[pull] master from flutter:master

TESTOWNERS

@@ -114,6 +114,7 @@
 /dev/devicelab/bin/tasks/tiles_scroll_perf__timeline_summary.dart @zanderso @flutter/engine
 
 ## Mac iOS DeviceLab tests
+/dev/devicelab/bin/tasks/animation_with_microtasks_perf_ios__timeline_summary.dart @iskakaushik @flutter/engine
 /dev/devicelab/bin/tasks/backdrop_filter_perf_ios__timeline_summary.dart @zanderso @flutter/engine
 /dev/devicelab/bin/tasks/basic_material_app_ios__compile.dart @zanderso @flutter/tool
 /dev/devicelab/bin/tasks/channels_integration_test_ios.dart @zanderso @flutter/engine

bin/internal/engine.version

@@ -1 +1 @@
-232f7e2e5420c8f5c9fc51f0504a113941c63052
+f18a930f7322e7fa3f02a347881393c9204da714

bin/internal/flutter_plugins.version

@@ -1 +1 @@
-1b7c4fbce75073042ef1fe9e92ddafa12f1d3b0b
+477a13d8b0af92aea5e8e53445b1bfd0ef28f32b

dev/integration_tests/android_views/android/app/src/main/java/io/flutter/integration/androidviews/MainActivity.java

@@ -10,7 +10,6 @@
 import android.os.Bundle;
 import android.view.MotionEvent;
 import android.view.View;
-import android.view.ViewGroup;
 
 import java.util.HashMap;
 
@@ -32,9 +31,7 @@ public class MainActivity extends FlutterActivity implements MethodChannel.Metho
     private MethodChannel.Result permissionResult;
 
     private View getFlutterView() {
-        // TODO(egarciad): Set an unique ID in FlutterView, so it's easier to look it up.
-        ViewGroup root = (ViewGroup)findViewById(android.R.id.content);
-        return ((ViewGroup)root.getChildAt(0)).getChildAt(0);
+      return findViewById(FLUTTER_VIEW_ID);
     }
 
     @Override

dev/integration_tests/hybrid_android_views/android/app/src/main/java/io/flutter/integration/androidviews/MainActivity.java

@@ -36,9 +36,7 @@ public class MainActivity extends FlutterActivity implements MethodChannel.Metho
     private MethodChannel.Result permissionResult;
 
     private View getFlutterView() {
-        // TODO(egarciad): Set an unique ID in FlutterView, so it's easier to look it up.
-        ViewGroup root = (ViewGroup)findViewById(android.R.id.content);
-        return ((ViewGroup)root.getChildAt(0)).getChildAt(0);
+      return findViewById(FLUTTER_VIEW_ID);
     }
 
     private String getViewName(View view) {

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

@@ -334,16 +334,29 @@ class ScrollbarPainter extends ChangeNotifier implements CustomPainter {
   Rect? _trackRect;
   late double _thumbOffset;
 
-  /// Update with new [ScrollMetrics]. The scrollbar will show and redraw itself
-  /// based on these new metrics.
+  /// Update with new [ScrollMetrics]. If the metrics change, the scrollbar will
+  /// show and redraw itself based on these new metrics.
   ///
   /// The scrollbar will remain on screen.
   void update(
     ScrollMetrics metrics,
     AxisDirection axisDirection,
   ) {
+    if (_lastMetrics != null &&
+        _lastMetrics!.extentBefore == metrics.extentBefore &&
+        _lastMetrics!.extentInside == metrics.extentInside &&
+        _lastMetrics!.extentAfter == metrics.extentAfter &&
+        _lastAxisDirection == axisDirection)
+      return;
+
+    final ScrollMetrics? oldMetrics = _lastMetrics;
     _lastMetrics = metrics;
     _lastAxisDirection = axisDirection;
+
+    bool _needPaint(ScrollMetrics? metrics) => metrics != null && metrics.maxScrollExtent > metrics.minScrollExtent;
+    if (!_needPaint(oldMetrics) && !_needPaint(metrics))
+      return;
+
     notifyListeners();
   }
 
@@ -526,7 +539,8 @@ class ScrollbarPainter extends ChangeNotifier implements CustomPainter {
   void paint(Canvas canvas, Size size) {
     if (_lastAxisDirection == null
         || _lastMetrics == null
-        || fadeoutOpacityAnimation.value == 0.0)
+        || fadeoutOpacityAnimation.value == 0.0
+        || _lastMetrics!.maxScrollExtent <= _lastMetrics!.minScrollExtent)
       return;
 
     // Skip painting if there's not enough space.
@@ -1519,18 +1533,37 @@ class RawScrollbarState<T extends RawScrollbar> extends State<T> with TickerProv
     );
   }
 
+  bool _handleScrollMetricsNotification(ScrollMetricsNotification notification) {
+    if (!widget.notificationPredicate(ScrollUpdateNotification(metrics: notification.metrics, context: notification.context)))
+      return false;
+    if (showScrollbar) {
+      if (_fadeoutAnimationController.status != AnimationStatus.forward
+          && _fadeoutAnimationController.status != AnimationStatus.completed)
+        _fadeoutAnimationController.forward();
+    }
+    scrollbarPainter.update(notification.metrics, notification.metrics.axisDirection);
+    return false;
+  }
+
   bool _handleScrollNotification(ScrollNotification notification) {
     if (!widget.notificationPredicate(notification))
       return false;
 
     final ScrollMetrics metrics = notification.metrics;
-    if (metrics.maxScrollExtent <= metrics.minScrollExtent)
+    if (metrics.maxScrollExtent <= metrics.minScrollExtent) {
+      // Hide the bar when the Scrollable widget has no space to scroll.
+      if (_fadeoutAnimationController.status != AnimationStatus.dismissed
+          && _fadeoutAnimationController.status != AnimationStatus.reverse)
+        _fadeoutAnimationController.reverse();
+      scrollbarPainter.update(metrics, metrics.axisDirection);
       return false;
+    }
 
     if (notification is ScrollUpdateNotification ||
       notification is OverscrollNotification) {
       // Any movements always makes the scrollbar start showing up.
-      if (_fadeoutAnimationController.status != AnimationStatus.forward)
+      if (_fadeoutAnimationController.status != AnimationStatus.forward
+          && _fadeoutAnimationController.status != AnimationStatus.completed)
         _fadeoutAnimationController.forward();
 
       _fadeoutTimer?.cancel();
@@ -1658,47 +1691,49 @@ class RawScrollbarState<T extends RawScrollbar> extends State<T> with TickerProv
     super.dispose();
   }
 
-
   @override
   Widget build(BuildContext context) {
     updateScrollbarPainter();
 
-    return NotificationListener<ScrollNotification>(
-      onNotification: _handleScrollNotification,
-      child: RepaintBoundary(
-        child: RawGestureDetector(
-          gestures: _gestures,
-          child: MouseRegion(
-            onExit: (PointerExitEvent event) {
-              switch(event.kind) {
-                case PointerDeviceKind.mouse:
-                  if (enableGestures)
-                    handleHoverExit(event);
-                  break;
-                case PointerDeviceKind.stylus:
-                case PointerDeviceKind.invertedStylus:
-                case PointerDeviceKind.unknown:
-                case PointerDeviceKind.touch:
-                  break;
-              }
-            },
-            onHover: (PointerHoverEvent event) {
-              switch(event.kind) {
-                case PointerDeviceKind.mouse:
-                  if (enableGestures)
-                    handleHover(event);
-                  break;
-                case PointerDeviceKind.stylus:
-                case PointerDeviceKind.invertedStylus:
-                case PointerDeviceKind.unknown:
-                case PointerDeviceKind.touch:
-                  break;
-              }
-            },
-            child: CustomPaint(
-              key: _scrollbarPainterKey,
-              foregroundPainter: scrollbarPainter,
-              child: RepaintBoundary(child: widget.child),
+    return NotificationListener<ScrollMetricsNotification>(
+      onNotification: _handleScrollMetricsNotification,
+      child: NotificationListener<ScrollNotification>(
+        onNotification: _handleScrollNotification,
+        child: RepaintBoundary(
+          child: RawGestureDetector(
+            gestures: _gestures,
+            child: MouseRegion(
+              onExit: (PointerExitEvent event) {
+                switch(event.kind) {
+                  case PointerDeviceKind.mouse:
+                    if (enableGestures)
+                      handleHoverExit(event);
+                    break;
+                  case PointerDeviceKind.stylus:
+                  case PointerDeviceKind.invertedStylus:
+                  case PointerDeviceKind.unknown:
+                  case PointerDeviceKind.touch:
+                    break;
+                }
+              },
+              onHover: (PointerHoverEvent event) {
+                switch(event.kind) {
+                  case PointerDeviceKind.mouse:
+                    if (enableGestures)
+                      handleHover(event);
+                    break;
+                  case PointerDeviceKind.stylus:
+                  case PointerDeviceKind.invertedStylus:
+                  case PointerDeviceKind.unknown:
+                  case PointerDeviceKind.touch:
+                    break;
+                }
+              },
+              child: CustomPaint(
+                key: _scrollbarPainterKey,
+                foregroundPainter: scrollbarPainter,
+                child: RepaintBoundary(child: widget.child),
+              ),
             ),
           ),
         ),

packages/flutter/test/rendering/viewport_test.dart

@@ -7,11 +7,7 @@
 // initialize a binding, which rendering_tester will attempt to re-initialize
 // (or vice versa).
 
-// TODO(gspencergoog): Remove this tag once this test's state leaks/test
-// dependencies have been fixed.
-// https://github.com/flutter/flutter/issues/85160
-// Fails with "flutter test --test-randomize-ordering-seed=123"
-@Tags(<String>['no-shuffle'])
+import 'dart:ui' as ui;
 
 import 'package:flutter/foundation.dart';
 import 'package:flutter/rendering.dart';
@@ -785,6 +781,12 @@ void main() {
     }
 
     testWidgets('Reverse List showOnScreen', (WidgetTester tester) async {
+      final ui.Size originalScreenSize = tester.binding.window.physicalSize;
+      final double originalDevicePixelRatio = tester.binding.window.devicePixelRatio;
+      addTearDown(() {
+        tester.binding.window.devicePixelRatioTestValue = originalDevicePixelRatio;
+        tester.binding.window.physicalSizeTestValue = originalScreenSize;
+      });
       const double screenHeight = 400.0;
       const double screenWidth = 400.0;
       const double itemHeight = screenHeight / 10.0;
@@ -1891,17 +1893,17 @@ void main() {
     controller.jumpTo(controller.position.maxScrollExtent);
     await tester.pumpAndSettle();
     expect(controller.offset, maxExtent);
-    expect(tester.getBottomLeft(find.text('Item 19')).dy, 400.0);
+    expect(tester.getBottomLeft(find.text('Item 19')).dy, 600.0);
 
     overscrollGesture = await tester.startGesture(tester.getCenter(find.byType(ListView)));
     await overscrollGesture.moveBy(const Offset(0, -25));
     await tester.pump();
     expect(controller.offset, greaterThan(maxExtent));
-    expect(tester.getBottomLeft(find.text('Item 19')).dy, 375.0);
+    expect(tester.getBottomLeft(find.text('Item 19')).dy, 575.0);
     await overscrollGesture.up();
     await tester.pumpAndSettle();
     expect(controller.offset, maxExtent);
-    expect(tester.getBottomLeft(find.text('Item 19')).dy, 400.0);
+    expect(tester.getBottomLeft(find.text('Item 19')).dy, 600.0);
   }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS, TargetPlatform.macOS }));
 
   testWidgets('Shrinkwrap allows overscrolling on default platforms - horizontal', (WidgetTester tester) async {
@@ -1930,17 +1932,17 @@ void main() {
     controller.jumpTo(controller.position.maxScrollExtent);
     await tester.pumpAndSettle();
     expect(controller.offset, maxExtent);
-    expect(tester.getTopRight(find.text('Item 19')).dx, 400.0);
+    expect(tester.getTopRight(find.text('Item 19')).dx, 800.0);
 
     overscrollGesture = await tester.startGesture(tester.getCenter(find.byType(ListView)));
     await overscrollGesture.moveBy(const Offset(-25, 0));
     await tester.pump();
     expect(controller.offset, greaterThan(maxExtent));
-    expect(tester.getTopRight(find.text('Item 19')).dx, 375.0);
+    expect(tester.getTopRight(find.text('Item 19')).dx, 775.0);
     await overscrollGesture.up();
     await tester.pumpAndSettle();
     expect(controller.offset, maxExtent);
-    expect(tester.getTopRight(find.text('Item 19')).dx, 400.0);
+    expect(tester.getTopRight(find.text('Item 19')).dx, 800.0);
   }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS, TargetPlatform.macOS }));
 
   testWidgets('Shrinkwrap allows overscrolling per physics - vertical', (WidgetTester tester) async {
@@ -1969,17 +1971,17 @@ void main() {
     controller.jumpTo(controller.position.maxScrollExtent);
     await tester.pumpAndSettle();
     expect(controller.offset, maxExtent);
-    expect(tester.getBottomLeft(find.text('Item 19')).dy, 400.0);
+    expect(tester.getBottomLeft(find.text('Item 19')).dy, 600.0);
 
     overscrollGesture = await tester.startGesture(tester.getCenter(find.byType(ListView)));
     await overscrollGesture.moveBy(const Offset(0, -25));
     await tester.pump();
     expect(controller.offset, greaterThan(maxExtent));
-    expect(tester.getBottomLeft(find.text('Item 19')).dy, 375.0);
+    expect(tester.getBottomLeft(find.text('Item 19')).dy, 575.0);
     await overscrollGesture.up();
     await tester.pumpAndSettle();
     expect(controller.offset, maxExtent);
-    expect(tester.getBottomLeft(find.text('Item 19')).dy, 400.0);
+    expect(tester.getBottomLeft(find.text('Item 19')).dy, 600.0);
   });
 
   testWidgets('Shrinkwrap allows overscrolling per physics - horizontal', (WidgetTester tester) async {
@@ -2012,17 +2014,17 @@ void main() {
     controller.jumpTo(controller.position.maxScrollExtent);
     await tester.pumpAndSettle();
     expect(controller.offset, maxExtent);
-    expect(tester.getTopRight(find.text('Item 19')).dx, 400.0);
+    expect(tester.getTopRight(find.text('Item 19')).dx, 800.0);
 
     overscrollGesture = await tester.startGesture(tester.getCenter(find.byType(ListView)));
     await overscrollGesture.moveBy(const Offset(-25, 0));
     await tester.pump();
     expect(controller.offset, greaterThan(maxExtent));
-    expect(tester.getTopRight(find.text('Item 19')).dx, 375.0);
+    expect(tester.getTopRight(find.text('Item 19')).dx, 775.0);
     await overscrollGesture.up();
     await tester.pumpAndSettle();
     expect(controller.offset, maxExtent);
-    expect(tester.getTopRight(find.text('Item 19')).dx, 400.0);
+    expect(tester.getTopRight(find.text('Item 19')).dx, 800.0);
   });
 
   testWidgets('Handles infinite constraints when TargetPlatform is iOS or macOS', (WidgetTester tester) async {

packages/flutter/test/widgets/scrollbar_test.dart

@@ -1565,4 +1565,76 @@ void main() {
           ..rect(rect: const Rect.fromLTRB(794.0, 0.0, 800.0, 8.0)));
   });
 
+  testWidgets('The bar can show or hide when the viewport size change', (WidgetTester tester) async {
+    final ScrollController scrollController = ScrollController();
+    Widget buildFrame(double height) {
+      return Directionality(
+        textDirection: TextDirection.ltr,
+        child: MediaQuery(
+          data: const MediaQueryData(),
+          child: RawScrollbar(
+            controller: scrollController,
+            isAlwaysShown: true,
+            child: SingleChildScrollView(
+                controller: scrollController,
+                child: SizedBox(width: double.infinity, height: height)
+            ),
+          ),
+        ),
+      );
+    }
+    await tester.pumpWidget(buildFrame(600.0));
+    await tester.pumpAndSettle();
+    expect(find.byType(RawScrollbar), isNot(paints..rect())); // Not shown.
+
+    await tester.pumpWidget(buildFrame(600.1));
+    await tester.pumpAndSettle();
+    expect(find.byType(RawScrollbar), paints..rect()..rect()); // Show the bar.
+
+    await tester.pumpWidget(buildFrame(600.0));
+    await tester.pumpAndSettle();
+    expect(find.byType(RawScrollbar), isNot(paints..rect())); // Hide the bar.
+  });
+
+  testWidgets('The bar can show or hide when the window size change', (WidgetTester tester) async {
+    final ScrollController scrollController = ScrollController();
+    Widget buildFrame() {
+      return Directionality(
+        textDirection: TextDirection.ltr,
+        child: MediaQuery(
+          data: const MediaQueryData(),
+          child: PrimaryScrollController(
+            controller: scrollController,
+            child: RawScrollbar(
+              isAlwaysShown: true,
+              controller: scrollController,
+              child: const SingleChildScrollView(
+                child: SizedBox(
+                  width: double.infinity,
+                  height: 600.0,
+                ),
+              ),
+            ),
+          ),
+        ),
+      );
+    }
+    tester.binding.window.physicalSizeTestValue = const Size(800.0, 600.0);
+    tester.binding.window.devicePixelRatioTestValue = 1;
+    addTearDown(tester.binding.window.clearPhysicalSizeTestValue);
+    addTearDown(tester.binding.window.clearDevicePixelRatioTestValue);
+
+    await tester.pumpWidget(buildFrame());
+    await tester.pumpAndSettle();
+    expect(scrollController.offset, 0.0);
+    expect(find.byType(RawScrollbar), isNot(paints..rect())); // Not shown.
+
+    tester.binding.window.physicalSizeTestValue = const Size(800.0, 599.0);
+    await tester.pumpAndSettle();
+    expect(find.byType(RawScrollbar), paints..rect()..rect()); // Show the bar.
+
+    tester.binding.window.physicalSizeTestValue = const Size(800.0, 600.0);
+    await tester.pumpAndSettle();
+    expect(find.byType(RawScrollbar), isNot(paints..rect())); // Not shown.
+  });
 }