Move FlutterPlatformViewsController into FlutterEngine.

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

@@ -44,12 +44,15 @@ @implementation FlutterEngine {
   fml::WeakPtr<FlutterViewController> _viewController;
   fml::scoped_nsobject<FlutterObservatoryPublisher> _publisher;
 
+  std::unique_ptr<shell::FlutterPlatformViewsController> _platformViewsController;
+
   // Channels
   fml::scoped_nsobject<FlutterPlatformPlugin> _platformPlugin;
   fml::scoped_nsobject<FlutterTextInputPlugin> _textInputPlugin;
   fml::scoped_nsobject<FlutterMethodChannel> _localizationChannel;
   fml::scoped_nsobject<FlutterMethodChannel> _navigationChannel;
   fml::scoped_nsobject<FlutterMethodChannel> _platformChannel;
+  fml::scoped_nsobject<FlutterMethodChannel> _platformViewsChannel;
   fml::scoped_nsobject<FlutterMethodChannel> _textInputChannel;
   fml::scoped_nsobject<FlutterBasicMessageChannel> _lifecycleChannel;
   fml::scoped_nsobject<FlutterBasicMessageChannel> _systemChannel;
@@ -73,6 +76,7 @@ - (instancetype)initWithName:(NSString*)labelPrefix project:(FlutterDartProject*
 
   _pluginPublications = [NSMutableDictionary new];
   _publisher.reset([[FlutterObservatoryPublisher alloc] init]);
+  _platformViewsController.reset(new shell::FlutterPlatformViewsController());
 
   [self setupChannels];
 
@@ -143,6 +147,9 @@ - (FlutterViewController*)viewController {
 - (FlutterPlatformPlugin*)platformPlugin {
   return _platformPlugin.get();
 }
+- (shell::FlutterPlatformViewsController*)platformViewsController {
+  return _platformViewsController.get();
+}
 - (FlutterTextInputPlugin*)textInputPlugin {
   return _textInputPlugin.get();
 }
@@ -184,6 +191,11 @@ - (void)setupChannels {
       binaryMessenger:self
                 codec:[FlutterJSONMethodCodec sharedInstance]]);
 
+  _platformViewsChannel.reset([[FlutterMethodChannel alloc]
+         initWithName:@"flutter/platform_views"
+      binaryMessenger:self
+                codec:[FlutterStandardMethodCodec sharedInstance]]);
+
   _textInputChannel.reset([[FlutterMethodChannel alloc]
          initWithName:@"flutter/textinput"
       binaryMessenger:self
@@ -218,6 +230,11 @@ - (void)maybeSetupPlatformViewChannels {
       [_platformPlugin.get() handleMethodCall:call result:result];
     }];
 
+    [_platformViewsChannel.get()
+        setMethodCallHandler:^(FlutterMethodCall* call, FlutterResult result) {
+          _platformViewsController->OnMethodCall(call, result);
+        }];
+
     [_textInputChannel.get() setMethodCallHandler:^(FlutterMethodCall* call, FlutterResult result) {
       [_textInputPlugin.get() handleMethodCall:call result:result];
     }];
@@ -379,6 +396,10 @@ - (void)performAction:(FlutterTextInputAction)action withClient:(int)client {
   return _shell->Screenshot(type, base64Encode);
 }
 
+- (flow::ExternalViewEmbedder*)externalViewEmbedder {
+  return _platformViewsController.get();
+}
+
 #pragma mark - FlutterBinaryMessenger
 
 - (void)sendOnChannel:(NSString*)channel message:(NSData*)message {
@@ -514,18 +535,7 @@ - (NSString*)lookupKeyForAsset:(NSString*)asset fromPackage:(NSString*)package {
 
 - (void)registerViewFactory:(NSObject<FlutterPlatformViewFactory>*)factory
                      withId:(NSString*)factoryId {
-  // TODO(amirh/dnfield): this shouldn't need to fail - PlatformViewsController should be
-  // independent. Dev builds of engine should just fail here.  We don't want to fail in release mode
-  // because this shouldn't ordinarily happen.
-  FML_DCHECK([_flutterEngine viewController])
-      << "Cannot register a view factory on a headless engine.";
-  if ([_flutterEngine viewController]) {
-    [[_flutterEngine viewController] platformViewsController]->RegisterViewFactory(factory,
-                                                                                   factoryId);
-  } else {
-    // Shouldn't ordinarily happen, but at least give warning if it does.
-    FML_LOG(ERROR) << "Cannot register a view factory on a headless engine.";
-  }
+  [_flutterEngine platformViewsController] -> RegisterViewFactory(factory, factoryId);
 }
 
 @end

shell/platform/darwin/ios/framework/Source/FlutterEngine_Internal.h

@@ -7,6 +7,8 @@
 
 #import "flutter/shell/platform/darwin/ios/framework/Headers/FlutterEngine.h"
 
+#import "FlutterPlatformViews_Internal.h"
+
 #include "flutter/fml/memory/weak_ptr.h"
 #include "flutter/fml/task_runner.h"
 #include "flutter/lib/ui/window/pointer_data_packet.h"
@@ -22,7 +24,7 @@
 
 #include "flutter/shell/platform/darwin/ios/framework/Headers/FlutterEngine.h"
 
-@interface FlutterEngine () <FlutterScreenshotDelegate>
+@interface FlutterEngine () <FlutterViewEngineDelegate>
 
 - (shell::Shell&)shell;
 
@@ -37,6 +39,7 @@
                                base64Encode:(bool)base64Encode;
 
 - (FlutterPlatformPlugin*)platformPlugin;
+- (shell::FlutterPlatformViewsController*)platformViewsController;
 - (FlutterTextInputPlugin*)textInputPlugin;
 - (void)launchEngine:(NSString*)entrypoint libraryURI:(NSString*)libraryOrNil;
 

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

@@ -14,17 +14,8 @@
 
 namespace shell {
 
-FlutterPlatformViewsController::FlutterPlatformViewsController(
-    NSObject<FlutterBinaryMessenger>* messenger,
-    FlutterView* flutter_view)
-    : flutter_view_([flutter_view retain]) {
-  channel_.reset([[FlutterMethodChannel alloc]
-         initWithName:@"flutter/platform_views"
-      binaryMessenger:messenger
-                codec:[FlutterStandardMethodCodec sharedInstance]]);
-  [channel_.get() setMethodCallHandler:^(FlutterMethodCall* call, FlutterResult result) {
-    OnMethodCall(call, result);
-  }];
+void FlutterPlatformViewsController::SetFlutterView(UIView* flutter_view) {
+  flutter_view_.reset(flutter_view);
 }
 
 void FlutterPlatformViewsController::OnMethodCall(FlutterMethodCall* call, FlutterResult& result) {
@@ -40,6 +31,15 @@
 }
 
 void FlutterPlatformViewsController::OnCreate(FlutterMethodCall* call, FlutterResult& result) {
+  if (!flutter_view_.get()) {
+    // Right now we assume we have a reference to FlutterView when creating a new view.
+    // TODO(amirh): support this by setting the refernce to FlutterView when it becomes available.
+    // https://github.com/flutter/flutter/issues/23787
+    result([FlutterError errorWithCode:@"create_failed"
+                               message:@"can't create a view on a headless engine"
+                               details:nil]);
+    return;
+  }
   NSDictionary<NSString*, id>* args = [call arguments];
 
   long viewId = [args[@"id"] longValue];
@@ -66,7 +66,7 @@
                flutterView:flutter_view_] autorelease];
   views_[viewId] = fml::scoped_nsobject<FlutterTouchInterceptingView>([view retain]);
 
-  FlutterView* flutter_view = flutter_view_.get();
+  UIView* flutter_view = flutter_view_.get();
   [flutter_view addSubview:views_[viewId].get()];
   result(nil);
 }

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

@@ -5,7 +5,6 @@
 #ifndef FLUTTER_SHELL_PLATFORM_DARWIN_IOS_FRAMEWORK_SOURCE_FLUTTERPLATFORMVIEWS_INTERNAL_H_
 #define FLUTTER_SHELL_PLATFORM_DARWIN_IOS_FRAMEWORK_SOURCE_FLUTTERPLATFORMVIEWS_INTERNAL_H_
 
-#include "FlutterView.h"
 #include "flutter/flow/embedded_views.h"
 #include "flutter/fml/platform/darwin/scoped_nsobject.h"
 #include "flutter/shell/common/shell.h"
@@ -29,20 +28,22 @@ namespace shell {
 
 class FlutterPlatformViewsController : public flow::ExternalViewEmbedder {
  public:
-  FlutterPlatformViewsController(NSObject<FlutterBinaryMessenger>* messenger,
-                                 FlutterView* flutter_view);
+  FlutterPlatformViewsController() = default;
+
+  void SetFlutterView(UIView* flutter_view);
 
   void RegisterViewFactory(NSObject<FlutterPlatformViewFactory>* factory, NSString* factoryId);
 
   void CompositeEmbeddedView(int view_id, const flow::EmbeddedViewParams& params);
 
+  void OnMethodCall(FlutterMethodCall* call, FlutterResult& result);
+
  private:
   fml::scoped_nsobject<FlutterMethodChannel> channel_;
-  fml::scoped_nsobject<FlutterView> flutter_view_;
+  fml::scoped_nsobject<UIView> flutter_view_;
   std::map<std::string, fml::scoped_nsobject<NSObject<FlutterPlatformViewFactory>>> factories_;
   std::map<int64_t, fml::scoped_nsobject<FlutterTouchInterceptingView>> views_;
 
-  void OnMethodCall(FlutterMethodCall* call, FlutterResult& result);
   void OnCreate(FlutterMethodCall* call, FlutterResult& result);
   void OnDispose(FlutterMethodCall* call, FlutterResult& result);
   void OnAcceptGesture(FlutterMethodCall* call, FlutterResult& result);

shell/platform/darwin/ios/framework/Source/FlutterView.h

@@ -9,16 +9,20 @@
 
 #include <memory>
 
+#import "FlutterPlatformViews_Internal.h"
+
 #include "flutter/flow/embedded_views.h"
 #include "flutter/fml/memory/weak_ptr.h"
 #include "flutter/shell/common/shell.h"
 #include "flutter/shell/platform/darwin/ios/ios_surface.h"
 
-@protocol FlutterScreenshotDelegate <NSObject>
+@protocol FlutterViewEngineDelegate <NSObject>
 
 - (shell::Rasterizer::Screenshot)takeScreenshot:(shell::Rasterizer::ScreenshotType)type
                                 asBase64Encoded:(BOOL)base64Encode;
 
+- (flow::ExternalViewEmbedder*)externalViewEmbedder;
+
 @end
 
 @interface FlutterView : UIView
@@ -27,7 +31,7 @@
 - (instancetype)initWithFrame:(CGRect)frame NS_UNAVAILABLE;
 - (instancetype)initWithCoder:(NSCoder*)aDecoder NS_UNAVAILABLE;
 
-- (instancetype)initWithDelegate:(id<FlutterScreenshotDelegate>)delegate
+- (instancetype)initWithDelegate:(id<FlutterViewEngineDelegate>)delegate
                           opaque:(BOOL)opaque NS_DESIGNATED_INITIALIZER;
 - (std::unique_ptr<shell::IOSSurface>)createSurface;
 

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

@@ -23,7 +23,7 @@ @interface FlutterView () <UIInputViewAudioFeedback>
 
 @implementation FlutterView
 
-id<FlutterScreenshotDelegate> _delegate;
+id<FlutterViewEngineDelegate> _delegate;
 
 - (instancetype)init {
   @throw([NSException exceptionWithName:@"FlutterView must initWithDelegate"
@@ -43,7 +43,7 @@ - (instancetype)initWithCoder:(NSCoder*)aDecoder {
                                userInfo:nil]);
 }
 
-- (instancetype)initWithDelegate:(id<FlutterScreenshotDelegate>)delegate opaque:(BOOL)opaque {
+- (instancetype)initWithDelegate:(id<FlutterViewEngineDelegate>)delegate opaque:(BOOL)opaque {
   FML_DCHECK(delegate) << "Delegate must not be nil.";
   self = [super initWithFrame:CGRectNull];
 
@@ -55,23 +55,6 @@ - (instancetype)initWithDelegate:(id<FlutterScreenshotDelegate>)delegate opaque:
   return self;
 }
 
-- (FlutterViewController*)flutterViewController {
-  // Find the first view controller in the responder chain and see if it is a FlutterViewController.
-  for (UIResponder* responder = self.nextResponder; responder != nil;
-       responder = responder.nextResponder) {
-    if ([responder isKindOfClass:[UIViewController class]]) {
-      if ([responder isKindOfClass:[FlutterViewController class]]) {
-        return reinterpret_cast<FlutterViewController*>(responder);
-      } else {
-        // Should only happen if a non-FlutterViewController tries to somehow (via dynamic class
-        // resolution or reparenting) set a FlutterView as its view.
-        return nil;
-      }
-    }
-  }
-  return nil;
-}
-
 - (void)layoutSubviews {
   if ([self.layer isKindOfClass:[CAEAGLLayer class]]) {
     CAEAGLLayer* layer = reinterpret_cast<CAEAGLLayer*>(self.layer);
@@ -93,16 +76,15 @@ + (Class)layerClass {
 }
 
 - (std::unique_ptr<shell::IOSSurface>)createSurface {
-  ::shell::GetExternalViewEmbedder get_view_embedder = [[^() {
-    return [[self flutterViewController] viewEmbedder];
-  } copy] autorelease];
   if ([self.layer isKindOfClass:[CAEAGLLayer class]]) {
     fml::scoped_nsobject<CAEAGLLayer> eagl_layer(
         reinterpret_cast<CAEAGLLayer*>([self.layer retain]));
-    return std::make_unique<shell::IOSSurfaceGL>(std::move(eagl_layer), get_view_embedder);
+    return std::make_unique<shell::IOSSurfaceGL>(std::move(eagl_layer),
+                                                 *[_delegate externalViewEmbedder]);
   } else {
     fml::scoped_nsobject<CALayer> layer(reinterpret_cast<CALayer*>([self.layer retain]));
-    return std::make_unique<shell::IOSSurfaceSoftware>(std::move(layer), get_view_embedder);
+    return std::make_unique<shell::IOSSurfaceSoftware>(std::move(layer),
+                                                       *[_delegate externalViewEmbedder]);
   }
 }
 

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

@@ -113,8 +113,6 @@ - (void)performCommonViewControllerInitialization {
   _statusBarStyle = UIStatusBarStyleDefault;
 
   [self setupNotificationCenterObservers];
-  _platformViewsController.reset(
-      new shell::FlutterPlatformViewsController(_engine.get(), _flutterView.get()));
 }
 
 - (fml::scoped_nsobject<FlutterEngine>)engine {
@@ -125,10 +123,6 @@ - (void)performCommonViewControllerInitialization {
   return _weakFactory->GetWeakPtr();
 }
 
-- (flow::ExternalViewEmbedder*)viewEmbedder {
-  return _platformViewsController.get();
-}
-
 - (void)setupNotificationCenterObservers {
   NSNotificationCenter* center = [NSNotificationCenter defaultCenter];
   [center addObserver:self
@@ -364,10 +358,11 @@ - (void)surfaceUpdated:(BOOL)appeared {
   // NotifyCreated/NotifyDestroyed are synchronous and require hops between the UI and GPU thread.
   if (appeared) {
     [self installSplashScreenViewCallback];
+    [_engine.get() platformViewsController] -> SetFlutterView(_flutterView.get());
     [_engine.get() platformView] -> NotifyCreated();
-
   } else {
     [_engine.get() platformView] -> NotifyDestroyed();
+    [_engine.get() platformViewsController] -> SetFlutterView(nullptr);
   }
 }
 

shell/platform/darwin/ios/framework/Source/FlutterViewController_Internal.h

@@ -19,8 +19,6 @@
 
 @property(readonly) fml::scoped_nsobject<FlutterEngine> engine;
 
-- (flow::ExternalViewEmbedder*)viewEmbedder;
-
 @end
 
 #endif  // FLUTTER_SHELL_PLATFORM_DARWIN_IOS_FRAMEWORK_SOURCE_FLUTTERVIEWCONTROLLER_INTERNAL_H_

shell/platform/darwin/ios/ios_surface.h

@@ -13,8 +13,6 @@
 
 namespace shell {
 
-typedef flow::ExternalViewEmbedder* (^GetExternalViewEmbedder)(void);
-
 class IOSSurface {
  public:
   IOSSurface();

shell/platform/darwin/ios/ios_surface_gl.h

@@ -18,7 +18,7 @@ namespace shell {
 class IOSSurfaceGL : public IOSSurface, public GPUSurfaceGLDelegate {
  public:
   IOSSurfaceGL(fml::scoped_nsobject<CAEAGLLayer> layer,
-               ::shell::GetExternalViewEmbedder get_view_embedder);
+               flow::ExternalViewEmbedder& external_view_embedder);
 
   ~IOSSurfaceGL() override;
 
@@ -46,7 +46,7 @@ class IOSSurfaceGL : public IOSSurface, public GPUSurfaceGLDelegate {
  private:
   IOSGLContext context_;
 
-  fml::scoped_nsprotocol<::shell::GetExternalViewEmbedder> get_view_embedder_;
+  flow::ExternalViewEmbedder& external_view_embedder_;
 
   FML_DISALLOW_COPY_AND_ASSIGN(IOSSurfaceGL);
 };

shell/platform/darwin/ios/ios_surface_gl.mm

@@ -10,8 +10,8 @@
 namespace shell {
 
 IOSSurfaceGL::IOSSurfaceGL(fml::scoped_nsobject<CAEAGLLayer> layer,
-                           ::shell::GetExternalViewEmbedder get_view_embedder)
-    : context_(std::move(layer)), get_view_embedder_([get_view_embedder retain]) {}
+                           flow::ExternalViewEmbedder& view_embedder)
+    : context_(std::move(layer)), external_view_embedder_(view_embedder) {}
 
 IOSSurfaceGL::~IOSSurfaceGL() = default;
 
@@ -59,7 +59,7 @@
 }
 
 flow::ExternalViewEmbedder* IOSSurfaceGL::GetExternalViewEmbedder() {
-  return get_view_embedder_.get()();
+  return &external_view_embedder_;
 }
 
 }  // namespace shell

shell/platform/darwin/ios/ios_surface_software.h

@@ -17,7 +17,7 @@ namespace shell {
 class IOSSurfaceSoftware final : public IOSSurface, public GPUSurfaceSoftwareDelegate {
  public:
   IOSSurfaceSoftware(fml::scoped_nsobject<CALayer> layer,
-                     ::shell::GetExternalViewEmbedder get_view_embedder);
+                     flow::ExternalViewEmbedder& view_embedder);
 
   ~IOSSurfaceSoftware() override;
 
@@ -44,7 +44,7 @@ class IOSSurfaceSoftware final : public IOSSurface, public GPUSurfaceSoftwareDel
 
  private:
   fml::scoped_nsobject<CALayer> layer_;
-  fml::scoped_nsprotocol<::shell::GetExternalViewEmbedder> get_view_embedder_;
+  flow::ExternalViewEmbedder& external_view_embedder_;
   sk_sp<SkSurface> sk_surface_;
 
   FML_DISALLOW_COPY_AND_ASSIGN(IOSSurfaceSoftware);