Create FlutterPlatformViewController

Author: RichardJCai

ci/licenses_golden/licenses_flutter

@@ -1072,6 +1072,8 @@ FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterIOSur
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterIOSurfaceHolder.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterMouseCursorPlugin.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterMouseCursorPlugin.mm
+FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterPlatformViewController.h
+FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterPlatformViewController.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterPlatformViews.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterResizeSynchronizer.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterResizeSynchronizer.mm

shell/platform/darwin/macos/BUILD.gn

@@ -62,6 +62,8 @@ source_set("flutter_framework_source") {
     "framework/Source/FlutterIOSurfaceHolder.mm",
     "framework/Source/FlutterMouseCursorPlugin.h",
     "framework/Source/FlutterMouseCursorPlugin.mm",
+    "framework/Source/FlutterPlatformViewController.mm",
+    "framework/Source/FlutterPlatformViewController_Internal.h",
     "framework/Source/FlutterPlatformViews.h",
     "framework/Source/FlutterResizeSynchronizer.h",
     "framework/Source/FlutterResizeSynchronizer.mm",

shell/platform/darwin/macos/framework/Source/FlutterEngine.mm

@@ -11,6 +11,7 @@
 #import "flutter/shell/platform/darwin/macos/framework/Source/FlutterDartProject_Internal.h"
 #import "flutter/shell/platform/darwin/macos/framework/Source/FlutterExternalTextureGL.h"
 #import "flutter/shell/platform/darwin/macos/framework/Source/FlutterGLCompositor.h"
+#import "flutter/shell/platform/darwin/macos/framework/Source/FlutterPlatformViewController_Internal.h"
 #import "flutter/shell/platform/embedder/embedder.h"
 
 /**
@@ -204,6 +205,13 @@ @implementation FlutterEngine {
 
   // FlutterCompositor is copied and used in embedder.cc.
   FlutterCompositor _compositor;
+
+  // A method channel for platform view functionality.
+  FlutterMethodChannel* _platformViewsChannel;
+
+  // Used to support creation and deletion of platform views and
+  // registering platform view factories.
+  FlutterPlatformViewController* _platformViewController;
 }
 
 - (instancetype)initWithName:(NSString*)labelPrefix project:(FlutterDartProject*)project {
@@ -313,6 +321,9 @@ - (BOOL)runWithEntrypoint:(NSString*)entrypoint {
     flutterArguments.aot_data = _aotData;
   }
 
+  [self setupPlatformViewChannel];
+  [self createPlatformViewController];
+
   flutterArguments.compositor = [self createFlutterCompositor];
 
   FlutterEngineResult result = _embedderAPI.Initialize(
@@ -369,54 +380,6 @@ - (void)setViewController:(FlutterViewController*)controller {
   }
 }
 
-- (FlutterCompositor*)createFlutterCompositor {
-  // TODO(richardjcai): Add support for creating a FlutterGLCompositor
-  // with a nil _viewController for headless engines.
-  // https://github.com/flutter/flutter/issues/71606
-  if (_viewController == nullptr) {
-    return nullptr;
-  }
-
-  [_mainOpenGLContext makeCurrentContext];
-
-  _macOSGLCompositor = std::make_unique<flutter::FlutterGLCompositor>(_viewController);
-
-  _compositor = {};
-  _compositor.struct_size = sizeof(FlutterCompositor);
-  _compositor.user_data = _macOSGLCompositor.get();
-
-  _compositor.create_backing_store_callback = [](const FlutterBackingStoreConfig* config,  //
-                                                 FlutterBackingStore* backing_store_out,   //
-                                                 void* user_data                           //
-                                              ) {
-    return reinterpret_cast<flutter::FlutterGLCompositor*>(user_data)->CreateBackingStore(
-        config, backing_store_out);
-  };
-
-  _compositor.collect_backing_store_callback = [](const FlutterBackingStore* backing_store,  //
-                                                  void* user_data                            //
-                                               ) {
-    return reinterpret_cast<flutter::FlutterGLCompositor*>(user_data)->CollectBackingStore(
-        backing_store);
-  };
-
-  _compositor.present_layers_callback = [](const FlutterLayer** layers,  //
-                                           size_t layers_count,          //
-                                           void* user_data               //
-                                        ) {
-    return reinterpret_cast<flutter::FlutterGLCompositor*>(user_data)->Present(layers,
-                                                                               layers_count);
-  };
-
-  __weak FlutterEngine* weak_self = self;
-  _macOSGLCompositor->SetPresentCallback(
-      [weak_self]() { return [weak_self engineCallbackOnPresent]; });
-
-  _compositor.avoid_backing_store_cache = true;
-
-  return &_compositor;
-}
-
 - (id<FlutterBinaryMessenger>)binaryMessenger {
   // TODO(stuartmorgan): Switch to FlutterBinaryMessengerRelay to avoid plugins
   // keeping the engine alive.
@@ -493,6 +456,10 @@ - (void)sendPointerEvent:(const FlutterPointerEvent&)event {
   _embedderAPI.SendPointerEvent(_engine, &event, 1);
 }
 
+- (FlutterPlatformViewController*)platformViewController {
+  return _platformViewController;
+}
+
 #pragma mark - Private methods
 
 - (void)sendUserLocales {
@@ -600,6 +567,71 @@ - (void)shutDownEngine {
   _engine = nullptr;
 }
 
+- (FlutterCompositor*)createFlutterCompositor {
+  // TODO(richardjcai): Add support for creating a FlutterGLCompositor
+  // with a nil _viewController for headless engines.
+  // https://github.com/flutter/flutter/issues/71606
+  if (_viewController == nullptr) {
+    return nullptr;
+  }
+
+  [_mainOpenGLContext makeCurrentContext];
+
+  _macOSGLCompositor =
+      std::make_unique<flutter::FlutterGLCompositor>(_viewController, _platformViewController);
+
+  _compositor = {};
+  _compositor.struct_size = sizeof(FlutterCompositor);
+  _compositor.user_data = _macOSGLCompositor.get();
+
+  _compositor.create_backing_store_callback = [](const FlutterBackingStoreConfig* config,  //
+                                                 FlutterBackingStore* backing_store_out,   //
+                                                 void* user_data                           //
+                                              ) {
+    return reinterpret_cast<flutter::FlutterGLCompositor*>(user_data)->CreateBackingStore(
+        config, backing_store_out);
+  };
+
+  _compositor.collect_backing_store_callback = [](const FlutterBackingStore* backing_store,  //
+                                                  void* user_data                            //
+                                               ) {
+    return reinterpret_cast<flutter::FlutterGLCompositor*>(user_data)->CollectBackingStore(
+        backing_store);
+  };
+
+  _compositor.present_layers_callback = [](const FlutterLayer** layers,  //
+                                           size_t layers_count,          //
+                                           void* user_data               //
+                                        ) {
+    return reinterpret_cast<flutter::FlutterGLCompositor*>(user_data)->Present(layers,
+                                                                               layers_count);
+  };
+
+  __weak FlutterEngine* weak_self = self;
+  _macOSGLCompositor->SetPresentCallback(
+      [weak_self]() { return [weak_self engineCallbackOnPresent]; });
+
+  _compositor.avoid_backing_store_cache = true;
+
+  return &_compositor;
+}
+
+- (void)createPlatformViewController {
+  _platformViewController = [[FlutterPlatformViewController alloc] init];
+}
+
+- (void)setupPlatformViewChannel {
+  _platformViewsChannel =
+      [FlutterMethodChannel methodChannelWithName:@"flutter/platform_views"
+                                  binaryMessenger:self.binaryMessenger
+                                            codec:[FlutterStandardMethodCodec sharedInstance]];
+
+  __weak FlutterEngine* weak_self = self;
+  [_platformViewsChannel setMethodCallHandler:^(FlutterMethodCall* call, FlutterResult result) {
+    [[weak_self platformViewController] handleMethodCall:call result:result];
+  }];
+}
+
 #pragma mark - FlutterBinaryMessenger
 
 - (void)sendOnChannel:(nonnull NSString*)channel message:(nullable NSData*)message {

shell/platform/darwin/macos/framework/Source/FlutterGLCompositor.h

@@ -6,6 +6,7 @@
 
 #include "flutter/fml/macros.h"
 #include "flutter/shell/platform/darwin/macos/framework/Source/FlutterBackingStoreData.h"
+#include "flutter/shell/platform/darwin/macos/framework/Source/FlutterPlatformViewController_Internal.h"
 #include "flutter/shell/platform/darwin/macos/framework/Source/FlutterSurfaceManager.h"
 #include "flutter/shell/platform/darwin/macos/framework/Source/FlutterViewController_Internal.h"
 #include "flutter/shell/platform/embedder/embedder.h"
@@ -19,7 +20,8 @@ namespace flutter {
 // FlutterGLCompositor is created and destroyed by FlutterEngine.
 class FlutterGLCompositor {
  public:
-  FlutterGLCompositor(FlutterViewController* view_controller);
+  FlutterGLCompositor(FlutterViewController* view_controller,
+                      FlutterPlatformViewController* platform_view_controller);
 
   // Creates a BackingStore and saves updates the backing_store_out
   // data with the new BackingStore data.
@@ -50,6 +52,7 @@ class FlutterGLCompositor {
 
  private:
   const FlutterViewController* view_controller_;
+  const FlutterPlatformViewController* platform_view_controller_;
   const NSOpenGLContext* open_gl_context_;
   PresentCallback present_callback_;
 
@@ -75,9 +78,6 @@ class FlutterGLCompositor {
   // Set frame_started_ to true and reset all layer state.
   void StartFrame();
 
-  // Remove platform views that are specified for deletion.
-  void DisposePlatformViews();
-
   // Creates a CALayer and adds it to ca_layer_map_ and increments
   // ca_layer_count_; Returns the key value (size_t) for the layer in
   // ca_layer_map_.

shell/platform/darwin/macos/framework/Source/FlutterGLCompositor.mm

@@ -18,10 +18,15 @@
 
 namespace flutter {
 
-FlutterGLCompositor::FlutterGLCompositor(FlutterViewController* view_controller)
+FlutterGLCompositor::FlutterGLCompositor(FlutterViewController* view_controller,
+                                         FlutterPlatformViewController* platform_view_controller)
     : open_gl_context_(view_controller.flutterView.openGLContext) {
   FML_CHECK(view_controller != nullptr) << "FlutterViewController* cannot be nullptr";
+  FML_CHECK(platform_view_controller != nullptr)
+      << "FlutterPlatformViewController* cannot be nullptr";
+
   view_controller_ = view_controller;
+  platform_view_controller_ = platform_view_controller;
 }
 
 bool FlutterGLCompositor::CreateBackingStore(const FlutterBackingStoreConfig* config,
@@ -71,7 +76,7 @@
 }
 
 bool FlutterGLCompositor::Present(const FlutterLayer** layers, size_t layers_count) {
-  DisposePlatformViews();
+  [platform_view_controller_ disposePlatformViews];
   for (size_t i = 0; i < layers_count; ++i) {
     const auto* layer = layers[i];
     FlutterBackingStore* backing_store = const_cast<FlutterBackingStore*>(layer->backing_store);
@@ -85,9 +90,15 @@
         break;
       }
       case kFlutterLayerContentTypePlatformView:
-        FML_CHECK([[NSThread currentThread] isMainThread])
+        FML_DCHECK([[NSThread currentThread] isMainThread])
             << "Must be on the main thread to handle presenting platform views";
-        NSView* platform_view = view_controller_.platformViews[layer->platform_view->identifier];
+
+        FML_DCHECK(platform_view_controller_.platformViews.count(layer->platform_view->identifier))
+            << "Platform view not found for id: " << layer->platform_view->identifier;
+
+        NSView* platform_view =
+            platform_view_controller_.platformViews[layer->platform_view->identifier];
+
         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);
@@ -108,15 +119,15 @@
 void FlutterGLCompositor::PresentBackingStoreContent(
     FlutterBackingStoreData* flutter_backing_store_data,
     size_t layer_position) {
-  FML_CHECK([[NSThread currentThread] isMainThread])
+  FML_DCHECK([[NSThread currentThread] isMainThread])
       << "Must be on the main thread to update CALayer contents";
 
   FlutterIOSurfaceHolder* io_surface_holder = [flutter_backing_store_data ioSurfaceHolder];
   size_t layer_id = [flutter_backing_store_data layerId];
 
   CALayer* content_layer = ca_layer_map_[layer_id];
 
-  FML_CHECK(content_layer) << "Unable to find a content layer with layer id " << layer_id;
+  FML_DCHECK(content_layer) << "Unable to find a content layer with layer id " << layer_id;
 
   content_layer.frame = content_layer.superlayer.bounds;
   content_layer.zPosition = layer_position;
@@ -158,20 +169,4 @@
   return ca_layer_count_++;
 }
 
-void FlutterGLCompositor::DisposePlatformViews() {
-  auto views_to_dispose = view_controller_.platformViewsToDispose;
-  if (views_to_dispose.empty()) {
-    return;
-  }
-
-  for (int64_t viewId : views_to_dispose) {
-    FML_CHECK([[NSThread currentThread] isMainThread])
-        << "Must be on the main thread to handle disposing platform views";
-    NSView* view = view_controller_.platformViews[viewId];
-    [view removeFromSuperview];
-    view_controller_.platformViews.erase(viewId);
-  }
-  views_to_dispose.clear();
-}
-
 }  // namespace flutter

shell/platform/darwin/macos/framework/Source/FlutterGLCompositorUnittests.mm

@@ -5,16 +5,19 @@
 #import <Foundation/Foundation.h>
 
 #import "flutter/shell/platform/darwin/macos/framework/Source/FlutterGLCompositor.h"
+#import "flutter/shell/platform/darwin/macos/framework/Source/FlutterPlatformViewController_Internal.h"
 #import "flutter/shell/platform/darwin/macos/framework/Source/FlutterViewControllerTestUtils.h"
 #import "flutter/testing/testing.h"
 
 namespace flutter::testing {
 
 TEST(FlutterGLCompositorTest, TestPresent) {
   id mockViewController = CreateMockViewController(nil);
+  FlutterPlatformViewController* platformViewController =
+      [[FlutterPlatformViewController alloc] init];
 
   std::unique_ptr<flutter::FlutterGLCompositor> macos_compositor =
-      std::make_unique<FlutterGLCompositor>(mockViewController);
+      std::make_unique<FlutterGLCompositor>(mockViewController, platformViewController);
 
   bool flag = false;
   macos_compositor->SetPresentCallback([f = &flag]() {