From 2e955d8a3d37d3eef397a37068890b76d8483bb7 Mon Sep 17 00:00:00 2001
From: Huan Lin <hellohuanlin@gmail.com>
Date: Mon, 7 Oct 2024 15:09:29 -0700
Subject: [PATCH] [ios][platform_view]fix forwarding gesture recognizer state
 stuck at the ended state

---
 .../Source/FlutterPlatformViewsTest.mm        | 68 +++++++++++++++++++
 .../Source/FlutterPlatformViews_Internal.mm   |  5 +-
 2 files changed, 69 insertions(+), 4 deletions(-)

diff --git a/shell/platform/darwin/ios/framework/Source/FlutterPlatformViewsTest.mm b/shell/platform/darwin/ios/framework/Source/FlutterPlatformViewsTest.mm
index 904a3eace2564..186cfe9ea6a76 100644
--- a/shell/platform/darwin/ios/framework/Source/FlutterPlatformViewsTest.mm
+++ b/shell/platform/darwin/ios/framework/Source/FlutterPlatformViewsTest.mm
@@ -2782,6 +2782,74 @@ - (void)testFlutterPlatformViewTouchesCancelledEventAreForcedToBeCancelled {
   flutterPlatformViewsController->Reset();
 }
 
+- (void)testFlutterPlatformViewTouchesEndedOrTouchesCancelledEventDoesNotFailTheGestureRecognizer {
+  flutter::FlutterPlatformViewsTestMockPlatformViewDelegate mock_delegate;
+
+  flutter::TaskRunners runners(/*label=*/self.name.UTF8String,
+                               /*platform=*/GetDefaultTaskRunner(),
+                               /*raster=*/GetDefaultTaskRunner(),
+                               /*ui=*/GetDefaultTaskRunner(),
+                               /*io=*/GetDefaultTaskRunner());
+  auto flutterPlatformViewsController = std::make_shared<flutter::PlatformViewsController>();
+  flutterPlatformViewsController->SetTaskRunner(GetDefaultTaskRunner());
+  auto platform_view = std::make_unique<flutter::PlatformViewIOS>(
+      /*delegate=*/mock_delegate,
+      /*rendering_api=*/mock_delegate.settings_.enable_impeller
+          ? flutter::IOSRenderingAPI::kMetal
+          : flutter::IOSRenderingAPI::kSoftware,
+      /*platform_views_controller=*/flutterPlatformViewsController,
+      /*task_runners=*/runners,
+      /*worker_task_runner=*/nil,
+      /*is_gpu_disabled_jsync_switch=*/std::make_shared<fml::SyncSwitch>());
+
+  FlutterPlatformViewsTestMockFlutterPlatformFactory* factory =
+      [[FlutterPlatformViewsTestMockFlutterPlatformFactory alloc] init];
+  flutterPlatformViewsController->RegisterViewFactory(
+      factory, @"MockFlutterPlatformView",
+      FlutterPlatformViewGestureRecognizersBlockingPolicyEager);
+  FlutterResult result = ^(id result) {
+  };
+  flutterPlatformViewsController->OnMethodCall(
+      [FlutterMethodCall
+          methodCallWithMethodName:@"create"
+                         arguments:@{@"id" : @2, @"viewType" : @"MockFlutterPlatformView"}],
+      result);
+
+  XCTAssertNotNil(gMockPlatformView);
+
+  // Find touch inteceptor view
+  UIView* touchInteceptorView = gMockPlatformView;
+  while (touchInteceptorView != nil &&
+         ![touchInteceptorView isKindOfClass:[FlutterTouchInterceptingView class]]) {
+    touchInteceptorView = touchInteceptorView.superview;
+  }
+  XCTAssertNotNil(touchInteceptorView);
+
+  // Find ForwardGestureRecognizer
+  UIGestureRecognizer* forwardGestureRecognizer = nil;
+  for (UIGestureRecognizer* gestureRecognizer in touchInteceptorView.gestureRecognizers) {
+    if ([gestureRecognizer isKindOfClass:NSClassFromString(@"ForwardingGestureRecognizer")]) {
+      forwardGestureRecognizer = gestureRecognizer;
+      break;
+    }
+  }
+  id flutterViewContoller = OCMClassMock([FlutterViewController class]);
+
+  flutterPlatformViewsController->SetFlutterViewController(flutterViewContoller);
+
+  NSSet* touches1 = [NSSet setWithObject:@1];
+  id event1 = OCMClassMock([UIEvent class]);
+  [forwardGestureRecognizer touchesBegan:touches1 withEvent:event1];
+  [forwardGestureRecognizer touchesEnded:touches1 withEvent:event1];
+  XCTAssert(forwardGestureRecognizer.state == UIGestureRecognizerStatePossible);
+
+  [forwardGestureRecognizer touchesBegan:touches1 withEvent:event1];
+  [forwardGestureRecognizer touchesCancelled:touches1 withEvent:event1];
+  XCTAssert(forwardGestureRecognizer.state == UIGestureRecognizerStatePossible);
+
+  flutterPlatformViewsController->Reset();
+}
+
 - (void)testFlutterPlatformViewControllerSubmitFrameWithoutFlutterViewNotCrashing {
   flutter::FlutterPlatformViewsTestMockPlatformViewDelegate mock_delegate;
 
diff --git a/shell/platform/darwin/ios/framework/Source/FlutterPlatformViews_Internal.mm b/shell/platform/darwin/ios/framework/Source/FlutterPlatformViews_Internal.mm
index 5e76654bed179..a0c8c82ff5a51 100644
--- a/shell/platform/darwin/ios/framework/Source/FlutterPlatformViews_Internal.mm
+++ b/shell/platform/darwin/ios/framework/Source/FlutterPlatformViews_Internal.mm
@@ -736,10 +736,8 @@ - (void)touchesEnded:(NSSet*)touches withEvent:(UIEvent*)event {
   _currentTouchPointersCount -= touches.count;
   // Touches in one touch sequence are sent to the touchesEnded method separately if different
   // fingers stop touching the screen at different time. So one touchesEnded method triggering does
-  // not necessarially mean the touch sequence has ended. We Only set the state to
-  // UIGestureRecognizerStateFailed when all the touches in the current touch sequence is ended.
+  // not necessarially mean the touch sequence has ended.
   if (_currentTouchPointersCount == 0) {
-    self.state = UIGestureRecognizerStateFailed;
     _flutterViewController.reset(nil);
   }
 }
@@ -753,7 +751,6 @@ - (void)touchesCancelled:(NSSet*)touches withEvent:(UIEvent*)event {
   [_flutterViewController.get() forceTouchesCancelled:touches];
   _currentTouchPointersCount -= touches.count;
   if (_currentTouchPointersCount == 0) {
-    self.state = UIGestureRecognizerStateFailed;
     _flutterViewController.reset(nil);
   }
 }