flutter · cyanglaz · Jul 19, 2023 · Aug 24, 2023 · Aug 29, 2023 · Aug 29, 2023
diff --git a/shell/platform/darwin/ios/framework/Source/FlutterEngine.mm b/shell/platform/darwin/ios/framework/Source/FlutterEngine.mm
@@ -36,6 +36,7 @@
 #import "flutter/shell/platform/darwin/ios/framework/Source/platform_message_response_darwin.h"
 #import "flutter/shell/platform/darwin/ios/framework/Source/profiler_metrics_ios.h"
 #import "flutter/shell/platform/darwin/ios/framework/Source/vsync_waiter_ios.h"
+#import "flutter/shell/platform/darwin/ios/platform_message_handler_ios.h"
 #import "flutter/shell/platform/darwin/ios/platform_view_ios.h"
 #import "flutter/shell/platform/darwin/ios/rendering_api_selection.h"
 #include "flutter/shell/profiling/sampling_profiler.h"
@@ -82,6 +83,31 @@ static void IOSPlatformThreadConfigSetter(const fml::Thread::ThreadConfig& confi
 NSString* const kFlutterKeyDataChannel = @"flutter/keydata";
 static constexpr int kNumProfilerSamplesPerSec = 5;
 
+@interface PlatformViewChannelTaskQueue : NSObject <FlutterTaskQueue>
+
+- (instancetype)initWithTaskRunner:(fml::RefPtr<fml::TaskRunner>)taskRunner;
+- (void)dispatch:(dispatch_block_t)block;
+@end
+
+@implementation PlatformViewChannelTaskQueue {
+  fml::RefPtr<fml::TaskRunner> _taskRunner;
+}
+
+- (instancetype)initWithTaskRunner:(fml::RefPtr<fml::TaskRunner>)taskRunner {
+  self = [super init];
+  if (!self) {
+    return nil;
+  }
+  _taskRunner = taskRunner;
+  return self;
+}
+
+- (void)dispatch:(dispatch_block_t)block {
+  fml::TaskRunner::RunNowOrPostTask(_taskRunner,
+                                    [block_copy = Block_copy(block)]() { block_copy(); });
+}
+@end
+
 @interface FlutterEngineRegistrar : NSObject <FlutterPluginRegistrar>
 @property(nonatomic, assign) FlutterEngine* flutterEngine;
 - (instancetype)initWithPlugin:(NSString*)pluginKey flutterEngine:(FlutterEngine*)flutterEngine;
@@ -100,6 +126,7 @@ @interface FlutterEngine () <FlutterIndirectScribbleDelegate,
 @property(nonatomic, readwrite, copy) NSString* isolateId;
 @property(nonatomic, copy) NSString* initialRoute;
 @property(nonatomic, retain) id<NSObject> flutterViewControllerWillDeallocObserver;
+@property(nonatomic, retain) PlatformViewChannelTaskQueue* platformViewTaskQueue;
 
 #pragma mark - Embedder API properties
 
@@ -308,6 +335,7 @@ - (void)dealloc {
   [_textureRegistry release];
   _textureRegistry = nil;
   [_isolateId release];
+  [_platformViewTaskQueue release];
 
   NSNotificationCenter* center = [NSNotificationCenter defaultCenter];
   if (_flutterViewControllerWillDeallocObserver) {
@@ -620,7 +648,8 @@ - (void)setUpChannels {
   _platformViewsChannel.reset([[FlutterMethodChannel alloc]
          initWithName:@"flutter/platform_views"
       binaryMessenger:self.binaryMessenger
-                codec:[FlutterStandardMethodCodec sharedInstance]]);
+                codec:[FlutterStandardMethodCodec sharedInstance]
+            taskQueue:_platformViewTaskQueue]);
 
   _textInputChannel.reset([[FlutterMethodChannel alloc]
          initWithName:@"flutter/textinput"
@@ -716,11 +745,12 @@ - (void)maybeSetupPlatformViewChannels {
       [platformPlugin handleMethodCall:call result:result];
     }];
 
-    fml::WeakPtr<FlutterEngine> weakSelf = [self getWeakPtr];
+    std::weak_ptr<flutter::FlutterPlatformViewsController> weakPlatformViewsController =
+        _platformViewsController;
     [_platformViewsChannel.get()
         setMethodCallHandler:^(FlutterMethodCall* call, FlutterResult result) {
-          if (weakSelf) {
-            weakSelf.get().platformViewsController->OnMethodCall(call, result);
+          if (!weakPlatformViewsController.expired()) {
+            weakPlatformViewsController.lock()->OnMethodCall(call, result);
           }
         }];
 

diff --git a/shell/platform/darwin/ios/framework/Source/FlutterPlatformViews.mm b/shell/platform/darwin/ios/framework/Source/FlutterPlatformViews.mm
@@ -174,14 +174,35 @@ static bool ClipRRectContainsPlatformViewBoundingRect(const SkRRect& clip_rrect,
 }
 
 void FlutterPlatformViewsController::OnMethodCall(FlutterMethodCall* call, FlutterResult& result) {
+  // This method is invoked on UI thread.
+  // Generally, all the method channel calls need to be dispatched to the main thread.
+  // The exceptions being gesture handling.
+  BOOL hitTestBlocking = [[[NSBundle mainBundle]
+      objectForInfoDictionaryKey:@"FLTPlatformViewHitTestBlocking"] boolValue];
   if ([[call method] isEqualToString:@"create"]) {
-    OnCreate(call, result);
+    dispatch_async(dispatch_get_main_queue(), ^{
+      OnCreate(call, result);
+    });
   } else if ([[call method] isEqualToString:@"dispose"]) {
-    OnDispose(call, result);
+    dispatch_async(dispatch_get_main_queue(), ^{
+      OnDispose(call, result);
+    });
   } else if ([[call method] isEqualToString:@"acceptGesture"]) {
-    OnAcceptGesture(call, result);
+    if (hitTestBlocking) {
+      OnHitTestResult(call, result, YES);
+    } else {
+      dispatch_async(dispatch_get_main_queue(), ^{
+        OnAcceptGesture(call, result);
+      });
+    }
   } else if ([[call method] isEqualToString:@"rejectGesture"]) {
-    OnRejectGesture(call, result);
+    if (hitTestBlocking) {
+      OnHitTestResult(call, result, NO);
+    } else {
+      dispatch_async(dispatch_get_main_queue(), ^{
+        OnRejectGesture(call, result);
+      });
+    }
   } else {
     result(FlutterMethodNotImplemented);
   }
@@ -198,6 +219,7 @@ static bool ClipRRectContainsPlatformViewBoundingRect(const SkRRect& clip_rrect,
     result([FlutterError errorWithCode:@"recreating_view"
                                message:@"trying to create an already created view"
                                details:[NSString stringWithFormat:@"view id: '%lld'", viewId]]);
+    return;
   }
 
   NSObject<FlutterPlatformViewFactory>* factory = factories_[viewType].get();
@@ -207,7 +229,8 @@ static bool ClipRRectContainsPlatformViewBoundingRect(const SkRRect& clip_rrect,
               message:[NSString stringWithFormat:@"A UIKitView widget is trying to create a "
                                                  @"PlatformView with an unregistered type: < %@ >",
                                                  viewTypeString]
-              details:@"If you are the author of the PlatformView, make sure `registerViewFactory` "
+              details:@"If you are the author of the PlatformView, make sure "
+                      @"`registerViewFactory` "
                       @"is invoked.\n"
                       @"See: "
                       @"https://docs.flutter.dev/development/platform-integration/"
@@ -303,6 +326,25 @@ static bool ClipRRectContainsPlatformViewBoundingRect(const SkRRect& clip_rrect,
   result(nil);
 }
 
+void FlutterPlatformViewsController::OnHitTestResult(FlutterMethodCall* call,
+                                                     FlutterResult& result,
+                                                     BOOL platformViewConsumesTouches) {
+  NSDictionary<NSString*, id>* args = [call arguments];
+  int64_t viewId = [args[@"id"] longLongValue];
+
+  if (views_.count(viewId) == 0) {
+    result([FlutterError errorWithCode:@"unknown_view"
+                               message:@"trying to send hit test result for an unknown view"
+                               details:[NSString stringWithFormat:@"view id: '%lld'", viewId]]);
+    return;
+  }
+
+  FlutterTouchInterceptingView* view = touch_interceptors_[viewId].get();
+  [view respondToHitTestResult:platformViewConsumesTouches];
+
+  result(nil);
+}
+
 void FlutterPlatformViewsController::RegisterViewFactory(
     NSObject<FlutterPlatformViewFactory>* factory,
     NSString* factoryId,
@@ -378,6 +420,14 @@ static bool ClipRRectContainsPlatformViewBoundingRect(const SkRRect& clip_rrect,
   }
 }
 
+void FlutterPlatformViewsController::BlockPlatformThread() {
+  platform_thread_mutex_.lock();
+}
+
+void FlutterPlatformViewsController::ReleasePlatformThread() {
+  platform_thread_mutex_.unlock();
+}
+
 void FlutterPlatformViewsController::PrerollCompositeEmbeddedView(
     int64_t view_id,
     std::unique_ptr<EmbeddedViewParams> params) {
@@ -957,6 +1007,9 @@ @implementation FlutterTouchInterceptingView {
   fml::scoped_nsobject<DelayingGestureRecognizer> _delayingRecognizer;
   FlutterPlatformViewGestureRecognizersBlockingPolicy _blockingPolicy;
   UIView* _embeddedView;
+  FlutterViewController* _flutterViewController;
+  BOOL _platformViewConsumesTouches;
+  flutter::FlutterPlatformViewsController* _platformViewsController;
 }
 - (instancetype)initWithEmbeddedView:(UIView*)embeddedView
              platformViewsController:
@@ -965,12 +1018,16 @@ - (instancetype)initWithEmbeddedView:(UIView*)embeddedView
         (FlutterPlatformViewGestureRecognizersBlockingPolicy)blockingPolicy {
   self = [super initWithFrame:embeddedView.frame];
   if (self) {
+    _platformViewConsumesTouches = YES;
     self.multipleTouchEnabled = YES;
     _embeddedView = embeddedView;
     embeddedView.autoresizingMask =
         (UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight);
 
     [self addSubview:embeddedView];
+    _platformViewsController = platformViewsController.get();
+    _flutterViewController =
+        ((FlutterViewController*)_platformViewsController->getFlutterViewController());
 
     ForwardingGestureRecognizer* forwardingRecognizer = [[[ForwardingGestureRecognizer alloc]
                  initWithTarget:self
@@ -981,9 +1038,14 @@ - (instancetype)initWithEmbeddedView:(UIView*)embeddedView
                       action:nil
         forwardingRecognizer:forwardingRecognizer]);
     _blockingPolicy = blockingPolicy;
-
-    [self addGestureRecognizer:_delayingRecognizer.get()];
-    [self addGestureRecognizer:forwardingRecognizer];
+    forwardingRecognizer.enabled = NO;
+    _delayingRecognizer.get().enabled = NO;
+    BOOL hitTestBlocking = [[[NSBundle mainBundle]
+        objectForInfoDictionaryKey:@"FLTPlatformViewHitTestBlocking"] boolValue];
+    if (!hitTestBlocking) {
+      [self addGestureRecognizer:_delayingRecognizer.get()];
+      [self addGestureRecognizer:forwardingRecognizer];
+    }
   }
   return self;
 }
@@ -992,6 +1054,12 @@ - (UIView*)embeddedView {
   return [[_embeddedView retain] autorelease];
 }
 
+- (void)respondToHitTestResult:(BOOL)platformViewConsumesTouches {
+  NSLog(@"respondToHitTestResult: %@", @(platformViewConsumesTouches));
+  _platformViewConsumesTouches = platformViewConsumesTouches;
+  _platformViewsController->ReleasePlatformThread();
+}
+
 - (void)releaseGesture {
   _delayingRecognizer.get().state = UIGestureRecognizerStateFailed;
 }
@@ -1020,6 +1088,39 @@ - (void)blockGesture {
   }
 }
 
+- (UIView*)hitTest:(CGPoint)point withEvent:(UIEvent*)event {
+  if (event.type != UIEventTypeTouches) {
+    UIView* hittest = [super hitTest:point withEvent:event];
+    NSLog(@"not touch type, platform view takes the gesture, hittest: %@", hittest);
+    return hittest;
+  }
+  BOOL hasDownTouch = NO;
+  for (UITouch* touch in event.allTouches) {
+    NSLog(@"phase %@", @(touch.phase));
+    // Gesture arena for PlatformView hit tests only cares about the touch began location.
+    if (touch.phase == UITouchPhaseBegan) {
+      hasDownTouch = YES;
+      break;
+    }
+  }
+  if (event.allTouches.count > 0 && !hasDownTouch) {
+    UIView* hittest = [super hitTest:point withEvent:event];
+    NSLog(@"not a down touch, defaults to default hittest: %@", hittest);
+    return _platformViewConsumesTouches ? hittest : nil;
+  }
+  [_flutterViewController sendFakeTouchEventWithLocation:point
+                                                  change:flutter::PointerData::Change::kDown];
+  [_flutterViewController sendFakeTouchEventWithLocation:point
+                                                  change:flutter::PointerData::Change::kUp];
+  NSLog(@"send fake down touch, lock");
+  _platformViewsController->BlockPlatformThread();
+  UIView* hittest = [super hitTest:point withEvent:event];
+  if (_platformViewConsumesTouches) {
+    NSLog(@"unlocked platformview consumes gesture, hit test %@", hittest);
+  }
+  return _platformViewConsumesTouches ? hittest : nil;
+}
+
 // We want the intercepting view to consume the touches and not pass the touches up to the parent
 // view. Make the touch event method not call super will not pass the touches up to the parent view.
 // Hence we overide the touch event methods and do nothing.

diff --git a/shell/platform/darwin/ios/framework/Source/FlutterPlatformViews_Internal.h b/shell/platform/darwin/ios/framework/Source/FlutterPlatformViews_Internal.h
@@ -266,15 +266,22 @@ class FlutterPlatformViewsController {
   // Pushes the view id of a visted platform view to the list of visied platform views.
   void PushVisitedPlatformView(int64_t view_id) { visited_platform_views_.push_back(view_id); }
 
+  void BlockPlatformThread();
+  void ReleasePlatformThread();
+
  private:
   static const size_t kMaxLayerAllocations = 2;
+  std::mutex platform_thread_mutex_;
 
   using LayersMap = std::map<int64_t, std::vector<std::shared_ptr<FlutterPlatformViewLayer>>>;
 
   void OnCreate(FlutterMethodCall* call, FlutterResult& result);
   void OnDispose(FlutterMethodCall* call, FlutterResult& result);
   void OnAcceptGesture(FlutterMethodCall* call, FlutterResult& result);
   void OnRejectGesture(FlutterMethodCall* call, FlutterResult& result);
+  void OnHitTestResult(FlutterMethodCall* call,
+                       FlutterResult& result,
+                       BOOL platformViewConsumesTouches);
   // Dispose the views in `views_to_dispose_`.
   void DisposeViews();
 
@@ -416,6 +423,8 @@ class FlutterPlatformViewsController {
     gestureRecognizersBlockingPolicy:
         (FlutterPlatformViewGestureRecognizersBlockingPolicy)blockingPolicy;
 
+- (void)respondToHitTestResult:(BOOL)platformViewConsumesTouches;
+
 // Stop delaying any active touch sequence (and let it arrive the embedded view).
 - (void)releaseGesture;
 

diff --git a/shell/platform/darwin/ios/framework/Source/FlutterViewController.mm b/shell/platform/darwin/ios/framework/Source/FlutterViewController.mm
@@ -517,18 +517,20 @@ - (void)loadView {
   return pointer_data;
 }
 
-static void SendFakeTouchEvent(UIScreen* screen,
-                               FlutterEngine* engine,
-                               CGPoint location,
-                               flutter::PointerData::Change change) {
+- (void)sendFakeTouchEventWithLocation:(CGPoint)location
+                                change:(flutter::PointerData::Change)change {
+  UIScreen* screen = [self flutterScreenIfViewLoaded];
+  if (!screen) {
+    return;
+  }
   const CGFloat scale = screen.scale;
-  flutter::PointerData pointer_data = [[engine viewController] generatePointerDataForFake];
+  flutter::PointerData pointer_data = [[_engine.get() viewController] generatePointerDataForFake];
   pointer_data.physical_x = location.x * scale;
   pointer_data.physical_y = location.y * scale;
   auto packet = std::make_unique<flutter::PointerDataPacket>(/*count=*/1);
   pointer_data.change = change;
   packet->SetPointerData(0, pointer_data);
-  [engine dispatchPointerDataPacket:std::move(packet)];
+  [_engine.get() dispatchPointerDataPacket:std::move(packet)];
 }
 
 - (BOOL)scrollViewShouldScrollToTop:(UIScrollView*)scrollView {
@@ -538,8 +540,8 @@ - (BOOL)scrollViewShouldScrollToTop:(UIScrollView*)scrollView {
   CGPoint statusBarPoint = CGPointZero;
   UIScreen* screen = [self flutterScreenIfViewLoaded];
   if (screen) {
-    SendFakeTouchEvent(screen, _engine.get(), statusBarPoint, flutter::PointerData::Change::kDown);
-    SendFakeTouchEvent(screen, _engine.get(), statusBarPoint, flutter::PointerData::Change::kUp);
+    [self sendFakeTouchEventWithLocation:statusBarPoint change:flutter::PointerData::Change::kDown];
+    [self sendFakeTouchEventWithLocation:statusBarPoint change:flutter::PointerData::Change::kUp];
   }
   return NO;
 }

diff --git a/shell/platform/darwin/ios/framework/Source/FlutterViewController_Internal.h b/shell/platform/darwin/ios/framework/Source/FlutterViewController_Internal.h
@@ -6,6 +6,7 @@
 #define FLUTTER_SHELL_PLATFORM_DARWIN_IOS_FRAMEWORK_SOURCE_FLUTTERVIEWCONTROLLER_INTERNAL_H_
 
 #include "flutter/fml/memory/weak_ptr.h"
+#include "flutter/lib/ui/window/pointer_data.h"
 
 #import "flutter/shell/platform/darwin/ios/framework/Headers/FlutterViewController.h"
 #import "flutter/shell/platform/darwin/ios/framework/Source/FlutterKeySecondaryResponder.h"
@@ -65,6 +66,8 @@ typedef void (^FlutterKeyboardAnimationCallback)(fml::TimePoint);
 - (void)addInternalPlugins;
 - (void)deregisterNotifications;
 - (int32_t)accessibilityFlags;
+- (void)sendFakeTouchEventWithLocation:(CGPoint)location
+                                change:(flutter::PointerData::Change)change;
 
 @end