Analyze sample code (#10619)

dev/bots/test.dart

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
@@ -37,6 +41,11 @@ Future<Null> main() async {
       options: <String>['--flutter-repo'],
     );
 
+    // Analyze all the sample code in the repo
+    await _runCommand(dart, <String>[path.join(flutterRoot, 'dev', 'bots', 'analyze-sample-code.dart')],
+      workingDirectory: flutterRoot,
+    );
+
     // Try with the --watch analyzer, to make sure it returns success also.
     // The --benchmark argument exits after one run.
     await _runFlutterAnalyze(flutterRoot,

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

@@ -5,8 +5,6 @@
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 
-const Color _kBlue = const Color(0xFF007AFF);
-
 class CupertinoButtonsDemo extends StatefulWidget {
   static const String routeName = '/cupertino/buttons';
 
@@ -27,15 +25,17 @@ class _CupertinoButtonDemoState extends State<CupertinoButtonsDemo> {
         children: <Widget> [
           const Padding(
             padding: const EdgeInsets.all(16.0),
-            child: const Text('iOS themed buttons are flat. They can have borders or backgrounds but '
-                'only when necessary.'),
+            child: const Text(
+              'iOS themed buttons are flat. They can have borders or backgrounds but '
+              'only when necessary.'
+            ),
           ),
           new Expanded(
             child: new Column(
               mainAxisAlignment: MainAxisAlignment.center,
               children: <Widget> [
                 new Text(_pressedCount > 0
-                    ? 'Button pressed $_pressedCount time${_pressedCount == 1 ? '' : 's'}'
+                    ? 'Button pressed $_pressedCount time${_pressedCount == 1 ? "" : "s"}'
                     : ' '),
                 const Padding(padding: const EdgeInsets.all(12.0)),
                 new Align(
@@ -46,7 +46,7 @@ class _CupertinoButtonDemoState extends State<CupertinoButtonsDemo> {
                       new CupertinoButton(
                         child: const Text('Cupertino Button'),
                         onPressed: () {
-                          setState(() {_pressedCount++;});
+                          setState(() { _pressedCount += 1; });
                         }
                       ),
                       const CupertinoButton(
@@ -59,15 +59,15 @@ class _CupertinoButtonDemoState extends State<CupertinoButtonsDemo> {
                 const Padding(padding: const EdgeInsets.all(12.0)),
                 new CupertinoButton(
                   child: const Text('With Background'),
-                  color: _kBlue,
+                  color: CupertinoColors.activeBlue,
                   onPressed: () {
-                    setState(() {_pressedCount++;});
+                    setState(() { _pressedCount += 1; });
                   }
                 ),
                 const Padding(padding: const EdgeInsets.all(12.0)),
                 const CupertinoButton(
                   child: const Text('Disabled'),
-                  color: _kBlue,
+                  color: CupertinoColors.activeBlue,
                   onPressed: null,
                 ),
               ],

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

@@ -5,8 +5,6 @@
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 
-const Color _kBlue = const Color(0xFF007AFF);
-
 class CupertinoDialogDemo extends StatefulWidget {
   static const String routeName = '/cupertino/dialog';
 
@@ -44,7 +42,7 @@ class _CupertinoDialogDemoState extends State<CupertinoDialogDemo> {
         children: <Widget> [
           new CupertinoButton(
             child: const Text('Alert'),
-            color: _kBlue,
+            color: CupertinoColors.activeBlue,
             onPressed: () {
               showDemoDialog<String>(
                 context: context,
@@ -69,7 +67,7 @@ class _CupertinoDialogDemoState extends State<CupertinoDialogDemo> {
           const Padding(padding: const EdgeInsets.all(8.0)),
           new CupertinoButton(
             child: const Text('Alert with Title'),
-            color: _kBlue,
+            color: CupertinoColors.activeBlue,
             padding: const EdgeInsets.symmetric(vertical: 16.0, horizontal: 36.0),
             onPressed: () {
               showDemoDialog<String>(

packages/flutter/lib/foundation.dart

@@ -16,6 +16,15 @@ export 'package:meta/meta.dart' show
   protected,
   required;
 
+// Examples can assume:
+// bool _first;
+// bool _lights;
+// bool _visible;
+// double _volume;
+// dynamic _selection;
+// dynamic _last;
+// dynamic _calculation;
+
 export 'src/foundation/assertions.dart';
 export 'src/foundation/basic_types.dart';
 export 'src/foundation/binding.dart';

packages/flutter/lib/src/animation/animation_controller.dart

@@ -15,6 +15,9 @@ import 'listener_helpers.dart';
 
 export 'package:flutter/scheduler.dart' show TickerFuture, TickerCanceled;
 
+// Examples can assume:
+// AnimationController _controller;
+
 /// The direction in which an animation is running.
 enum _AnimationDirection {
   /// The animation is running from beginning to end.
@@ -44,17 +47,20 @@ const Tolerance _kFlingTolerance = const Tolerance(
 /// * Define the [upperBound] and [lowerBound] values of an animation.
 /// * Create a [fling] animation effect using a physics simulation.
 ///
-/// By default, an [AnimationController] linearly produces values that range from 0.0 to 1.0, during
-/// a given duration. The animation controller generates a new value whenever the device running
-/// your app is ready to display a new frame (typically, this rate is around 60 values per second).
+/// By default, an [AnimationController] linearly produces values that range
+/// from 0.0 to 1.0, during a given duration. The animation controller generates
+/// a new value whenever the device running your app is ready to display a new
+/// frame (typically, this rate is around 60 values per second).
 ///
-/// An AnimationController needs a [TickerProvider], which is configured using the `vsync` argument
-/// on the constructor. If you are creating an AnimationController from a [State], then you can use
-/// the [TickerProviderStateMixin] and [SingleTickerProviderStateMixin] classes to obtain a suitable
-/// [TickerProvider]. The widget test framework [WidgetTester] object can be used as a ticker provider
-/// in the context of tests. In other contexts, you will have to either pass a [TickerProvider] from
-/// a higher level (e.g. indirectly from a [State] that mixes in [TickerProviderStateMixin]), or
-/// create a custom [TickerProvider] subclass.
+/// An AnimationController needs a [TickerProvider], which is configured using
+/// the `vsync` argument on the constructor. If you are creating an
+/// AnimationController from a [State], then you can use the
+/// [TickerProviderStateMixin] and [SingleTickerProviderStateMixin] classes to
+/// obtain a suitable [TickerProvider]. The widget test framework [WidgetTester]
+/// object can be used as a ticker provider in the context of tests. In other
+/// contexts, you will have to either pass a [TickerProvider] from a higher
+/// level (e.g. indirectly from a [State] that mixes in
+/// [TickerProviderStateMixin]), or create a custom [TickerProvider] subclass.
 ///
 /// The methods that start animations return a [TickerFuture] object which
 /// completes when the animation completes successfully, and never throws an

packages/flutter/lib/src/animation/tween.dart

@@ -97,7 +97,7 @@ class _ChainedEvaluation<T> extends Animatable<T> {
 /// `_animation`:
 ///
 /// ```dart
-/// _animation = new Tween<Offset>(
+/// Animation<Offset> _animation = new Tween<Offset>(
 ///   begin: const Offset(100.0, 50.0),
 ///   end: const Offset(200.0, 300.0),
 /// ).animate(_controller);

packages/flutter/lib/src/cupertino/colors.dart

@@ -4,7 +4,8 @@
 
 import 'dart:ui' show Color;
 
-/// [Color] constants that describe colors commonly used in iOS applications.
+/// A palette of [Color] constants that describe colors commonly used when
+/// matching the iOS platform aesthetics.
 class CupertinoColors {
   CupertinoColors._();
 
@@ -18,9 +19,18 @@ class CupertinoColors {
   static const Color activeGreen = const Color(0xFF4CD964);
 
   /// Opaque white color. Used for backgrounds and fonts against dark backgrounds.
+  ///
+  /// See also:
+  ///
+  ///  * [Colors.white], the same color, in the material design palette.
+  ///  * [black], opaque black in the [CupertinoColors] palette.
   static const Color white = const Color(0xFFFFFFFF);
 
   /// Opaque black color. Used for texts against light backgrounds.
+  ///
+  /// See also:
+  ///
+  ///  * [Colors.black], the same color, in the material design palette.
   static const Color black = const Color(0xFF000000);
 
   /// Used in iOS 10 for light background fills such as the chat bubble background.

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

@@ -22,8 +22,28 @@ import 'thumb_painter.dart';
 /// that use a switch will listen for the [onChanged] callback and rebuild the
 /// switch with a new [value] to update the visual appearance of the switch.
 ///
+/// ## Sample code
+///
+/// This sample shows how to use a [CupertinoSwitch] in a [ListTile]. The
+/// [MergeSemantics] is used to turn the entire [ListTile] into a single item
+/// for accessibility tools.
+///
+/// ```dart
+/// new MergeSemantics(
+///   child: new ListTile(
+///     title: new Text('Lights'),
+///     trailing: new CupertinoSwitch(
+///       value: _lights,
+///       onChanged: (bool value) { setState(() { _lights = value; }); },
+///     ),
+///     onTap: () { setState(() { _lights = !_lights; }); },
+///   ),
+/// )
+/// ```
+///
 /// See also:
 ///
+///  * [Switch], the material design equivalent.
 ///  * <https://developer.apple.com/ios/human-interface-guidelines/ui-controls/switches/>
 class CupertinoSwitch extends StatefulWidget {
   /// Creates an iOS-style switch.

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

@@ -21,6 +21,11 @@ import 'tabs.dart';
 import 'theme.dart';
 import 'typography.dart';
 
+// Examples can assume:
+// void _airDress() { }
+// void _restitchDress() { }
+// void _repairDress() { }
+
 const double _kLeadingWidth = kToolbarHeight; // So the leading button is square.
 
 // Bottom justify the kToolbarHeight child which may overflow the top.

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

@@ -9,6 +9,9 @@ import 'constants.dart';
 import 'theme.dart';
 import 'typography.dart';
 
+// Examples can assume:
+// String userAvatarUrl;
+
 /// A circle that represents a user.
 ///
 /// Typically used with a user's profile image, or, in the absence of

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

@@ -16,6 +16,10 @@ import 'list_tile.dart';
 import 'material.dart';
 import 'theme.dart';
 
+// Examples can assume:
+// enum Commands { heroAndScholar, hurricaneCame }
+// dynamic _heroAndScholar;
+
 const Duration _kMenuDuration = const Duration(milliseconds: 300);
 const double _kBaselineOffsetFromBottom = 20.0;
 const double _kMenuCloseIntervalEnd = 2.0 / 3.0;
@@ -133,7 +137,7 @@ class _PopupMenuDividerState extends State<PopupMenuDivider> {
 /// const PopupMenuItem<WhyFarther>(
 ///   value: WhyFarther.harder,
 ///   child: const Text('Working a lot harder'),
-/// ),
+/// )
 /// ```
 ///
 /// See the example at [PopupMenuButton] for how this example could be used in a
@@ -616,6 +620,8 @@ typedef List<PopupMenuEntry<T>> PopupMenuItemBuilder<T>(BuildContext context);
 /// the selected menu item. If child is null then a standard 'navigation/more_vert'
 /// icon is created.
 ///
+/// ## Sample code
+///
 /// This example shows a menu with four items, selecting between an enum's
 /// values and setting a `_selection` field based on the selection.
 ///

packages/flutter/lib/src/painting/box_fit.dart

@@ -3,7 +3,6 @@
 // found in the LICENSE file.
 
 import 'dart:math' as math;
-import 'dart:ui' show Image; // to disambiguate mentions of Image in the dartdocs
 
 import 'package:flutter/foundation.dart';
 
@@ -105,16 +104,18 @@ class FittedSizes {
 ///
 /// ## Sample code
 ///
-/// This example paints an [Image] `image` onto the [Rect] `outputRect` on a
-/// [Canvas] `canvas`, using a [Paint] paint, applying the [BoxFit] algorithm
+/// This function paints a [dart:ui.Image] `image` onto the [Rect] `outputRect` on a
+/// [Canvas] `canvas`, using a [Paint] `paint`, applying the [BoxFit] algorithm
 /// `fit`:
 ///
 /// ```dart
-/// final Size imageSize = new Size(image.width.toDouble(), image.height.toDouble());
-/// final FittedSizes sizes = applyBoxFit(fit, imageSize, outputRect.size);
-/// final Rect inputSubrect = FractionalOffset.center.inscribe(sizes.source, Offset.zero & imageSize);
-/// final Rect outputSubrect = FractionalOffset.center.inscribe(sizes.destination, outputRect);
-/// canvas.drawImageRect(image, inputSubrect, outputSubrect, paint);
+/// void paintImage(ui.Image image, Rect outputRect, Canvas canvas, Paint paint, BoxFit fit) {
+///   final Size imageSize = new Size(image.width.toDouble(), image.height.toDouble());
+///   final FittedSizes sizes = applyBoxFit(fit, imageSize, outputRect.size);
+///   final Rect inputSubrect = FractionalOffset.center.inscribe(sizes.source, Offset.zero & imageSize);
+///   final Rect outputSubrect = FractionalOffset.center.inscribe(sizes.destination, outputRect);
+///   canvas.drawImageRect(image, inputSubrect, outputSubrect, paint);
+/// }
 /// ```
 ///
 /// See also:

packages/flutter/lib/src/painting/box_painter.dart

@@ -328,18 +328,21 @@ class BorderSide {
 ///
 /// ## Sample code
 ///
+/// All four borders the same, two-pixel wide solid white:
+///
 /// ```dart
-/// // All four borders the same, two-pixel wide solid white:
 /// new Border.all(width: 2.0, color: const Color(0xFFFFFFFF))
 /// ```
 ///
+/// The border for a material design divider:
+///
 /// ```dart
-/// // The border for a material design divider:
 /// new Border(bottom: new BorderSide(color: Theme.of(context).dividerColor))
 /// ```
 ///
+/// A 1990s-era "OK" button:
+///
 /// ```dart
-/// // A 1990s-era "OK" button:
 /// new Container(
 ///   decoration: const BoxDecoration(
 ///     border: const Border(
@@ -1013,21 +1016,24 @@ class LinearGradient extends Gradient {
 ///
 /// ## Sample code
 ///
+/// This function draws a gradient that looks like a sun in a blue sky.
+///
 /// ```dart
-/// // This gradient looks like a sun in a blue sky.
-/// var gradient = new RadialGradient(
-///   center: const FractionalOffset(0.7, 0.2), // near the top right
-///   radius: 0.2,
-///   colors: [
-///     const Color(0xFFFFFF00), // yellow sun
-///     const Color(0xFF0099FF), // blue sky
-///   ],
-///   stops: [0.4, 1.0],
-/// );
-/// // rect is the area we are painting over
-/// var paint = new Paint()
-///   ..shader = gradient.createShader(rect);
-/// canvas.drawRect(rect, paint);
+/// void paintSky(Canvas canvas, Rect rect) {
+///   var gradient = new RadialGradient(
+///     center: const FractionalOffset(0.7, 0.2), // near the top right
+///     radius: 0.2,
+///     colors: [
+///       const Color(0xFFFFFF00), // yellow sun
+///       const Color(0xFF0099FF), // blue sky
+///     ],
+///     stops: [0.4, 1.0],
+///   );
+///   // rect is the area we are painting over
+///   var paint = new Paint()
+///     ..shader = gradient.createShader(rect);
+///   canvas.drawRect(rect, paint);
+/// }
 /// ```
 ///
 /// See also:

packages/flutter/lib/src/painting/edge_insets.dart

@@ -26,14 +26,21 @@ enum Axis {
 ///
 /// Here are some examples of how to create [EdgeInsets] instances:
 ///
+/// Typical eight-pixel margin on all sides:
+///
 /// ```dart
-/// // typical 8-pixel margin on all sides
 /// const EdgeInsets.all(8.0)
+/// ```
+///
+/// Eight pixel margin above and below, no horizontal margins:
 ///
-/// // 8-pixel margin above and below, no horizontal margins
+/// ```dart
 /// const EdgeInsets.symmetric(vertical: 8.0)
+/// ```
 ///
-/// // left-margin indent of 40 pixels
+/// Left margin indent of 40 pixels:
+///
+/// ```dart
 /// const EdgeInsets.only(left: 40.0)
 /// ```
 ///
@@ -49,8 +56,9 @@ class EdgeInsets {
   ///
   /// ## Sample code
   ///
+  /// Typical eight-pixel margin on all sides:
+  ///
   /// ```dart
-  /// // typical 8-pixel margin on all sides
   /// const EdgeInsets.all(8.0)
   /// ```
   const EdgeInsets.all(double value)
@@ -60,8 +68,9 @@ class EdgeInsets {
   ///
   /// ## Sample code
   ///
+  /// Left margin indent of 40 pixels:
+  ///
   /// ```dart
-  /// // left-margin indent of 40 pixels
   /// const EdgeInsets.only(left: 40.0)
   /// ```
   const EdgeInsets.only({
@@ -75,8 +84,9 @@ class EdgeInsets {
   ///
   /// ## Sample code
   ///
+  /// Eight pixel margin above and below, no horizontal margins:
+  ///
   /// ```dart
-  /// // 8-pixel margin above and below, no horizontal margins
   /// const EdgeInsets.symmetric(vertical: 8.0)
   /// ```
   const EdgeInsets.symmetric({ double vertical: 0.0,

packages/flutter/lib/src/physics/gravity_simulation.dart

@@ -8,6 +8,30 @@ import 'simulation.dart';
 ///
 /// Models a particle that follows Newton's second law of motion. The simulation
 /// ends when the position reaches a defined point.
+///
+/// ## Sample code
+///
+/// This method triggers an [AnimationController] (a previously constructed
+/// `_controller` field) to simulate a fall of 300 pixels.
+///
+/// ```dart
+/// void _startFall() {
+///   _controller.animateWith(new GravitySimulation(
+///     10.0, // acceleration, pixels per second per second
+///     0.0, // starting position, pixels
+///     300.0, // ending position, pixels
+///     0.0, // starting velocity, pixels per second
+///   ));
+/// }
+/// ```
+///
+/// This [AnimationController] could be used with an [AnimatedBuilder] to
+/// animate the position of a child as if it was falling.
+///
+/// See also:
+///
+///  * [Curves.bounceOut], a [Curve] that has a similar aesthetics but includes
+///    a bouncing effect.
 class GravitySimulation extends Simulation {
   /// Creates a [GravitySimulation] using the given arguments, which are,
   /// respectively: an acceleration that is to be applied continually over time;

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

@@ -50,7 +50,7 @@ enum CrossFadeState {
 ///   duration: const Duration(seconds: 3),
 ///   firstChild: const FlutterLogo(style: FlutterLogoStyle.horizontal, size: 100.0),
 ///   secondChild: const FlutterLogo(style: FlutterLogoStyle.stacked, size: 100.0),
-///   crossFadeState: _on ? CrossFadeState.showFirst : CrossFadeState.showSecond,
+///   crossFadeState: _first ? CrossFadeState.showFirst : CrossFadeState.showSecond,
 /// )
 /// ```
 ///

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

@@ -12,6 +12,9 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';
 import 'package:meta/meta.dart' show required;
 
+// Examples can assume:
+// dynamic _lot;
+
 /// Base class for widgets that build themselves based on interaction with
 /// a specified [Stream].
 ///

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

@@ -350,7 +350,7 @@ class CustomPaint extends SingleChildRenderObjectWidget {
 ///   child: new Align(
 ///     alignment: FractionalOffset.topCenter,
 ///     heightFactor: 0.5,
-///     child: new Image(...),
+///     child: new Image.network(userAvatarUrl),
 ///   ),
 /// )
 /// ```

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

@@ -35,14 +35,14 @@ export 'dart:ui' show AppLifecycleState, Locale;
 /// lifecycle messages. See [didChangeAppLifecycleState].
 ///
 /// ```dart
-/// class Reactor extends StatefulWidget {
-///   const Reactor({ Key key }) : super(key: key);
+/// class AppLifecycleReactor extends StatefulWidget {
+///   const AppLifecycleReactor({ Key key }) : super(key: key);
 ///
 ///   @override
-///   _ReactorState createState() => new _ReactorState();
+///   _AppLifecycleReactorState createState() => new _AppLifecycleReactorState();
 /// }
 ///
-/// class _ReactorState extends State<Reactor> with WidgetsBindingObserver {
+/// class _AppLifecycleReactorState extends State<AppLifecycleReactor> with WidgetsBindingObserver {
 ///   @override
 ///   void initState() {
 ///     super.initState();
@@ -104,14 +104,14 @@ abstract class WidgetsBindingObserver {
   /// rotated (or otherwise changes dimensions).
   ///
   /// ```dart
-  /// class Reactor extends StatefulWidget {
-  ///   const Reactor({ Key key }) : super(key: key);
+  /// class MetricsReactor extends StatefulWidget {
+  ///   const MetricsReactor({ Key key }) : super(key: key);
   ///
   ///   @override
-  ///   _ReactorState createState() => new _ReactorState();
+  ///   _MetricsReactorState createState() => new _MetricsReactorState();
   /// }
   ///
-  /// class _ReactorState extends State<Reactor> with WidgetsBindingObserver {
+  /// class _MetricsReactorState extends State<MetricsReactor> with WidgetsBindingObserver {
   ///   @override
   ///   void initState() {
   ///     super.initState();

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

@@ -17,6 +17,15 @@ export 'package:flutter/foundation.dart' show FlutterError, debugPrint, debugPri
 export 'package:flutter/foundation.dart' show VoidCallback, ValueChanged, ValueGetter, ValueSetter;
 export 'package:flutter/rendering.dart' show RenderObject, RenderBox, debugDumpRenderTree, debugDumpLayerTree;
 
+// Examples can assume:
+// BuildContext context;
+// void setState(VoidCallback fn) { }
+
+// Examples can assume:
+// abstract class RenderFrogJar extends RenderObject { }
+// abstract class FrogJar extends RenderObjectWidget { }
+// abstract class FrogJarParentData extends ParentData { Size size; }
+
 // KEYS
 
 /// A [Key] is an identifier for [Widget]s and [Element]s.
@@ -643,20 +652,20 @@ abstract class StatelessWidget extends Widget {
 ///
 /// ## Sample code
 ///
-/// The following is a skeleton of a stateful widget subclass called `GreenFrog`:
+/// The following is a skeleton of a stateful widget subclass called `YellowBird`:
 ///
 /// ```dart
-/// class GreenFrog extends StatefulWidget {
-///   const GreenFrog({ Key key }) : super(key: key);
+/// class YellowBird extends StatefulWidget {
+///   const YellowBird({ Key key }) : super(key: key);
 ///
 ///   @override
-///   _GreenFrogState createState() => new _GreenFrogState();
+///   _YellowBirdState createState() => new _YellowBirdState();
 /// }
 ///
-/// class _GreenFrogState extends State<GreenFrog> {
+/// class _YellowBirdState extends State<YellowBird> {
 ///   @override
 ///   Widget build(BuildContext context) {
-///     return new Container(color: const Color(0xFF2DBD3A));
+///     return new Container(color: const Color(0xFFFFE306));
 ///   }
 /// }
 /// ```
@@ -665,15 +674,15 @@ abstract class StatelessWidget extends Widget {
 /// represented as private member fields. Also, normally widgets have more
 /// constructor arguments, each of which corresponds to a `final` property.
 ///
-/// The next example shows the more generic widget `Frog` which can be given a
+/// The next example shows the more generic widget `Bird` which can be given a
 /// color and a child, and which has some internal state with a method that
 /// can be called to mutate it:
 ///
 /// ```dart
-/// class Frog extends StatefulWidget {
-///   const Frog({
+/// class Bird extends StatefulWidget {
+///   const Bird({
 ///     Key key,
-///     this.color: const Color(0xFF2DBD3A),
+///     this.color: const Color(0xFFFFE306),
 ///     this.child,
 ///   }) : super(key: key);
 ///
@@ -681,10 +690,10 @@ abstract class StatelessWidget extends Widget {
 ///
 ///   final Widget child;
 ///
-///   _FrogState createState() => new _FrogState();
+///   _BirdState createState() => new _BirdState();
 /// }
 ///
-/// class _FrogState extends State<Frog> {
+/// class _BirdState extends State<Bird> {
 ///   double _size = 1.0;
 ///
 ///   void grow() {
@@ -695,7 +704,7 @@ abstract class StatelessWidget extends Widget {
 ///   Widget build(BuildContext context) {
 ///     return new Container(
 ///       color: widget.color,
-///       transform: new Matrix4.diagonalValues(_size, _size, 1.0),
+///       transform: new Matrix4.diagonal3Values(_size, _size, 1.0),
 ///       child: widget.child,
 ///     );
 ///   }
@@ -1309,7 +1318,7 @@ abstract class ProxyWidget extends Widget {
 ///
 /// ```dart
 /// class FrogSize extends ParentDataWidget<FrogJar> {
-///   Pond({
+///   FrogSize({
 ///     Key key,
 ///     @required this.size,
 ///     @required Widget child,
@@ -1425,7 +1434,7 @@ abstract class ParentDataWidget<T extends RenderObjectWidget> extends ProxyWidge
 ///
 /// ```dart
 /// class FrogColor extends InheritedWidget {
-///   const FrogColor(
+///   const FrogColor({
 ///     Key key,
 ///     @required this.color,
 ///     @required Widget child,

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

@@ -408,10 +408,10 @@ class GestureDetector extends StatelessWidget {
 ///       () => new TapGestureRecognizer(),
 ///       (TapGestureRecognizer instance) {
 ///         instance
-///           ..onTapDown = (TapDownDetails details) { setState(() { _last = 'down'; }); },
-///           ..onTapUp = (TapUpDetails details) { setState(() { _last = 'up'; }); },
-///           ..onTap = () { setState(() { _last = 'tap'; }); },
-///           ..onTapCancel = () { setState(() { _last = 'cancel'; }); },
+///           ..onTapDown = (TapDownDetails details) { setState(() { _last = 'down'; }); }
+///           ..onTapUp = (TapUpDetails details) { setState(() { _last = 'up'; }); }
+///           ..onTap = () { setState(() { _last = 'tap'; }); }
+///           ..onTapCancel = () { setState(() { _last = 'cancel'; }); };
 ///       },
 ///     ),
 ///   },