✨ Android Q transition by default (#98559)

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

@@ -63,19 +63,24 @@ class MaterialPageRoute<T> extends PageRoute<T> with MaterialRouteTransitionMixi
 /// A mixin that provides platform-adaptive transitions for a [PageRoute].
 ///
 /// {@template flutter.material.materialRouteTransitionMixin}
-/// For Android, the entrance transition for the page slides the route upwards
-/// and fades it in. The exit transition is the same, but in reverse.
-///
-/// The transition is adaptive to the platform and on iOS, the route slides in
-/// from the right and exits in reverse. The route also shifts to the left in
-/// parallax when another page enters to cover it. (These directions are flipped
-/// in environments with a right-to-left reading direction.)
+/// For Android, the entrance transition for the page zooms in and fades in
+/// while the exiting page zooms out and fades out. The exit transition is similar,
+/// but in reverse.
+///
+/// For iOS, the page slides in from the right and exits in reverse. The page
+/// also shifts to the left in parallax when another page enters to cover it.
+/// (These directions are flipped in environments with a right-to-left reading
+/// direction.)
 /// {@endtemplate}
 ///
 /// See also:
 ///
 ///  * [PageTransitionsTheme], which defines the default page transitions used
 ///    by the [MaterialRouteTransitionMixin.buildTransitions].
+///  * [ZoomPageTransitionsBuilder], which is the default page transition used
+///    by the [PageTransitionsTheme].
+///  * [CupertinoPageTransitionsBuilder], which is the default page transition
+///    for iOS and macOS.
 mixin MaterialRouteTransitionMixin<T> on PageRoute<T> {
   /// Builds the primary contents of the route.
   @protected

packages/flutter/test/material/bottom_navigation_bar_theme_test.dart

@@ -151,13 +151,27 @@ void main() {
       ),
     );
 
+    final Finder findACTransform = find.descendant(
+      of: find.byType(BottomNavigationBar),
+      matching: find.ancestor(
+        of: find.text('AC'),
+        matching: find.byType(Transform),
+      ),
+    );
+    final Finder findAlarmTransform = find.descendant(
+      of: find.byType(BottomNavigationBar),
+      matching: find.ancestor(
+        of: find.text('Alarm'),
+        matching: find.byType(Transform),
+      ),
+    );
     final TextStyle selectedFontStyle = tester.renderObject<RenderParagraph>(find.text('AC')).text.style!;
     final TextStyle selectedIcon = _iconStyle(tester, Icons.ac_unit);
     final TextStyle unselectedIcon = _iconStyle(tester, Icons.access_alarm);
     expect(selectedFontStyle.fontSize, selectedFontStyle.fontSize);
     // Unselected label has a font size of 22 but is scaled down to be font size 21.
     expect(
-      tester.firstWidget<Transform>(find.ancestor(of: find.text('Alarm'), matching: find.byType(Transform))).transform,
+      tester.firstWidget<Transform>(findAlarmTransform).transform,
       equals(Matrix4.diagonal3(Vector3.all(unselectedTextStyle.fontSize! / selectedTextStyle.fontSize!))),
     );
     expect(selectedIcon.color, equals(selectedItemColor));
@@ -179,14 +193,8 @@ void main() {
     expect(_material(tester).elevation, equals(elevation));
     expect(_material(tester).color, equals(backgroundColor));
 
-    final Offset selectedBarItem = tester.getCenter(
-      find.ancestor(of: find.text('AC'),
-      matching: find.byType(Transform))
-    );
-    final Offset unselectedBarItem = tester.getCenter(
-      find.ancestor(of: find.text('Alarm'),
-      matching: find.byType(Transform))
-    );
+    final Offset selectedBarItem = tester.getCenter(findACTransform);
+    final Offset unselectedBarItem = tester.getCenter(findAlarmTransform);
     final TestGesture gesture = await tester.createGesture(kind: PointerDeviceKind.mouse);
     await gesture.addPointer();
     addTearDown(gesture.removePointer);
@@ -270,13 +278,27 @@ void main() {
       ),
     );
 
+    Finder findDescendantOfBottomNavigationBar(Finder finder) {
+      return find.descendant(
+        of: find.byType(BottomNavigationBar),
+        matching: finder,
+      );
+    }
+
     final TextStyle selectedFontStyle = tester.renderObject<RenderParagraph>(find.text('AC')).text.style!;
     final TextStyle selectedIcon = _iconStyle(tester, Icons.ac_unit);
     final TextStyle unselectedIcon = _iconStyle(tester, Icons.access_alarm);
     expect(selectedFontStyle.fontSize, selectedFontStyle.fontSize);
     // Unselected label has a font size of 22 but is scaled down to be font size 21.
     expect(
-      tester.firstWidget<Transform>(find.ancestor(of: find.text('Alarm'), matching: find.byType(Transform))).transform,
+      tester.firstWidget<Transform>(
+        findDescendantOfBottomNavigationBar(
+          find.ancestor(
+            of: find.text('Alarm'),
+            matching: find.byType(Transform),
+          ),
+        ),
+      ).transform,
       equals(Matrix4.diagonal3(Vector3.all(unselectedTextStyle.fontSize! / selectedTextStyle.fontSize!))),
     );
     expect(selectedIcon.color, equals(selectedItemColor));
@@ -285,13 +307,11 @@ void main() {
     expect(unselectedIcon.fontSize, equals(unselectedIconTheme.size));
     // There should not be any [Opacity] or [FadeTransition] widgets
     // since showUnselectedLabels and showSelectedLabels are true.
-    final Finder findOpacity = find.descendant(
-      of: find.byType(BottomNavigationBar),
-      matching: find.byType(Opacity),
+    final Finder findOpacity = findDescendantOfBottomNavigationBar(
+      find.byType(Opacity),
     );
-    final Finder findFadeTransition = find.descendant(
-      of: find.byType(BottomNavigationBar),
-      matching: find.byType(FadeTransition),
+    final Finder findFadeTransition = findDescendantOfBottomNavigationBar(
+      find.byType(FadeTransition),
     );
     expect(findOpacity, findsNothing);
     expect(findFadeTransition, findsNothing);
@@ -299,8 +319,12 @@ void main() {
     expect(_material(tester).color, equals(backgroundColor));
 
     final Offset barItem = tester.getCenter(
-      find.ancestor(of: find.text('AC'),
-      matching: find.byType(Transform))
+      findDescendantOfBottomNavigationBar(
+        find.ancestor(
+          of: find.text('AC'),
+          matching: find.byType(Transform),
+        ),
+      ),
     );
     final TestGesture gesture = await tester.createGesture(kind: PointerDeviceKind.mouse);
     await gesture.addPointer();

packages/flutter/test/material/data_table_test.dart

@@ -467,7 +467,11 @@ void main() {
       home: Material(child: buildTable()),
     ));
     // The `tester.widget` ensures that there is exactly one upward arrow.
-    Transform transformOfArrow = tester.widget<Transform>(find.widgetWithIcon(Transform, Icons.arrow_upward));
+    final Finder iconFinder = find.descendant(
+      of: find.byType(DataTable),
+      matching: find.widgetWithIcon(Transform, Icons.arrow_upward),
+    );
+    Transform transformOfArrow = tester.widget<Transform>(iconFinder);
     expect(
       transformOfArrow.transform.getRotation(),
       equals(Matrix3.identity()),
@@ -479,7 +483,7 @@ void main() {
     ));
     await tester.pumpAndSettle();
     // The `tester.widget` ensures that there is exactly one upward arrow.
-    transformOfArrow = tester.widget<Transform>(find.widgetWithIcon(Transform, Icons.arrow_upward));
+    transformOfArrow = tester.widget<Transform>(iconFinder);
     expect(
       transformOfArrow.transform.getRotation(),
       equals(Matrix3.rotationZ(math.pi)),
@@ -515,7 +519,10 @@ void main() {
       home: Material(child: buildTable()),
     ));
     // The `tester.widget` ensures that there is exactly one upward arrow.
-    final Finder iconFinder = find.widgetWithIcon(Transform, Icons.arrow_upward);
+    final Finder iconFinder = find.descendant(
+      of: find.byType(DataTable),
+      matching: find.widgetWithIcon(Transform, Icons.arrow_upward),
+    );
     Transform transformOfArrow = tester.widget<Transform>(iconFinder);
     expect(
       transformOfArrow.transform.getRotation(),
@@ -565,7 +572,10 @@ void main() {
       home: Material(child: buildTable()),
     ));
     // The `tester.widget` ensures that there is exactly one upward arrow.
-    final Finder iconFinder = find.widgetWithIcon(Transform, Icons.arrow_upward);
+    final Finder iconFinder = find.descendant(
+      of: find.byType(DataTable),
+      matching: find.widgetWithIcon(Transform, Icons.arrow_upward),
+    );
     Transform transformOfArrow = tester.widget<Transform>(iconFinder);
     expect(
       transformOfArrow.transform.getRotation(),

packages/flutter/test/material/flexible_space_bar_test.dart

@@ -102,7 +102,12 @@ void main() {
     );
 
     final RenderBox clipRect = tester.renderObject(find.byType(ClipRect).first);
-    final Transform transform = tester.firstWidget(find.byType(Transform));
+    final Transform transform = tester.firstWidget(
+      find.descendant(
+        of: find.byType(FlexibleSpaceBar),
+        matching: find.byType(Transform),
+      ),
+    );
 
     // The current (200) is half way between the min (100) and max (300) and the
     // lerp values used to calculate the scale are 1 and 1.5, so we check for 1.25.

packages/flutter/test/material/page_test.dart

@@ -10,10 +10,17 @@ import 'package:flutter_test/flutter_test.dart';
 import '../rendering/mock_canvas.dart';
 
 void main() {
-  testWidgets('test page transition', (WidgetTester tester) async {
+  testWidgets('test page transition (_FadeUpwardsPageTransition)', (WidgetTester tester) async {
     await tester.pumpWidget(
       MaterialApp(
         home: const Material(child: Text('Page 1')),
+        theme: ThemeData(
+          pageTransitionsTheme: const PageTransitionsTheme(
+            builders: <TargetPlatform, PageTransitionsBuilder>{
+              TargetPlatform.android: FadeUpwardsPageTransitionsBuilder(),
+            },
+          ),
+        ),
         routes: <String, WidgetBuilder>{
           '/next': (BuildContext context) {
             return const Material(child: Text('Page 2'));
@@ -67,7 +74,7 @@ void main() {
     expect(find.text('Page 2'), findsNothing);
   }, variant: TargetPlatformVariant.only(TargetPlatform.android));
 
-  testWidgets('test page transition', (WidgetTester tester) async {
+  testWidgets('test page transition (CupertinoPageTransition)', (WidgetTester tester) async {
     final Key page2Key = UniqueKey();
     await tester.pumpWidget(
       MaterialApp(
@@ -148,6 +155,80 @@ void main() {
     expect(widget1InitialTopLeft == widget1TransientTopLeft, true);
   }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS, TargetPlatform.macOS }));
 
+  testWidgets('test page transition (_ZoomPageTransition)', (WidgetTester tester) async {
+    Iterable<T> _findWidgets<T extends Widget>(Finder of) {
+      return tester.widgetList<T>(
+        find.ancestor(of: of, matching: find.byType(T)),
+      );
+    }
+
+    FadeTransition _findForwardFadeTransition(Finder of) {
+      return _findWidgets<FadeTransition>(of).where(
+            (FadeTransition t) => t.opacity.status == AnimationStatus.forward,
+      ).first;
+    }
+
+    ScaleTransition _findForwardScaleTransition(Finder of) {
+      return _findWidgets<ScaleTransition>(of).where(
+            (ScaleTransition t) => t.scale.status == AnimationStatus.forward,
+      ).first;
+    }
+
+    await tester.pumpWidget(
+      MaterialApp(
+        home: const Material(child: Text('Page 1')),
+        routes: <String, WidgetBuilder>{
+          '/next': (BuildContext context) {
+            return const Material(child: Text('Page 2'));
+          },
+        },
+      ),
+    );
+
+    tester.state<NavigatorState>(find.byType(Navigator)).pushNamed('/next');
+    await tester.pump();
+    await tester.pump(const Duration(milliseconds: 50));
+
+    ScaleTransition widget1Scale = _findForwardScaleTransition(find.text('Page 1'));
+    ScaleTransition widget2Scale = _findForwardScaleTransition(find.text('Page 2'));
+    FadeTransition widget2Opacity = _findForwardFadeTransition(find.text('Page 2'));
+
+    // Page 1 is enlarging, starts from 1.0.
+    expect(widget1Scale.scale.value, greaterThan(1.0));
+    // Page 2 is enlarging from the value less than 1.0.
+    expect(widget2Scale.scale.value, lessThan(1.0));
+    // Page 2 is becoming none transparent.
+    expect(widget2Opacity.opacity.value, lessThan(1.0));
+
+    await tester.pump(const Duration(milliseconds: 250));
+    await tester.pump(const Duration(milliseconds: 1));
+
+    // Page 2 covers page 1.
+    expect(find.text('Page 1'), findsNothing);
+    expect(find.text('Page 2'), isOnstage);
+
+    tester.state<NavigatorState>(find.byType(Navigator)).pop();
+    await tester.pump();
+    await tester.pump(const Duration(milliseconds: 100));
+
+    widget1Scale = _findForwardScaleTransition(find.text('Page 1'));
+    widget2Scale = _findForwardScaleTransition(find.text('Page 2'));
+    widget2Opacity = _findForwardFadeTransition(find.text('Page 2'));
+
+    // Page 1 is narrowing down, but still larger than 1.0.
+    expect(widget1Scale.scale.value, greaterThan(1.0));
+    // Page 2 is smaller than 1.0.
+    expect(widget2Scale.scale.value, lessThan(1.0));
+    // Page 2 is becoming transparent.
+    expect(widget2Opacity.opacity.value, lessThan(1.0));
+
+    await tester.pump(const Duration(milliseconds: 200));
+    await tester.pump(const Duration(milliseconds: 1));
+
+    expect(find.text('Page 1'), isOnstage);
+    expect(find.text('Page 2'), findsNothing);
+  }, variant: TargetPlatformVariant.only(TargetPlatform.android));
+
   testWidgets('test fullscreen dialog transition', (WidgetTester tester) async {
     await tester.pumpWidget(
       const MaterialApp(

packages/flutter/test/material/page_transitions_theme_test.dart

@@ -13,15 +13,30 @@ void main() {
     final PageTransitionsTheme theme = Theme.of(tester.element(find.text('home'))).pageTransitionsTheme;
     expect(theme.builders, isNotNull);
     for (final TargetPlatform platform in TargetPlatform.values) {
-      if (platform == TargetPlatform.fuchsia) {
-        // No builder on Fuchsia.
-        continue;
+      switch (platform) {
+        case TargetPlatform.android:
+        case TargetPlatform.iOS:
+        case TargetPlatform.macOS:
+          expect(
+            theme.builders[platform],
+            isNotNull,
+            reason: 'theme builder for $platform is null',
+          );
+          break;
+        case TargetPlatform.fuchsia:
+        case TargetPlatform.linux:
+        case TargetPlatform.windows:
+          expect(
+            theme.builders[platform],
+            isNull,
+            reason: 'theme builder for $platform is not null',
+          );
+          break;
       }
-      expect(theme.builders[platform], isNotNull, reason: 'theme builder for $platform is null');
     }
   });
 
-  testWidgets('Default PageTransitionsTheme builds a CupertionPageTransition', (WidgetTester tester) async {
+  testWidgets('Default PageTransitionsTheme builds a CupertinoPageTransition', (WidgetTester tester) async {
     final Map<String, WidgetBuilder> routes = <String, WidgetBuilder>{
       '/': (BuildContext context) => Material(
         child: TextButton(
@@ -47,7 +62,7 @@ void main() {
     expect(find.byType(CupertinoPageTransition), findsOneWidget);
   }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
 
-  testWidgets('Default PageTransitionsTheme builds a _FadeUpwardsPageTransition for android', (WidgetTester tester) async {
+  testWidgets('Default PageTransitionsTheme builds a _ZoomPageTransition for android', (WidgetTester tester) async {
     final Map<String, WidgetBuilder> routes = <String, WidgetBuilder>{
       '/': (BuildContext context) => Material(
         child: TextButton(
@@ -64,20 +79,20 @@ void main() {
       ),
     );
 
-    Finder findFadeUpwardsPageTransition() {
+    Finder findZoomPageTransition() {
       return find.descendant(
         of: find.byType(MaterialApp),
-        matching: find.byWidgetPredicate((Widget w) => '${w.runtimeType}' == '_FadeUpwardsPageTransition'),
+        matching: find.byWidgetPredicate((Widget w) => '${w.runtimeType}' == '_ZoomPageTransition'),
       );
     }
 
     expect(Theme.of(tester.element(find.text('push'))).platform, debugDefaultTargetPlatformOverride);
-    expect(findFadeUpwardsPageTransition(), findsOneWidget);
+    expect(findZoomPageTransition(), findsOneWidget);
 
     await tester.tap(find.text('push'));
     await tester.pumpAndSettle();
     expect(find.text('page b'), findsOneWidget);
-    expect(findFadeUpwardsPageTransition(), findsOneWidget);
+    expect(findZoomPageTransition(), findsOneWidget);
   }, variant: TargetPlatformVariant.only(TargetPlatform.android));
 
   testWidgets('PageTransitionsTheme override builds a _OpenUpwardsPageTransition', (WidgetTester tester) async {
@@ -120,7 +135,7 @@ void main() {
     expect(findOpenUpwardsPageTransition(), findsOneWidget);
   }, variant: TargetPlatformVariant.only(TargetPlatform.android));
 
-  testWidgets('PageTransitionsTheme override builds a _ZoomPageTransition', (WidgetTester tester) async {
+  testWidgets('PageTransitionsTheme override builds a _FadeUpwardsTransition', (WidgetTester tester) async {
     final Map<String, WidgetBuilder> routes = <String, WidgetBuilder>{
       '/': (BuildContext context) => Material(
         child: TextButton(
@@ -136,7 +151,7 @@ void main() {
         theme: ThemeData(
           pageTransitionsTheme: const PageTransitionsTheme(
             builders: <TargetPlatform, PageTransitionsBuilder>{
-              TargetPlatform.android: ZoomPageTransitionsBuilder(), // creates a _ZoomPageTransition
+              TargetPlatform.android: FadeUpwardsPageTransitionsBuilder(), // creates a _FadeUpwardsTransition
             },
           ),
         ),
@@ -144,20 +159,20 @@ void main() {
       ),
     );
 
-    Finder findZoomPageTransition() {
+    Finder findFadeUpwardsPageTransition() {
       return find.descendant(
         of: find.byType(MaterialApp),
-        matching: find.byWidgetPredicate((Widget w) => '${w.runtimeType}' == '_ZoomPageTransition'),
+        matching: find.byWidgetPredicate((Widget w) => '${w.runtimeType}' == '_FadeUpwardsPageTransition'),
       );
     }
 
     expect(Theme.of(tester.element(find.text('push'))).platform, debugDefaultTargetPlatformOverride);
-    expect(findZoomPageTransition(), findsOneWidget);
+    expect(findFadeUpwardsPageTransition(), findsOneWidget);
 
     await tester.tap(find.text('push'));
     await tester.pumpAndSettle();
     expect(find.text('page b'), findsOneWidget);
-    expect(findZoomPageTransition(), findsOneWidget);
+    expect(findFadeUpwardsPageTransition(), findsOneWidget);
   }, variant: TargetPlatformVariant.only(TargetPlatform.android));
 
   testWidgets('_ZoomPageTransition only cause child widget built once', (WidgetTester tester) async {

packages/flutter/test/material/user_accounts_drawer_header_test.dart

@@ -70,6 +70,12 @@ Future<void> pumpTestWidget(
 }
 
 void main() {
+  // Find the exact transform which is the descendant of [UserAccountsDrawerHeader].
+  final Finder findTransform = find.descendant(
+    of: find.byType(UserAccountsDrawerHeader),
+    matching: find.byType(Transform),
+  );
+
   testWidgets('UserAccountsDrawerHeader test', (WidgetTester tester) async {
     await pumpTestWidget(tester);
 
@@ -127,7 +133,7 @@ void main() {
 
   testWidgets('UserAccountsDrawerHeader icon rotation test', (WidgetTester tester) async {
     await pumpTestWidget(tester);
-    Transform transformWidget = tester.firstWidget(find.byType(Transform));
+    Transform transformWidget = tester.firstWidget(findTransform);
 
     // Icon is right side up.
     expect(transformWidget.transform.getRotation()[0], 1.0);
@@ -140,7 +146,7 @@ void main() {
 
     await tester.pumpAndSettle();
     await tester.pump();
-    transformWidget = tester.firstWidget(find.byType(Transform));
+    transformWidget = tester.firstWidget(findTransform);
 
     // Icon has rotated 180 degrees.
     expect(transformWidget.transform.getRotation()[0], -1.0);
@@ -153,7 +159,7 @@ void main() {
 
     await tester.pumpAndSettle();
     await tester.pump();
-    transformWidget = tester.firstWidget(find.byType(Transform));
+    transformWidget = tester.firstWidget(findTransform);
 
     // Icon has rotated 180 degrees back to the original position.
     expect(transformWidget.transform.getRotation()[0], 1.0);
@@ -178,7 +184,7 @@ void main() {
       ),
     ));
 
-    Transform transformWidget = tester.firstWidget(find.byType(Transform));
+    Transform transformWidget = tester.firstWidget(findTransform);
 
     // Icon is right side up.
     expect(transformWidget.transform.getRotation()[0], 1.0);
@@ -189,7 +195,7 @@ void main() {
     expect(tester.hasRunningAnimations, isFalse);
 
     expect(await tester.pumpAndSettle(), 1);
-    transformWidget = tester.firstWidget(find.byType(Transform));
+    transformWidget = tester.firstWidget(findTransform);
 
     // Icon has not rotated.
     expect(transformWidget.transform.getRotation()[0], 1.0);
@@ -198,7 +204,7 @@ void main() {
 
   testWidgets('UserAccountsDrawerHeader icon rotation test speeeeeedy', (WidgetTester tester) async {
     await pumpTestWidget(tester);
-    Transform transformWidget = tester.firstWidget(find.byType(Transform));
+    Transform transformWidget = tester.firstWidget(findTransform);
 
     // Icon is right side up.
     expect(transformWidget.transform.getRotation()[0], 1.0);
@@ -230,7 +236,7 @@ void main() {
 
     await tester.pumpAndSettle();
     await tester.pump();
-    transformWidget = tester.firstWidget(find.byType(Transform));
+    transformWidget = tester.firstWidget(findTransform);
 
     // Icon has rotated 180 degrees back to the original position.
     expect(transformWidget.transform.getRotation()[0], 1.0);

packages/flutter/test/widgets/heroes_test.dart

@@ -728,7 +728,14 @@ Future<void> main() async {
 
   testWidgets('Hero pop transition interrupted by a push', (WidgetTester tester) async {
     await tester.pumpWidget(
-      MaterialApp(routes: routes),
+      MaterialApp(
+        routes: routes,
+        theme: ThemeData(pageTransitionsTheme: const PageTransitionsTheme(
+          builders: <TargetPlatform, PageTransitionsBuilder>{
+            TargetPlatform.android: FadeUpwardsPageTransitionsBuilder(),
+          },
+        )),
+      ),
     );
 
     // Pushes MaterialPageRoute '/two'.