flutter · cbracken · Nov 16, 2022 · Nov 15, 2022
diff --git a/ci/licenses_golden/licenses_flutter b/ci/licenses_golden/licenses_flutter
@@ -2596,6 +2596,7 @@ FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterChann
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterChannelKeyResponderUnittests.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterCompositor.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterCompositor.mm
+FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterCompositorUnittests.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterDartProject.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterDartProject_Internal.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterEmbedderExternalTextureUnittests.mm
@@ -2621,9 +2622,6 @@ FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterMenuP
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterMenuPlugin.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterMenuPluginTest.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterMenuPlugin_Internal.h
-FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterMetalCompositor.h
-FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterMetalCompositor.mm
-FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterMetalCompositorUnittests.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterMetalRenderer.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterMetalRenderer.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterMetalRendererTest.mm

diff --git a/shell/platform/darwin/macos/BUILD.gn b/shell/platform/darwin/macos/BUILD.gn
@@ -82,8 +82,6 @@ source_set("flutter_framework_source") {
     "framework/Source/FlutterMenuPlugin.h",
     "framework/Source/FlutterMenuPlugin.mm",
     "framework/Source/FlutterMenuPlugin_Internal.h",
-    "framework/Source/FlutterMetalCompositor.h",
-    "framework/Source/FlutterMetalCompositor.mm",
     "framework/Source/FlutterMetalRenderer.h",
     "framework/Source/FlutterMetalRenderer.mm",
     "framework/Source/FlutterMouseCursorPlugin.h",
@@ -171,14 +169,14 @@ executable("flutter_desktop_darwin_unittests") {
   sources = [
     "framework/Source/AccessibilityBridgeMacTest.mm",
     "framework/Source/FlutterChannelKeyResponderUnittests.mm",
+    "framework/Source/FlutterCompositorUnittests.mm",
     "framework/Source/FlutterEmbedderExternalTextureUnittests.mm",
     "framework/Source/FlutterEmbedderKeyResponderUnittests.mm",
     "framework/Source/FlutterEngineTest.mm",
     "framework/Source/FlutterEngineTestUtils.h",
     "framework/Source/FlutterEngineTestUtils.mm",
     "framework/Source/FlutterKeyboardManagerUnittests.mm",
     "framework/Source/FlutterMenuPluginTest.mm",
-    "framework/Source/FlutterMetalCompositorUnittests.mm",
     "framework/Source/FlutterMetalRendererTest.mm",
     "framework/Source/FlutterMetalSurfaceManagerTest.mm",
     "framework/Source/FlutterPlatformNodeDelegateMacTest.mm",

diff --git a/shell/platform/darwin/macos/framework/Source/FlutterCompositor.h b/shell/platform/darwin/macos/framework/Source/FlutterCompositor.h
@@ -9,6 +9,7 @@
 #include <list>
 
 #include "flutter/fml/macros.h"
+#import "flutter/shell/platform/darwin/macos/framework/Source/FlutterPlatformViewController.h"
 #include "flutter/shell/platform/darwin/macos/framework/Source/FlutterView.h"
 #include "flutter/shell/platform/darwin/macos/framework/Source/FlutterViewProvider.h"
 #include "flutter/shell/platform/embedder/embedder.h"
@@ -25,52 +26,57 @@ class FlutterCompositor {
   // The view_provider is used to query FlutterViews from view IDs,
   // which are used for presenting and creating backing stores.
   // It must not be null, and is typically FlutterViewEngineProvider.
-  explicit FlutterCompositor(id<FlutterViewProvider> view_provider);
+  explicit FlutterCompositor(
+      id<FlutterViewProvider> view_provider,
+      FlutterPlatformViewController* platform_views_controller,
+      id<MTLDevice> mtl_device);
 
-  virtual ~FlutterCompositor() = default;
+  ~FlutterCompositor() = default;
 
-  // Creates a BackingStore and saves updates the backing_store_out
-  // data with the new BackingStore data.
-  // If the backing store is being requested for the first time
-  // for a given frame, this compositor does not create a new backing
-  // store but rather returns the backing store associated with the
-  // FlutterView's FlutterSurfaceManager.
+  // Creates a backing store and saves updates the backing_store_out data with
+  // the new FlutterBackingStore data.
   //
-  // Any additional state allocated for the backing store and
-  // saved as user_data in the backing store must be collected
-  // in the backing_store's destruction_callback field which will
-  // be called when the embedder collects the backing store.
-  virtual bool CreateBackingStore(const FlutterBackingStoreConfig* config,
-                                  FlutterBackingStore* backing_store_out) = 0;
+  // If the backing store is being requested for the first time for a given
+  // frame, this compositor does not create a new backing store but rather
+  // returns the backing store associated with the FlutterView's
+  // FlutterSurfaceManager.
+  //
+  // Any additional state allocated for the backing store and saved as
+  // user_data in the backing store must be collected in the backing_store's
+  // destruction_callback field which will be called when the embedder collects
+  // the backing store.
+  bool CreateBackingStore(const FlutterBackingStoreConfig* config,
+                          FlutterBackingStore* backing_store_out);
 
-  // Releases the memory for any state used by the backing store.
-  virtual bool CollectBackingStore(
-      const FlutterBackingStore* backing_store) = 0;
+  // Releases the memory for any resources that were allocated for the
+  // specified backing store.
+  bool CollectBackingStore(const FlutterBackingStore* backing_store);
 
   // Presents the FlutterLayers by updating the FlutterView specified by
-  // `view_id` using the layer content.
-  // Present sets frame_started_ to false.
-  virtual bool Present(uint64_t view_id,
-                       const FlutterLayer** layers,
-                       size_t layers_count) = 0;
+  // `view_id` using the layer content. Sets frame_started_ to false.
+  bool Present(uint64_t view_id,
+               const FlutterLayer** layers,
+               size_t layers_count);
 
+  // Callback triggered at the end of the Present function. has_flutter_content
+  // is true when Flutter content was rendered, otherwise false.
   using PresentCallback = std::function<bool(bool has_flutter_content)>;
 
-  // PresentCallback is called at the end of the Present function.
+  // Registers a callback to be triggered at the end of the Present function.
+  // If a callback was previously registered, it will be replaced.
   void SetPresentCallback(const PresentCallback& present_callback);
 
-  // Denotes the current status of the frame being composited.
-  // Started: A new frame has begun and we have cleared the old layer tree
-  //          and are now creating backingstore(s) for the embedder to use.
+  // The status of the frame being composited.
+  // Started: A new frame has begun and we have cleared the old layer tree and
+  //     are now creating backingstore(s) for the embedder to use.
   // Presenting: the embedder has finished rendering into the provided
-  //             backingstore(s) and we are creating the layer tree for the
-  //             system compositor to present with.
-  // Ended: The frame has been presented and we are no longer processing
-  //        it.
+  //     backingstore(s) and we are creating the layer tree for the system
+  //     compositor to present with.
+  // Ended: The frame has been presented and we are no longer processing it.
   typedef enum { kStarted, kPresenting, kEnded } FrameStatus;
 
  protected:
-  // Get the view associated with the view ID.
+  // Returns the view associated with the view ID.
   //
   // Returns nil if the ID is invalid.
   FlutterView* GetView(uint64_t view_id);
@@ -94,12 +100,25 @@ class FlutterCompositor {
       CATransform3D transform = CATransform3DIdentity);
 
  private:
+  // Presents the platform view layer represented by `layer`. `layer_index` is
+  // used to position the layer in the z-axis. If the layer does not have a
+  // superview, it will become subview of `default_base_view`.
+  void PresentPlatformView(FlutterView* default_base_view,
+                           const FlutterLayer* layer,
+                           size_t layer_position);
+
   // A list of the active CALayer objects for the frame that need to be removed.
   std::list<CALayer*> active_ca_layers_;
 
   // Where the compositor can query FlutterViews. Must not be null.
   id<FlutterViewProvider> const view_provider_;
 
+  // The controller used to manage creation and deletion of platform views.
+  const FlutterPlatformViewController* platform_view_controller_;
+
+  // The Metal device used to draw graphics.
+  const id<MTLDevice> mtl_device_;
+
   // Callback set by the embedder to be called when the layer tree has been
   // correctly set up for this frame.
   PresentCallback present_callback_;

diff --git a/shell/platform/darwin/macos/framework/Source/FlutterCompositor.mm b/shell/platform/darwin/macos/framework/Source/FlutterCompositor.mm
@@ -3,13 +3,139 @@
 // found in the LICENSE file.
 
 #import "flutter/shell/platform/darwin/macos/framework/Source/FlutterCompositor.h"
+
 #include "flutter/fml/logging.h"
+#import "flutter/shell/platform/darwin/macos/framework/Source/FlutterIOSurfaceHolder.h"
 
 namespace flutter {
 
-FlutterCompositor::FlutterCompositor(id<FlutterViewProvider> view_provider)
-    : view_provider_(view_provider) {
-  FML_CHECK(view_provider != nullptr) << "FlutterViewProvider* cannot be nullptr";
+FlutterCompositor::FlutterCompositor(id<FlutterViewProvider> view_provider,
+                                     FlutterPlatformViewController* platform_view_controller,
+                                     id<MTLDevice> mtl_device)
+    : view_provider_(view_provider),
+      platform_view_controller_(platform_view_controller),
+      mtl_device_(mtl_device) {
+  FML_CHECK(view_provider != nullptr) << "view_provider cannot be nullptr";
+}
+
+bool FlutterCompositor::CreateBackingStore(const FlutterBackingStoreConfig* config,
+                                           FlutterBackingStore* backing_store_out) {
+  // TODO(dkwingsmt): This class only supports single-view for now. As more
+  // classes are gradually converted to multi-view, it should get the view ID
+  // from somewhere.
+  FlutterView* view = GetView(kFlutterDefaultViewId);
+  if (!view) {
+    return false;
+  }
+
+  CGSize size = CGSizeMake(config->size.width, config->size.height);
+
+  backing_store_out->metal.struct_size = sizeof(FlutterMetalBackingStore);
+  backing_store_out->metal.texture.struct_size = sizeof(FlutterMetalTexture);
+
+  if (GetFrameStatus() != FrameStatus::kStarted) {
+    StartFrame();
+    // If the backing store is for the first layer, return the MTLTexture for the
+    // FlutterView.
+    FlutterMetalRenderBackingStore* backingStore =
+        reinterpret_cast<FlutterMetalRenderBackingStore*>([view backingStoreForSize:size]);
+    backing_store_out->metal.texture.texture =
+        (__bridge FlutterMetalTextureHandle)backingStore.texture;
+  } else {
+    FlutterIOSurfaceHolder* io_surface_holder = [[FlutterIOSurfaceHolder alloc] init];
+    [io_surface_holder recreateIOSurfaceWithSize:size];
+    auto texture_descriptor =
+        [MTLTextureDescriptor texture2DDescriptorWithPixelFormat:MTLPixelFormatBGRA8Unorm
+                                                           width:size.width
+                                                          height:size.height
+                                                       mipmapped:NO];
+    texture_descriptor.usage =
+        MTLTextureUsageShaderRead | MTLTextureUsageRenderTarget | MTLTextureUsageShaderWrite;
+
+    backing_store_out->metal.texture.texture = (__bridge_retained FlutterMetalTextureHandle)
+        [mtl_device_ newTextureWithDescriptor:texture_descriptor
+                                    iosurface:[io_surface_holder ioSurface]
+                                        plane:0];
+
+    backing_store_out->metal.texture.user_data = (__bridge_retained void*)io_surface_holder;
+  }
+
+  backing_store_out->type = kFlutterBackingStoreTypeMetal;
+  backing_store_out->metal.texture.destruction_callback = [](void* user_data) {
+    if (user_data != nullptr) {
+      CFRelease(user_data);
+    }
+  };
+
+  return true;
+}
+
+bool FlutterCompositor::CollectBackingStore(const FlutterBackingStore* backing_store) {
+  // If we allocated this MTLTexture ourselves, user_data is not null, and we will need
+  // to release it manually.
+  if (backing_store->metal.texture.user_data != nullptr &&
+      backing_store->metal.texture.texture != nullptr) {
+    CFRelease(backing_store->metal.texture.texture);
+  }
+  return true;
+}
+
+bool FlutterCompositor::Present(uint64_t view_id,
+                                const FlutterLayer** layers,
+                                size_t layers_count) {
+  FlutterView* view = GetView(view_id);
+  if (!view) {
+    return false;
+  }
+
+  SetFrameStatus(FrameStatus::kPresenting);
+
+  bool has_flutter_content = false;
+  for (size_t i = 0; i < layers_count; ++i) {
+    const auto* layer = layers[i];
+    FlutterBackingStore* backing_store = const_cast<FlutterBackingStore*>(layer->backing_store);
+
+    switch (layer->type) {
+      case kFlutterLayerContentTypeBackingStore: {
+        if (backing_store->metal.texture.user_data) {
+          FlutterIOSurfaceHolder* io_surface_holder =
+              (__bridge FlutterIOSurfaceHolder*)backing_store->metal.texture.user_data;
+          IOSurfaceRef io_surface = [io_surface_holder ioSurface];
+          InsertCALayerForIOSurface(view, io_surface);
+        }
+        has_flutter_content = true;
+        break;
+      }
+      case kFlutterLayerContentTypePlatformView: {
+        PresentPlatformView(view, layer, i);
+        break;
+      }
+    };
+  }
+
+  return EndFrame(has_flutter_content);
+}
+
+void FlutterCompositor::PresentPlatformView(FlutterView* default_base_view,
+                                            const FlutterLayer* layer,
+                                            size_t layer_position) {
+  // TODO (https://github.com/flutter/flutter/issues/96668)
+  // once the issue is fixed, this check will pass.
+  FML_DCHECK([[NSThread currentThread] isMainThread])
+      << "Must be on the main thread to present platform views";
+
+  int64_t platform_view_id = layer->platform_view->identifier;
+  NSView* platform_view = [platform_view_controller_ platformViewWithID:platform_view_id];
+
+  FML_DCHECK(platform_view) << "Platform view not found for id: " << platform_view_id;
+
+  CGFloat scale = [[NSScreen mainScreen] backingScaleFactor];
+  platform_view.frame = CGRectMake(layer->offset.x / scale, layer->offset.y / scale,
+                                   layer->size.width / scale, layer->size.height / scale);
+  if (platform_view.superview == nil) {
+    [default_base_view addSubview:platform_view];
+  }
+  platform_view.layer.zPosition = layer_position;
 }
 
 void FlutterCompositor::SetPresentCallback(

diff --git a/...Source/FlutterMetalCompositorUnittests.mm → ...work/Source/FlutterCompositorUnittests.mm b/...Source/FlutterMetalCompositorUnittests.mm → ...work/Source/FlutterCompositorUnittests.mm
@@ -5,7 +5,7 @@
 #import <Foundation/Foundation.h>
 #import <OCMock/OCMock.h>
 
-#import "flutter/shell/platform/darwin/macos/framework/Source/FlutterMetalCompositor.h"
+#import "flutter/shell/platform/darwin/macos/framework/Source/FlutterCompositor.h"
 #import "flutter/shell/platform/darwin/macos/framework/Source/FlutterView.h"
 #import "flutter/shell/platform/darwin/macos/framework/Source/FlutterViewProvider.h"
 #import "flutter/testing/testing.h"
@@ -62,10 +62,10 @@ - (nullable FlutterView*)getView:(uint64_t)viewId {
 }
 }  // namespace
 
-TEST(FlutterMetalCompositorTest, TestPresent) {
-  std::unique_ptr<flutter::FlutterMetalCompositor> macos_compositor =
-      std::make_unique<FlutterMetalCompositor>(
-          MockViewProvider(), /*platform_view_controller*/ nullptr, /*mtl_device*/ nullptr);
+TEST(FlutterCompositorTest, TestPresent) {
+  std::unique_ptr<flutter::FlutterCompositor> macos_compositor =
+      std::make_unique<FlutterCompositor>(MockViewProvider(), /*platform_view_controller*/ nullptr,
+                                          /*mtl_device*/ nullptr);
 
   bool flag = false;
   macos_compositor->SetPresentCallback([f = &flag](bool has_flutter_content) {
@@ -77,10 +77,10 @@ - (nullable FlutterView*)getView:(uint64_t)viewId {
   ASSERT_TRUE(flag);
 }
 
-TEST(FlutterMetalCompositorTest, TestCreate) {
-  std::unique_ptr<flutter::FlutterMetalCompositor> macos_compositor =
-      std::make_unique<FlutterMetalCompositor>(
-          MockViewProvider(), /*platform_view_controller*/ nullptr, /*mtl_device*/ nullptr);
+TEST(FlutterCompositorTest, TestCreate) {
+  std::unique_ptr<flutter::FlutterCompositor> macos_compositor =
+      std::make_unique<FlutterCompositor>(MockViewProvider(), /*platform_view_controller*/ nullptr,
+                                          /*mtl_device*/ nullptr);
 
   FlutterBackingStore backing_store;
   FlutterBackingStoreConfig config;
@@ -96,10 +96,10 @@ - (nullable FlutterView*)getView:(uint64_t)viewId {
   ASSERT_EQ(texture.height, 600ul);
 }
 
-TEST(FlutterMetalCompositorTest, TestCompositing) {
-  std::unique_ptr<flutter::FlutterMetalCompositor> macos_compositor =
-      std::make_unique<FlutterMetalCompositor>(
-          MockViewProvider(), /*platform_view_controller*/ nullptr, /*mtl_device*/ nullptr);
+TEST(FlutterCompositorTest, TestCompositing) {
+  std::unique_ptr<flutter::FlutterCompositor> macos_compositor =
+      std::make_unique<FlutterCompositor>(MockViewProvider(), /*platform_view_controller*/ nullptr,
+                                          /*mtl_device*/ nullptr);
 
   FlutterBackingStore backing_store;
   FlutterBackingStoreConfig config;

diff --git a/shell/platform/darwin/macos/framework/Source/FlutterEngine.mm b/shell/platform/darwin/macos/framework/Source/FlutterEngine.mm
@@ -9,9 +9,9 @@
 #include <iostream>
 #include <vector>
 
+#import "flutter/shell/platform/darwin/macos/framework/Source/FlutterCompositor.h"
 #import "flutter/shell/platform/darwin/macos/framework/Source/FlutterDartProject_Internal.h"
 #import "flutter/shell/platform/darwin/macos/framework/Source/FlutterMenuPlugin.h"
-#import "flutter/shell/platform/darwin/macos/framework/Source/FlutterMetalCompositor.h"
 #import "flutter/shell/platform/darwin/macos/framework/Source/FlutterMetalRenderer.h"
 #import "flutter/shell/platform/darwin/macos/framework/Source/FlutterMouseCursorPlugin.h"
 #import "flutter/shell/platform/darwin/macos/framework/Source/FlutterPlatformViewController.h"
@@ -202,9 +202,8 @@ @implementation FlutterEngine {
   // Pointer to the Dart AOT snapshot and instruction data.
   _FlutterEngineAOTData* _aotData;
 
-  // _macOSCompositor is created when the engine is created and
-  // its destruction is handled by ARC when the engine is destroyed.
-  // This is either a FlutterGLCompositor or a FlutterMetalCompositor instance.
+  // _macOSCompositor is created when the engine is created and its destruction is handled by ARC
+  // when the engine is destroyed.
   std::unique_ptr<flutter::FlutterCompositor> _macOSCompositor;
 
   FlutterViewEngineProvider* _viewProvider;
@@ -424,7 +423,7 @@ - (FlutterCompositor*)createFlutterCompositor {
   __weak FlutterEngine* weakSelf = self;
 
   FlutterMetalRenderer* metalRenderer = reinterpret_cast<FlutterMetalRenderer*>(_renderer);
-  _macOSCompositor = std::make_unique<flutter::FlutterMetalCompositor>(
+  _macOSCompositor = std::make_unique<flutter::FlutterCompositor>(
       _viewProvider, _platformViewController, metalRenderer.device);
   _macOSCompositor->SetPresentCallback([weakSelf](bool has_flutter_content) {
     if (has_flutter_content) {