[framework] re-rasterize when window size or insets changes (#113647)

Author: Jonah Williams

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

@@ -291,6 +291,7 @@ class _ZoomEnterTransitionState extends State<_ZoomEnterTransition> with _ZoomTr
   bool get useSnapshot => !kIsWeb && widget.allowSnapshotting;
 
   late _ZoomEnterTransitionPainter delegate;
+  MediaQueryData? mediaQueryData;
 
   static final Animatable<double> _fadeInTransition = Tween<double>(
     begin: 0.0,
@@ -355,6 +356,18 @@ class _ZoomEnterTransitionState extends State<_ZoomEnterTransition> with _ZoomTr
     super.didUpdateWidget(oldWidget);
   }
 
+  @override
+  void didChangeDependencies() {
+    // If the screen size changes during the transition, perhaps due to
+    // a keyboard dismissal, then ensure that contents are re-rasterized once.
+    final MediaQueryData? data = MediaQuery.maybeOf(context);
+    if (mediaQueryDataChanged(mediaQueryData, data)) {
+      controller.clear();
+    }
+    mediaQueryData = data;
+    super.didChangeDependencies();
+  }
+
   @override
   void dispose() {
     widget.animation.removeListener(onAnimationValueChange);
@@ -394,6 +407,7 @@ class _ZoomExitTransition extends StatefulWidget {
 
 class _ZoomExitTransitionState extends State<_ZoomExitTransition> with _ZoomTransitionBase {
   late _ZoomExitTransitionPainter delegate;
+  MediaQueryData? mediaQueryData;
 
   // See SnapshotWidget doc comment, this is disabled on web because the HTML backend doesn't
   // support this functionality and the canvaskit backend uses a single thread for UI and raster
@@ -458,6 +472,18 @@ class _ZoomExitTransitionState extends State<_ZoomExitTransition> with _ZoomTran
     super.didUpdateWidget(oldWidget);
   }
 
+  @override
+  void didChangeDependencies() {
+    // If the screen size changes during the transition, perhaps due to
+    // a keyboard dismissal, then ensure that contents are re-rasterized once.
+    final MediaQueryData? data = MediaQuery.maybeOf(context);
+    if (mediaQueryDataChanged(mediaQueryData, data)) {
+      controller.clear();
+    }
+    mediaQueryData = data;
+    super.didChangeDependencies();
+  }
+
   @override
   void dispose() {
     widget.animation.removeListener(onAnimationValueChange);
@@ -804,6 +830,13 @@ mixin _ZoomTransitionBase {
         break;
     }
   }
+
+  // Whether any of the properties that would impact the page transition
+  // changed.
+  bool mediaQueryDataChanged(MediaQueryData? oldData, MediaQueryData? newData) {
+    return oldData?.size != newData?.size ||
+      oldData?.viewInsets != newData?.viewInsets;
+  }
 }
 
 class _ZoomEnterTransitionPainter extends SnapshotPainter {

packages/flutter/test/material/page_test.dart

@@ -2,7 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+@Tags(<String>['reduced-test-set'])
 import 'package:flutter/cupertino.dart' show CupertinoPageRoute;
+import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter_test/flutter_test.dart';
@@ -234,6 +236,47 @@ void main() {
     expect(find.text('Page 2'), findsNothing);
   }, variant: TargetPlatformVariant.only(TargetPlatform.android));
 
+  testWidgets('test page transition (_ZoomPageTransition) with rasterization re-rasterizes when window size changes', (WidgetTester tester) async {
+    // Shrink the window size.
+    late Size oldSize;
+    try {
+      oldSize = tester.binding.window.physicalSize;
+      tester.binding.window.physicalSizeTestValue = const Size(1000, 1000);
+
+      final Key key = GlobalKey();
+      await tester.pumpWidget(
+        RepaintBoundary(
+          key: key,
+          child: MaterialApp(
+            onGenerateRoute: (RouteSettings settings) {
+              return MaterialPageRoute<void>(
+                builder: (BuildContext context) {
+                  return const Material(child: SizedBox.shrink());
+                },
+              );
+            },
+          ),
+        ),
+      );
+
+      tester.state<NavigatorState>(find.byType(Navigator)).pushNamed('/next');
+      await tester.pump();
+      await tester.pump(const Duration(milliseconds: 50));
+
+      await expectLater(find.byKey(key), matchesGoldenFile('zoom_page_transition.small.png'));
+
+       // Increase the window size.
+      tester.binding.window.physicalSizeTestValue = const Size(1000, 2000);
+
+      await tester.pump();
+      await tester.pump(const Duration(milliseconds: 50));
+
+      await expectLater(find.byKey(key), matchesGoldenFile('zoom_page_transition.big.png'));
+    } finally {
+      tester.binding.window.physicalSizeTestValue = oldSize;
+    }
+  }, variant: TargetPlatformVariant.only(TargetPlatform.android), skip: kIsWeb); // [intended] rasterization is not used on the web.
+
   testWidgets('test fullscreen dialog transition', (WidgetTester tester) async {
     await tester.pumpWidget(
       const MaterialApp(