
                 value: TabsDemoStyle.textOnly,
-                child: new Text('Text only')
+                child: const Text('Text only')
               ),
             ],
           ),

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

@@ -18,7 +18,7 @@ class _SliderDemoState extends State<SliderDemo> {
   @override
   Widget build(BuildContext context) {
     return new Scaffold(
-      appBar: new AppBar(title: new Text('Sliders')),
+      appBar: new AppBar(title: const Text('Sliders')),
       body: new Center(
         child: new Column(
           mainAxisAlignment: MainAxisAlignment.spaceAround,
@@ -37,14 +37,14 @@ class _SliderDemoState extends State<SliderDemo> {
                     });
                   }
                 ),
-                new Text('Continuous'),
+                const Text('Continuous'),
               ]
             ),
             new Column(
               mainAxisSize: MainAxisSize.min,
               children: <Widget> [
                 new Slider(value: 0.25, thumbOpenAtMin: true, onChanged: null),
-                new Text('Disabled'),
+                const Text('Disabled'),
               ]
             ),
             new Column(
@@ -63,7 +63,7 @@ class _SliderDemoState extends State<SliderDemo> {
                     });
                   }
                 ),
-                new Text('Discrete'),
+                const Text('Discrete'),
               ],
             ),
           ],

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

@@ -32,11 +32,11 @@ class _SnackBarDemoState extends State<SnackBarDemo> {
     return new ListView(
       padding: const EdgeInsets.all(24.0),
       children: <Widget>[
-        new Text(_text1),
-        new Text(_text2),
+        const Text(_text1),
+        const Text(_text2),
         new Center(
           child: new RaisedButton(
-            child: new Text('SHOW A SNACKBAR'),
+            child: const Text('SHOW A SNACKBAR'),
             onPressed: () {
               final int thisSnackBarIndex = _snackBarIndex++;
               Scaffold.of(context).showSnackBar(new SnackBar(
@@ -53,7 +53,7 @@ class _SnackBarDemoState extends State<SnackBarDemo> {
             }
           )
         ),
-        new Text(_text3),
+        const Text(_text3),
       ]
       .map((Widget child) {
         return new Container(
@@ -69,7 +69,7 @@ class _SnackBarDemoState extends State<SnackBarDemo> {
   Widget build(BuildContext context) {
     return new Scaffold(
       appBar: new AppBar(
-        title: new Text('Snackbar')
+        title: const Text('Snackbar')
       ),
       body: new Builder(
         // Create an inner BuildContext so that the snackBar onPressed methods

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

@@ -120,7 +120,7 @@ class TabsDemo extends StatelessWidget {
       length: _allPages.length,
       child: new Scaffold(
         appBar: new AppBar(
-          title: new Text('Tabs and scrolling'),
+          title: const Text('Tabs and scrolling'),
           bottom: new TabBar(
             tabs: _allPages.keys.map((_Page page) => new Tab(text: page.label)).toList(),
           ),

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

@@ -106,7 +106,7 @@ class _TabsFabDemoState extends State<TabsFabDemo> with SingleTickerProviderStat
     return new Scaffold(
       key: _scaffoldKey,
       appBar: new AppBar(
-        title: new Text('FAB per tab'),
+        title: const Text('FAB per tab'),
         bottom: new TabBar(
           controller: _controller,
           tabs: _allPages.map((_Page page) => new Tab(text: page.label.toUpperCase())).toList(),

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

@@ -83,15 +83,15 @@ class TextFormFieldDemoState extends State<TextFormFieldDemo> {
     return await showDialog<bool>(
       context: context,
       child: new AlertDialog(
-        title: new Text('This form has errors'),
-        content: new Text('Really leave this form?'),
+        title: const Text('This form has errors'),
+        content: const Text('Really leave this form?'),
         actions: <Widget> [
           new FlatButton(
-            child: new Text('YES'),
+            child: const Text('YES'),
             onPressed: () { Navigator.of(context).pop(true); },
           ),
           new FlatButton(
-            child: new Text('NO'),
+            child: const Text('NO'),
             onPressed: () { Navigator.of(context).pop(false); },
           ),
         ],
@@ -104,7 +104,7 @@ class TextFormFieldDemoState extends State<TextFormFieldDemo> {
     return new Scaffold(
       key: _scaffoldKey,
       appBar: new AppBar(
-        title: new Text('Text fields'),
+        title: const Text('Text fields'),
       ),
       body: new Form(
         key: _formKey,
@@ -170,7 +170,7 @@ class TextFormFieldDemoState extends State<TextFormFieldDemo> {
               padding: const EdgeInsets.all(20.0),
               alignment: const FractionalOffset(0.5, 0.5),
               child: new RaisedButton(
-                child: new Text('SUBMIT'),
+                child: const Text('SUBMIT'),
                 onPressed: _handleSubmitted,
               ),
             ),

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

@@ -18,7 +18,7 @@ class TooltipDemo extends StatelessWidget {
     final ThemeData theme = Theme.of(context);
     return new Scaffold(
       appBar: new AppBar(
-        title: new Text('Tooltips')
+        title: const Text('Tooltips')
       ),
       body: new Builder(
         builder: (BuildContext context) {
@@ -42,12 +42,12 @@ class TooltipDemo extends StatelessWidget {
               new Center(
                 child: new IconButton(
                   iconSize: 48.0,
-                  icon: new Icon(Icons.call),
+                  icon: const Icon(Icons.call),
                   color: theme.iconTheme.color,
                   tooltip: 'Place a phone call',
                   onPressed: () {
                     Scaffold.of(context).showSnackBar(new SnackBar(
-                       content: new Text('That was an ordinary tap.')
+                       content: const Text('That was an ordinary tap.')
                     ));
                   }
                 )

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

@@ -10,23 +10,23 @@ class TwoLevelListDemo extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return new Scaffold(
-      appBar: new AppBar(title: new Text('Expand/collapse list control')),
+      appBar: new AppBar(title: const Text('Expand/collapse list control')),
       body: new TwoLevelList(
         type: MaterialListType.oneLine,
         children: <Widget>[
-          new TwoLevelListItem(title: new Text('Top')),
+          new TwoLevelListItem(title: const Text('Top')),
           new TwoLevelSublist(
-             title: new Text('Sublist'),
+             title: const Text('Sublist'),
              backgroundColor: Theme.of(context).accentColor.withOpacity(0.025),
              children: <Widget>[
-               new TwoLevelListItem(title: new Text('One')),
-               new TwoLevelListItem(title: new Text('Two')),
+               new TwoLevelListItem(title: const Text('One')),
+               new TwoLevelListItem(title: const Text('Two')),
                // https://en.wikipedia.org/wiki/Free_Four
-               new TwoLevelListItem(title: new Text('Free')),
-               new TwoLevelListItem(title: new Text('Four'))
+               new TwoLevelListItem(title: const Text('Free')),
+               new TwoLevelListItem(title: const Text('Four'))
              ]
           ),
-           new TwoLevelListItem(title: new Text('Bottom'))
+           new TwoLevelListItem(title: const Text('Bottom'))
         ]
       )
     );

examples/flutter_gallery/lib/demo/pesto_demo.dart

@@ -82,10 +82,10 @@ class _RecipeGridPageState extends State<RecipeGridPage> {
       child: new Scaffold(
         key: scaffoldKey,
         floatingActionButton: new FloatingActionButton(
-          child: new Icon(Icons.edit),
+          child: const Icon(Icons.edit),
           onPressed: () {
             scaffoldKey.currentState.showSnackBar(new SnackBar(
-              content: new Text('Not supported.'),
+              content: const Text('Not supported.'),
             ));
           },
         ),
@@ -105,11 +105,11 @@ class _RecipeGridPageState extends State<RecipeGridPage> {
       expandedHeight: _kAppBarHeight,
       actions: <Widget>[
         new IconButton(
-          icon: new Icon(Icons.search),
+          icon: const Icon(Icons.search),
           tooltip: 'Search',
           onPressed: () {
             scaffoldKey.currentState.showSnackBar(new SnackBar(
-              content: new Text('Not supported.'),
+              content: const Text('Not supported.'),
             ));
           },
         ),

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

@@ -181,7 +181,7 @@ class _Heading extends StatelessWidget {
               ),
               new LayoutId(
                 id: _HeadingLayout.icon,
-                child: new Icon(
+                child: const Icon(
                   Icons.info_outline,
                   size: 24.0,
                   color: const Color(0xFFFFE0E0),
@@ -275,7 +275,7 @@ class _OrderPageState extends State<OrderPage> {
           );
         },
         backgroundColor: const Color(0xFF16F0F0),
-        child: new Icon(
+        child: const Icon(
           Icons.add_shopping_cart,
           color: Colors.black,
         ),

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

@@ -54,9 +54,9 @@ class ShrinePageState extends State<ShrinePage> {
   void _showShoppingCart() {
     showModalBottomSheet<Null>(context: context, builder: (BuildContext context) {
       if (config.shoppingCart.isEmpty) {
-        return new Padding(
+        return const Padding(
           padding: const EdgeInsets.all(24.0),
-          child: new Text('The shopping cart is empty')
+          child: const Text('The shopping cart is empty')
         );
       }
       return new ListView(
@@ -82,7 +82,7 @@ class ShrinePageState extends State<ShrinePage> {
 
   void _emptyCart() {
     config.shoppingCart.clear();
-    config.scaffoldKey.currentState.showSnackBar(new SnackBar(content: new Text('Shopping cart is empty')));
+    config.scaffoldKey.currentState.showSnackBar(new SnackBar(content: const Text('Shopping cart is empty')));
   }
 
   @override
@@ -107,7 +107,7 @@ class ShrinePageState extends State<ShrinePage> {
         ),
         actions: <Widget>[
           new IconButton(
-            icon: new Icon(Icons.shopping_cart),
+            icon: const Icon(Icons.shopping_cart),
             tooltip: 'Shopping cart',
             onPressed: _showShoppingCart
           ),
@@ -115,15 +115,15 @@ class ShrinePageState extends State<ShrinePage> {
             itemBuilder: (BuildContext context) => <PopupMenuItem<ShrineAction>>[
               new PopupMenuItem<ShrineAction>(
                 value: ShrineAction.sortByPrice,
-                child: new Text('Sort by price')
+                child: const Text('Sort by price')
               ),
               new PopupMenuItem<ShrineAction>(
                 value: ShrineAction.sortByProduct,
-                child: new Text('Sort by product')
+                child: const Text('Sort by product')
               ),
               new PopupMenuItem<ShrineAction>(
                 value: ShrineAction.emptyCart,
-                child: new Text('Empty shopping cart')
+                child: const Text('Empty shopping cart')
               )
             ],
             onSelected: (ShrineAction action) {

examples/flutter_gallery/lib/demo/typography_demo.dart

@@ -71,7 +71,7 @@ class TypographyDemo extends StatelessWidget {
     }
 
     return new Scaffold(
-      appBar: new AppBar(title: new Text('Typography')),
+      appBar: new AppBar(title: const Text('Typography')),
       body: new ListView(children: styleItems)
     );
   }

examples/flutter_gallery/lib/gallery/demo.dart

@@ -61,7 +61,7 @@ class TabbedComponentDemoScaffold extends StatelessWidget {
             new Builder(
               builder: (BuildContext context) {
                 return new IconButton(
-                  icon: new Icon(Icons.description),
+                  icon: const Icon(Icons.description),
                   tooltip: 'Show example code',
                   onPressed: () {
                     _showExampleCode(context);
@@ -150,10 +150,10 @@ class FullScreenCodeDialogState extends State<FullScreenCodeDialog> {
     return new Scaffold(
       appBar: new AppBar(
         leading: new IconButton(
-          icon: new Icon(Icons.clear),
+          icon: const Icon(Icons.clear),
           onPressed: () { Navigator.pop(context); }
         ),
-        title: new Text('Example code')
+        title: const Text('Example code')
       ),
       body: body
     );

examples/flutter_gallery/lib/gallery/drawer.dart

@@ -127,8 +127,8 @@ class GalleryDrawer extends StatelessWidget {
     final TextStyle linkStyle = themeData.textTheme.body2.copyWith(color: themeData.accentColor);
 
     final Widget lightThemeItem = new ListTile(
-      leading: new Icon(Icons.brightness_5),
-      title: new Text('Light'),
+      leading: const Icon(Icons.brightness_5),
+      title: const Text('Light'),
       trailing: new Radio<bool>(
         value: true,
         groupValue: useLightTheme,
@@ -141,8 +141,8 @@ class GalleryDrawer extends StatelessWidget {
     );
 
     final Widget darkThemeItem = new ListTile(
-      leading: new Icon(Icons.brightness_7),
-      title: new Text('Dark'),
+      leading: const Icon(Icons.brightness_7),
+      title: const Text('Dark'),
       trailing: new Radio<bool>(
         value: false,
         groupValue: useLightTheme,
@@ -157,7 +157,7 @@ class GalleryDrawer extends StatelessWidget {
     final Widget mountainViewItem = new ListTile(
       // on iOS, we don't want to show an Android phone icon
       leading: new Icon(defaultTargetPlatform == TargetPlatform.iOS ? Icons.star : Icons.phone_android),
-      title: new Text('Android'),
+      title: const Text('Android'),
       trailing: new Radio<TargetPlatform>(
         value: TargetPlatform.android,
         groupValue: Theme.of(context).platform,
@@ -172,7 +172,7 @@ class GalleryDrawer extends StatelessWidget {
     final Widget cupertinoItem = new ListTile(
       // on iOS, we don't want to show the iPhone icon
       leading: new Icon(defaultTargetPlatform == TargetPlatform.iOS ? Icons.star_border : Icons.phone_iphone),
-      title: new Text('iOS'),
+      title: const Text('iOS'),
       trailing: new Radio<TargetPlatform>(
         value: TargetPlatform.iOS,
         groupValue: Theme.of(context).platform,
@@ -185,8 +185,8 @@ class GalleryDrawer extends StatelessWidget {
     );
 
     final Widget animateSlowlyItem = new ListTile(
-      leading: new Icon(Icons.hourglass_empty),
-      title: new Text('Animate Slowly'),
+      leading: const Icon(Icons.hourglass_empty),
+      title: const Text('Animate Slowly'),
       trailing: new Checkbox(
         value: timeDilation != 1.0,
         onChanged: (bool value) {
@@ -200,8 +200,8 @@ class GalleryDrawer extends StatelessWidget {
     );
 
     final Widget sendFeedbackItem = new ListTile(
-      leading: new Icon(Icons.report),
-      title: new Text('Send feedback'),
+      leading: const Icon(Icons.report),
+      title: const Text('Send feedback'),
       onTap: onSendFeedback ?? () {
         UrlLauncher.launch('https://github.com/flutter/flutter/issues/new');
       },
@@ -266,8 +266,8 @@ class GalleryDrawer extends StatelessWidget {
 
     if (onShowPerformanceOverlayChanged != null) {
       allDrawerItems.insert(8, new ListTile(
-        leading: new Icon(Icons.assessment),
-        title: new Text('Performance Overlay'),
+        leading: const Icon(Icons.assessment),
+        title: const Text('Performance Overlay'),
         trailing: new Checkbox(
           value: showPerformanceOverlay,
           onChanged: (bool value) {
@@ -283,8 +283,8 @@ class GalleryDrawer extends StatelessWidget {
 
     if (onCheckerboardRasterCacheImagesChanged != null) {
       allDrawerItems.insert(8, new ListTile(
-        leading: new Icon(Icons.assessment),
-        title: new Text('Checkerboard Raster Cache Images'),
+        leading: const Icon(Icons.assessment),
+        title: const Text('Checkerboard Raster Cache Images'),
         trailing: new Checkbox(
           value: checkerboardRasterCacheImages,
           onChanged: (bool value) {

examples/flutter_gallery/lib/gallery/example_code.dart

@@ -16,7 +16,7 @@ class ButtonsDemo {
 // START buttons_raised
 // Create a raised button.
 new RaisedButton(
-  child: new Text('BUTTON TITLE'),
+  child: const Text('BUTTON TITLE'),
   onPressed: () {
     // Perform some action
   }
@@ -26,7 +26,7 @@ new RaisedButton(
 // Buttons are disabled when onPressed isn't
 // specified or is null.
 new RaisedButton(
-  child: new Text('BUTTON TITLE'),
+  child: const Text('BUTTON TITLE'),
   onPressed: null
 );
 // END
@@ -35,7 +35,7 @@ new RaisedButton(
 // START buttons_flat
 // Create a flat button.
 new FlatButton(
-  child: new Text('BUTTON TITLE'),
+  child: const Text('BUTTON TITLE'),
   onPressed: () {
     // Perform some action
   }
@@ -45,7 +45,7 @@ new FlatButton(
 // Buttons are disabled when onPressed isn't
 // specified or is null.
 new FlatButton(
-  child: new Text('BUTTON TITLE'),
+  child: const Text('BUTTON TITLE'),
   onPressed: null
 );
 // END
@@ -83,7 +83,7 @@ bool value;
 
 // Toggleable icon button.
 new IconButton(
-  icon: new Icon(Icons.thumb_up),
+  icon: const Icon(Icons.thumb_up),
   onPressed: () {
     setState(() => value = !value);
   },
@@ -96,10 +96,10 @@ new IconButton(
 // Floating action button in Scaffold.
 new Scaffold(
   appBar: new AppBar(
-    title: new Text('Demo')
+    title: const Text('Demo')
   ),
-  floatingActionButton: new FloatingActionButton(
-    child: new Icon(Icons.add),
+  floatingActionButton: const FloatingActionButton(
+    child: const Icon(Icons.add),
     onPressed: null
   )
 );

examples/flutter_gallery/lib/gallery/home.dart

@@ -170,7 +170,7 @@ class GalleryHomeState extends State<GalleryHome> with SingleTickerProviderState
             pinned: true,
             expandedHeight: _kFlexibleSpaceMaxHeight,
             flexibleSpace: new FlexibleSpaceBar(
-              title: new Text('Flutter Gallery'),
+              title: const Text('Flutter Gallery'),
               // TODO(abarth): Wire up to the parallax in a way that doesn't pop during hero transition.
               background: new _AppBarBackground(animation: kAlwaysDismissedAnimation),
             ),
@@ -194,7 +194,7 @@ class GalleryHomeState extends State<GalleryHome> with SingleTickerProviderState
           home,
           new FadeTransition(
             opacity: new CurvedAnimation(parent: _controller, curve: Curves.easeInOut),
-            child: new Banner(
+            child: const Banner(
               message: 'PREVIEW',
               location: BannerLocation.topRight,
             )

examples/flutter_gallery/lib/gallery/updates.dart

@@ -51,16 +51,16 @@ class UpdaterState extends State<Updater> {
     final TextStyle dialogTextStyle =
         theme.textTheme.subhead.copyWith(color: theme.textTheme.caption.color);
     return new AlertDialog(
-      title: new Text('Update Flutter Gallery?'),
+      title: const Text('Update Flutter Gallery?'),
       content: new Text('A newer version is available.', style: dialogTextStyle),
       actions: <Widget>[
         new FlatButton(
-            child: new Text('NO THANKS'),
+            child: const Text('NO THANKS'),
             onPressed: () {
               Navigator.pop(context, false);
             }),
         new FlatButton(
-            child: new Text('UPDATE'),
+            child: const Text('UPDATE'),
             onPressed: () {
               Navigator.pop(context, true);
             }),

examples/flutter_view/lib/main.dart

@@ -61,7 +61,7 @@ class _MyHomePageState extends State<MyHomePage> {
             child: new Center(
               child: new Text(
                 'Platform button tapped $_counter time${ _counter == 1 ? '' : 's' }.',
-                style: new TextStyle(fontSize: 17.0))
+                style: const TextStyle(fontSize: 17.0))
             ),
           ),
           new Container(
@@ -69,7 +69,7 @@ class _MyHomePageState extends State<MyHomePage> {
             child: new Row(
               children: <Widget>[
                 new Image.asset('assets/flutter-mark-square-64.png', scale: 1.5),
-                new Text('Flutter', style: new TextStyle(fontSize: 30.0)),
+                const Text('Flutter', style: const TextStyle(fontSize: 30.0)),
               ],
             ),
           ),
@@ -77,7 +77,7 @@ class _MyHomePageState extends State<MyHomePage> {
       ),
       floatingActionButton: new FloatingActionButton(
         onPressed: _sendFlutterIncrement,
-        child: new Icon(Icons.add),
+        child: const Icon(Icons.add),
       ),
     );
   }

examples/hello_world/lib/main.dart

@@ -4,4 +4,4 @@
 
 import 'package:flutter/widgets.dart';
 
-void main() => runApp(new Center(child: new Text('Hello, world!')));
+void main() => runApp(const Center(child: const Text('Hello, world!')));

examples/layers/rendering/touch_input.dart

@@ -102,8 +102,8 @@ class RenderDots extends RenderBox {
 void main() {
   // Create some styled text to tell the user to interact with the app.
   final RenderParagraph paragraph = new RenderParagraph(
-    new TextSpan(
-      style: new TextStyle(color: Colors.black87),
+    const TextSpan(
+      style: const TextStyle(color: Colors.black87),
       text: "Touch me!"
     )
   );

examples/layers/services/lifecycle.dart

@@ -35,7 +35,7 @@ class _LifecycleWatcherState extends State<LifecycleWatcher>
   @override
   Widget build(BuildContext context) {
     if (_lastLifecyleState == null)
-      return new Text('This widget has not observed any lifecycle changes.');
+      return const Text('This widget has not observed any lifecycle changes.');
     return new Text('The most recent lifecycle state this widget observed was: $_lastLifecyleState.');
   }
 }

examples/layers/widgets/custom_render_box.dart

@@ -46,5 +46,5 @@ class Dots extends SingleChildRenderObjectWidget {
 }
 
 void main() {
-  runApp(new Dots(child: new Center(child: new Text('Touch me!'))));
+  runApp(new Dots(child: const Center(child: const Text('Touch me!'))));
 }

examples/layers/widgets/gestures.dart

@@ -188,7 +188,7 @@ class _GestureDemoState extends State<GestureDemo> {
                         value: _scaleEnabled,
                         onChanged: (bool value) { setState(() { _scaleEnabled = value; }); }
                       ),
-                      new Text('Scale'),
+                      const Text('Scale'),
                     ]
                   ),
                   new Row(
@@ -197,7 +197,7 @@ class _GestureDemoState extends State<GestureDemo> {
                         value: _tapEnabled,
                         onChanged: (bool value) { setState(() { _tapEnabled = value; }); }
                       ),
-                      new Text('Tap'),
+                      const Text('Tap'),
                     ]
                   ),
                   new Row(
@@ -206,7 +206,7 @@ class _GestureDemoState extends State<GestureDemo> {
                         value: _doubleTapEnabled,
                         onChanged: (bool value) { setState(() { _doubleTapEnabled = value; }); }
                       ),
-                      new Text('Double Tap'),
+                      const Text('Double Tap'),
                     ]
                   ),
                   new Row(
@@ -215,7 +215,7 @@ class _GestureDemoState extends State<GestureDemo> {
                         value: _longPressEnabled,
                         onChanged: (bool value) { setState(() { _longPressEnabled = value; }); }
                       ),
-                      new Text('Long Press'),
+                      const Text('Long Press'),
                     ]
                   ),
                 ],
@@ -233,7 +233,7 @@ void main() {
   runApp(new MaterialApp(
     theme: new ThemeData.dark(),
     home: new Scaffold(
-      appBar: new AppBar(title: new Text('Gestures Demo')),
+      appBar: new AppBar(title: const Text('Gestures Demo')),
       body: new GestureDemo()
     )
   ));

examples/layers/widgets/hello_world.dart

@@ -4,4 +4,4 @@
 
 import 'package:flutter/widgets.dart';
 
-void main() => runApp(new Center(child: new Text('Hello, world!')));
+void main() => runApp(const Center(child: const Text('Hello, world!')));

examples/layers/widgets/media_query.dart

@@ -51,8 +51,8 @@ class AdaptedGridItem extends StatelessWidget {
                 new Expanded(
                   child: new Text(name)
                 ),
-                new IconButton(
-                  icon: new Icon(Icons.more_vert),
+                const IconButton(
+                  icon: const Icon(Icons.more_vert),
                   onPressed: null
                 )
               ]
@@ -103,7 +103,7 @@ void main() {
     title: 'Media Query Example',
     home: new Scaffold(
       appBar: new AppBar(
-        title: new Text('Media Query Example')
+        title: const Text('Media Query Example')
       ),
       body: new Material(child: new AdaptiveContainer(names: _kNames))
     )

examples/layers/widgets/sectors.dart

@@ -106,7 +106,7 @@ class SectorAppState extends State<SectorApp> {
                         margin: const EdgeInsets.only(right: 10.0),
                         child: new WidgetToRenderBoxAdapter(renderBox: sectorAddIcon)
                       ),
-                      new Text('ADD SECTOR'),
+                      const Text('ADD SECTOR'),
                     ]
                   )
                 )
@@ -121,7 +121,7 @@ class SectorAppState extends State<SectorApp> {
                         margin: const EdgeInsets.only(right: 10.0),
                         child: new WidgetToRenderBoxAdapter(renderBox: sectorRemoveIcon)
                       ),
-                      new Text('REMOVE SECTOR'),
+                      const Text('REMOVE SECTOR'),
                     ]
                   )
                 )
@@ -155,7 +155,7 @@ class SectorAppState extends State<SectorApp> {
       title: 'Sector Layout',
       home: new Scaffold(
         appBar: new AppBar(
-          title: new Text('Sector Layout in a Widget Tree')
+          title: const Text('Sector Layout in a Widget Tree')
         ),
         body: buildBody()
       )

examples/layers/widgets/spinning_mixed.dart

@@ -52,7 +52,7 @@ void attachWidgetTreeToRenderTree(RenderProxyBox container) {
                     child: new Row(
                       children: <Widget>[
                         new Image.network('https://flutter.io/images/favicon.png'),
-                        new Text('PRESS ME'),
+                        const Text('PRESS ME'),
                       ]
                     ),
                     onPressed: () {

examples/layers/widgets/styled_text.dart

@@ -124,7 +124,7 @@ void main() {
     theme: new ThemeData.light(),
     home: new Scaffold(
       appBar: new AppBar(
-        title: new Text('Hal and Dave')
+        title: const Text('Hal and Dave')
       ),
       body: new Material(
         color: Colors.grey.shade50,

examples/platform_channel/lib/main.dart

@@ -62,11 +62,11 @@ class _PlatformChannelState extends State<PlatformChannel> {
           new Column(
             mainAxisAlignment: MainAxisAlignment.center,
             children: <Widget>[
-              new Text(_batteryLevel, key: new Key('Battery level label')),
+              new Text(_batteryLevel, key: const Key('Battery level label')),
               new Padding(
-                padding: new EdgeInsets.all(16.0),
+                padding: const EdgeInsets.all(16.0),
                 child: new RaisedButton(
-                  child: new Text('Refresh'),
+                  child: const Text('Refresh'),
                   onPressed: _getBatteryLevel,
                 ),
               ),

examples/platform_channel_swift/lib/main.dart

@@ -37,10 +37,10 @@ class _PlatformChannelState extends State<PlatformChannel> {
           mainAxisAlignment: MainAxisAlignment.spaceEvenly,
           children: <Widget>[
             new RaisedButton(
-              child: new Text('Get Battery Level'),
+              child: const Text('Get Battery Level'),
               onPressed: _getBatteryLevel,
             ),
-            new Text(_batteryLevel, key: new Key('Battery level label')),
+            new Text(_batteryLevel, key: const Key('Battery level label')),
           ],
         ),
       ),

examples/stocks/lib/stock_home.dart

@@ -20,21 +20,21 @@ class _NotImplementedDialog extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return new AlertDialog(
-      title: new Text('Not Implemented'),
-      content: new Text('This feature has not yet been implemented.'),
+      title: const Text('Not Implemented'),
+      content: const Text('This feature has not yet been implemented.'),
       actions: <Widget>[
         new FlatButton(
           onPressed: debugDumpApp,
           child: new Row(
             children: <Widget>[
-              new Icon(
+              const Icon(
                 Icons.dvr,
                 size: 18.0,
               ),
               new Container(
                 width: 8.0,
               ),
-              new Text('DUMP APP TO CONSOLE'),
+              const Text('DUMP APP TO CONSOLE'),
             ],
           ),
         ),
@@ -42,7 +42,7 @@ class _NotImplementedDialog extends StatelessWidget {
           onPressed: () {
             Navigator.pop(context, false);
           },
-          child: new Text('OH WELL'),
+          child: const Text('OH WELL'),
         ),
       ],
     );
@@ -117,20 +117,20 @@ class StockHomeState extends State<StockHome> {
     return new Drawer(
       child: new ListView(
         children: <Widget>[
-          new DrawerHeader(child: new Center(child: new Text('Stocks'))),
+          const DrawerHeader(child: const Center(child: const Text('Stocks'))),
           new ListTile(
-            leading: new Icon(Icons.assessment),
-            title: new Text('Stock List'),
+            leading: const Icon(Icons.assessment),
+            title: const Text('Stock List'),
             selected: true,
           ),
           new ListTile(
-            leading: new Icon(Icons.account_balance),
-            title: new Text('Account Balance'),
+            leading: const Icon(Icons.account_balance),
+            title: const Text('Account Balance'),
             enabled: false,
           ),
           new ListTile(
-            leading: new Icon(Icons.dvr),
-            title: new Text('Dump App to Console'),
+            leading: const Icon(Icons.dvr),
+            title: const Text('Dump App to Console'),
             onTap: () {
               try {
                 debugDumpApp();
@@ -144,8 +144,8 @@ class StockHomeState extends State<StockHome> {
           ),
           new Divider(),
           new ListTile(
-            leading: new Icon(Icons.thumb_up),
-            title: new Text('Optimistic'),
+            leading: const Icon(Icons.thumb_up),
+            title: const Text('Optimistic'),
             trailing: new Radio<StockMode>(
               value: StockMode.optimistic,
               groupValue: config.configuration.stockMode,
@@ -156,8 +156,8 @@ class StockHomeState extends State<StockHome> {
             },
           ),
           new ListTile(
-            leading: new Icon(Icons.thumb_down),
-            title: new Text('Pessimistic'),
+            leading: const Icon(Icons.thumb_down),
+            title: const Text('Pessimistic'),
             trailing: new Radio<StockMode>(
               value: StockMode.pessimistic,
               groupValue: config.configuration.stockMode,
@@ -169,13 +169,13 @@ class StockHomeState extends State<StockHome> {
           ),
           new Divider(),
           new ListTile(
-            leading: new Icon(Icons.settings),
-            title: new Text('Settings'),
+            leading: const Icon(Icons.settings),
+            title: const Text('Settings'),
             onTap: _handleShowSettings,
           ),
           new ListTile(
-            leading: new Icon(Icons.help),
-            title: new Text('About'),
+            leading: const Icon(Icons.help),
+            title: const Text('About'),
             onTap: _handleShowAbout,
           ),
         ],
@@ -197,7 +197,7 @@ class StockHomeState extends State<StockHome> {
       title: new Text(StockStrings.of(context).title()),
       actions: <Widget>[
         new IconButton(
-          icon: new Icon(Icons.search),
+          icon: const Icon(Icons.search),
           onPressed: _handleSearchBegin,
           tooltip: 'Search',
         ),
@@ -207,19 +207,19 @@ class StockHomeState extends State<StockHome> {
             new CheckedPopupMenuItem<_StockMenuItem>(
               value: _StockMenuItem.autorefresh,
               checked: _autorefresh,
-              child: new Text('Autorefresh'),
+              child: const Text('Autorefresh'),
             ),
             new PopupMenuItem<_StockMenuItem>(
               value: _StockMenuItem.refresh,
-              child: new Text('Refresh'),
+              child: const Text('Refresh'),
             ),
             new PopupMenuItem<_StockMenuItem>(
               value: _StockMenuItem.speedUp,
-              child: new Text('Increase animation speed'),
+              child: const Text('Increase animation speed'),
             ),
             new PopupMenuItem<_StockMenuItem>(
               value: _StockMenuItem.speedDown,
-              child: new Text('Decrease animation speed'),
+              child: const Text('Decrease animation speed'),
             ),
           ],
         ),
@@ -287,7 +287,7 @@ class StockHomeState extends State<StockHome> {
   Widget buildSearchBar() {
     return new AppBar(
       leading: new IconButton(
-        icon: new Icon(Icons.arrow_back),
+        icon: const Icon(Icons.arrow_back),
         color: Theme.of(context).accentColor,
         onPressed: _handleSearchEnd,
         tooltip: 'Back',
@@ -313,7 +313,7 @@ class StockHomeState extends State<StockHome> {
   Widget buildFloatingActionButton() {
     return new FloatingActionButton(
       tooltip: 'Create company',
-      child: new Icon(Icons.add),
+      child: const Icon(Icons.add),
       backgroundColor: Colors.redAccent,
       onPressed: _handleCreateCompany,
     );

examples/stocks/lib/stock_settings.dart

@@ -68,17 +68,17 @@ class StockSettingsState extends State<StockSettings> {
         showDialog<bool>(
           context: context,
           child: new AlertDialog(
-            title: new Text("Change mode?"),
-            content: new Text("Optimistic mode means everything is awesome. Are you sure you can handle that?"),
+            title: const Text("Change mode?"),
+            content: const Text("Optimistic mode means everything is awesome. Are you sure you can handle that?"),
             actions: <Widget>[
               new FlatButton(
-                child: new Text('NO THANKS'),
+                child: const Text('NO THANKS'),
                 onPressed: () {
                   Navigator.pop(context, false);
                 }
               ),
               new FlatButton(
-                child: new Text('AGREE'),
+                child: const Text('AGREE'),
                 onPressed: () {
                   Navigator.pop(context, true);
                 }
@@ -97,15 +97,15 @@ class StockSettingsState extends State<StockSettings> {
 
   Widget buildAppBar(BuildContext context) {
     return new AppBar(
-      title: new Text('Settings')
+      title: const Text('Settings')
     );
   }
 
   Widget buildSettingsPane(BuildContext context) {
     final List<Widget> rows = <Widget>[
       new ListTile(
-        leading: new Icon(Icons.thumb_up),
-        title: new Text('Everything is awesome'),
+        leading: const Icon(Icons.thumb_up),
+        title: const Text('Everything is awesome'),
         onTap: _confirmOptimismChange,
         trailing: new Checkbox(
           value: config.configuration.stockMode == StockMode.optimistic,
@@ -113,8 +113,8 @@ class StockSettingsState extends State<StockSettings> {
         ),
       ),
       new ListTile(
-        leading: new Icon(Icons.backup),
-        title: new Text('Back up stock list to the cloud'),
+        leading: const Icon(Icons.backup),
+        title: const Text('Back up stock list to the cloud'),
         onTap: () { _handleBackupChanged(!(config.configuration.backupMode == BackupMode.enabled)); },
         trailing: new Switch(
           value: config.configuration.backupMode == BackupMode.enabled,
@@ -122,8 +122,8 @@ class StockSettingsState extends State<StockSettings> {
         ),
       ),
       new ListTile(
-        leading: new Icon(Icons.picture_in_picture),
-        title: new Text('Show rendering performance overlay'),
+        leading: const Icon(Icons.picture_in_picture),
+        title: const Text('Show rendering performance overlay'),
         onTap: () { _handleShowPerformanceOverlayChanged(!config.configuration.showPerformanceOverlay); },
         trailing: new Switch(
           value: config.configuration.showPerformanceOverlay,
@@ -131,8 +131,8 @@ class StockSettingsState extends State<StockSettings> {
         ),
       ),
       new ListTile(
-        leading: new Icon(Icons.accessibility),
-        title: new Text('Show semantics overlay'),
+        leading: const Icon(Icons.accessibility),
+        title: const Text('Show semantics overlay'),
         onTap: () { _handleShowSemanticsDebuggerChanged(!config.configuration.showSemanticsDebugger); },
         trailing: new Switch(
           value: config.configuration.showSemanticsDebugger,
@@ -144,8 +144,8 @@ class StockSettingsState extends State<StockSettings> {
       // material grid and size construction lines are only available in checked mode
       rows.addAll(<Widget>[
         new ListTile(
-          leading: new Icon(Icons.border_clear),
-          title: new Text('Show material grid (for debugging)'),
+          leading: const Icon(Icons.border_clear),
+          title: const Text('Show material grid (for debugging)'),
           onTap: () { _handleShowGridChanged(!config.configuration.debugShowGrid); },
           trailing: new Switch(
             value: config.configuration.debugShowGrid,
@@ -153,8 +153,8 @@ class StockSettingsState extends State<StockSettings> {
           ),
         ),
         new ListTile(
-          leading: new Icon(Icons.border_all),
-          title: new Text('Show construction lines (for debugging)'),
+          leading: const Icon(Icons.border_all),
+          title: const Text('Show construction lines (for debugging)'),
           onTap: () { _handleShowSizesChanged(!config.configuration.debugShowSizes); },
           trailing: new Switch(
             value: config.configuration.debugShowSizes,
@@ -162,8 +162,8 @@ class StockSettingsState extends State<StockSettings> {
           ),
         ),
         new ListTile(
-          leading: new Icon(Icons.format_color_text),
-          title: new Text('Show baselines (for debugging)'),
+          leading: const Icon(Icons.format_color_text),
+          title: const Text('Show baselines (for debugging)'),
           onTap: () { _handleShowBaselinesChanged(!config.configuration.debugShowBaselines); },
           trailing: new Switch(
             value: config.configuration.debugShowBaselines,
@@ -171,8 +171,8 @@ class StockSettingsState extends State<StockSettings> {
           ),
         ),
         new ListTile(
-          leading: new Icon(Icons.filter_none),
-          title: new Text('Show layer boundaries (for debugging)'),
+          leading: const Icon(Icons.filter_none),
+          title: const Text('Show layer boundaries (for debugging)'),
           onTap: () { _handleShowLayersChanged(!config.configuration.debugShowLayers); },
           trailing: new Switch(
             value: config.configuration.debugShowLayers,
@@ -180,8 +180,8 @@ class StockSettingsState extends State<StockSettings> {
           ),
         ),
         new ListTile(
-          leading: new Icon(Icons.mouse),
-          title: new Text('Show pointer hit-testing (for debugging)'),
+          leading: const Icon(Icons.mouse),
+          title: const Text('Show pointer hit-testing (for debugging)'),
           onTap: () { _handleShowPointersChanged(!config.configuration.debugShowPointers); },
           trailing: new Switch(
             value: config.configuration.debugShowPointers,
@@ -189,8 +189,8 @@ class StockSettingsState extends State<StockSettings> {
           ),
         ),
         new ListTile(
-          leading: new Icon(Icons.gradient),
-          title: new Text('Show repaint rainbow (for debugging)'),
+          leading: const Icon(Icons.gradient),
+          title: const Text('Show repaint rainbow (for debugging)'),
           onTap: () { _handleShowRainbowChanged(!config.configuration.debugShowRainbow); },
           trailing: new Switch(
             value: config.configuration.debugShowRainbow,

examples/stocks/lib/stock_symbol_viewer.dart

@@ -100,8 +100,8 @@ class StockSymbolBottomSheet extends StatelessWidget {
   Widget build(BuildContext context) {
     return new Container(
       padding: const EdgeInsets.all(10.0),
-      decoration: new BoxDecoration(
-        border: new Border(top: new BorderSide(color: Colors.black26))
+      decoration: const BoxDecoration(
+        border: const Border(top: const BorderSide(color: Colors.black26))
       ),
       child: new _StockSymbolView(
         stock: stock,

packages/flutter/lib/src/material/about.dart

@@ -290,7 +290,7 @@ class AboutDialog extends StatelessWidget {
       ),
       actions: <Widget>[
         new FlatButton(
-          child: new Text('VIEW LICENSES'),
+          child: const Text('VIEW LICENSES'),
           onPressed: () {
             showLicensePage(
               context: context,
@@ -302,7 +302,7 @@ class AboutDialog extends StatelessWidget {
           }
         ),
         new FlatButton(
-          child: new Text('CLOSE'),
+          child: const Text('CLOSE'),
           onPressed: () {
             Navigator.pop(context);
           }
@@ -377,9 +377,9 @@ class _LicensePageState extends State<LicensePage> {
       if (!mounted)
         return;
       setState(() {
-        _licenses.add(new Padding(
+        _licenses.add(const Padding(
           padding: const EdgeInsets.symmetric(vertical: 18.0),
-          child: new Text(
+          child: const Text(
             '🍀‬', // That's U+1F340. Could also use U+2766 (❦) if U+1F340 doesn't work everywhere.
             textAlign: TextAlign.center
           )
@@ -443,7 +443,7 @@ class _LicensePageState extends State<LicensePage> {
     }
     return new Scaffold(
       appBar: new AppBar(
-        title: new Text('Licenses')
+        title: const Text('Licenses')
       ),
       body: new DefaultTextStyle(
         style: Theme.of(context).textTheme.caption,

packages/flutter/lib/src/material/data_table.dart

@@ -450,7 +450,7 @@ class DataTable extends StatelessWidget {
   }) {
     final bool isLightTheme = Theme.of(context).brightness == Brightness.light;
     if (showEditIcon) {
-      final Widget icon = new Icon(Icons.edit, size: 18.0);
+      final Widget icon = const Icon(Icons.edit, size: 18.0);
       label = new Expanded(child: label);
       label = new Row(children: numeric ? <Widget>[ icon, label ] : <Widget>[ label, icon ]);
     }
@@ -523,7 +523,7 @@ class DataTable extends StatelessWidget {
 
     int displayColumnIndex = 0;
     if (showCheckboxColumn) {
-      tableColumns[0] = new FixedColumnWidth(_kTablePadding + Checkbox.width + _kTablePadding / 2.0);
+      tableColumns[0] = const FixedColumnWidth(_kTablePadding + Checkbox.width + _kTablePadding / 2.0);
       tableRows[0].children[0] = _buildCheckbox(
         color: theme.accentColor,
         checked: allChecked,

packages/flutter/lib/src/material/date_picker.dart

@@ -677,11 +677,11 @@ class _DatePickerDialogState extends State<_DatePickerDialog> {
       child: new ButtonBar(
         children: <Widget>[
           new FlatButton(
-            child: new Text('CANCEL'),
+            child: const Text('CANCEL'),
             onPressed: _handleCancel,
           ),
           new FlatButton(
-            child: new Text('OK'),
+            child: const Text('OK'),
             onPressed: _handleOk,
           ),
         ],

packages/flutter/lib/src/material/expand_icon.dart

@@ -107,7 +107,7 @@ class _ExpandIconState extends State<ExpandIcon> with SingleTickerProviderStateM
       onPressed: config.onPressed == null ? null : _handlePressed,
       icon: new RotationTransition(
         turns: _iconTurns,
-        child: new Icon(Icons.expand_more)
+        child: const Icon(Icons.expand_more)
       )
     );
   }

packages/flutter/lib/src/material/input_decorator.dart

@@ -305,7 +305,7 @@ class InputDecorator extends StatelessWidget {
 
     if (decoration.hideDivider) {
       return new Container(
-        margin: margin + new EdgeInsets.only(bottom: bottomBorder),
+        margin: margin + const EdgeInsets.only(bottom: bottomBorder),
         padding: padding,
         child: child,
       );

packages/flutter/lib/src/material/list_tile.dart

@@ -106,7 +106,7 @@ class ListTileTheme extends InheritedWidget {
   /// ```
   static ListTileTheme of(BuildContext context) {
     final ListTileTheme result = context.inheritFromWidgetOfExactType(ListTileTheme);
-    return result ?? new ListTileTheme();
+    return result ?? const ListTileTheme();
   }
 
   @override

packages/flutter/lib/src/material/paginated_data_table.dart

@@ -298,7 +298,7 @@ class PaginatedDataTableState extends State<PaginatedDataTable> {
       }
     } else if (_selectedRowCount == 1) {
       // TODO(ianh): Real l10n.
-      headerWidgets.add(new Expanded(child: new Text('1 item selected')));
+      headerWidgets.add(const Expanded(child: const Text('1 item selected')));
     } else {
       headerWidgets.add(new Expanded(child: new Text('$_selectedRowCount items selected')));
     }
@@ -328,7 +328,7 @@ class PaginatedDataTableState extends State<PaginatedDataTable> {
         })
         .toList();
       footerWidgets.addAll(<Widget>[
-        new Text('Rows per page:'),
+        const Text('Rows per page:'),
         new DropdownButtonHideUnderline(
           child: new DropdownButton<int>(
             items: availableRowsPerPage,
@@ -347,7 +347,7 @@ class PaginatedDataTableState extends State<PaginatedDataTable> {
       ),
       new Container(width: 32.0),
       new IconButton(
-        icon: new Icon(Icons.chevron_left),
+        icon: const Icon(Icons.chevron_left),
         padding: EdgeInsets.zero,
         tooltip: 'Previous page',
         onPressed: _firstRowIndex <= 0 ? null : () {
@@ -356,7 +356,7 @@ class PaginatedDataTableState extends State<PaginatedDataTable> {
       ),
       new Container(width: 24.0),
       new IconButton(
-        icon: new Icon(Icons.chevron_right),
+        icon: const Icon(Icons.chevron_right),
         padding: EdgeInsets.zero,
         tooltip: 'Next page',
         onPressed: (!_rowCountApproximate && (_firstRowIndex + config.rowsPerPage >= _rowCount)) ? null : () {

packages/flutter/lib/src/material/popup_menu.dart

@@ -547,7 +547,7 @@ class _PopupMenuButtonState<T> extends State<PopupMenuButton<T>> {
   Widget build(BuildContext context) {
     if (config.child == null) {
       return new IconButton(
-        icon: new Icon(Icons.more_vert),
+        icon: const Icon(Icons.more_vert),
         padding: config.padding,
         tooltip: config.tooltip,
         onPressed: showButtonMenu,

packages/flutter/lib/src/material/stepper.dart

@@ -249,7 +249,7 @@ class _StepperState extends State<Stepper> with TickerProviderStateMixin {
           color: isDarkActive ? _kCircleActiveDark : _kCircleActiveLight,
         );
       case StepState.error:
-        return new Text('!', style: _kStepStyle);
+        return const Text('!', style: _kStepStyle);
     }
     return null;
   }
@@ -351,7 +351,7 @@ class _StepperState extends State<Stepper> with TickerProviderStateMixin {
               color: _isDark() ? themeData.backgroundColor : themeData.primaryColor,
               textColor: Colors.white,
               textTheme: ButtonTextTheme.normal,
-              child: new Text('CONTINUE'),
+              child: const Text('CONTINUE'),
             ),
             new Container(
               margin: const EdgeInsets.only(left: 8.0),
@@ -359,7 +359,7 @@ class _StepperState extends State<Stepper> with TickerProviderStateMixin {
                 onPressed: config.onStepCancel,
                 textColor: cancelColor,
                 textTheme: ButtonTextTheme.normal,
-                child: new Text('CANCEL'),
+                child: const Text('CANCEL'),
               ),
             ),
           ],

packages/flutter/lib/src/material/text_selection.dart

@@ -27,17 +27,17 @@ class _TextSelectionToolbar extends StatelessWidget {
     final List<Widget> items = <Widget>[];
 
     if (!value.selection.isCollapsed) {
-      items.add(new FlatButton(child: new Text('CUT'), onPressed: _handleCut));
-      items.add(new FlatButton(child: new Text('COPY'), onPressed: _handleCopy));
+      items.add(new FlatButton(child: const Text('CUT'), onPressed: _handleCut));
+      items.add(new FlatButton(child: const Text('COPY'), onPressed: _handleCopy));
     }
     items.add(new FlatButton(
-      child: new Text('PASTE'),
+      child: const Text('PASTE'),
       // TODO(mpcomplete): This should probably be grayed-out if there is nothing to paste.
       onPressed: _handlePaste
     ));
     if (value.text.isNotEmpty) {
       if (value.selection.isCollapsed)
-        items.add(new FlatButton(child: new Text('SELECT ALL'), onPressed: _handleSelectAll));
+        items.add(new FlatButton(child: const Text('SELECT ALL'), onPressed: _handleSelectAll));
     }
 
     return new Material(

packages/flutter/lib/src/material/time_picker.dart

@@ -702,11 +702,11 @@ class _TimePickerDialogState extends State<_TimePickerDialog> {
       child: new ButtonBar(
         children: <Widget>[
           new FlatButton(
-            child: new Text('CANCEL'),
+            child: const Text('CANCEL'),
             onPressed: _handleCancel
           ),
           new FlatButton(
-            child: new Text('OK'),
+            child: const Text('OK'),
             onPressed: _handleOk
           ),
         ]

packages/flutter/lib/src/material/two_level_list.dart

@@ -213,7 +213,7 @@ class _TwoLevelSublistState extends State<TwoLevelSublist> with SingleTickerProv
               ),
               trailing: new RotationTransition(
                 turns: _iconTurns,
-                child: new Icon(Icons.expand_more)
+                child: const Icon(Icons.expand_more)
               )
             )
           ),

packages/flutter/lib/src/widgets/container.dart

@@ -21,15 +21,14 @@ class DecoratedBox extends SingleChildRenderObjectWidget {
   ///
   /// The [decoration] and [position] arguments must not be null. By default the
   /// decoration paints behind the child.
-  DecoratedBox({
+  const DecoratedBox({
     Key key,
     @required this.decoration,
     this.position: DecorationPosition.background,
     Widget child
-  }) : super(key: key, child: child) {
-    assert(decoration != null);
-    assert(position != null);
-  }
+  }) : assert(decoration != null),
+       assert(position != null),
+       super(key: key, child: child);
 
   /// What decoration to paint.
   ///

packages/flutter/lib/src/widgets/text.dart

@@ -14,7 +14,7 @@ class DefaultTextStyle extends InheritedWidget {
   ///
   /// Consider using [DefaultTextStyle.merge] to inherit styling information
   /// from the current default text style for a given [BuildContext].
-  DefaultTextStyle({
+  const DefaultTextStyle({
     Key key,
     @required this.style,
     this.textAlign,
@@ -22,12 +22,11 @@ class DefaultTextStyle extends InheritedWidget {
     this.overflow: TextOverflow.clip,
     this.maxLines,
     @required Widget child,
-  }) : super(key: key, child: child) {
-    assert(style != null);
-    assert(softWrap != null);
-    assert(overflow != null);
-    assert(child != null);
-  }
+  }) : assert(style != null),
+       assert(softWrap != null),
+       assert(overflow != null),
+       assert(child != null),
+       super(key: key, child: child);
 
   /// A const-constructible default text style that provides fallback values.
   ///
@@ -140,7 +139,7 @@ class Text extends StatelessWidget {
   ///
   /// If the [style] argument is null, the text will use the style from the
   /// closest enclosing [DefaultTextStyle].
-  Text(this.data, {
+  const Text(this.data, {
     Key key,
     this.style,
     this.textAlign,
@@ -148,9 +147,8 @@ class Text extends StatelessWidget {
     this.overflow,
     this.textScaleFactor,
     this.maxLines,
-  }) : super(key: key) {
-    assert(data != null);
-  }
+  }) : assert(data != null),
+       super(key: key);
 
   /// The text to display.
   final String data;

packages/flutter/test/cupertino/button_test.dart

@@ -16,7 +16,7 @@ void main() {
   testWidgets('Default layout minimum size', (WidgetTester tester) async {
     await tester.pumpWidget(
       new Center(child: new CupertinoButton(
-        child: new Text('X', style: testStyle),
+        child: const Text('X', style: testStyle),
         onPressed: null,
       ))
     );
@@ -32,7 +32,7 @@ void main() {
     final double minSize = 60.0;
     await tester.pumpWidget(
       new Center(child: new CupertinoButton(
-        child: new Text('X', style: testStyle),
+        child: const Text('X', style: testStyle),
         onPressed: null,
         minSize: minSize,
       ))
@@ -48,7 +48,7 @@ void main() {
   testWidgets('Size grows with text', (WidgetTester tester) async {
     await tester.pumpWidget(
       new Center(child: new CupertinoButton(
-        child: new Text('XXXX', style: testStyle),
+        child: const Text('XXXX', style: testStyle),
         onPressed: null,
       ))
     );
@@ -62,7 +62,7 @@ void main() {
 
   testWidgets('Button with background is wider', (WidgetTester tester) async {
     await tester.pumpWidget(new Center(child: new CupertinoButton(
-      child: new Text('X', style: testStyle),
+      child: const Text('X', style: testStyle),
       onPressed: null,
       color: const Color(0xFFFFFFFF),
     )));
@@ -76,7 +76,7 @@ void main() {
 
   testWidgets('Custom padding', (WidgetTester tester) async {
     await tester.pumpWidget(new Center(child: new CupertinoButton(
-      child: new Text(' ', style: testStyle),
+      child: const Text(' ', style: testStyle),
       onPressed: null,
       padding: const EdgeInsets.all(100.0),
     )));
@@ -94,7 +94,7 @@ void main() {
         builder: (BuildContext context, StateSetter setState) {
           return new Center(
             child: new CupertinoButton(
-              child: new Text('Tap me'),
+              child: const Text('Tap me'),
               onPressed: () {
                 setState(() {
                   value = true;
@@ -117,7 +117,7 @@ void main() {
 
   testWidgets('Disabled button doesn\'t animate', (WidgetTester tester) async {
     await tester.pumpWidget(new Center(child: new CupertinoButton(
-      child: new Text('Tap me'),
+      child: const Text('Tap me'),
       onPressed: null,
     )));
     expect(SchedulerBinding.instance.transientCallbackCount, equals(0));
@@ -128,7 +128,7 @@ void main() {
 
   testWidgets('pressedOpacity defaults to 0.1', (WidgetTester tester) async {
     await tester.pumpWidget(new Center(child: new CupertinoButton(
-      child: new Text('Tap me'),
+      child: const Text('Tap me'),
       onPressed: () { },
     )));
 
@@ -149,7 +149,7 @@ void main() {
     final double pressedOpacity = 0.5;
     await tester.pumpWidget(new Center(child: new CupertinoButton(
       pressedOpacity: pressedOpacity,
-      child: new Text('Tap me'),
+      child: const Text('Tap me'),
       onPressed: () { },
     )));
 

packages/flutter/test/cupertino/dialog_test.dart

@@ -20,11 +20,11 @@ void main() {
                   showDialog<Null>(
                     context: context,
                     child: new CupertinoAlertDialog(
-                      title: new Text('The title'),
-                      content: new Text('The content'),
+                      title: const Text('The title'),
+                      content: const Text('The content'),
                       actions: <Widget>[
                         new CupertinoDialogAction(
-                          child: new Text('Cancel'),
+                          child: const Text('Cancel'),
                         ),
                         new CupertinoDialogAction(
                           isDestructive: true,
@@ -32,13 +32,13 @@ void main() {
                             didDelete = true;
                             Navigator.pop(context);
                           },
-                          child: new Text('Delete'),
+                          child: const Text('Delete'),
                         ),
                       ],
                     ),
                   );
                 },
-                child: new Text('Go'),
+                child: const Text('Go'),
               );
             },
           ),
@@ -66,7 +66,7 @@ void main() {
   testWidgets('Dialog action styles', (WidgetTester tester) async {
     await tester.pumpWidget(new CupertinoDialogAction(
       isDestructive: true,
-      child: new Text('Ok'),
+      child: const Text('Ok'),
     ));
 
     final DefaultTextStyle widget = tester.widget(find.byType(DefaultTextStyle));

packages/flutter/test/foundation/error_reporting_test.dart

@@ -199,7 +199,7 @@ Future<Null> main() async {
 
   test('Error reporting - NoSuchMethodError', () async {
     expect(console, isEmpty);
-    FlutterError.dumpErrorToConsole(new FlutterErrorDetails(
+    FlutterError.dumpErrorToConsole(const FlutterErrorDetails(
       exception: 'hello',
     ));
     expect(console.join('\n'), matches(new RegExp(
@@ -209,7 +209,7 @@ Future<Null> main() async {
       '════════════════════════════════════════════════════════════════════════════════════════════════════\$',
     )));
     console.clear();
-    FlutterError.dumpErrorToConsole(new FlutterErrorDetails(
+    FlutterError.dumpErrorToConsole(const FlutterErrorDetails(
       exception: 'hello again',
     ));
     expect(console.join('\n'), 'Another exception was thrown: hello again');

packages/flutter/test/material/about_test.dart

@@ -15,7 +15,7 @@ void main() {
         title: 'Pirate app',
         home: new Scaffold(
           appBar: new AppBar(
-            title: new Text('Home'),
+            title: const Text('Home'),
           ),
           drawer: new Drawer(
             child: new ListView(
@@ -25,7 +25,7 @@ void main() {
                   applicationIcon: const FlutterLogo(),
                   applicationLegalese: 'I am the very model of a modern major general.',
                   aboutBoxChildren: <Widget>[
-                    new Text('About box'),
+                    const Text('About box'),
                   ]
                 ),
               ],
@@ -89,7 +89,7 @@ void main() {
       ]);
     });
 
-    await tester.pumpWidget(new Center(
+    await tester.pumpWidget(const Center(
       child: const LicensePage()
     ));
 

packages/flutter/test/material/app_bar_test.dart

@@ -15,7 +15,7 @@ Widget buildSliverAppBarApp({ bool floating, bool pinned, double expandedHeight
         primary: true,
         slivers: <Widget>[
           new SliverAppBar(
-            title: new Text('AppBar Title'),
+            title: const Text('AppBar Title'),
             floating: floating,
             pinned: pinned,
             expandedHeight: expandedHeight,
@@ -63,7 +63,7 @@ void main() {
         theme: new ThemeData(platform: TargetPlatform.android),
         home: new Scaffold(
           appBar: new AppBar(
-            title: new Text('X'),
+            title: const Text('X'),
           ),
         ),
       ),
@@ -82,7 +82,7 @@ void main() {
         theme: new ThemeData(platform: TargetPlatform.iOS),
         home: new Scaffold(
           appBar: new AppBar(
-            title: new Text('X'),
+            title: const Text('X'),
           ),
         ),
       ),
@@ -101,7 +101,7 @@ void main() {
         home: new Scaffold(
           appBar: new AppBar(
             centerTitle: true,
-            title: new Text('X'),
+            title: const Text('X'),
           )
         )
       )
@@ -121,7 +121,7 @@ void main() {
         home: new Scaffold(
           appBar: new AppBar(
             centerTitle: false,
-            title: new Text('X'),
+            title: const Text('X'),
           ),
         ),
       ),
@@ -138,7 +138,7 @@ void main() {
         home: new Scaffold(
           appBar: new AppBar(
             centerTitle: false,
-            title: new Text('X'),
+            title: const Text('X'),
           ),
           // A drawer causes a leading hamburger.
           drawer: new Drawer(),
@@ -254,9 +254,9 @@ void main() {
       new SizedBox(
         height: kToolbarHeight,
         child: new AppBar(
-          leading: new Text('L'),
-          title: new Text('No Scaffold'),
-          actions: <Widget>[new Text('A1'), new Text('A2')],
+          leading: const Text('L'),
+          title: const Text('No Scaffold'),
+          actions: <Widget>[const Text('A1'), const Text('A2')],
         ),
       ),
     );
@@ -276,7 +276,7 @@ void main() {
           width: 0.0,
           child: new Scaffold(
             appBar: new AppBar(
-              title: new Text('X'),
+              title: const Text('X'),
             ),
           ),
         ),
@@ -325,7 +325,7 @@ void main() {
         theme: new ThemeData(platform: TargetPlatform.android),
         home: new Scaffold(
           appBar: new AppBar(
-            title: new Text('X'),
+            title: const Text('X'),
           ),
           drawer: new Column(), // Doesn't really matter. Triggers a hamburger regardless.
         ),
@@ -343,16 +343,16 @@ void main() {
         theme: new ThemeData(platform: TargetPlatform.android),
         home: new Scaffold(
           appBar: new AppBar(
-            title: new Text('X'),
+            title: const Text('X'),
             actions: <Widget> [
-              new IconButton(
-                icon: new Icon(Icons.share),
+              const IconButton(
+                icon: const Icon(Icons.share),
                 onPressed: null,
                 tooltip: 'Share',
                 iconSize: 20.0,
               ),
-              new IconButton(
-                icon: new Icon(Icons.add),
+              const IconButton(
+                icon: const Icon(Icons.add),
                 onPressed: null,
                 tooltip: 'Add',
                 iconSize: 60.0,

packages/flutter/test/material/app_test.dart

@@ -30,7 +30,7 @@ void main() {
     await tester.pumpWidget(
       new MaterialApp(
         home: new MaterialApp(
-          home: new Text('Home sweet home'),
+          home: const Text('Home sweet home'),
         ),
       ),
     );
@@ -58,7 +58,7 @@ void main() {
       autofocus: true,
       node: focusScopeNode,
       child: new MaterialApp(
-        home: new Text('Home'),
+        home: const Text('Home'),
       ),
     ));
 
@@ -95,7 +95,7 @@ void main() {
           builder: (BuildContext context) {
             return new Material(
               child: new RaisedButton(
-                child: new Text('X'),
+                child: const Text('X'),
                 onPressed: () { Navigator.of(context).pushNamed('/next'); },
               ),
             );
@@ -132,7 +132,7 @@ void main() {
   });
 
   testWidgets('Cannot pop the initial route', (WidgetTester tester) async {
-    await tester.pumpWidget(new MaterialApp(home: new Text('Home')));
+    await tester.pumpWidget(new MaterialApp(home: const Text('Home')));
 
     expect(find.text('Home'), findsOneWidget);
 

packages/flutter/test/material/back_button_test.dart

@@ -9,11 +9,11 @@ void main() {
   testWidgets('BackButton control test', (WidgetTester tester) async {
     await tester.pumpWidget(
       new MaterialApp(
-        home: new Material(child: new Text('Home')),
+        home: new Material(child: const Text('Home')),
         routes: <String, WidgetBuilder>{
           '/next': (BuildContext context) {
             return new Material(
-              child: new Center(
+              child: const Center(
                 child: const BackButton(),
               )
             );

packages/flutter/test/material/bottom_navigation_bar_test.dart

@@ -14,12 +14,12 @@ void main() {
         bottomNavigationBar: new BottomNavigationBar(
           items: <BottomNavigationBarItem>[
             new BottomNavigationBarItem(
-              icon: new Icon(Icons.ac_unit),
-              title: new Text('AC')
+              icon: const Icon(Icons.ac_unit),
+              title: const Text('AC')
             ),
             new BottomNavigationBarItem(
-              icon: new Icon(Icons.access_alarm),
-              title: new Text('Alarm')
+              icon: const Icon(Icons.access_alarm),
+              title: const Text('Alarm')
             )
           ],
           onTap: (int index) {
@@ -40,12 +40,12 @@ void main() {
         bottomNavigationBar: new BottomNavigationBar(
           items: <BottomNavigationBarItem>[
             new BottomNavigationBarItem(
-              icon: new Icon(Icons.ac_unit),
-              title: new Text('AC')
+              icon: const Icon(Icons.ac_unit),
+              title: const Text('AC')
             ),
             new BottomNavigationBarItem(
-              icon: new Icon(Icons.access_alarm),
-              title: new Text('Alarm')
+              icon: const Icon(Icons.access_alarm),
+              title: const Text('Alarm')
             )
           ]
         )
@@ -65,12 +65,12 @@ void main() {
           type: BottomNavigationBarType.shifting,
           items: <BottomNavigationBarItem>[
             new BottomNavigationBarItem(
-              icon: new Icon(Icons.ac_unit),
-              title: new Text('AC')
+              icon: const Icon(Icons.ac_unit),
+              title: const Text('AC')
             ),
             new BottomNavigationBarItem(
-              icon: new Icon(Icons.access_alarm),
-              title: new Text('Alarm')
+              icon: const Icon(Icons.access_alarm),
+              title: const Text('Alarm')
             )
           ]
         )
@@ -89,12 +89,12 @@ void main() {
           type: BottomNavigationBarType.shifting,
           items: <BottomNavigationBarItem>[
             new BottomNavigationBarItem(
-              icon: new Icon(Icons.ac_unit),
-              title: new Text('AC')
+              icon: const Icon(Icons.ac_unit),
+              title: const Text('AC')
             ),
             new BottomNavigationBarItem(
-              icon: new Icon(Icons.access_alarm),
-              title: new Text('Alarm')
+              icon: const Icon(Icons.access_alarm),
+              title: const Text('Alarm')
             )
           ]
         )
@@ -116,20 +116,20 @@ void main() {
           type: BottomNavigationBarType.shifting,
           items: <BottomNavigationBarItem>[
             new BottomNavigationBarItem(
-              icon: new Icon(Icons.ac_unit),
-              title: new Text('AC')
+              icon: const Icon(Icons.ac_unit),
+              title: const Text('AC')
             ),
             new BottomNavigationBarItem(
-              icon: new Icon(Icons.access_alarm),
-              title: new Text('Alarm')
+              icon: const Icon(Icons.access_alarm),
+              title: const Text('Alarm')
             ),
             new BottomNavigationBarItem(
-              icon: new Icon(Icons.access_time),
-              title: new Text('Time')
+              icon: const Icon(Icons.access_time),
+              title: const Text('Time')
             ),
             new BottomNavigationBarItem(
-              icon: new Icon(Icons.add),
-              title: new Text('Add')
+              icon: const Icon(Icons.add),
+              title: const Text('Add')
             )
           ]
         )
@@ -176,20 +176,20 @@ void main() {
                         type: BottomNavigationBarType.shifting,
                         items: <BottomNavigationBarItem>[
                           new BottomNavigationBarItem(
-                              icon: new Icon(Icons.ac_unit),
-                              title: new Text('AC')
+                              icon: const Icon(Icons.ac_unit),
+                              title: const Text('AC')
                           ),
                           new BottomNavigationBarItem(
-                              icon: new Icon(Icons.access_alarm),
-                              title: new Text('Alarm')
+                              icon: const Icon(Icons.access_alarm),
+                              title: const Text('Alarm')
                           ),
                           new BottomNavigationBarItem(
-                              icon: new Icon(Icons.access_time),
-                              title: new Text('Time')
+                              icon: const Icon(Icons.access_time),
+                              title: const Text('Time')
                           ),
                           new BottomNavigationBarItem(
-                              icon: new Icon(Icons.add),
-                              title: new Text('Add')
+                              icon: const Icon(Icons.add),
+                              title: const Text('Add')
                           )
                         ]
                     )
@@ -214,20 +214,20 @@ void main() {
                         type: BottomNavigationBarType.fixed,
                         items: <BottomNavigationBarItem>[
                           new BottomNavigationBarItem(
-                              icon: new Icon(Icons.ac_unit),
-                              title: new Text('AC')
+                              icon: const Icon(Icons.ac_unit),
+                              title: const Text('AC')
                           ),
                           new BottomNavigationBarItem(
-                              icon: new Icon(Icons.access_alarm),
-                              title: new Text('Alarm')
+                              icon: const Icon(Icons.access_alarm),
+                              title: const Text('Alarm')
                           ),
                           new BottomNavigationBarItem(
-                              icon: new Icon(Icons.access_time),
-                              title: new Text('Time')
+                              icon: const Icon(Icons.access_time),
+                              title: const Text('Time')
                           ),
                           new BottomNavigationBarItem(
-                              icon: new Icon(Icons.add),
-                              title: new Text('Add')
+                              icon: const Icon(Icons.add),
+                              title: const Text('Add')
                           )
                         ]
                     )
@@ -249,11 +249,11 @@ void main() {
           iconSize: 12.0,
           items: <BottomNavigationBarItem>[
             new BottomNavigationBarItem(
-              title: new Text('A'),
-              icon: new Icon(Icons.ac_unit),
+              title: const Text('A'),
+              icon: const Icon(Icons.ac_unit),
             ),
             new BottomNavigationBarItem(
-              title: new Text('B'),
+              title: const Text('B'),
               icon: new Builder(
                 builder: (BuildContext context) {
                   builderIconSize = IconTheme.of(context).size;

packages/flutter/test/material/buttons_test.dart

@@ -18,7 +18,7 @@ void main() {
         child: new Center(
           child: new FlatButton(
             onPressed: () { },
-            child: new Text('ABC')
+            child: const Text('ABC')
           )
         )
       )
@@ -43,8 +43,8 @@ void main() {
   });
 
   testWidgets('Does button highlight + splash colors work if set directly', (WidgetTester tester) async {
-    final Color directSplashColor = new Color(0xFF000011);
-    final Color directHighlightColor = new Color(0xFF000011);
+    final Color directSplashColor = const Color(0xFF000011);
+    final Color directHighlightColor = const Color(0xFF000011);
 
     Widget buttonWidget = new Material(
       child: new Center(
@@ -66,7 +66,7 @@ void main() {
     final Point center = tester.getCenter(find.byType(MaterialButton));
     final TestGesture gesture = await tester.startGesture(center);
     await tester.pump(); // start gesture
-    await tester.pump(new Duration(milliseconds: 200)); // wait for splash to be well under way
+    await tester.pump(const Duration(milliseconds: 200)); // wait for splash to be well under way
 
     expect(
       Material.of(tester.element(find.byType(MaterialButton))),
@@ -75,8 +75,8 @@ void main() {
         ..rrect(color: directHighlightColor)
     );
 
-    final Color themeSplashColor1 = new Color(0xFF001100);
-    final Color themeHighlightColor1 = new Color(0xFF001100);
+    final Color themeSplashColor1 = const Color(0xFF001100);
+    final Color themeHighlightColor1 = const Color(0xFF001100);
 
     buttonWidget = new Material(
       child: new Center(
@@ -103,8 +103,8 @@ void main() {
         ..rrect(color: themeHighlightColor1)
     );
 
-    final Color themeSplashColor2 = new Color(0xFF002200);
-    final Color themeHighlightColor2 = new Color(0xFF002200);
+    final Color themeSplashColor2 = const Color(0xFF002200);
+    final Color themeHighlightColor2 = const Color(0xFF002200);
 
     await tester.pumpWidget(
       new Theme(

packages/flutter/test/material/chip_test.dart

@@ -14,9 +14,9 @@ void main() {
           child: new Center(
             child: new Chip(
               avatar: new CircleAvatar(
-                child: new Text('C')
+                child: const Text('C')
               ),
-              label: new Text('Chip'),
+              label: const Text('Chip'),
               onDeleted: () {
                 didDeleteChip = true;
               }

packages/flutter/test/material/circle_avatar_test.dart

@@ -14,7 +14,7 @@ void main() {
         child: new CircleAvatar(
           backgroundColor: backgroundColor,
           radius: 50.0,
-          child: new Text('Z'),
+          child: const Text('Z'),
         ),
       ),
     );
@@ -36,7 +36,7 @@ void main() {
       new Center(
         child: new CircleAvatar(
           foregroundColor: foregroundColor,
-          child: new Text('Z'),
+          child: const Text('Z'),
         ),
       ),
     );
@@ -64,7 +64,7 @@ void main() {
         data: theme,
         child: new Center(
           child: new CircleAvatar(
-            child: new Text('Z'),
+            child: const Text('Z'),
           ),
         ),
       ),

packages/flutter/test/material/colors_test.dart

@@ -11,7 +11,7 @@ const List<int> accentKeys =  const <int>[100, 200, 400, 700];
 
 void main() {
   test('MaterialColor basic functionality', () {
-    final MaterialColor color = new MaterialColor(
+    final MaterialColor color = const MaterialColor(
       500,
       const <int, Color>{
          50: const Color(50),

packages/flutter/test/material/data_table_test.dart

@@ -19,12 +19,12 @@ void main() {
           log.add('select-all: $value');
         },
         columns: <DataColumn>[
-          new DataColumn(
-            label: new Text('Name'),
+          const DataColumn(
+            label: const Text('Name'),
             tooltip: 'Name',
           ),
           new DataColumn(
-            label: new Text('Calories'),
+            label: const Text('Calories'),
             tooltip: 'Calories',
             numeric: true,
             onSort: (int columnIndex, bool ascending) {

packages/flutter/test/material/date_picker_test.dart

@@ -127,7 +127,7 @@ void main() {
               onPressed: () {
                 buttonContext = context;
               },
-              child: new Text('Go'),
+              child: const Text('Go'),
             );
           },
         ),

packages/flutter/test/material/debug_test.dart

@@ -9,7 +9,7 @@ void main() {
   testWidgets('debugCheckHasMaterial control test', (WidgetTester tester) async {
     await tester.pumpWidget(new FlatButton(
       onPressed: null,
-      child: new Text('Go'),
+      child: const Text('Go'),
     ));
     expect(tester.takeException(), isFlutterError);
   });

packages/flutter/test/material/dialog_test.dart

@@ -16,7 +16,7 @@ void main() {
             builder: (BuildContext context) {
               return new Center(
                 child: new RaisedButton(
-                  child: new Text('X'),
+                  child: const Text('X'),
                   onPressed: () {
                     showDialog<Null>(
                       context: context,
@@ -33,7 +33,7 @@ void main() {
                             onPressed: () {
                               didPressOk = true;
                             },
-                            child: new Text('OK')
+                            child: const Text('OK')
                           )
                         ]
                       )
@@ -66,13 +66,13 @@ void main() {
             builder: (BuildContext context) {
               return new Center(
                 child: new RaisedButton(
-                  child: new Text('X'),
+                  child: const Text('X'),
                   onPressed: () {
                     showDialog<Null>(
                       context: context,
                       child: new AlertDialog(
-                        title: new Text('Title'),
-                        content: new Text('Y'),
+                        title: const Text('Title'),
+                        content: const Text('Y'),
                         actions: <Widget>[ ],
                       ),
                     );
@@ -104,7 +104,7 @@ void main() {
           child: new Center(
             child: new RaisedButton(
               onPressed: null,
-              child: new Text('Go'),
+              child: const Text('Go'),
             ),
           ),
         ),
@@ -116,16 +116,16 @@ void main() {
     final Future<int> result = showDialog(
       context: context,
       child: new SimpleDialog(
-        title: new Text('Title'),
+        title: const Text('Title'),
         children: <Widget>[
           new SimpleDialogOption(
             onPressed: () {
               Navigator.pop(context, 42);
             },
-            child: new Text('First option'),
+            child: const Text('First option'),
           ),
           new SimpleDialogOption(
-            child: new Text('Second option'),
+            child: const Text('Second option'),
           ),
         ],
       ),
@@ -145,7 +145,7 @@ void main() {
           child: new Center(
             child: new RaisedButton(
               onPressed: null,
-              child: new Text('Go'),
+              child: const Text('Go'),
             ),
           ),
         ),
@@ -160,7 +160,7 @@ void main() {
         width: 100.0,
         height: 100.0,
         alignment: FractionalOffset.center,
-        child: new Text('Dialog1'),
+        child: const Text('Dialog1'),
       ),
     );
 
@@ -180,7 +180,7 @@ void main() {
         width: 100.0,
         height: 100.0,
         alignment: FractionalOffset.center,
-        child: new Text('Dialog2'),
+        child: const Text('Dialog2'),
       ),
     );