Migrate more doc samples (#72392)
diff --git a/packages/flutter/lib/src/widgets/container.dart b/packages/flutter/lib/src/widgets/container.dart index ff0943c..852ff33 100644 --- a/packages/flutter/lib/src/widgets/container.dart +++ b/packages/flutter/lib/src/widgets/container.dart
@@ -11,8 +11,7 @@ import 'image.dart'; // Examples can assume: -// // @dart = 2.9 -// BuildContext context; +// late BuildContext context; /// A widget that paints a [Decoration] either before or after its child paints. /// @@ -219,7 +218,7 @@ /// ```dart /// Container( /// constraints: BoxConstraints.expand( -/// height: Theme.of(context).textTheme.headline4.fontSize * 1.1 + 200.0, +/// height: Theme.of(context).textTheme.headline4!.fontSize! * 1.1 + 200.0, /// ), /// padding: const EdgeInsets.all(8.0), /// color: Colors.blue[600], @@ -227,7 +226,7 @@ /// child: Text('Hello World', /// style: Theme.of(context) /// .textTheme -/// .headline4 +/// .headline4! /// .copyWith(color: Colors.white)), /// transform: Matrix4.rotationZ(0.1), /// )
diff --git a/packages/flutter/lib/src/widgets/fade_in_image.dart b/packages/flutter/lib/src/widgets/fade_in_image.dart index b44ac4e..1ce7699 100644 --- a/packages/flutter/lib/src/widgets/fade_in_image.dart +++ b/packages/flutter/lib/src/widgets/fade_in_image.dart
@@ -14,8 +14,7 @@ import 'transitions.dart'; // Examples can assume: -// // @dart = 2.9 -// Uint8List bytes; +// late Uint8List bytes; /// An image that shows a [placeholder] image while the target [image] is /// loading, then fades in the new image when it loads.
diff --git a/packages/flutter/lib/src/widgets/framework.dart b/packages/flutter/lib/src/widgets/framework.dart index 1fd9418..e734190 100644 --- a/packages/flutter/lib/src/widgets/framework.dart +++ b/packages/flutter/lib/src/widgets/framework.dart
@@ -30,12 +30,11 @@ export 'package:flutter/rendering.dart' show RenderObject, RenderBox, debugDumpRenderTree, debugDumpLayerTree; // Examples can assume: -// // @dart = 2.9 -// BuildContext context; +// late BuildContext context; // void setState(VoidCallback fn) { } // abstract class RenderFrogJar extends RenderObject { } // abstract class FrogJar extends RenderObjectWidget { } -// abstract class FrogJarParentData extends ParentData { Size size; } +// abstract class FrogJarParentData extends ParentData { late Size size; } // KEYS @@ -624,7 +623,7 @@ /// /// ```dart /// class GreenFrog extends StatelessWidget { -/// const GreenFrog({ Key key }) : super(key: key); +/// const GreenFrog({ Key? key }) : super(key: key); /// /// @override /// Widget build(BuildContext context) { @@ -642,13 +641,13 @@ /// ```dart /// class Frog extends StatelessWidget { /// const Frog({ -/// Key key, +/// Key? key, /// this.color = const Color(0xFF2DBD3A), /// this.child, /// }) : super(key: key); /// /// final Color color; -/// final Widget child; +/// final Widget? child; /// /// @override /// Widget build(BuildContext context) { @@ -841,7 +840,7 @@ /// /// ```dart /// class YellowBird extends StatefulWidget { -/// const YellowBird({ Key key }) : super(key: key); +/// const YellowBird({ Key? key }) : super(key: key); /// /// @override /// _YellowBirdState createState() => _YellowBirdState(); @@ -864,13 +863,13 @@ /// ```dart /// class Bird extends StatefulWidget { /// const Bird({ -/// Key key, +/// Key? key, /// this.color = const Color(0xFFFFE306), /// this.child, /// }) : super(key: key); /// /// final Color color; -/// final Widget child; +/// final Widget? child; /// /// _BirdState createState() => _BirdState(); /// } @@ -1531,21 +1530,19 @@ /// ```dart /// class FrogSize extends ParentDataWidget<FrogJarParentData> { /// FrogSize({ -/// Key key, -/// @required this.size, -/// @required Widget child, -/// }) : assert(child != null), -/// assert(size != null), -/// super(key: key, child: child); +/// Key? key, +/// required this.size, +/// required Widget child, +/// }) : super(key: key, child: child); /// /// final Size size; /// /// @override /// void applyParentData(RenderObject renderObject) { -/// final FrogJarParentData parentData = renderObject.parentData; +/// final FrogJarParentData parentData = renderObject.parentData! as FrogJarParentData; /// if (parentData.size != size) { /// parentData.size = size; -/// final RenderFrogJar targetParent = renderObject.parent; +/// final RenderFrogJar targetParent = renderObject.parent! as RenderFrogJar; /// targetParent.markNeedsLayout(); /// } /// } @@ -1684,17 +1681,17 @@ /// ```dart /// class FrogColor extends InheritedWidget { /// const FrogColor({ -/// Key key, -/// @required this.color, -/// @required Widget child, -/// }) : assert(color != null), -/// assert(child != null), -/// super(key: key, child: child); +/// Key? key, +/// required this.color, +/// required Widget child, +/// }) : super(key: key, child: child); /// /// final Color color; /// /// static FrogColor of(BuildContext context) { -/// return context.dependOnInheritedWidgetOfExactType<FrogColor>(); +/// final FrogColor? result = context.dependOnInheritedWidgetOfExactType<FrogColor>(); +/// assert(result != null, 'No FrogColor found in context'); +/// return result!; /// } /// /// @override @@ -2420,7 +2417,7 @@ /// {@tool snippet} /// /// ```dart - /// ScrollableState scrollable = context.findAncestorStateOfType<ScrollableState>(); + /// ScrollableState? scrollable = context.findAncestorStateOfType<ScrollableState>(); /// ``` /// {@end-tool} T? findAncestorStateOfType<T extends State>(); @@ -4436,7 +4433,7 @@ /// /// It is possible to override this widget. /// -/// {@tool sample --template=freeform_no_null_safety} +/// {@tool sample --template=freeform} /// ```dart /// import 'package:flutter/material.dart'; ///
diff --git a/packages/flutter/lib/src/widgets/page_view.dart b/packages/flutter/lib/src/widgets/page_view.dart index df66139..ff8c88d 100644 --- a/packages/flutter/lib/src/widgets/page_view.dart +++ b/packages/flutter/lib/src/widgets/page_view.dart
@@ -27,9 +27,6 @@ import 'sliver_fill.dart'; import 'viewport.dart'; -// Examples can assume: -// // @dart = 2.9 - /// A controller for [PageView]. /// /// A page controller lets you manipulate which page is visible in a [PageView]. @@ -49,19 +46,13 @@ /// /// ```dart /// class MyPageView extends StatefulWidget { -/// MyPageView({Key key}) : super(key: key); +/// MyPageView({Key? key}) : super(key: key); /// /// _MyPageViewState createState() => _MyPageViewState(); /// } /// /// class _MyPageViewState extends State<MyPageView> { -/// PageController _pageController; -/// -/// @override -/// void initState() { -/// super.initState(); -/// _pageController = PageController(); -/// } +/// PageController _pageController = PageController(); /// /// @override /// void dispose() { @@ -725,7 +716,7 @@ /// }, /// childCount: items.length, /// findChildIndexCallback: (Key key) { - /// final ValueKey valueKey = key; + /// final ValueKey<String> valueKey = key as ValueKey<String>; /// final String data = valueKey.value; /// return items.indexOf(data); /// } @@ -748,7 +739,7 @@ /// } /// /// class KeepAlive extends StatefulWidget { - /// const KeepAlive({Key key, this.data}) : super(key: key); + /// const KeepAlive({Key? key, required this.data}) : super(key: key); /// /// final String data; ///
diff --git a/packages/flutter/lib/src/widgets/scroll_physics.dart b/packages/flutter/lib/src/widgets/scroll_physics.dart index 7af0a1d..9ae3cb3 100644 --- a/packages/flutter/lib/src/widgets/scroll_physics.dart +++ b/packages/flutter/lib/src/widgets/scroll_physics.dart
@@ -17,12 +17,15 @@ export 'package:flutter/physics.dart' show Simulation, ScrollSpringSimulation, Tolerance; // Examples can assume: -// // @dart = 2.9 // class FooScrollPhysics extends ScrollPhysics { -// const FooScrollPhysics({ ScrollPhysics parent }): super(parent: parent); +// const FooScrollPhysics({ ScrollPhysics? parent }): super(parent: parent); +// @override +// FooScrollPhysics applyTo(ScrollPhysics? ancestor) { +// return FooScrollPhysics(parent: buildParent(ancestor)); +// } // } // class BarScrollPhysics extends ScrollPhysics { -// const BarScrollPhysics({ ScrollPhysics parent }): super(parent: parent); +// const BarScrollPhysics({ ScrollPhysics? parent }): super(parent: parent); // } /// Determines the physics of a [Scrollable] widget.
diff --git a/packages/flutter/lib/src/widgets/value_listenable_builder.dart b/packages/flutter/lib/src/widgets/value_listenable_builder.dart index c2d3e37..1d9d32d 100644 --- a/packages/flutter/lib/src/widgets/value_listenable_builder.dart +++ b/packages/flutter/lib/src/widgets/value_listenable_builder.dart
@@ -6,9 +6,6 @@ import 'framework.dart'; -// Examples can assume: -// // @dart = 2.9 - /// Builds a [Widget] when given a concrete value of a [ValueListenable<T>]. /// /// If the `child` parameter provided to the [ValueListenableBuilder] is not @@ -50,7 +47,7 @@ /// /// ```dart /// class MyHomePage extends StatefulWidget { -/// MyHomePage({Key key, this.title}) : super(key: key); +/// MyHomePage({Key? key, required this.title}) : super(key: key); /// final String title; /// /// @override @@ -72,14 +69,14 @@ /// children: <Widget>[ /// Text('You have pushed the button this many times:'), /// ValueListenableBuilder( -/// builder: (BuildContext context, int value, Widget child) { +/// builder: (BuildContext context, int value, Widget? child) { /// // This builder will only get called when the _counter /// // is updated. /// return Row( /// mainAxisAlignment: MainAxisAlignment.spaceEvenly, /// children: <Widget>[ /// Text('$value'), -/// child, +/// child!, /// ], /// ); /// },