recycle maskView at the begining of the frame

shell/platform/darwin/ios/framework/Source/FlutterPlatformViews.mm

@@ -18,8 +18,6 @@
 #import "flutter/shell/platform/darwin/ios/framework/Source/FlutterViewController_Internal.h"
 #import "flutter/shell/platform/darwin/ios/ios_surface.h"
 
-static const NSUInteger kFlutterClippingMaskViewPoolCapacity = 5;
-
 @implementation UIView (FirstResponder)
 - (BOOL)flt_hasFirstResponderInViewHierarchySubtree {
   if (self.isFirstResponder) {
@@ -461,11 +459,7 @@ static bool ClipRRectContainsPlatformViewBoundingRect(const SkRRect& clip_rrect,
   NSMutableArray* blurFilters = [[[NSMutableArray alloc] init] autorelease];
   FML_DCHECK(!clipView.maskView ||
              [clipView.maskView isKindOfClass:[FlutterClippingMaskView class]]);
-  if (mask_view_pool_.get() == nil) {
-    mask_view_pool_.reset([[FlutterClippingMaskViewPool alloc]
-        initWithCapacity:kFlutterClippingMaskViewPoolCapacity]);
-  }
-  [mask_view_pool_.get() recycleMaskViews];
+
   clipView.maskView = nil;
   CGFloat screenScale = [UIScreen mainScreen].scale;
   auto iter = mutators_stack.Begin();
@@ -899,6 +893,7 @@ static bool ClipRRectContainsPlatformViewBoundingRect(const SkRRect& clip_rrect,
   slices_.clear();
   composition_order_.clear();
   visited_platform_views_.clear();
+  [mask_view_pool_.get() recycleMaskViews];
 }
 
 }  // namespace flutter

shell/platform/darwin/ios/framework/Source/FlutterPlatformViewsTest.mm

@@ -2727,17 +2727,17 @@ - (void)testClipMaskViewIsReused {
   auto embeddedViewParams1 = std::make_unique<flutter::EmbeddedViewParams>(
       screenScaleMatrix, SkSize::Make(10, 10), stack1);
 
-  flutter::MutatorsStack stack2;
-  auto embeddedViewParams2 = std::make_unique<flutter::EmbeddedViewParams>(
-      screenScaleMatrix, SkSize::Make(10, 10), stack2);
-
   flutterPlatformViewsController->PrerollCompositeEmbeddedView(1, std::move(embeddedViewParams1));
   flutterPlatformViewsController->CompositeEmbeddedView(1);
   UIView* childClippingView1 = gMockPlatformView.superview.superview;
   UIView* maskView1 = childClippingView1.maskView;
   XCTAssertNotNil(maskView1);
 
   // Composite a new frame.
+  flutterPlatformViewsController->BeginFrame(SkISize::Make(100, 100));
+  flutter::MutatorsStack stack2;
+  auto embeddedViewParams2 = std::make_unique<flutter::EmbeddedViewParams>(
+      screenScaleMatrix, SkSize::Make(10, 10), stack2);
   auto embeddedViewParams3 = std::make_unique<flutter::EmbeddedViewParams>(
       screenScaleMatrix, SkSize::Make(10, 10), stack2);
   flutterPlatformViewsController->PrerollCompositeEmbeddedView(1, std::move(embeddedViewParams3));
@@ -2763,6 +2763,77 @@ - (void)testClipMaskViewIsReused {
   XCTAssertNil(childClippingView1.maskView);
 }
 
+- (void)testDifferentClipMaskViewIsUsedForEachView {
+  flutter::FlutterPlatformViewsTestMockPlatformViewDelegate mock_delegate;
+  auto thread_task_runner = CreateNewThread("FlutterPlatformViewsTest");
+  flutter::TaskRunners runners(/*label=*/self.name.UTF8String,
+                               /*platform=*/thread_task_runner,
+                               /*raster=*/thread_task_runner,
+                               /*ui=*/thread_task_runner,
+                               /*io=*/thread_task_runner);
+  auto flutterPlatformViewsController = std::make_shared<flutter::FlutterPlatformViewsController>();
+  auto platform_view = std::make_unique<flutter::PlatformViewIOS>(
+      /*delegate=*/mock_delegate,
+      /*rendering_api=*/flutter::IOSRenderingAPI::kSoftware,
+      /*platform_views_controller=*/flutterPlatformViewsController,
+      /*task_runners=*/runners);
+
+  FlutterPlatformViewsTestMockFlutterPlatformFactory* factory =
+      [[FlutterPlatformViewsTestMockFlutterPlatformFactory new] autorelease];
+  flutterPlatformViewsController->RegisterViewFactory(
+      factory, @"MockFlutterPlatformView",
+      FlutterPlatformViewGestureRecognizersBlockingPolicyEager);
+  FlutterResult result = ^(id result) {
+  };
+
+  flutterPlatformViewsController->OnMethodCall(
+      [FlutterMethodCall
+          methodCallWithMethodName:@"create"
+                         arguments:@{@"id" : @1, @"viewType" : @"MockFlutterPlatformView"}],
+      result);
+  UIView* view1 = gMockPlatformView;
+
+  // This overwrites `gMockPlatformView` to another view.
+  flutterPlatformViewsController->OnMethodCall(
+      [FlutterMethodCall
+          methodCallWithMethodName:@"create"
+                         arguments:@{@"id" : @2, @"viewType" : @"MockFlutterPlatformView"}],
+      result);
+  UIView* view2 = gMockPlatformView;
+
+  XCTAssertNotNil(gMockPlatformView);
+  UIView* mockFlutterView = [[[UIView alloc] initWithFrame:CGRectMake(0, 0, 10, 10)] autorelease];
+  flutterPlatformViewsController->SetFlutterView(mockFlutterView);
+  // Create embedded view params
+  flutter::MutatorsStack stack1;
+  // Layer tree always pushes a screen scale factor to the stack
+  SkMatrix screenScaleMatrix =
+      SkMatrix::Scale([UIScreen mainScreen].scale, [UIScreen mainScreen].scale);
+  stack1.PushTransform(screenScaleMatrix);
+  // Push a clip rect
+  SkRect rect = SkRect::MakeXYWH(2, 2, 3, 3);
+  stack1.PushClipRect(rect);
+
+  auto embeddedViewParams1 = std::make_unique<flutter::EmbeddedViewParams>(
+      screenScaleMatrix, SkSize::Make(10, 10), stack1);
+
+  flutter::MutatorsStack stack2;
+  stack2.PushClipRect(rect);
+  auto embeddedViewParams2 = std::make_unique<flutter::EmbeddedViewParams>(
+      screenScaleMatrix, SkSize::Make(10, 10), stack2);
+
+  flutterPlatformViewsController->PrerollCompositeEmbeddedView(1, std::move(embeddedViewParams1));
+  flutterPlatformViewsController->CompositeEmbeddedView(1);
+  UIView* childClippingView1 = view1.superview.superview;
+
+  flutterPlatformViewsController->PrerollCompositeEmbeddedView(2, std::move(embeddedViewParams2));
+  flutterPlatformViewsController->CompositeEmbeddedView(2);
+  UIView* childClippingView2 = view2.superview.superview;
+  UIView* maskView1 = childClippingView1.maskView;
+  UIView* maskView2 = childClippingView2.maskView;
+  XCTAssertNotEqual(maskView1, maskView2);
+}
+
 // Return true if a correct visual effect view is found. It also implies all the validation in this
 // method passes.
 //

shell/platform/darwin/ios/framework/Source/FlutterPlatformViews_Internal.mm

@@ -9,6 +9,7 @@
 #import "flutter/shell/platform/darwin/ios/ios_surface.h"
 
 static int kMaxPointsInVerb = 4;
+static const NSUInteger kFlutterClippingMaskViewPoolCapacity = 5;
 
 namespace flutter {
 
@@ -26,7 +27,10 @@
 
 FlutterPlatformViewsController::FlutterPlatformViewsController()
     : layer_pool_(std::make_unique<FlutterPlatformViewLayerPool>()),
-      weak_factory_(std::make_unique<fml::WeakPtrFactory<FlutterPlatformViewsController>>(this)){};
+      weak_factory_(std::make_unique<fml::WeakPtrFactory<FlutterPlatformViewsController>>(this)) {
+  mask_view_pool_.reset(
+      [[FlutterClippingMaskViewPool alloc] initWithCapacity:kFlutterClippingMaskViewPoolCapacity]);
+};
 
 FlutterPlatformViewsController::~FlutterPlatformViewsController() = default;
 

testing/scenario_app/ios/Scenarios/Scenarios.xcodeproj/project.pbxproj

@@ -38,6 +38,9 @@
 		6816DBA12317573300A51400 /* GoldenImage.m in Sources */ = {isa = PBXBuildFile; fileRef = 6816DBA02317573300A51400 /* GoldenImage.m */; };
 		6816DBA42318358200A51400 /* GoldenTestManager.m in Sources */ = {isa = PBXBuildFile; fileRef = 6816DBA32318358200A51400 /* GoldenTestManager.m */; };
 		682C5873299C182A00915E5C /* golden_platform_view_cliprect_after_moved_iPhone 8_16.0_simulator.png in Resources */ = {isa = PBXBuildFile; fileRef = 682C5872299C182A00915E5C /* golden_platform_view_cliprect_after_moved_iPhone 8_16.0_simulator.png */; };
+		684FFF9329FB89EF00281002 /* golden_two_platform_view_clip_rrect_iPhone 8_16.0_simulator.png in Resources */ = {isa = PBXBuildFile; fileRef = 684FFF9029FB89EE00281002 /* golden_two_platform_view_clip_rrect_iPhone 8_16.0_simulator.png */; };
+		684FFF9429FB89EF00281002 /* golden_two_platform_view_clip_path_iPhone 8_16.0_simulator.png in Resources */ = {isa = PBXBuildFile; fileRef = 684FFF9129FB89EF00281002 /* golden_two_platform_view_clip_path_iPhone 8_16.0_simulator.png */; };
+		684FFF9529FB89EF00281002 /* golden_two_platform_view_clip_rect_iPhone 8_16.0_simulator.png in Resources */ = {isa = PBXBuildFile; fileRef = 684FFF9229FB89EF00281002 /* golden_two_platform_view_clip_rect_iPhone 8_16.0_simulator.png */; };
 		685B9F392977B73100B45442 /* golden_platform_view_large_cliprrect_with_transform_iPhone 8_16.0_simulator.png in Resources */ = {isa = PBXBuildFile; fileRef = 685B9F372977B73100B45442 /* golden_platform_view_large_cliprrect_with_transform_iPhone 8_16.0_simulator.png */; };
 		685B9F3A2977B73100B45442 /* golden_platform_view_large_cliprrect_iPhone 8_16.0_simulator.png in Resources */ = {isa = PBXBuildFile; fileRef = 685B9F382977B73100B45442 /* golden_platform_view_large_cliprrect_iPhone 8_16.0_simulator.png */; };
 		687AF8E9291EBDE0003912C7 /* golden_platform_view_clippath_with_transform_iPhone 8_16.0_simulator.png in Resources */ = {isa = PBXBuildFile; fileRef = 687AF8E8291EBDE0003912C7 /* golden_platform_view_clippath_with_transform_iPhone 8_16.0_simulator.png */; };
@@ -155,6 +158,9 @@
 		6816DBA22318358200A51400 /* GoldenTestManager.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = GoldenTestManager.h; sourceTree = "<group>"; };
 		6816DBA32318358200A51400 /* GoldenTestManager.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = GoldenTestManager.m; sourceTree = "<group>"; };
 		682C5872299C182A00915E5C /* golden_platform_view_cliprect_after_moved_iPhone 8_16.0_simulator.png */ = {isa = PBXFileReference; lastKnownFileType = image.png; path = "golden_platform_view_cliprect_after_moved_iPhone 8_16.0_simulator.png"; sourceTree = "<group>"; };
+		684FFF9029FB89EE00281002 /* golden_two_platform_view_clip_rrect_iPhone 8_16.0_simulator.png */ = {isa = PBXFileReference; lastKnownFileType = image.png; path = "golden_two_platform_view_clip_rrect_iPhone 8_16.0_simulator.png"; sourceTree = "<group>"; };
+		684FFF9129FB89EF00281002 /* golden_two_platform_view_clip_path_iPhone 8_16.0_simulator.png */ = {isa = PBXFileReference; lastKnownFileType = image.png; path = "golden_two_platform_view_clip_path_iPhone 8_16.0_simulator.png"; sourceTree = "<group>"; };
+		684FFF9229FB89EF00281002 /* golden_two_platform_view_clip_rect_iPhone 8_16.0_simulator.png */ = {isa = PBXFileReference; lastKnownFileType = image.png; path = "golden_two_platform_view_clip_rect_iPhone 8_16.0_simulator.png"; sourceTree = "<group>"; };
 		685B9F372977B73100B45442 /* golden_platform_view_large_cliprrect_with_transform_iPhone 8_16.0_simulator.png */ = {isa = PBXFileReference; lastKnownFileType = image.png; path = "golden_platform_view_large_cliprrect_with_transform_iPhone 8_16.0_simulator.png"; sourceTree = "<group>"; };
 		685B9F382977B73100B45442 /* golden_platform_view_large_cliprrect_iPhone 8_16.0_simulator.png */ = {isa = PBXFileReference; lastKnownFileType = image.png; path = "golden_platform_view_large_cliprrect_iPhone 8_16.0_simulator.png"; sourceTree = "<group>"; };
 		687AF8E8291EBDE0003912C7 /* golden_platform_view_clippath_with_transform_iPhone 8_16.0_simulator.png */ = {isa = PBXFileReference; lastKnownFileType = image.png; path = "golden_platform_view_clippath_with_transform_iPhone 8_16.0_simulator.png"; sourceTree = "<group>"; };
@@ -302,6 +308,9 @@
 		F7B464DC2759D02B00079189 /* Goldens */ = {
 			isa = PBXGroup;
 			children = (
+				684FFF9129FB89EF00281002 /* golden_two_platform_view_clip_path_iPhone 8_16.0_simulator.png */,
+				684FFF9229FB89EF00281002 /* golden_two_platform_view_clip_rect_iPhone 8_16.0_simulator.png */,
+				684FFF9029FB89EE00281002 /* golden_two_platform_view_clip_rrect_iPhone 8_16.0_simulator.png */,
 				682C5872299C182A00915E5C /* golden_platform_view_cliprect_after_moved_iPhone 8_16.0_simulator.png */,
 				685B9F382977B73100B45442 /* golden_platform_view_large_cliprrect_iPhone 8_16.0_simulator.png */,
 				685B9F372977B73100B45442 /* golden_platform_view_large_cliprrect_with_transform_iPhone 8_16.0_simulator.png */,
@@ -461,15 +470,18 @@
 				F7B464EE2759D0A900079189 /* golden_platform_view_transform_iPhone 8_16.0_simulator.png in Resources */,
 				F7B464F32759D0A900079189 /* golden_platform_view_multiple_background_foreground_iPhone 8_16.0_simulator.png in Resources */,
 				F7B464F72759D0A900079189 /* golden_platform_view_rotate_iPhone 8_16.0_simulator.png in Resources */,
+				684FFF9329FB89EF00281002 /* golden_two_platform_view_clip_rrect_iPhone 8_16.0_simulator.png in Resources */,
 				F7B464ED2759D0A900079189 /* golden_platform_view_cliprrect_iPhone 8_16.0_simulator.png in Resources */,
 				685B9F3A2977B73100B45442 /* golden_platform_view_large_cliprrect_iPhone 8_16.0_simulator.png in Resources */,
 				68D5003F291ED645001ACFE1 /* golden_platform_view_cliprrect_with_transform_iPhone 8_16.0_simulator.png in Resources */,
 				F7B464EB2759D0A900079189 /* golden_two_platform_views_with_other_backdrop_filter_iPhone 8_16.0_simulator.png in Resources */,
+				684FFF9529FB89EF00281002 /* golden_two_platform_view_clip_rect_iPhone 8_16.0_simulator.png in Resources */,
 				F7B464F42759D0A900079189 /* golden_platform_view_with_other_backdrop_filter_iPhone 8_16.0_simulator.png in Resources */,
 				687AF8E9291EBDE0003912C7 /* golden_platform_view_clippath_with_transform_iPhone 8_16.0_simulator.png in Resources */,
 				685B9F392977B73100B45442 /* golden_platform_view_large_cliprrect_with_transform_iPhone 8_16.0_simulator.png in Resources */,
 				F769EB53276312BB007AC10F /* golden_platform_view_cliprect_iPhone 8_16.0_simulator.png in Resources */,
 				F7B464EF2759D0A900079189 /* golden_platform_view_multiple_iPhone 8_16.0_simulator.png in Resources */,
+				684FFF9429FB89EF00281002 /* golden_two_platform_view_clip_path_iPhone 8_16.0_simulator.png in Resources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};

testing/scenario_app/ios/Scenarios/Scenarios/AppDelegate.m

@@ -69,7 +69,10 @@ - (BOOL)application:(UIApplication*)application
     @"--spawn-engine-works" : @"spawn_engine_works",
     @"--pointer-events" : @"pointer_events",
     @"--platform-view-scrolling-under-widget" : @"platform_view_scrolling_under_widget",
-    @"--platform-view-cliprect-after-moved" : @"platform_view_cliprect_after_moved"
+    @"--platform-view-cliprect-after-moved" : @"platform_view_cliprect_after_moved",
+    @"--two-platform-view-clip-rect" : @"two_platform_view_clip_rect",
+    @"--two-platform-view-clip-rrect" : @"two_platform_view_clip_rrect",
+    @"--two-platform-view-clip-path" : @"two_platform_view_clip_path",
   };
   __block NSString* flutterViewControllerTestName = nil;
   [launchArgsMap

testing/scenario_app/ios/Scenarios/ScenariosUITests/GoldenTestManager.m

@@ -47,6 +47,9 @@ - (instancetype)initWithLaunchArg:(NSString*)launchArg {
         @"--bogus-font-text" : @"bogus_font_text",
         @"--spawn-engine-works" : @"spawn_engine_works",
         @"--platform-view-cliprect-after-moved" : @"platform_view_cliprect_after_moved",
+        @"--two-platform-view-clip-rect" : @"two_platform_view_clip_rect",
+        @"--two-platform-view-clip-rrect" : @"two_platform_view_clip_rrect",
+        @"--two-platform-view-clip-path" : @"two_platform_view_clip_path",
       };
     });
     _identifier = launchArgsMap[launchArg];

testing/scenario_app/ios/Scenarios/ScenariosUITests/PlatformViewUITests.m

@@ -254,6 +254,60 @@ - (void)testPlatformView {
 
 @end
 
+@interface TwoPlatformViewClipRectTests : GoldenPlatformViewTests
+
+@end
+
+@implementation TwoPlatformViewClipRectTests
+
+- (instancetype)initWithInvocation:(NSInvocation*)invocation {
+  GoldenTestManager* manager =
+      [[GoldenTestManager alloc] initWithLaunchArg:@"--two-platform-view-clip-rect"];
+  return [super initWithManager:manager invocation:invocation];
+}
+
+- (void)testPlatformView {
+  [self checkPlatformViewGolden];
+}
+
+@end
+
+@interface TwoPlatformViewClipRRectTests : GoldenPlatformViewTests
+
+@end
+
+@implementation TwoPlatformViewClipRRectTests
+
+- (instancetype)initWithInvocation:(NSInvocation*)invocation {
+  GoldenTestManager* manager =
+      [[GoldenTestManager alloc] initWithLaunchArg:@"--two-platform-view-clip-rrect"];
+  return [super initWithManager:manager invocation:invocation];
+}
+
+- (void)testPlatformView {
+  [self checkPlatformViewGolden];
+}
+
+@end
+
+@interface TwoPlatformViewClipPathTests : GoldenPlatformViewTests
+
+@end
+
+@implementation TwoPlatformViewClipPathTests
+
+- (instancetype)initWithInvocation:(NSInvocation*)invocation {
+  GoldenTestManager* manager =
+      [[GoldenTestManager alloc] initWithLaunchArg:@"--two-platform-view-clip-path"];
+  return [super initWithManager:manager invocation:invocation];
+}
+
+- (void)testPlatformView {
+  [self checkPlatformViewGolden];
+}
+
+@end
+
 @interface PlatformViewMutationTransformTests : GoldenPlatformViewTests
 
 @end