Update the mouse cursor handler to work with multi-view on Windows (#163855)

Partially fixes https://github.com/flutter/flutter/issues/142845.

This PR removes implicit view assumptions from the
`'flutter/mousecursor'` channel handler on Windows.

The cursor is now set for all existing views, ensuring that the current
`FlutterWindow` with the cursor in its client area uses the correct
cursor. The method arguments remain unchanged.

Cursor handler tests have also been updated to avoid assuming an
implicit view.

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel
on [Discord].

<!-- Links -->
[Contributor Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview
[Tree Hygiene]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md
[test-exempt]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests
[Flutter Style Guide]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md
[Features we expect every widget to implement]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement
[CLA]: https://cla.developers.google.com/
[flutter/tests]: https://github.com/flutter/tests
[breaking change policy]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes
[Discord]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md
[Data Driven Fixes]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md

engine/src/flutter/shell/platform/windows/cursor_handler.cc

@@ -8,7 +8,6 @@
 
 #include "flutter/shell/platform/common/client_wrapper/include/flutter/standard_method_codec.h"
 #include "flutter/shell/platform/windows/flutter_windows_engine.h"
-#include "flutter/shell/platform/windows/flutter_windows_view.h"
 
 static constexpr char kChannelName[] = "flutter/mousecursor";
 
@@ -74,16 +73,7 @@ void CursorHandler::HandleMethodCall(
       return;
     }
     const auto& kind = std::get<std::string>(kind_iter->second);
-
-    // TODO(loicsharma): Remove implicit view assumption.
-    // https://github.com/flutter/flutter/issues/142845
-    FlutterWindowsView* view = engine_->view(kImplicitViewId);
-    if (view == nullptr) {
-      result->Error(kCursorError,
-                    "Cursor is not available in Windows headless mode");
-      return;
-    }
-    view->UpdateFlutterCursor(kind);
+    engine_->UpdateFlutterCursor(kind);
     result->Success();
   } else if (method.compare(kCreateCustomCursorMethod) == 0) {
     const auto& arguments = std::get<EncodableMap>(*method_call.arguments());
@@ -167,16 +157,7 @@ void CursorHandler::HandleMethodCall(
       return;
     }
     HCURSOR cursor = custom_cursors_[name];
-
-    // TODO(loicsharma): Remove implicit view assumption.
-    // https://github.com/flutter/flutter/issues/142845
-    FlutterWindowsView* view = engine_->view(kImplicitViewId);
-    if (view == nullptr) {
-      result->Error(kCursorError,
-                    "Cursor is not available in Windows headless mode");
-      return;
-    }
-    view->SetFlutterCursor(cursor);
+    engine_->SetFlutterCursor(cursor);
     result->Success();
   } else if (method.compare(kDeleteCustomCursorMethod) == 0) {
     const auto& arguments = std::get<EncodableMap>(*method_call.arguments());

engine/src/flutter/shell/platform/windows/cursor_handler_unittests.cc

@@ -14,6 +14,7 @@
 #include "flutter/shell/platform/windows/testing/engine_modifier.h"
 #include "flutter/shell/platform/windows/testing/flutter_windows_engine_builder.h"
 #include "flutter/shell/platform/windows/testing/mock_window_binding_handler.h"
+#include "flutter/shell/platform/windows/testing/mock_windows_proc_table.h"
 #include "flutter/shell/platform/windows/testing/test_binary_messenger.h"
 #include "flutter/shell/platform/windows/testing/windows_test.h"
 #include "gmock/gmock.h"
@@ -24,6 +25,7 @@ namespace testing {
 
 namespace {
 using ::testing::_;
+using ::testing::IsNull;
 using ::testing::NotNull;
 using ::testing::Return;
 
@@ -63,6 +65,7 @@ class CursorHandlerTest : public WindowsTest {
   FlutterWindowsEngine* engine() { return engine_.get(); }
   FlutterWindowsView* view() { return view_.get(); }
   MockWindowBindingHandler* window() { return window_; }
+  MockWindowsProcTable* proc_table() { return windows_proc_table_.get(); }
 
   void UseHeadlessEngine() {
     FlutterWindowsEngineBuilder builder{GetContext()};
@@ -71,7 +74,10 @@ class CursorHandlerTest : public WindowsTest {
   }
 
   void UseEngineWithView() {
+    windows_proc_table_ = std::make_shared<MockWindowsProcTable>();
+
     FlutterWindowsEngineBuilder builder{GetContext()};
+    builder.SetWindowsProcTable(windows_proc_table_);
 
     auto window = std::make_unique<MockWindowBindingHandler>();
     EXPECT_CALL(*window.get(), SetView).Times(1);
@@ -79,17 +85,14 @@ class CursorHandlerTest : public WindowsTest {
 
     window_ = window.get();
     engine_ = builder.Build();
-    view_ = std::make_unique<FlutterWindowsView>(kImplicitViewId, engine_.get(),
-                                                 std::move(window));
-
-    EngineModifier modifier{engine_.get()};
-    modifier.SetImplicitView(view_.get());
+    view_ = engine_->CreateView(std::move(window));
   }
 
  private:
   std::unique_ptr<FlutterWindowsEngine> engine_;
   std::unique_ptr<FlutterWindowsView> view_;
   MockWindowBindingHandler* window_;
+  std::shared_ptr<MockWindowsProcTable> windows_proc_table_;
 
   FML_DISALLOW_COPY_AND_ASSIGN(CursorHandlerTest);
 };
@@ -100,7 +103,8 @@ TEST_F(CursorHandlerTest, ActivateSystemCursor) {
   TestBinaryMessenger messenger;
   CursorHandler cursor_handler(&messenger, engine());
 
-  EXPECT_CALL(*window(), UpdateFlutterCursor("click")).Times(1);
+  EXPECT_CALL(*proc_table(), LoadCursor(IsNull(), IDC_HAND)).Times(1);
+  EXPECT_CALL(*proc_table(), SetCursor).Times(1);
 
   bool success = false;
   MethodResultFunctions<> result_handler(
@@ -120,33 +124,6 @@ TEST_F(CursorHandlerTest, ActivateSystemCursor) {
   EXPECT_TRUE(success);
 }
 
-TEST_F(CursorHandlerTest, ActivateSystemCursorRequiresView) {
-  UseHeadlessEngine();
-
-  TestBinaryMessenger messenger;
-  CursorHandler cursor_handler(&messenger, engine());
-
-  bool error = false;
-  MethodResultFunctions<> result_handler(
-      nullptr,
-      [&error](const std::string& error_code, const std::string& error_message,
-               const EncodableValue* value) {
-        error = true;
-        EXPECT_EQ(error_message,
-                  "Cursor is not available in Windows headless mode");
-      },
-      nullptr);
-
-  SimulateCursorMessage(&messenger, kActivateSystemCursorMethod,
-                        std::make_unique<EncodableValue>(EncodableMap{
-                            {EncodableValue("device"), EncodableValue(0)},
-                            {EncodableValue("kind"), EncodableValue("click")},
-                        }),
-                        &result_handler);
-
-  EXPECT_TRUE(error);
-}
-
 TEST_F(CursorHandlerTest, CreateCustomCursor) {
   UseEngineWithView();
 
@@ -196,7 +173,8 @@ TEST_F(CursorHandlerTest, SetCustomCursor) {
       },
       nullptr, nullptr);
 
-  EXPECT_CALL(*window(), SetFlutterCursor(/*cursor=*/NotNull())).Times(1);
+  EXPECT_CALL(*proc_table(), LoadCursor).Times(0);
+  EXPECT_CALL(*proc_table(), SetCursor(NotNull())).Times(1);
 
   SimulateCursorMessage(&messenger, kCreateCustomCursorMethod,
                         std::make_unique<EncodableValue>(EncodableMap{
@@ -218,47 +196,6 @@ TEST_F(CursorHandlerTest, SetCustomCursor) {
   EXPECT_TRUE(success);
 }
 
-TEST_F(CursorHandlerTest, SetCustomCursorRequiresView) {
-  UseHeadlessEngine();
-
-  TestBinaryMessenger messenger;
-  CursorHandler cursor_handler(&messenger, engine());
-
-  // Create a 4x4 raw BGRA test cursor buffer.
-  std::vector<uint8_t> buffer(4 * 4 * 4, 0);
-
-  bool error = false;
-  MethodResultFunctions<> create_result_handler(nullptr, nullptr, nullptr);
-  MethodResultFunctions<> set_result_handler(
-      nullptr,
-      [&error](const std::string& error_code, const std::string& error_message,
-               const EncodableValue* value) {
-        error = true;
-        EXPECT_EQ(error_message,
-                  "Cursor is not available in Windows headless mode");
-      },
-      nullptr);
-
-  SimulateCursorMessage(&messenger, kCreateCustomCursorMethod,
-                        std::make_unique<EncodableValue>(EncodableMap{
-                            {EncodableValue("name"), EncodableValue("hello")},
-                            {EncodableValue("buffer"), EncodableValue(buffer)},
-                            {EncodableValue("width"), EncodableValue(4)},
-                            {EncodableValue("height"), EncodableValue(4)},
-                            {EncodableValue("hotX"), EncodableValue(0.0)},
-                            {EncodableValue("hotY"), EncodableValue(0.0)},
-                        }),
-                        &create_result_handler);
-
-  SimulateCursorMessage(&messenger, kSetCustomCursorMethod,
-                        std::make_unique<EncodableValue>(EncodableMap{
-                            {EncodableValue("name"), EncodableValue("hello")},
-                        }),
-                        &set_result_handler);
-
-  EXPECT_TRUE(error);
-}
-
 TEST_F(CursorHandlerTest, SetNonexistentCustomCursor) {
   UseEngineWithView();
 
@@ -277,7 +214,8 @@ TEST_F(CursorHandlerTest, SetNonexistentCustomCursor) {
       },
       nullptr);
 
-  EXPECT_CALL(*window(), SetFlutterCursor).Times(0);
+  EXPECT_CALL(*proc_table(), LoadCursor).Times(0);
+  EXPECT_CALL(*proc_table(), SetCursor).Times(0);
 
   SimulateCursorMessage(&messenger, kSetCustomCursorMethod,
                         std::make_unique<EncodableValue>(EncodableMap{

engine/src/flutter/shell/platform/windows/flutter_window.cc

@@ -30,49 +30,6 @@ static const int kMaxTouchDeviceId = 128;
 
 static const int kLinesPerScrollWindowsDefault = 3;
 
-// Maps a Flutter cursor name to an HCURSOR.
-//
-// Returns the arrow cursor for unknown constants.
-//
-// This map must be kept in sync with Flutter framework's
-// services/mouse_cursor.dart.
-static HCURSOR GetCursorByName(const std::string& cursor_name) {
-  static auto* cursors = new std::map<std::string, const wchar_t*>{
-      {"allScroll", IDC_SIZEALL},
-      {"basic", IDC_ARROW},
-      {"click", IDC_HAND},
-      {"forbidden", IDC_NO},
-      {"help", IDC_HELP},
-      {"move", IDC_SIZEALL},
-      {"none", nullptr},
-      {"noDrop", IDC_NO},
-      {"precise", IDC_CROSS},
-      {"progress", IDC_APPSTARTING},
-      {"text", IDC_IBEAM},
-      {"resizeColumn", IDC_SIZEWE},
-      {"resizeDown", IDC_SIZENS},
-      {"resizeDownLeft", IDC_SIZENESW},
-      {"resizeDownRight", IDC_SIZENWSE},
-      {"resizeLeft", IDC_SIZEWE},
-      {"resizeLeftRight", IDC_SIZEWE},
-      {"resizeRight", IDC_SIZEWE},
-      {"resizeRow", IDC_SIZENS},
-      {"resizeUp", IDC_SIZENS},
-      {"resizeUpDown", IDC_SIZENS},
-      {"resizeUpLeft", IDC_SIZENWSE},
-      {"resizeUpRight", IDC_SIZENESW},
-      {"resizeUpLeftDownRight", IDC_SIZENWSE},
-      {"resizeUpRightDownLeft", IDC_SIZENESW},
-      {"wait", IDC_WAIT},
-  };
-  const wchar_t* idc_name = IDC_ARROW;
-  auto it = cursors->find(cursor_name);
-  if (it != cursors->end()) {
-    idc_name = it->second;
-  }
-  return ::LoadCursor(nullptr, idc_name);
-}
-
 static constexpr int32_t kDefaultPointerDeviceId = 0;
 
 // This method is only valid during a window message related to mouse/touch
@@ -144,7 +101,6 @@ FlutterWindow::FlutterWindow(
   keyboard_manager_ = std::make_unique<KeyboardManager>(this);
 
   InitializeChild("FLUTTERVIEW", width, height);
-  current_cursor_ = ::LoadCursor(nullptr, IDC_ARROW);
 }
 
 // Base constructor for mocks
@@ -176,15 +132,6 @@ PhysicalWindowBounds FlutterWindow::GetPhysicalWindowBounds() {
   return {GetCurrentWidth(), GetCurrentHeight()};
 }
 
-void FlutterWindow::UpdateFlutterCursor(const std::string& cursor_name) {
-  SetFlutterCursor(GetCursorByName(cursor_name));
-}
-
-void FlutterWindow::SetFlutterCursor(HCURSOR cursor) {
-  current_cursor_ = cursor;
-  ::SetCursor(current_cursor_);
-}
-
 bool FlutterWindow::Focus() {
   auto hwnd = GetWindowHandle();
   if (hwnd == nullptr) {
@@ -257,10 +204,6 @@ void FlutterWindow::OnPointerLeave(double x,
   binding_handler_delegate_->OnPointerLeave(x, y, device_kind, device_id);
 }
 
-void FlutterWindow::OnSetCursor() {
-  ::SetCursor(current_cursor_);
-}
-
 void FlutterWindow::OnText(const std::u16string& text) {
   binding_handler_delegate_->OnText(text);
 }
@@ -649,7 +592,8 @@ FlutterWindow::HandleMessage(UINT const message,
     case WM_SETCURSOR: {
       UINT hit_test_result = LOWORD(lparam);
       if (hit_test_result == HTCLIENT) {
-        OnSetCursor();
+        // Halt further processing to prevent DefWindowProc from setting the
+        // cursor back to the registered class cursor.
         return TRUE;
       }
       break;

engine/src/flutter/shell/platform/windows/flutter_window.h

@@ -104,9 +104,6 @@ class FlutterWindow : public KeyboardManager::WindowDelegate,
                               FlutterPointerDeviceKind device_kind,
                               int32_t device_id);
 
-  // Called when the cursor should be set for the client area.
-  virtual void OnSetCursor();
-
   // |WindowBindingHandlerDelegate|
   virtual void OnText(const std::u16string& text) override;
 
@@ -161,12 +158,6 @@ class FlutterWindow : public KeyboardManager::WindowDelegate,
   // |FlutterWindowBindingHandler|
   virtual PhysicalWindowBounds GetPhysicalWindowBounds() override;
 
-  // |FlutterWindowBindingHandler|
-  virtual void UpdateFlutterCursor(const std::string& cursor_name) override;
-
-  // |FlutterWindowBindingHandler|
-  virtual void SetFlutterCursor(HCURSOR cursor) override;
-
   // |FlutterWindowBindingHandler|
   virtual bool OnBitmapSurfaceCleared() override;
 
@@ -329,9 +320,6 @@ class FlutterWindow : public KeyboardManager::WindowDelegate,
   // windowing and input state.
   WindowBindingHandlerDelegate* binding_handler_delegate_ = nullptr;
 
-  // The last cursor set by Flutter. Defaults to the arrow cursor.
-  HCURSOR current_cursor_;
-
   // The cursor rect set by Flutter.
   RECT cursor_rect_;
 

engine/src/flutter/shell/platform/windows/flutter_window_unittests.cc

@@ -66,7 +66,6 @@ class MockFlutterWindow : public FlutterWindow {
               OnPointerLeave,
               (double, double, FlutterPointerDeviceKind, int32_t),
               (override));
-  MOCK_METHOD(void, OnSetCursor, (), (override));
   MOCK_METHOD(float, GetScrollOffsetMultiplier, (), (override));
   MOCK_METHOD(float, GetDpiScale, (), (override));
   MOCK_METHOD(void, UpdateCursorRect, (const Rect&), (override));
@@ -422,12 +421,5 @@ TEST_F(FlutterWindowTest, CachedLifecycleMessage) {
   EXPECT_TRUE(restored);
 }
 
-TEST_F(FlutterWindowTest, UpdateCursor) {
-  FlutterWindow win32window(100, 100);
-  win32window.UpdateFlutterCursor("text");
-  HCURSOR cursor = ::GetCursor();
-  EXPECT_EQ(cursor, ::LoadCursor(nullptr, IDC_IBEAM));
-}
-
 }  // namespace testing
 }  // namespace flutter

engine/src/flutter/shell/platform/windows/flutter_windows_engine.cc

@@ -801,6 +801,44 @@ void FlutterWindowsEngine::SetNextFrameCallback(fml::closure callback) {
       this);
 }
 
+HCURSOR FlutterWindowsEngine::GetCursorByName(
+    const std::string& cursor_name) const {
+  static auto* cursors = new std::map<std::string, const wchar_t*>{
+      {"allScroll", IDC_SIZEALL},
+      {"basic", IDC_ARROW},
+      {"click", IDC_HAND},
+      {"forbidden", IDC_NO},
+      {"help", IDC_HELP},
+      {"move", IDC_SIZEALL},
+      {"none", nullptr},
+      {"noDrop", IDC_NO},
+      {"precise", IDC_CROSS},
+      {"progress", IDC_APPSTARTING},
+      {"text", IDC_IBEAM},
+      {"resizeColumn", IDC_SIZEWE},
+      {"resizeDown", IDC_SIZENS},
+      {"resizeDownLeft", IDC_SIZENESW},
+      {"resizeDownRight", IDC_SIZENWSE},
+      {"resizeLeft", IDC_SIZEWE},
+      {"resizeLeftRight", IDC_SIZEWE},
+      {"resizeRight", IDC_SIZEWE},
+      {"resizeRow", IDC_SIZENS},
+      {"resizeUp", IDC_SIZENS},
+      {"resizeUpDown", IDC_SIZENS},
+      {"resizeUpLeft", IDC_SIZENWSE},
+      {"resizeUpRight", IDC_SIZENESW},
+      {"resizeUpLeftDownRight", IDC_SIZENWSE},
+      {"resizeUpRightDownLeft", IDC_SIZENESW},
+      {"wait", IDC_WAIT},
+  };
+  const wchar_t* idc_name = IDC_ARROW;
+  auto it = cursors->find(cursor_name);
+  if (it != cursors->end()) {
+    idc_name = it->second;
+  }
+  return windows_proc_table_->LoadCursor(nullptr, idc_name);
+}
+
 void FlutterWindowsEngine::SendSystemLocales() {
   std::vector<LanguageInfo> languages =
       GetPreferredLanguageInfo(*windows_proc_table_);
@@ -995,6 +1033,15 @@ std::optional<LRESULT> FlutterWindowsEngine::ProcessExternalWindowMessage(
   return std::nullopt;
 }
 
+void FlutterWindowsEngine::UpdateFlutterCursor(
+    const std::string& cursor_name) const {
+  SetFlutterCursor(GetCursorByName(cursor_name));
+}
+
+void FlutterWindowsEngine::SetFlutterCursor(HCURSOR cursor) const {
+  windows_proc_table_->SetCursor(cursor);
+}
+
 void FlutterWindowsEngine::OnChannelUpdate(std::string name, bool listening) {
   if (name == "flutter/platform" && listening) {
     lifecycle_manager_->BeginProcessingExit();

engine/src/flutter/shell/platform/windows/flutter_windows_engine.h

@@ -307,6 +307,13 @@ class FlutterWindowsEngine {
     return windows_proc_table_;
   }
 
+  // Sets the cursor that should be used when the mouse is over the Flutter
+  // content. See mouse_cursor.dart for the values and meanings of cursor_name.
+  void UpdateFlutterCursor(const std::string& cursor_name) const;
+
+  // Sets the cursor directly from a cursor handle.
+  void SetFlutterCursor(HCURSOR cursor) const;
+
  protected:
   // Creates the keyboard key handler.
   //
@@ -341,6 +348,14 @@ class FlutterWindowsEngine {
   // Allows swapping out embedder_api_ calls in tests.
   friend class EngineModifier;
 
+  // Maps a Flutter cursor name to an HCURSOR.
+  //
+  // Returns the arrow cursor for unknown constants.
+  //
+  // This map must be kept in sync with Flutter framework's
+  // services/mouse_cursor.dart.
+  HCURSOR GetCursorByName(const std::string& cursor_name) const;
+
   // Sends system locales to the engine.
   //
   // Should be called just after the engine is run, and after any relevant

engine/src/flutter/shell/platform/windows/flutter_windows_view.cc

@@ -176,14 +176,6 @@ bool FlutterWindowsView::OnFrameGenerated(size_t width, size_t height) {
   return true;
 }
 
-void FlutterWindowsView::UpdateFlutterCursor(const std::string& cursor_name) {
-  binding_handler_->UpdateFlutterCursor(cursor_name);
-}
-
-void FlutterWindowsView::SetFlutterCursor(HCURSOR cursor) {
-  binding_handler_->SetFlutterCursor(cursor);
-}
-
 void FlutterWindowsView::ForceRedraw() {
   if (resize_status_ == ResizeState::kDone) {
     // Request new frame.

engine/src/flutter/shell/platform/windows/flutter_windows_view.h

@@ -125,13 +125,6 @@ class FlutterWindowsView : public WindowBindingHandlerDelegate {
   // This completes a view resize if one is pending.
   virtual void OnFramePresented();
 
-  // Sets the cursor that should be used when the mouse is over the Flutter
-  // content. See mouse_cursor.dart for the values and meanings of cursor_name.
-  void UpdateFlutterCursor(const std::string& cursor_name);
-
-  // Sets the cursor directly from a cursor handle.
-  void SetFlutterCursor(HCURSOR cursor);
-
   // |WindowBindingHandlerDelegate|
   bool OnWindowSizeChanged(size_t width, size_t height) override;
 

engine/src/flutter/shell/platform/windows/testing/mock_window.h

@@ -54,7 +54,6 @@ class MockWindow : public FlutterWindow {
               OnPointerLeave,
               (double, double, FlutterPointerDeviceKind, int32_t),
               (override));
-  MOCK_METHOD(void, OnSetCursor, (), (override));
   MOCK_METHOD(void, OnText, (const std::u16string&), (override));
   MOCK_METHOD(void,
               OnKey,

engine/src/flutter/shell/platform/windows/testing/mock_window_binding_handler.h

@@ -23,11 +23,6 @@ class MockWindowBindingHandler : public WindowBindingHandler {
   MOCK_METHOD(HWND, GetWindowHandle, (), (override));
   MOCK_METHOD(float, GetDpiScale, (), (override));
   MOCK_METHOD(PhysicalWindowBounds, GetPhysicalWindowBounds, (), (override));
-  MOCK_METHOD(void,
-              UpdateFlutterCursor,
-              (const std::string& cursor_name),
-              (override));
-  MOCK_METHOD(void, SetFlutterCursor, (HCURSOR cursor_name), (override));
   MOCK_METHOD(void, OnCursorRectUpdated, (const Rect& rect), (override));
   MOCK_METHOD(void, OnResetImeComposing, (), (override));
   MOCK_METHOD(bool, OnBitmapSurfaceCleared, (), (override));

engine/src/flutter/shell/platform/windows/testing/mock_windows_proc_table.h

@@ -34,6 +34,13 @@ class MockWindowsProcTable : public WindowsProcTable {
 
   MOCK_METHOD(HRESULT, DwmFlush, (), (const, override));
 
+  MOCK_METHOD(HCURSOR,
+              LoadCursor,
+              (HINSTANCE instance, LPCWSTR cursor_name),
+              (const, override));
+
+  MOCK_METHOD(HCURSOR, SetCursor, (HCURSOR cursor), (const, override));
+
  private:
   FML_DISALLOW_COPY_AND_ASSIGN(MockWindowsProcTable);
 };

engine/src/flutter/shell/platform/windows/window_binding_handler.h

@@ -54,13 +54,6 @@ class WindowBindingHandler {
   // Returns the bounds of the backing window in physical pixels.
   virtual PhysicalWindowBounds GetPhysicalWindowBounds() = 0;
 
-  // Sets the cursor that should be used when the mouse is over the Flutter
-  // content. See mouse_cursor.dart for the values and meanings of cursor_name.
-  virtual void UpdateFlutterCursor(const std::string& cursor_name) = 0;
-
-  // Sets the cursor directly from a cursor handle.
-  virtual void SetFlutterCursor(HCURSOR cursor) = 0;
-
   // Invoked when the cursor/composing rect has been updated in the framework.
   virtual void OnCursorRectUpdated(const Rect& rect) = 0;
 

engine/src/flutter/shell/platform/windows/windows_proc_table.cc

@@ -58,4 +58,13 @@ HRESULT WindowsProcTable::DwmFlush() const {
   return ::DwmFlush();
 }
 
+HCURSOR WindowsProcTable::LoadCursor(HINSTANCE instance,
+                                     LPCWSTR cursor_name) const {
+  return ::LoadCursorW(instance, cursor_name);
+}
+
+HCURSOR WindowsProcTable::SetCursor(HCURSOR cursor) const {
+  return ::SetCursor(cursor);
+}
+
 }  // namespace flutter

engine/src/flutter/shell/platform/windows/windows_proc_table.h

@@ -57,6 +57,19 @@ class WindowsProcTable {
   // https://learn.microsoft.com/windows/win32/api/dwmapi/nf-dwmapi-dwmflush
   virtual HRESULT DwmFlush() const;
 
+  // Loads the specified cursor resource from the executable (.exe) file
+  // associated with an application instance.
+  //
+  // See:
+  // https://learn.microsoft.com/windows/win32/api/winuser/nf-winuser-loadcursorw
+  virtual HCURSOR LoadCursor(HINSTANCE instance, LPCWSTR cursor_name) const;
+
+  // Sets the cursor shape.
+  //
+  // See:
+  // https://learn.microsoft.com/windows/win32/api/winuser/nf-winuser-setcursor
+  virtual HCURSOR SetCursor(HCURSOR cursor) const;
+
  private:
   using GetPointerType_ = BOOL __stdcall(UINT32 pointerId,
                                          POINTER_INPUT_TYPE* pointerType);

packages/flutter/lib/src/services/mouse_cursor.dart

@@ -408,8 +408,7 @@ abstract final class SystemMouseCursors {
   //
   // * Android: shell/platform/android/io/flutter/plugin/mouse/MouseCursorPlugin.java
   // * Web: lib/web_ui/lib/src/engine/mouse_cursor.dart
-  // * Windows: shell/platform/windows/win32_flutter_window_win32.cc
-  // * Windows UWP: shell/platform/windows/win32_flutter_window_winuwp.cc
+  // * Windows: shell/platform/windows/flutter_windows_engine.cc
   // * Linux: shell/platform/linux/fl_mouse_cursor_plugin.cc
   // * macOS: shell/platform/darwin/macos/framework/Source/FlutterMouseCursorPlugin.mm