`Hero`: Add an example for `createRectTween` (#102650)

examples/api/lib/widgets/heroes/hero.0.dart

@@ -6,29 +6,26 @@
 
 import 'package:flutter/material.dart';
 
-void main() => runApp(const MyApp());
+void main() => runApp(const HeroApp());
 
-class MyApp extends StatelessWidget {
-  const MyApp({Key? key}) : super(key: key);
-
-  static const String _title = 'Flutter Code Sample';
+class HeroApp extends StatelessWidget {
+  const HeroApp({Key? key}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
-      title: _title,
       home: Scaffold(
-        appBar: AppBar(title: const Text(_title)),
+        appBar: AppBar(title: const Text('Hero Sample')),
         body: const Center(
-          child: MyStatelessWidget(),
+          child: HeroExample(),
         ),
       ),
     );
   }
 }
 
-class MyStatelessWidget extends StatelessWidget {
-  const MyStatelessWidget({Key? key}) : super(key: key);
+class HeroExample extends StatelessWidget {
+  const HeroExample({Key? key}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
@@ -41,17 +38,18 @@ class MyStatelessWidget extends StatelessWidget {
         ListTile(
           leading: Hero(
             tag: 'hero-rectangle',
-            child: _blueRectangle(const Size(50, 50)),
+            child: _box(const Size(50, 50)),
           ),
           onTap: () => _gotoDetailsPage(context),
-          title:
-              const Text('Tap on the icon to view hero animation transition.'),
+          title: const Text(
+            'Tap on the icon to view hero animation transition.',
+          ),
         ),
       ],
     );
   }
 
-  Widget _blueRectangle(Size size) {
+  Widget _box(Size size) {
     return Container(
       width: size.width,
       height: size.height,
@@ -63,7 +61,7 @@ class MyStatelessWidget extends StatelessWidget {
     Navigator.of(context).push(MaterialPageRoute<void>(
       builder: (BuildContext context) => Scaffold(
         appBar: AppBar(
-          title: const Text('second Page'),
+          title: const Text('Second Page'),
         ),
         body: Center(
           child: Column(
@@ -71,7 +69,7 @@ class MyStatelessWidget extends StatelessWidget {
             children: <Widget>[
               Hero(
                 tag: 'hero-rectangle',
-                child: _blueRectangle(const Size(200, 200)),
+                child: _box(const Size(200, 200)),
               ),
             ],
           ),

examples/api/lib/widgets/heroes/hero.1.dart

+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flutter code sample for Hero
+
+import 'package:flutter/material.dart';
+import 'package:flutter/scheduler.dart';
+
+void main() {
+  // Slow down time to see Hero flight animation.
+  timeDilation = 15.0;
+  runApp(const HeroApp());
+}
+
+class HeroApp extends StatelessWidget {
+  const HeroApp({Key? key}) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      home: Scaffold(
+        appBar: AppBar(title: const Text('Hero Sample')),
+        body: const Center(
+          child: HeroExample(),
+        ),
+      ),
+    );
+  }
+}
+
+class HeroExample extends StatelessWidget {
+  const HeroExample({Key? key}) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return Column(
+      children: <Widget>[
+        ListTile(
+          leading: Hero(
+            tag: 'hero-default-tween',
+            child: _box(size: 50.0, color: Colors.red[700]!.withOpacity(0.5)),
+          ),
+          title: const Text(
+            'This red icon will use a default rect tween during the hero flight.',
+          ),
+        ),
+        const SizedBox(height: 10.0),
+        ListTile(
+          leading: Hero(
+            tag: 'hero-custom-tween',
+            createRectTween: (Rect? begin, Rect? end) {
+              return MaterialRectCenterArcTween(begin: begin, end: end);
+            },
+            child: _box(size: 50.0, color: Colors.blue[700]!.withOpacity(0.5)),
+          ),
+          title: const Text(
+            'This blue icon will use a custom rect tween during the hero flight.',
+          ),
+        ),
+        const SizedBox(height: 10),
+        ElevatedButton(
+          onPressed: () => _gotoDetailsPage(context),
+          child: const Text('Tap to trigger hero flight'),
+        ),
+      ],
+    );
+  }
+
+  Widget _box({double? size, Color? color}) {
+    return Container(
+      color: color,
+      child: FlutterLogo(size: size),
+    );
+  }
+
+  void _gotoDetailsPage(BuildContext context) {
+    Navigator.of(context).push(MaterialPageRoute<void>(
+      builder: (BuildContext context) => Scaffold(
+        appBar: AppBar(
+          title: const Text('Second Page'),
+        ),
+        body: Align(
+          alignment: Alignment.bottomRight,
+          child: Stack(
+            children: <Widget>[
+              Hero(
+                tag: 'hero-custom-tween',
+                createRectTween: (Rect? begin, Rect? end) {
+                  return MaterialRectCenterArcTween(begin: begin, end: end);
+                },
+                child: _box(
+                  size: 400.0,
+                  color: Colors.blue[700]!.withOpacity(0.5),
+                ),
+              ),
+              Hero(
+                tag: 'hero-default-tween',
+                child: _box(
+                  size: 400.0,
+                  color: Colors.red[700]!.withOpacity(0.5),
+                ),
+              ),
+            ],
+          ),
+        ),
+      ),
+    ));
+  }
+}

examples/api/test/widgets/heroes/hero.0_test.dart

+// Copyright 2014 The Flutter 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 'package:flutter/material.dart';
+import 'package:flutter_api_samples/widgets/heroes/hero.0.dart' as example;
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  testWidgets('Has Hero animation', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      const example.HeroApp(),
+    );
+
+    expect(find.text('Hero Sample'), findsOneWidget);
+    await tester.tap(find.byType(Container));
+    await tester.pump();
+
+    Size heroSize = tester.getSize(find.byType(Container));
+
+    // Jump 25% into the transition (total length = 300ms)
+    await tester.pump(const Duration(milliseconds: 75)); // 25% of 300ms
+    heroSize = tester.getSize(find.byType(Container));
+    expect(heroSize.width.roundToDouble(), 103.0);
+    expect(heroSize.height.roundToDouble(), 60.0);
+
+    // Jump to 50% into the transition.
+    await tester.pump(const Duration(milliseconds: 75)); // 25% of 300ms
+    heroSize = tester.getSize(find.byType(Container));
+    expect(heroSize.width.roundToDouble(), 189.0);
+    expect(heroSize.height.roundToDouble(), 146.0);
+
+    // Jump to 75% into the transition.
+    await tester.pump(const Duration(milliseconds: 75)); // 25% of 300ms
+    heroSize = tester.getSize(find.byType(Container));
+    expect(heroSize.width.roundToDouble(), 199.0);
+    expect(heroSize.height.roundToDouble(), 190.0);
+
+    // Jump to 100% into the transition.
+    await tester.pump(const Duration(milliseconds: 75)); // 25% of 300ms
+    heroSize = tester.getSize(find.byType(Container));
+    expect(heroSize, const Size(200.0, 200.0));
+
+    expect(find.byIcon(Icons.arrow_back), findsOneWidget);
+    await tester.tap(find.byIcon(Icons.arrow_back));
+    await tester.pump();
+
+    // Jump 25% into the transition (total length = 300ms)
+    await tester.pump(const Duration(milliseconds: 75)); // 25% of 300ms
+    heroSize = tester.getSize(find.byType(Container));
+    expect(heroSize.width.roundToDouble(), 199.0);
+    expect(heroSize.height.roundToDouble(), 190.0);
+
+    // Jump to 50% into the transition.
+    await tester.pump(const Duration(milliseconds: 75)); // 25% of 300ms
+    heroSize = tester.getSize(find.byType(Container));
+    expect(heroSize.width.roundToDouble(), 189.0);
+    expect(heroSize.height.roundToDouble(), 146.0);
+
+    // Jump to 75% into the transition.
+    await tester.pump(const Duration(milliseconds: 75)); // 25% of 300ms
+    heroSize = tester.getSize(find.byType(Container));
+    expect(heroSize.width.roundToDouble(), 103.0);
+    expect(heroSize.height.roundToDouble(), 60.0);
+
+    // Jump to 100% into the transition.
+    await tester.pump(const Duration(milliseconds: 75)); // 25% of 300ms
+    heroSize = tester.getSize(find.byType(Container));
+    expect(heroSize, const Size(50.0, 50.0));
+  });
+}

examples/api/test/widgets/heroes/hero.1_test.dart

+// Copyright 2014 The Flutter 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 'package:flutter/material.dart';
+import 'package:flutter_api_samples/widgets/heroes/hero.1.dart' as example;
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  testWidgets('Hero flight animation with default rect tween', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      const example.HeroApp(),
+    );
+
+    expect(find.text('Hero Sample'), findsOneWidget);
+    await tester.tap(find.byType(ElevatedButton));
+    await tester.pump();
+
+    Size heroSize = tester.getSize(find.byType(Container).first);
+    expect(heroSize, const Size(50.0, 50.0));
+
+    // Jump 25% into the transition (total length = 300ms)
+    await tester.pump(const Duration(milliseconds: 75)); // 25% of 300ms
+    heroSize = tester.getSize(find.byType(Container).first);
+    expect(heroSize.width.roundToDouble(), 171.0);
+    expect(heroSize.height.roundToDouble(), 73.0);
+
+    // Jump to 50% into the transition.
+    await tester.pump(const Duration(milliseconds: 75)); // 25% of 300ms
+    heroSize = tester.getSize(find.byType(Container).first);
+    expect(heroSize.width.roundToDouble(), 371.0);
+    expect(heroSize.height.roundToDouble(), 273.0);
+
+    // Jump to 75% into the transition.
+    await tester.pump(const Duration(milliseconds: 75)); // 25% of 300ms
+    heroSize = tester.getSize(find.byType(Container).first);
+    expect(heroSize.width.roundToDouble(), 398.0);
+    expect(heroSize.height.roundToDouble(), 376.0);
+
+    // Jump to 100% into the transition.
+    await tester.pump(const Duration(milliseconds: 75)); // 25% of 300ms
+    heroSize = tester.getSize(find.byType(Container).first);
+    expect(heroSize, const Size(400.0, 400.0));
+
+    expect(find.byIcon(Icons.arrow_back), findsOneWidget);
+    await tester.tap(find.byIcon(Icons.arrow_back));
+    await tester.pump();
+
+    // Jump 25% into the transition (total length = 300ms)
+    await tester.pump(const Duration(milliseconds: 75)); // 25% of 300ms
+    heroSize = tester.getSize(find.byType(Container).first);
+    expect(heroSize.width.roundToDouble(), 398.0);
+    expect(heroSize.height.roundToDouble(), 376.0);
+
+    // Jump to 50% into the transition.
+    await tester.pump(const Duration(milliseconds: 75)); // 25% of 300ms
+    heroSize = tester.getSize(find.byType(Container).first);
+    expect(heroSize.width.roundToDouble(), 371.0);
+    expect(heroSize.height.roundToDouble(), 273.0);
+
+    // Jump to 75% into the transition.
+    await tester.pump(const Duration(milliseconds: 75)); // 25% of 300ms
+    heroSize = tester.getSize(find.byType(Container).first);
+    expect(heroSize.width.roundToDouble(), 171.0);
+    expect(heroSize.height.roundToDouble(), 73.0);
+
+    // Jump to 100% into the transition.
+    await tester.pump(const Duration(milliseconds: 75)); // 25% of 300ms
+    heroSize = tester.getSize(find.byType(Container).first);
+    expect(heroSize, const Size(50.0, 50.0));
+  });
+
+  testWidgets('Hero flight animation with custom rect tween', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      const example.HeroApp(),
+    );
+
+    expect(find.text('Hero Sample'), findsOneWidget);
+    await tester.tap(find.byType(ElevatedButton));
+    await tester.pump();
+
+    Size heroSize = tester.getSize(find.byType(Container).last);
+    expect(heroSize, const Size(50.0, 50.0));
+
+    // Jump 25% into the transition (total length = 300ms)
+    await tester.pump(const Duration(milliseconds: 75)); // 25% of 300ms
+    heroSize = tester.getSize(find.byType(Container).last);
+    expect(heroSize.width.roundToDouble(), 133.0);
+    expect(heroSize.height.roundToDouble(), 133.0);
+
+    // Jump to 50% into the transition.
+    await tester.pump(const Duration(milliseconds: 75)); // 25% of 300ms
+    heroSize = tester.getSize(find.byType(Container).last);
+    expect(heroSize.width.roundToDouble(), 321.0);
+    expect(heroSize.height.roundToDouble(), 321.0);
+
+    // Jump to 75% into the transition.
+    await tester.pump(const Duration(milliseconds: 75)); // 25% of 300ms
+    heroSize = tester.getSize(find.byType(Container).first);
+    expect(heroSize.width.roundToDouble(), 398.0);
+    expect(heroSize.height.roundToDouble(), 376.0);
+
+    // Jump to 100% into the transition.
+    await tester.pump(const Duration(milliseconds: 75)); // 25% of 300ms
+    heroSize = tester.getSize(find.byType(Container).last);
+    expect(heroSize, const Size(400.0, 400.0));
+
+    expect(find.byIcon(Icons.arrow_back), findsOneWidget);
+    await tester.tap(find.byIcon(Icons.arrow_back));
+    await tester.pump();
+
+    // Jump 25% into the transition (total length = 300ms)
+    await tester.pump(const Duration(milliseconds: 75)); // 25% of 300ms
+    heroSize = tester.getSize(find.byType(Container).last);
+    expect(heroSize.width.roundToDouble(), 386.0);
+    expect(heroSize.height.roundToDouble(), 386.0);
+
+    // Jump to 50% into the transition.
+    await tester.pump(const Duration(milliseconds: 75)); // 25% of 300ms
+    heroSize = tester.getSize(find.byType(Container).last);
+    expect(heroSize.width.roundToDouble(), 321.0);
+    expect(heroSize.height.roundToDouble(), 321.0);
+
+    // Jump to 75% into the transition.
+    await tester.pump(const Duration(milliseconds: 75)); // 25% of 300ms
+    heroSize = tester.getSize(find.byType(Container).last);
+    expect(heroSize.width.roundToDouble(), 133.0);
+    expect(heroSize.height.roundToDouble(), 133.0);
+
+    // Jump to 100% into the transition.
+    await tester.pump(const Duration(milliseconds: 75)); // 25% of 300ms
+    heroSize = tester.getSize(find.byType(Container).last);
+    expect(heroSize, const Size(50.0, 50.0));
+  });
+}

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

@@ -71,7 +71,6 @@ enum HeroFlightDirection {
   pop,
 }
 
-
 /// A widget that marks its child as being a candidate for
 /// [hero animations](https://flutter.dev/docs/development/ui/animations/hero-animations).
 ///
@@ -116,6 +115,13 @@ enum HeroFlightDirection {
 /// ** See code in examples/api/lib/widgets/heroes/hero.0.dart **
 /// {@end-tool}
 ///
+/// {@tool dartpad}
+/// This sample shows [Hero] flight animations using default tween
+/// and custom rect tween.
+///
+/// ** See code in examples/api/lib/widgets/heroes/hero.1.dart **
+/// {@end-tool}
+///
 /// ## Discussion
 ///
 /// Heroes and the [Navigator]'s [Overlay] [Stack] must be axis-aligned for

packages/flutter/test/widgets/heroes_test.dart

@@ -2649,7 +2649,6 @@ Future<void> main() async {
       end: const Size(100, 100),
     ).chain(CurveTween(curve: Curves.fastOutSlowIn));
 
-
     await tester.pumpWidget(
       MaterialApp(
         navigatorKey: navigator,