[rename fixit] *Component* -> *Widget*

This patch renames StatelessComponent to StatelessWidget and
StatefulComponent to StatefulWidget.

Fixes #2308

dev/manual_tests/card_collection.dart

@@ -16,7 +16,7 @@ class CardModel {
   Key get key => new ObjectKey(this);
 }
 
-class CardCollection extends StatefulComponent {
+class CardCollection extends StatefulWidget {
   CardCollectionState createState() => new CardCollectionState();
 }
 

dev/manual_tests/drag_and_drop.dart

@@ -6,7 +6,7 @@ import 'dart:math' as math;
 
 import 'package:flutter/material.dart';
 
-class ExampleDragTarget extends StatefulComponent {
+class ExampleDragTarget extends StatefulWidget {
   ExampleDragTargetState createState() => new ExampleDragTargetState();
 }
 
@@ -39,7 +39,7 @@ class ExampleDragTargetState extends State<ExampleDragTarget> {
   }
 }
 
-class Dot extends StatefulComponent {
+class Dot extends StatefulWidget {
   Dot({ Key key, this.color, this.size, this.child, this.tappable: false }) : super(key: key);
   final Color color;
   final double size;
@@ -66,7 +66,7 @@ class DotState extends State<Dot> {
   }
 }
 
-class ExampleDragSource extends StatelessComponent {
+class ExampleDragSource extends StatelessWidget {
   ExampleDragSource({
     Key key,
     this.color,
@@ -162,7 +162,7 @@ class DashOutlineCirclePainter extends CustomPainter {
   bool shouldRepaint(DashOutlineCirclePainter oldPainter) => false;
 }
 
-class MovableBall extends StatelessComponent {
+class MovableBall extends StatelessWidget {
   MovableBall(this.position, this.ballPosition, this.callback);
 
   final int position;
@@ -212,7 +212,7 @@ class MovableBall extends StatelessComponent {
   }
 }
 
-class DragAndDropApp extends StatefulComponent {
+class DragAndDropApp extends StatefulWidget {
   DragAndDropAppState createState() => new DragAndDropAppState();
 }
 

dev/manual_tests/mozart.dart

@@ -32,7 +32,7 @@ enum WindowSide {
   bottomRight,
 }
 
-class WindowDecoration extends StatelessComponent {
+class WindowDecoration extends StatelessWidget {
   WindowDecoration({
     Key key,
     this.side,
@@ -87,7 +87,7 @@ class WindowDecoration extends StatelessComponent {
   }
 }
 
-class Window extends StatefulComponent {
+class Window extends StatefulWidget {
   Window({ Key key, this.child, this.onClose }) : super(key: key);
 
   final ChildViewConnection child;
@@ -155,7 +155,7 @@ class _WindowState extends State<Window> {
   }
 }
 
-class LauncherItem extends StatelessComponent {
+class LauncherItem extends StatelessWidget {
   LauncherItem({
     Key key,
     this.url,
@@ -175,7 +175,7 @@ class LauncherItem extends StatelessComponent {
   }
 }
 
-class Launcher extends StatelessComponent {
+class Launcher extends StatelessWidget {
   Launcher({ Key key, this.items }) : super(key: key);
 
   final List<Widget> items;
@@ -188,7 +188,7 @@ class Launcher extends StatelessComponent {
   }
 }
 
-class WindowManager extends StatefulComponent {
+class WindowManager extends StatefulWidget {
   _WindowManagerState createState() => new _WindowManagerState();
 }
 

dev/manual_tests/overlay_geometry.dart

@@ -52,7 +52,7 @@ class _MarkerPainter extends CustomPainter {
   }
 }
 
-class Marker extends StatelessComponent {
+class Marker extends StatelessWidget {
   Marker({
     this.type: MarkerType.touch,
     this.position,
@@ -82,7 +82,7 @@ class Marker extends StatelessComponent {
   }
 }
 
-class OverlayGeometryApp extends StatefulComponent {
+class OverlayGeometryApp extends StatefulWidget {
   OverlayGeometryAppState createState() => new OverlayGeometryAppState();
 }
 

dev/manual_tests/pageable_list.dart

@@ -13,7 +13,7 @@ class CardModel {
   Key get key => new ObjectKey(this);
 }
 
-class PageableListApp extends StatefulComponent {
+class PageableListApp extends StatefulWidget {
   PageableListAppState createState() => new PageableListAppState();
 }
 

dev/manual_tests/raw_keyboard.dart

@@ -30,7 +30,7 @@ void main() {
   );
 }
 
-class RawKeyboardDemo extends StatefulComponent {
+class RawKeyboardDemo extends StatefulWidget {
   RawKeyboardDemo({ GlobalKey key }) : super(key: key);
 
   _HardwareKeyDemoState createState() => new _HardwareKeyDemoState();

examples/layers/services/media_service.dart

@@ -51,7 +51,7 @@ class PianoKey {
   }
 }
 
-class PianoApp extends StatelessComponent {
+class PianoApp extends StatelessWidget {
   final List<PianoKey> keys = <PianoKey>[
     new PianoKey(Colors.red[500], chimes),
     new PianoKey(Colors.orange[500], chainsaw),

examples/layers/widgets/autolayout.dart

@@ -46,7 +46,7 @@ class _MyAutoLayoutDelegate extends AutoLayoutDelegate {
   bool shouldUpdateConstraints(_MyAutoLayoutDelegate oldDelegate) => true;
 }
 
-class ColoredBoxes extends StatefulComponent {
+class ColoredBoxes extends StatefulWidget {
   _ColoredBoxesState createState() => new _ColoredBoxesState();
 }
 

examples/layers/widgets/gestures.dart

@@ -54,7 +54,7 @@ class _GesturePainter extends CustomPainter {
   }
 }
 
-class GestureDemo extends StatefulComponent {
+class GestureDemo extends StatefulWidget {
   _GestureDemoState createState() => new _GestureDemoState();
 }
 

examples/layers/widgets/media_query.dart

@@ -4,7 +4,7 @@
 
 import 'package:flutter/material.dart';
 
-class AdaptedListItem extends StatelessComponent {
+class AdaptedListItem extends StatelessWidget {
   AdaptedListItem({ Key key, this.name }) : super(key: key);
 
   final String name;
@@ -26,7 +26,7 @@ class AdaptedListItem extends StatelessComponent {
   }
 }
 
-class AdaptedGridItem extends StatelessComponent {
+class AdaptedGridItem extends StatelessWidget {
   AdaptedGridItem({ Key key, this.name }) : super(key: key);
 
   final String name;
@@ -65,7 +65,7 @@ const double _kListItemExtent = 50.0;
 const double _kMaxTileWidth = 150.0;
 const double _kGridViewBreakpoint = 450.0;
 
-class AdaptiveContainer extends StatelessComponent {
+class AdaptiveContainer extends StatelessWidget {
   AdaptiveContainer({ Key key, this.names }) : super(key: key);
 
   final List<String> names;

examples/layers/widgets/sectors.dart

@@ -16,7 +16,7 @@ RenderBox initCircle() {
   );
 }
 
-class SectorApp extends StatefulComponent {
+class SectorApp extends StatefulWidget {
   SectorAppState createState() => new SectorAppState();
 }
 

examples/layers/widgets/spinning_mixed.dart

@@ -16,7 +16,7 @@ void addFlexChildSolidColor(RenderFlex parent, Color backgroundColor, { int flex
 }
 
 // Solid colour, Widget version
-class Rectangle extends StatelessComponent {
+class Rectangle extends StatelessWidget {
   Rectangle(this.color, { Key key }) : super(key: key);
   final Color color;
   Widget build(BuildContext context) {

examples/layers/widgets/spinning_square.dart

@@ -4,7 +4,7 @@
 
 import 'package:flutter/widgets.dart';
 
-class SpinningSquare extends StatefulComponent {
+class SpinningSquare extends StatefulWidget {
   _SpinningSquareState createState() => new _SpinningSquareState();
 }
 

examples/layers/widgets/styled_text.dart

@@ -57,7 +57,7 @@ Widget toStyledText(String name, String text) {
 
 Widget toPlainText(String name, String text) => new Text(name + ":" + text);
 
-class SpeakerSeparator extends StatelessComponent {
+class SpeakerSeparator extends StatelessWidget {
   Widget build(BuildContext context) {
     return new Container(
       constraints: const BoxConstraints.expand(height: 0.0),
@@ -71,7 +71,7 @@ class SpeakerSeparator extends StatelessComponent {
   }
 }
 
-class StyledTextDemo extends StatefulComponent {
+class StyledTextDemo extends StatefulWidget {
   _StyledTextDemoState createState() => new _StyledTextDemoState();
 }
 

examples/material_gallery/lib/demo/buttons_demo.dart

@@ -55,7 +55,7 @@ class _ButtonDemo {
   int get hashCode => hashValues(title.hashCode, text.hashCode);
 }
 
-class ButtonsDemo extends StatefulComponent {
+class ButtonsDemo extends StatefulWidget {
   _ButtonsDemoState createState() => new _ButtonsDemoState();
 }
 

examples/material_gallery/lib/demo/cards_demo.dart

@@ -36,7 +36,7 @@ final List<TravelDestination> destinations = <TravelDestination>[
   )
 ];
 
-class TravelDestinationItem extends StatelessComponent {
+class TravelDestinationItem extends StatelessWidget {
   TravelDestinationItem({ Key key, this.destination }) : super(key: key) {
     assert(destination != null && destination.isValid);
   }
@@ -114,7 +114,7 @@ class TravelDestinationItem extends StatelessComponent {
   }
 }
 
-class CardsDemo extends StatelessComponent {
+class CardsDemo extends StatelessWidget {
   Widget build(BuildContext context) {
     return new Scaffold(
       toolBar: new ToolBar(

examples/material_gallery/lib/demo/chip_demo.dart

@@ -4,7 +4,7 @@
 
 import 'package:flutter/material.dart';
 
-class ChipDemo extends StatefulComponent {
+class ChipDemo extends StatefulWidget {
   _ChipDemoState createState() => new _ChipDemoState();
 }
 

examples/material_gallery/lib/demo/colors_demo.dart

@@ -41,7 +41,7 @@ const List<ColorSwatch> colorSwatches = const <ColorSwatch>[
 ];
 
 
-class ColorItem extends StatelessComponent {
+class ColorItem extends StatelessWidget {
   ColorItem({ Key key, this.index, this.color, this.prefix: '' }) : super(key: key) {
     assert(index != null);
     assert(color != null);
@@ -71,7 +71,7 @@ class ColorItem extends StatelessComponent {
   }
 }
 
-class ColorSwatchTabView extends StatelessComponent {
+class ColorSwatchTabView extends StatelessWidget {
   ColorSwatchTabView({ Key key, this.swatch }) : super(key: key) {
     assert(swatch != null && swatch.isValid);
   }
@@ -106,7 +106,7 @@ class ColorSwatchTabView extends StatelessComponent {
   }
 }
 
-class ColorsDemo extends StatelessComponent {
+class ColorsDemo extends StatelessWidget {
   Widget build(BuildContext context) {
     return new TabBarSelection<ColorSwatch>(
       values: colorSwatches,

examples/material_gallery/lib/demo/date_picker_demo.dart

@@ -7,7 +7,7 @@ import 'dart:async';
 import 'package:flutter/material.dart';
 import 'package:intl/intl.dart';
 
-class DatePickerDemo extends StatefulComponent {
+class DatePickerDemo extends StatefulWidget {
   _DatePickerDemoState createState() => new _DatePickerDemoState();
 }
 

examples/material_gallery/lib/demo/dialog_demo.dart

@@ -20,7 +20,7 @@ const String _alertWithTitleText =
   "Let Google help apps determine location. This means sending anyonmous location "
   "data to Google, even when no apps are running.";
 
-class DialogDemoItem extends StatelessComponent {
+class DialogDemoItem extends StatelessWidget {
   DialogDemoItem({ Key key, this.icon, this.color, this.text, this.onPressed }) : super(key: key);
 
   final IconData icon;
@@ -53,7 +53,7 @@ class DialogDemoItem extends StatelessComponent {
   }
 }
 
-class DialogDemo extends StatefulComponent {
+class DialogDemo extends StatefulWidget {
   DialogDemoState createState() => new DialogDemoState();
 }
 

examples/material_gallery/lib/demo/drop_down_demo.dart

@@ -4,7 +4,7 @@
 
 import 'package:flutter/material.dart';
 
-class DropDownDemo extends StatefulComponent {
+class DropDownDemo extends StatefulWidget {
   _DropDownDemoState createState() => new _DropDownDemoState();
 }
 

examples/material_gallery/lib/demo/fitness_demo.dart

@@ -13,7 +13,7 @@ import 'package:vector_math/vector_math_64.dart' as vec;
 ImageMap _images;
 SpriteSheet _sprites;
 
-class FitnessDemo extends StatelessComponent {
+class FitnessDemo extends StatelessWidget {
   FitnessDemo({ Key key }) : super(key: key);
 
   Widget build(BuildContext context) {
@@ -26,7 +26,7 @@ class FitnessDemo extends StatelessComponent {
   }
 }
 
-class _FitnessDemoContents extends StatefulComponent {
+class _FitnessDemoContents extends StatefulWidget {
   _FitnessDemoContents({ Key key }) : super(key: key);
   _FitnessDemoContentsState createState() => new _FitnessDemoContentsState();
 }
@@ -510,7 +510,7 @@ class _JumpingJackPart extends Sprite {
   }
 }
 
-class _Fireworks extends StatefulComponent {
+class _Fireworks extends StatefulWidget {
   _Fireworks({ Key key }) : super(key: key);
 
   _FireworksState createState() => new _FireworksState();

examples/material_gallery/lib/demo/flexible_space_demo.dart

@@ -5,7 +5,7 @@
 import 'package:flutter/material.dart';
 import 'package:flutter/widgets.dart';
 
-class _ContactCategory extends StatelessComponent {
+class _ContactCategory extends StatelessWidget {
   _ContactCategory({ Key key, this.icon, this.children }) : super(key: key);
 
   final IconData icon;
@@ -33,7 +33,7 @@ class _ContactCategory extends StatelessComponent {
   }
 }
 
-class _ContactItem extends StatelessComponent {
+class _ContactItem extends StatelessWidget {
   _ContactItem({ Key key, this.icon, this.lines }) : super(key: key) {
     assert(lines.length > 1);
   }
@@ -67,7 +67,7 @@ class _ContactItem extends StatelessComponent {
   }
 }
 
-class FlexibleSpaceDemo extends StatefulComponent {
+class FlexibleSpaceDemo extends StatefulWidget {
   FlexibleSpaceDemoState createState() => new FlexibleSpaceDemoState();
 }
 

examples/material_gallery/lib/demo/full_screen_dialog_demo.dart

@@ -15,7 +15,7 @@ enum DismissDialogAction {
   save,
 }
 
-class DateTimeItem extends StatelessComponent {
+class DateTimeItem extends StatelessWidget {
   DateTimeItem({ Key key, DateTime dateTime, this.onChanged })
     : date = new DateTime(dateTime.year, dateTime.month, dateTime.day),
       time = new TimeOfDay(hour: dateTime.hour, minute: dateTime.minute),
@@ -92,7 +92,7 @@ class DateTimeItem extends StatelessComponent {
   }
 }
 
-class FullScreenDialogDemo extends StatefulComponent {
+class FullScreenDialogDemo extends StatefulWidget {
   FullScreenDialogDemoState createState() => new FullScreenDialogDemoState();
 }
 

examples/material_gallery/lib/demo/grid_list_demo.dart

@@ -28,7 +28,7 @@ final List<Photo> photos = new List<Photo>.generate(16, (int index) {
   return const Photo(assetName: 'packages/flutter_gallery_assets/kangaroo_valley_safari.png');
 });
 
-class GridDemoPhotoItem extends StatelessComponent {
+class GridDemoPhotoItem extends StatelessWidget {
   GridDemoPhotoItem({ Key key, this.photo, this.tileStyle }) : super(key: key) {
     assert(photo != null && photo.isValid);
     assert(tileStyle != null);
@@ -128,7 +128,7 @@ class GridListDemoGridDelegate extends FixedColumnCountGridDelegate {
   }
 }
 
-class GridListDemo extends StatefulComponent {
+class GridListDemo extends StatefulWidget {
   GridListDemo({ Key key }) : super(key: key);
 
   GridListDemoState createState() => new GridListDemoState();

examples/material_gallery/lib/demo/icons_demo.dart

@@ -4,7 +4,7 @@
 
 import 'package:flutter/material.dart';
 
-class IconsDemo extends StatefulComponent {
+class IconsDemo extends StatefulWidget {
   IconsDemoState createState() => new IconsDemoState();
 }
 

examples/material_gallery/lib/demo/leave_behind_demo.dart

@@ -25,7 +25,7 @@ class LeaveBehindItem {
   final String body;
 }
 
-class LeaveBehindDemo extends StatefulComponent {
+class LeaveBehindDemo extends StatefulWidget {
   LeaveBehindDemo({ Key key }) : super(key: key);
 
   LeaveBehindDemoState createState() => new LeaveBehindDemoState();

examples/material_gallery/lib/demo/list_demo.dart

@@ -10,7 +10,7 @@ enum ListDemoItemSize {
   threeLine
 }
 
-class ListDemo extends StatefulComponent {
+class ListDemo extends StatefulWidget {
   ListDemo({ Key key }) : super(key: key);
 
   ListDemoState createState() => new ListDemoState();

examples/material_gallery/lib/demo/menu_demo.dart

@@ -4,7 +4,7 @@
 
 import 'package:flutter/material.dart';
 
-class MenuDemo extends StatefulComponent {
+class MenuDemo extends StatefulWidget {
   MenuDemo({ Key key }) : super(key: key);
 
   MenuDemoState createState() => new MenuDemoState();

examples/material_gallery/lib/demo/modal_bottom_sheet_demo.dart

@@ -4,7 +4,7 @@
 
 import 'package:flutter/material.dart';
 
-class ModalBottomSheetDemo extends StatelessComponent {
+class ModalBottomSheetDemo extends StatelessWidget {
   final TextStyle textStyle = new TextStyle(
     color: Colors.indigo[400],
     fontSize: 24.0,

examples/material_gallery/lib/demo/page_selector_demo.dart

@@ -4,7 +4,7 @@
 
 import 'package:flutter/material.dart';
 
-class PageSelectorDemo extends StatelessComponent {
+class PageSelectorDemo extends StatelessWidget {
 
   void _handleArrowButtonPress(BuildContext context, int delta) {
     final TabBarSelectionState<IconData> selection = TabBarSelection.of/*<IconData>*/(context);

examples/material_gallery/lib/demo/persistent_bottom_sheet_demo.dart

@@ -4,7 +4,7 @@
 
 import 'package:flutter/material.dart';
 
-class PersistentBottomSheetDemo extends StatelessComponent {
+class PersistentBottomSheetDemo extends StatelessWidget {
 
   final TextStyle textStyle = new TextStyle(
     color: Colors.indigo[400],

examples/material_gallery/lib/demo/progress_indicator_demo.dart

@@ -4,7 +4,7 @@
 
 import 'package:flutter/material.dart';
 
-class ProgressIndicatorDemo extends StatefulComponent {
+class ProgressIndicatorDemo extends StatefulWidget {
   _ProgressIndicatorDemoState createState() => new _ProgressIndicatorDemoState();
 }
 

examples/material_gallery/lib/demo/scrolling_techniques_demo.dart

@@ -6,7 +6,7 @@ import 'package:flutter/material.dart';
 
 import 'flexible_space_demo.dart';
 
-class _BarGraphic extends StatelessComponent {
+class _BarGraphic extends StatelessWidget {
   _BarGraphic({ Key key, this.height, this.color, this.leftText, this.rightText: '' })
     : super(key: key) {
     assert(height != null);
@@ -74,7 +74,7 @@ class _FlexibleSpaceGraphic extends _BarGraphic {
   );
 }
 
-class _TechniqueItem extends StatelessComponent {
+class _TechniqueItem extends StatelessWidget {
   _TechniqueItem({ this.titleText, this.barGraphics, this.builder });
 
   final String titleText;
@@ -110,7 +110,7 @@ const String _introText =
   "it appears behind the device's status bar. When a flexible space Widget is "
   "specified it is stacked on top of the ToolBar.";
 
-class ScrollingTechniquesDemo extends StatelessComponent {
+class ScrollingTechniquesDemo extends StatelessWidget {
   Widget build(BuildContext context) {
     return new Scaffold(
       toolBar: new ToolBar(center: new Text('Scrolling Techniques')),

examples/material_gallery/lib/demo/slider_demo.dart

@@ -4,7 +4,7 @@
 
 import 'package:flutter/material.dart';
 
-class SliderDemo extends StatefulComponent {
+class SliderDemo extends StatefulWidget {
   _SliderDemoState createState() => new _SliderDemoState();
 }
 

examples/material_gallery/lib/demo/snack_bar_demo.dart

@@ -17,7 +17,7 @@ const String _text2 =
 const String _text3 =
   "By default snackbars automatically disappear after a few seconds ";
 
-class SnackBarDemo extends StatelessComponent {
+class SnackBarDemo extends StatelessWidget {
   SnackBarDemo({ Key key }) : super(key: key);
 
   Widget buildBody(BuildContext context) {

examples/material_gallery/lib/demo/tabs_demo.dart

@@ -4,7 +4,7 @@
 
 import 'package:flutter/material.dart';
 
-class TabsDemo extends StatelessComponent {
+class TabsDemo extends StatelessWidget {
   final List<IconData> icons = <IconData>[
     Icons.event,
     Icons.home,

examples/material_gallery/lib/demo/tabs_fab_demo.dart

@@ -25,7 +25,7 @@ const String _explanatoryText =
   "with a FloatingActionButton that the Scaffold distinguishes from the others "
   "by its key.";
 
-class TabsFabDemo extends StatefulComponent {
+class TabsFabDemo extends StatefulWidget {
   _TabsFabDemoState createState() => new _TabsFabDemoState();
 }
 

examples/material_gallery/lib/demo/text_field_demo.dart

@@ -4,7 +4,7 @@
 
 import 'package:flutter/material.dart';
 
-class TextFieldDemo extends StatefulComponent {
+class TextFieldDemo extends StatefulWidget {
   TextFieldDemo({ Key key }) : super(key: key);
 
   TextFieldDemoState createState() => new TextFieldDemoState();

examples/material_gallery/lib/demo/time_picker_demo.dart

@@ -6,7 +6,7 @@ import 'dart:async';
 
 import 'package:flutter/material.dart';
 
-class TimePickerDemo extends StatefulComponent {
+class TimePickerDemo extends StatefulWidget {
   _TimePickerDemoState createState() => new _TimePickerDemoState();
 }
 

examples/material_gallery/lib/demo/toggle_controls_demo.dart

@@ -4,7 +4,7 @@
 
 import 'package:flutter/material.dart';
 
-class ToggleControlsDemo extends StatefulComponent {
+class ToggleControlsDemo extends StatefulWidget {
   _ToggleControlsDemoState createState() => new _ToggleControlsDemoState();
 }
 

examples/material_gallery/lib/demo/tooltip_demo.dart

@@ -9,7 +9,7 @@ const String _introText =
   "a long press. Tooltip messages are also used by services that make Flutter "
   "apps accessible, like screen readers.";
 
-class TooltipDemo extends StatelessComponent {
+class TooltipDemo extends StatelessWidget {
   Widget build(BuildContext context) {
     final ThemeData theme = Theme.of(context);
     return new Scaffold(

examples/material_gallery/lib/demo/two_level_list_demo.dart

@@ -4,7 +4,7 @@
 
 import 'package:flutter/material.dart';
 
-class TwoLevelListDemo extends StatelessComponent {
+class TwoLevelListDemo extends StatelessWidget {
   Widget build(BuildContext context) {
     return new Scaffold(
       toolBar: new ToolBar(center: new Text('Expand/Collapse List Control')),

examples/material_gallery/lib/demo/typography_demo.dart

@@ -5,7 +5,7 @@
 import 'package:flutter/material.dart';
 import 'package:flutter/widgets.dart';
 
-class TextStyleItem extends StatelessComponent {
+class TextStyleItem extends StatelessWidget {
   TextStyleItem({ Key key, this.name, this.style, this.text }) : super(key: key) {
     assert(name != null);
     assert(style != null);
@@ -37,7 +37,7 @@ class TextStyleItem extends StatelessComponent {
   }
 }
 
-class TypographyDemo extends StatelessComponent {
+class TypographyDemo extends StatelessWidget {
   Widget build(BuildContext context) {
     final TextTheme textTheme = Theme.of(context).textTheme;
     final List<Widget> styleItems = <Widget>[

examples/material_gallery/lib/demo/weather_demo.dart

@@ -17,7 +17,7 @@ enum WeatherType {
   snow
 }
 
-class WeatherDemo extends StatefulComponent {
+class WeatherDemo extends StatefulWidget {
   WeatherDemo({ Key key }) : super(key: key);
   _WeatherDemoState createState() => new _WeatherDemoState();
 }
@@ -125,7 +125,7 @@ class _WeatherDemoState extends State<WeatherDemo> {
 const double _kWeatherButtonSize = 56.0;
 const double _kWeatherIconSize = 36.0;
 
-class WeatherButton extends StatelessComponent {
+class WeatherButton extends StatelessWidget {
   WeatherButton({ this.icon, this.selected, this.onPressed, Key key }) : super(key: key);
 
   final String icon;

examples/material_gallery/lib/gallery/app.dart

@@ -6,7 +6,7 @@ import 'package:flutter/material.dart';
 
 import 'home.dart';
 
-class GalleryApp extends StatefulComponent {
+class GalleryApp extends StatefulWidget {
   GalleryApp({ Key key }) : super(key: key);
 
   static GalleryAppState of(BuildContext context) => context.ancestorStateOfType(const TypeMatcher<GalleryAppState>());

examples/material_gallery/lib/gallery/drawer.dart

@@ -8,7 +8,7 @@ import 'package:flutter/widgets.dart';
 
 import 'app.dart';
 
-class GalleryDrawer extends StatelessComponent {
+class GalleryDrawer extends StatelessWidget {
   GalleryDrawer({ Key key }) : super(key: key);
 
   void _changeTheme(BuildContext context, bool value) {

examples/material_gallery/lib/gallery/home.dart

@@ -39,7 +39,7 @@ import '../demo/two_level_list_demo.dart';
 import '../demo/typography_demo.dart';
 import '../demo/weather_demo.dart';
 
-class GalleryHome extends StatefulComponent {
+class GalleryHome extends StatefulWidget {
   GalleryHome({ Key key }) : super(key: key);
 
   GalleryHomeState createState() => new GalleryHomeState();

examples/material_gallery/lib/gallery/section.dart

@@ -7,7 +7,7 @@ import 'package:flutter/widgets.dart';
 
 import 'demo.dart';
 
-class GallerySection extends StatelessComponent {
+class GallerySection extends StatelessWidget {
   GallerySection({ this.title, this.image, this.colors, this.demos });
 
   final String title;

examples/stocks/lib/main.dart

@@ -23,7 +23,7 @@ import 'stock_strings.dart';
 import 'stock_symbol_viewer.dart';
 import 'stock_types.dart';
 
-class StocksApp extends StatefulComponent {
+class StocksApp extends StatefulWidget {
   StocksAppState createState() => new StocksAppState();
 }
 

examples/stocks/lib/stock_arrow.dart

@@ -50,7 +50,7 @@ class StockArrowPainter extends CustomPainter {
   }
 }
 
-class StockArrow extends StatelessComponent {
+class StockArrow extends StatelessWidget {
   StockArrow({ Key key, this.percentChange }) : super(key: key);
 
   final double percentChange;

examples/stocks/lib/stock_home.dart

@@ -18,7 +18,7 @@ typedef void ModeUpdater(StockMode mode);
 enum _StockMenuItem { autorefresh, refresh, speedUp, speedDown }
 enum StockHomeTab { market, portfolio }
 
-class _NotImplementedDialog extends StatelessComponent {
+class _NotImplementedDialog extends StatelessWidget {
   Widget build(BuildContext context) {
     return new Dialog(
       title: new Text('Not Implemented'),
@@ -50,7 +50,7 @@ class _NotImplementedDialog extends StatelessComponent {
   }
 }
 
-class StockHome extends StatefulComponent {
+class StockHome extends StatefulWidget {
   const StockHome(this.stocks, this.symbols, this.configuration, this.updater);
 
   final Map<String, Stock> stocks;
@@ -355,7 +355,7 @@ class StockHomeState extends State<StockHome> {
   }
 }
 
-class _CreateCompanySheet extends StatefulComponent {
+class _CreateCompanySheet extends StatefulWidget {
   _CreateCompanySheetState createState() => new _CreateCompanySheetState();
 }
 

examples/stocks/lib/stock_list.dart

@@ -7,7 +7,7 @@ import 'package:flutter/material.dart';
 import 'stock_data.dart';
 import 'stock_row.dart';
 
-class StockList extends StatelessComponent {
+class StockList extends StatelessWidget {
   StockList({ Key key, this.keySalt, this.stocks, this.onOpen, this.onShow, this.onAction }) : super(key: key);
 
   final Object keySalt;

examples/stocks/lib/stock_row.dart

@@ -30,7 +30,7 @@ class StockRowPartKey extends Key {
 
 typedef void StockRowActionCallback(Stock stock, Key arrowKey);
 
-class StockRow extends StatelessComponent {
+class StockRow extends StatelessWidget {
   StockRow({
     Stock stock,
     Object keySalt,

examples/stocks/lib/stock_settings.dart

@@ -6,7 +6,7 @@ import 'package:flutter/material.dart';
 
 import 'stock_types.dart';
 
-class StockSettings extends StatefulComponent {
+class StockSettings extends StatefulWidget {
   const StockSettings(this.configuration, this.updater);
 
   final StockConfiguration configuration;

examples/stocks/lib/stock_symbol_viewer.dart

@@ -8,7 +8,7 @@ import 'stock_data.dart';
 import 'stock_arrow.dart';
 import 'stock_row.dart';
 
-class StockSymbolView extends StatelessComponent {
+class StockSymbolView extends StatelessWidget {
   StockSymbolView({ this.stock });
 
   final Stock stock;
@@ -66,7 +66,7 @@ class StockSymbolView extends StatelessComponent {
   }
 }
 
-class StockSymbolPage extends StatelessComponent {
+class StockSymbolPage extends StatelessWidget {
   StockSymbolPage({ this.stock });
 
   final Stock stock;
@@ -88,7 +88,7 @@ class StockSymbolPage extends StatelessComponent {
   }
 }
 
-class StockSymbolBottomSheet extends StatelessComponent {
+class StockSymbolBottomSheet extends StatelessWidget {
   StockSymbolBottomSheet({ this.stock });
 
   final Stock stock;

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

@@ -15,7 +15,7 @@ const double _kCloseProgressThreshold = 0.5;
 const Color _kTransparent = const Color(0x00000000);
 const Color _kBarrierColor = Colors.black54;
 
-class BottomSheet extends StatefulComponent {
+class BottomSheet extends StatefulWidget {
   BottomSheet({
     Key key,
     this.animationController,
@@ -117,7 +117,7 @@ class _ModalBottomSheetLayout extends SingleChildLayoutDelegate {
   }
 }
 
-class _ModalBottomSheet<T> extends StatefulComponent {
+class _ModalBottomSheet<T> extends StatefulWidget {
   _ModalBottomSheet({ Key key, this.route }) : super(key: key);
 
   final _ModalBottomSheetRoute<T> route;

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

@@ -39,7 +39,7 @@ class ButtonTheme extends InheritedWidget {
 ///
 /// MaterialButtons whose [onPressed] handler is null will be disabled. To have
 /// an enabled button, make sure to pass a non-null value for onPressed.
-abstract class MaterialButton extends StatefulComponent {
+abstract class MaterialButton extends StatefulWidget {
   MaterialButton({
     Key key,
     this.child,

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

@@ -11,7 +11,7 @@ const EdgeInsets _kCardMargins = const EdgeInsets.all(4.0);
 /// A material design card
 ///
 /// <https://www.google.com/design/spec/components/cards.html>
-class Card extends StatelessComponent {
+class Card extends StatelessWidget {
   const Card({ Key key, this.child, this.color }) : super(key: key);
 
   final Widget child;

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

@@ -21,7 +21,7 @@ import 'toggleable.dart';
 /// the checkbox.
 ///
 /// <https://www.google.com/design/spec/components/lists-controls.html#lists-controls-types-of-list-controls>
-class Checkbox extends StatelessComponent {
+class Checkbox extends StatelessWidget {
   /// Constructs a checkbox
   ///
   /// * `value` determines whether the checkbox is checked.

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

@@ -21,7 +21,7 @@ const TextStyle _kLabelStyle = const TextStyle(
   textBaseline: TextBaseline.alphabetic
 );
 
-class Chip extends StatelessComponent {
+class Chip extends StatelessWidget {
   const Chip({
     Key key,
     this.avatar,

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

@@ -7,7 +7,7 @@ import 'package:flutter/widgets.dart';
 import 'constants.dart';
 import 'theme.dart';
 
-class CircleAvatar extends StatelessComponent {
+class CircleAvatar extends StatelessWidget {
   CircleAvatar({
     Key key,
     this.child,

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

@@ -17,7 +17,7 @@ import 'typography.dart';
 
 enum _DatePickerMode { day, year }
 
-class DatePicker extends StatefulComponent {
+class DatePicker extends StatefulWidget {
   DatePicker({
     this.selectedDate,
     this.onChanged,
@@ -105,7 +105,7 @@ class _DatePickerState extends State<DatePicker> {
 }
 
 // Shows the selected date in large font and toggles between year and day mode
-class _DatePickerHeader extends StatelessComponent {
+class _DatePickerHeader extends StatelessWidget {
   _DatePickerHeader({ this.selectedDate, this.mode, this.onModeChanged }) {
     assert(selectedDate != null);
     assert(mode != null);
@@ -163,7 +163,7 @@ class _DatePickerHeader extends StatelessComponent {
 }
 
 // Fixed height component shows a single month and allows choosing a day
-class DayPicker extends StatelessComponent {
+class DayPicker extends StatelessWidget {
   DayPicker({
     this.selectedDate,
     this.currentDate,
@@ -269,7 +269,7 @@ class DayPicker extends StatelessComponent {
   }
 }
 
-class MonthPicker extends StatefulComponent {
+class MonthPicker extends StatefulWidget {
   MonthPicker({
     Key key,
     this.selectedDate,
@@ -351,7 +351,7 @@ class _MonthPickerState extends State<MonthPicker> {
 }
 
 // Scrollable list of years to allow picking a year
-class YearPicker extends StatefulComponent {
+class YearPicker extends StatefulWidget {
   YearPicker({
     Key key,
     this.selectedDate,

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

@@ -10,7 +10,7 @@ import 'dialog.dart';
 import 'date_picker.dart';
 import 'flat_button.dart';
 
-class _DatePickerDialog extends StatefulComponent {
+class _DatePickerDialog extends StatefulWidget {
   _DatePickerDialog({
     Key key,
     this.initialDate,

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

@@ -16,7 +16,7 @@ typedef Widget DialogBuilder(NavigatorState navigator);
 /// A material design dialog
 ///
 /// <https://www.google.com/design/spec/components/dialogs.html>
-class Dialog extends StatelessComponent {
+class Dialog extends StatelessWidget {
   Dialog({
     Key key,
     this.title,

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

@@ -6,7 +6,7 @@ import 'package:flutter/widgets.dart';
 
 import 'theme.dart';
 
-class Divider extends StatelessComponent {
+class Divider extends StatelessWidget {
   Divider({ Key key, this.height: 16.0, this.indent: 0.0, this.color }) : super(key: key) {
     assert(height >= 1.0);
   }

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

@@ -26,7 +26,7 @@ const double _kEdgeDragWidth = 20.0;
 const double _kMinFlingVelocity = 365.0;
 const Duration _kBaseSettleDuration = const Duration(milliseconds: 246);
 
-class Drawer extends StatelessComponent {
+class Drawer extends StatelessWidget {
   Drawer({
     Key key,
     this.elevation: 16,
@@ -47,7 +47,7 @@ class Drawer extends StatelessComponent {
   }
 }
 
-class DrawerController extends StatefulComponent {
+class DrawerController extends StatefulWidget {
   DrawerController({
     GlobalKey key,
     this.child

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

@@ -11,7 +11,7 @@ import 'theme.dart';
 // TODO(jackson): This class should usually render the user's
 // preferred banner image rather than a solid background
 
-class DrawerHeader extends StatelessComponent {
+class DrawerHeader extends StatelessWidget {
   const DrawerHeader({ Key key, this.child }) : super(key: key);
 
   final Widget child;

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

@@ -11,7 +11,7 @@ import 'icons.dart';
 import 'ink_well.dart';
 import 'theme.dart';
 
-class DrawerItem extends StatelessComponent {
+class DrawerItem extends StatelessWidget {
   const DrawerItem({
     Key key,
     this.icon,

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

@@ -56,7 +56,7 @@ class _DropDownMenuPainter extends CustomPainter {
   }
 }
 
-class _DropDownMenu<T> extends StatusTransitionComponent {
+class _DropDownMenu<T> extends StatusTransitionWidget {
   _DropDownMenu({
     Key key,
     _DropDownRoute<T> route
@@ -197,7 +197,7 @@ class _DropDownRoute<T> extends PopupRoute<_DropDownRouteResult<T>> {
   }
 }
 
-class DropDownMenuItem<T> extends StatelessComponent {
+class DropDownMenuItem<T> extends StatelessWidget {
   DropDownMenuItem({
     Key key,
     this.value,
@@ -222,7 +222,7 @@ class DropDownMenuItem<T> extends StatelessComponent {
   }
 }
 
-class DropDownButton<T> extends StatefulComponent {
+class DropDownButton<T> extends StatefulWidget {
   DropDownButton({
     Key key,
     this.items,

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

@@ -11,7 +11,7 @@ import 'constants.dart';
 import 'scaffold.dart';
 import 'theme.dart';
 
-class FlexibleSpaceBar extends StatefulComponent {
+class FlexibleSpaceBar extends StatefulWidget {
   FlexibleSpaceBar({ Key key, this.title, this.image }) : super(key: key);
 
   final Widget title;

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

@@ -33,7 +33,7 @@ const Interval _kChildSegueInterval = const Interval(0.65, 1.0);
 ///
 /// See also:
 ///  * https://www.google.com/design/spec/components/buttons-floating-action-button.html
-class FloatingActionButton extends StatefulComponent {
+class FloatingActionButton extends StatefulWidget {
   const FloatingActionButton({
     Key key,
     this.child,

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

@@ -6,7 +6,7 @@ import 'package:flutter/widgets.dart';
 
 /// Creates a [Stack] with the header anchored across the top or a footer across the
 /// bottom. The [GridTileBar] class can be used to create grid tile headers and footers.
-class GridTile extends StatelessComponent {
+class GridTile extends StatelessWidget {
   GridTile({ Key key, this.header, this.footer, this.child }) : super(key: key) {
     assert(child != null);
   }

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

@@ -15,7 +15,7 @@ import 'typography.dart';
 /// https://www.google.com/design/spec/components/grid-lists.html#grid-lists-specs
 /// For a one-line header specify title and to add a second line specify caption.
 /// Use left or right to add an icon.
-class GridTileBar extends StatelessComponent {
+class GridTileBar extends StatelessWidget {
   GridTileBar({ Key key, this.backgroundColor, this.left, this.right, this.title, this.caption }) : super(key: key);
 
   final Color backgroundColor;

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

@@ -22,7 +22,7 @@ import 'theme.dart';
 /// in your project's `flutter.yaml` file. This ensures that the
 /// MaterialIcons font is included in your application. This font is
 /// used to display the icons.
-class Icon extends StatelessComponent {
+class Icon extends StatelessWidget {
   Icon({
     Key key,
     this.icon,

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

@@ -20,7 +20,7 @@ import 'tooltip.dart';
 ///
 /// If the [onPressed] callback is not specified or null, then the button will
 /// be disabled, will not react to touch.
-class IconButton extends StatelessComponent {
+class IconButton extends StatelessWidget {
   const IconButton({
     Key key,
     this.size: 24.0,

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

@@ -24,7 +24,7 @@ import 'theme.dart';
 /// at the top of its [build] function to call [debugCheckHasMaterial]:
 ///
 ///     assert(debugCheckHasMaterial(context));
-class InkResponse extends StatefulComponent {
+class InkResponse extends StatefulWidget {
   InkResponse({
     Key key,
     this.child,

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

@@ -14,7 +14,7 @@ import 'theme.dart';
 export 'package:sky_services/editing/editing.mojom.dart' show KeyboardType;
 
 /// A material design text input field.
-class Input extends StatefulComponent {
+class Input extends StatefulWidget {
   Input({
     Key key,
     this.value: InputValue.empty,

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

@@ -21,7 +21,7 @@ Map<MaterialListType, double> kListItemExtent = const <MaterialListType, double>
   MaterialListType.threeLine: kThreeLineListItemHeight,
 };
 
-class MaterialList extends StatefulComponent {
+class MaterialList extends StatefulWidget {
   MaterialList({
     Key key,
     this.initialScrollOffset,

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

@@ -15,7 +15,7 @@ import 'theme.dart';
 /// isThreeLine: true is specified. If dense: true is specified then the overall
 /// height of this list item and the size of the DefaultTextStyles that wrap
 /// the [primary] and [secondary] widget are reduced.
-class ListItem extends StatelessComponent {
+class ListItem extends StatelessWidget {
   ListItem({
     Key key,
     this.left,

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

@@ -73,7 +73,7 @@ abstract class MaterialInkController {
 /// list on the paper, and it's been scrolled), a LayoutChangedNotification must
 /// be dispatched at the relevant subtree. (This in particular means that
 /// Transitions should not be placed inside Material.)
-class Material extends StatefulComponent {
+class Material extends StatefulWidget {
   Material({
     Key key,
     this.child,

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

@@ -6,7 +6,7 @@ import 'dart:async';
 
 import 'package:flutter/widgets.dart';
 
-class _MaterialPageTransition extends AnimatedComponent {
+class _MaterialPageTransition extends AnimatedWidget {
   _MaterialPageTransition({
     Key key,
     Animation<double> animation,

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

@@ -28,7 +28,7 @@ const double _kMenuVerticalPadding = 8.0;
 const double _kMenuWidthStep = 56.0;
 const double _kMenuScreenPadding = 8.0;
 
-abstract class PopupMenuEntry<T> extends StatefulComponent {
+abstract class PopupMenuEntry<T> extends StatefulWidget {
   PopupMenuEntry({ Key key }) : super(key: key);
 
   double get height;
@@ -159,7 +159,7 @@ class _CheckedPopupMenuItemState<T> extends _PopupMenuItemState<CheckedPopupMenu
   }
 }
 
-class _PopupMenu<T> extends StatelessComponent {
+class _PopupMenu<T> extends StatelessWidget {
   _PopupMenu({
     Key key,
     this.route
@@ -357,7 +357,7 @@ typedef void PopupMenuItemSelected<T>(T value);
 /// because an item was selected. The value passed to [onSelected] is the value of
 /// the selected menu item. If child is null then a standard 'navigation/more_vert'
 /// icon is created.
-class PopupMenuButton<T> extends StatefulComponent {
+class PopupMenuButton<T> extends StatefulWidget {
   PopupMenuButton({
     Key key,
     this.items,

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

@@ -14,7 +14,7 @@ const double _kCircularProgressIndicatorStrokeWidth = 4.0;
 
 // TODO(hansmuller): implement the support for buffer indicator
 
-abstract class ProgressIndicator extends StatefulComponent {
+abstract class ProgressIndicator extends StatefulWidget {
   ProgressIndicator({
     Key key,
     this.value

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

@@ -14,7 +14,7 @@ const double _kDiameter = 16.0;
 const double _kOuterRadius = _kDiameter / 2.0;
 const double _kInnerRadius = 5.0;
 
-class Radio<T> extends StatelessComponent {
+class Radio<T> extends StatelessWidget {
   Radio({
     Key key,
     this.value,

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

@@ -107,7 +107,7 @@ class _ScaffoldLayout extends MultiChildLayoutDelegate {
   }
 }
 
-class _FloatingActionButtonTransition extends StatefulComponent {
+class _FloatingActionButtonTransition extends StatefulWidget {
   _FloatingActionButtonTransition({
     Key key,
     this.child
@@ -180,7 +180,7 @@ class _FloatingActionButtonTransitionState extends State<_FloatingActionButtonTr
 /// This class provides APIs for showing drawers, snackbars, and bottom sheets.
 ///
 /// See: <https://www.google.com/design/spec/layout/structure.html>
-class Scaffold extends StatefulComponent {
+class Scaffold extends StatefulWidget {
   Scaffold({
     Key key,
     this.toolBar,
@@ -572,7 +572,7 @@ class ScaffoldFeatureController<T extends Widget, U> {
   final StateSetter setState;
 }
 
-class _PersistentBottomSheet extends StatefulComponent {
+class _PersistentBottomSheet extends StatefulWidget {
   _PersistentBottomSheet({
     Key key,
     this.animationController,

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

@@ -7,7 +7,7 @@ import 'dart:ui' show Color, Offset;
 import 'package:flutter/painting.dart';
 
 // Based on http://www.google.com/design/spec/what-is-material/elevation-shadows.html
-// Currently, only the elevation values that are bound to one or more components are
+// Currently, only the elevation values that are bound to one or more widgets are
 // defined here.
 
 /// Map of elevation offsets used by material design to [BoxShadow] definitions.

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

@@ -11,7 +11,7 @@ import 'constants.dart';
 import 'debug.dart';
 import 'theme.dart';
 
-class Slider extends StatelessComponent {
+class Slider extends StatelessWidget {
   Slider({
     Key key,
     this.value,

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

@@ -37,7 +37,7 @@ const Curve _snackBarFadeCurve = const Interval(0.72, 1.0, curve: Curves.fastOut
 ///
 /// See also:
 ///  * https://www.google.com/design/spec/components/snackbars-toasts.html
-class SnackBarAction extends StatelessComponent {
+class SnackBarAction extends StatelessWidget {
   SnackBarAction({Key key, this.label, this.onPressed }) : super(key: key) {
     assert(label != null);
     assert(onPressed != null);
@@ -70,7 +70,7 @@ class SnackBarAction extends StatelessComponent {
 ///  * [Scaffold.of] and [ScaffoldState.showSnackBar]
 ///  * [SnackBarAction]
 ///  * https://www.google.com/design/spec/components/snackbars-toasts.html
-class SnackBar extends StatelessComponent {
+class SnackBar extends StatelessWidget {
   SnackBar({
     Key key,
     this.content,

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

@@ -13,7 +13,7 @@ import 'shadows.dart';
 import 'theme.dart';
 import 'toggleable.dart';
 
-class Switch extends StatelessComponent {
+class Switch extends StatelessWidget {
   Switch({ Key key, this.value, this.activeColor, this.onChanged })
       : super(key: key);
 

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

@@ -297,7 +297,7 @@ class TabLabel {
   final TabLabelIconBuilder iconBuilder;
 }
 
-class _Tab extends StatelessComponent {
+class _Tab extends StatelessWidget {
   _Tab({
     Key key,
     this.onSelected,
@@ -395,7 +395,7 @@ abstract class TabBarSelectionAnimationListener {
   void handleSelectionDeactivate();
 }
 
-class TabBarSelection<T> extends StatefulComponent {
+class TabBarSelection<T> extends StatefulWidget {
   TabBarSelection({
     Key key,
     this.value,
@@ -969,7 +969,7 @@ class _TabBarViewState<T> extends PageableListState<TabBarView<T>> implements Ta
   }
 }
 
-class TabPageSelector<T> extends StatelessComponent {
+class TabPageSelector<T> extends StatelessWidget {
   const TabPageSelector({ Key key }) : super(key: key);
 
   Widget _buildTabIndicator(TabBarSelectionState<T> selection, T tab, Animation<double> animation, ColorTween selectedColor, ColorTween previousColor) {

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

@@ -89,7 +89,7 @@ class TimeOfDay {
 
 enum _TimePickerMode { hour, minute }
 
-class TimePicker extends StatefulComponent {
+class TimePicker extends StatefulWidget {
   TimePicker({
     this.selectedTime,
     this.onChanged
@@ -141,7 +141,7 @@ class _TimePickerState extends State<TimePicker> {
 }
 
 // TODO(ianh): Localize!
-class _TimePickerHeader extends StatelessComponent {
+class _TimePickerHeader extends StatelessWidget {
   _TimePickerHeader({
     this.selectedTime,
     this.mode,
@@ -312,7 +312,7 @@ class _DialPainter extends CustomPainter {
   }
 }
 
-class _Dial extends StatefulComponent {
+class _Dial extends StatefulWidget {
   _Dial({
     this.selectedTime,
     this.mode,

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

@@ -10,7 +10,7 @@ import 'dialog.dart';
 import 'time_picker.dart';
 import 'flat_button.dart';
 
-class _TimePickerDialog extends StatefulComponent {
+class _TimePickerDialog extends StatefulWidget {
   _TimePickerDialog({
     Key key,
     this.initialTime

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

@@ -11,7 +11,7 @@ import 'material.dart';
 import 'theme.dart';
 import 'typography.dart';
 
-class ToolBar extends StatelessComponent {
+class ToolBar extends StatelessWidget {
   ToolBar({
     Key key,
     this.left,

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

@@ -18,7 +18,7 @@ const EdgeInsets _kDefaultTooltipScreenEdgeMargin = const EdgeInsets.all(10.0);
 const Duration _kDefaultTooltipFadeDuration = const Duration(milliseconds: 200);
 const Duration _kDefaultTooltipShowDuration = const Duration(seconds: 2);
 
-class Tooltip extends StatefulComponent {
+class Tooltip extends StatefulWidget {
   Tooltip({
     Key key,
     this.message,
@@ -234,7 +234,7 @@ class _TooltipPositionDelegate extends SingleChildLayoutDelegate {
   }
 }
 
-class _TooltipOverlay extends StatelessComponent {
+class _TooltipOverlay extends StatelessWidget {
   _TooltipOverlay({
     Key key,
     this.message,

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

@@ -14,7 +14,7 @@ import 'theme_data.dart';
 
 const Duration _kExpand = const Duration(milliseconds: 200);
 
-class TwoLevelListItem extends StatelessComponent {
+class TwoLevelListItem extends StatelessWidget {
   TwoLevelListItem({
     Key key,
     this.left,
@@ -49,7 +49,7 @@ class TwoLevelListItem extends StatelessComponent {
   }
 }
 
-class TwoLevelSublist extends StatefulComponent {
+class TwoLevelSublist extends StatefulWidget {
   TwoLevelSublist({ Key key, this.left, this.center, this.children }) : super(key: key);
 
   final Widget left;
@@ -149,7 +149,7 @@ class _TwoLevelSublistState extends State<TwoLevelSublist> {
   }
 }
 
-class TwoLevelList extends StatelessComponent {
+class TwoLevelList extends StatelessWidget {
   TwoLevelList({ Key key, this.items, this.type: MaterialListType.twoLine }) : super(key: key);
 
   final List<Widget> items;

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

@@ -36,7 +36,7 @@ typedef Widget RouteBuilder(RouteArguments args);
 
 typedef Future<LocaleQueryData> LocaleChangedCallback(Locale locale);
 
-class WidgetsApp extends StatefulComponent {
+class WidgetsApp extends StatefulWidget {
   WidgetsApp({
     Key key,
     this.title,

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

@@ -191,7 +191,7 @@ class _ResolutionAwareAssetResolver extends _VariantAssetResolver {
 /// icons/1.5x/heart.png
 /// icons/2.0x/heart.png
 /// ```
-class AssetVendor extends StatefulComponent {
+class AssetVendor extends StatefulWidget {
   AssetVendor({
     Key key,
     this.bundle,

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

@@ -888,7 +888,7 @@ class Viewport extends SingleChildRenderObjectWidget {
 // CONTAINER
 
 /// A convenience widget that combines common painting, positioning, and sizing widgets.
-class Container extends StatelessComponent {
+class Container extends StatelessWidget {
   Container({
     Key key,
     this.child,
@@ -1090,8 +1090,8 @@ class IndexedStack extends StackRenderObjectWidgetBase {
 /// Controls where a child of a [Stack] is positioned.
 ///
 /// This widget must be a descendant of a [Stack], and the path from this widget
-/// to its enclosing [Stack] must contain only components (e.g., not other
-/// kinds of widgets, like [RenderObjectWidget]s).
+/// to its enclosing [Stack] must contain only [StatelessWidget]s or
+/// [StatefulWidget]s (not other kinds of widgets, like [RenderObjectWidget]s).
 class Positioned extends ParentDataWidget<StackRenderObjectWidgetBase> {
   Positioned({
     Key key,
@@ -1426,8 +1426,8 @@ class Column extends Flex {
 ///
 /// This widget must be a descendant of a [Flex], [Row], or [Column], and the
 /// path from this widget to its enclosing [Flex], [Row], or [Column] must
-/// contain only components (e.g., not other kinds of widgets, like
-/// [RenderObjectWidget]s).
+/// contain only [StatelessWidget]s or [StatefulWidget]s (not other kinds of
+/// widgets, like [RenderObjectWidget]s).
 class Flexible extends ParentDataWidget<Flex> {
   Flexible({ Key key, this.flex: 1, Widget child })
     : super(key: key, child: child);
@@ -1507,7 +1507,7 @@ class DefaultTextStyle extends InheritedWidget {
 ///
 /// By default, the text will be styled using the closest enclosing
 /// [DefaultTextStyle].
-class Text extends StatelessComponent {
+class Text extends StatelessWidget {
   Text(this.data, { Key key, this.style }) : super(key: key) {
     assert(data != null);
   }
@@ -1666,7 +1666,7 @@ class RawImage extends LeafRenderObjectWidget {
 /// This widget is rarely used directly. Instead, consider using [AssetImage] or
 /// [NetworkImage], depending on whather you wish to display an image from the
 /// assert bundle or from the network.
-class RawImageResource extends StatefulComponent {
+class RawImageResource extends StatefulWidget {
   RawImageResource({
     Key key,
     this.image,
@@ -1785,7 +1785,7 @@ class _RawImageResourceState extends State<RawImageResource> {
 }
 
 /// Displays an image loaded from the network.
-class NetworkImage extends StatelessComponent {
+class NetworkImage extends StatelessWidget {
   NetworkImage({
     Key key,
     this.src,
@@ -1910,7 +1910,7 @@ class DefaultAssetBundle extends InheritedWidget {
 /// This widget lets you customize how images are loaded by supplying your own
 /// image provider. Internally, [NetworkImage] uses an [ImageProvider] that
 /// loads the image from the network.
-class AsyncImage extends StatelessComponent {
+class AsyncImage extends StatelessWidget {
   AsyncImage({
     Key key,
     this.provider,
@@ -2000,7 +2000,7 @@ class AsyncImage extends StatelessComponent {
 ///
 /// By default, asset image will load the image from the closest enclosing
 /// [DefaultAssetBundle].
-class AssetImage extends StatelessComponent {
+class AssetImage extends StatelessWidget {
   // Don't add asserts here unless absolutely necessary, since it will
   // require removing the const constructor, which is an API change.
   const AssetImage({
@@ -2293,7 +2293,7 @@ class Semantics extends SingleChildRenderObjectWidget {
 
 /// Causes all the semantics of the subtree rooted at this node to be
 /// merged into one node in the semantics tree. For example, if you
-/// have a component with a Text node next to a checkbox widget, this
+/// have a widget with a Text node next to a checkbox widget, this
 /// could be used to merge the label from the Text node with the
 /// "checked" semantic state of the checkbox into a single node that
 /// had both the label and the checked state. Otherwise, the label
@@ -2353,7 +2353,7 @@ class MetaData extends SingleChildRenderObjectWidget {
   }
 }
 
-class KeyedSubtree extends StatelessComponent {
+class KeyedSubtree extends StatelessWidget {
   KeyedSubtree({ Key key, this.child })
     : super(key: key);
 
@@ -2363,7 +2363,7 @@ class KeyedSubtree extends StatelessComponent {
 }
 
 /// A platonic widget that invokes a closure to obtain its child widget.
-class Builder extends StatelessComponent {
+class Builder extends StatelessWidget {
   Builder({ Key key, this.builder }) : super(key: key);
 
   /// Called to obtain the child widget.
@@ -2377,7 +2377,7 @@ class Builder extends StatelessComponent {
 }
 
 typedef Widget StatefulWidgetBuilder(BuildContext context, StateSetter setState);
-class StatefulBuilder extends StatefulComponent {
+class StatefulBuilder extends StatefulWidget {
   StatefulBuilder({ Key key, this.builder }) : super(key: key);
   final StatefulWidgetBuilder builder;
   _StatefulBuilderState createState() => new _StatefulBuilderState();

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

@@ -50,7 +50,7 @@ class _CheckedModeBannerPainter extends CustomPainter {
 
 /// Displays a banner saying "CHECKED" when running in checked mode.
 /// Does nothing in release mode.
-class CheckedModeBanner extends StatelessComponent {
+class CheckedModeBanner extends StatelessWidget {
   CheckedModeBanner({
     Key key,
     this.child