[Windows] Refactor logic when window resize completes

shell/platform/windows/angle_surface_manager.cc

@@ -329,7 +329,7 @@ bool AngleSurfaceManager::MakeResourceCurrent() {
                          egl_resource_context_) == EGL_TRUE);
 }
 
-EGLBoolean AngleSurfaceManager::SwapBuffers() {
+bool AngleSurfaceManager::SwapBuffers() {
   return (eglSwapBuffers(egl_display_, render_surface_));
 }
 

shell/platform/windows/angle_surface_manager.h

@@ -77,7 +77,7 @@ class AngleSurfaceManager {
 
   // Swaps the front and back buffers of the DX11 swapchain backing surface if
   // not null.
-  EGLBoolean SwapBuffers();
+  virtual bool SwapBuffers();
 
   // Creates a |EGLSurface| from the provided handle.
   EGLSurface CreateSurfaceFromHandle(EGLenum handle_type,

shell/platform/windows/compositor_opengl.cc

@@ -154,7 +154,12 @@ bool CompositorOpenGL::Present(const FlutterLayer** layers,
                        GL_NEAREST            // filter
   );
 
-  return engine_->view()->SwapBuffers();
+  if (!engine_->surface_manager()->SwapBuffers()) {
+    return false;
+  }
+
+  engine_->view()->OnFramePresented();
+  return true;
 }
 
 bool CompositorOpenGL::Initialize() {
@@ -188,7 +193,12 @@ bool CompositorOpenGL::ClearSurface() {
   gl_->ClearColor(0.0f, 0.0f, 0.0f, 0.0f);
   gl_->Clear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
 
-  return engine_->view()->SwapBuffers();
+  if (!engine_->surface_manager()->SwapBuffers()) {
+    return false;
+  }
+
+  engine_->view()->OnFramePresented();
+  return true;
 }
 
 }  // namespace flutter

shell/platform/windows/compositor_opengl_unittests.cc

@@ -11,6 +11,7 @@
 #include "flutter/shell/platform/windows/flutter_windows_view.h"
 #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_angle_surface_manager.h"
 #include "flutter/shell/platform/windows/testing/mock_window_binding_handler.h"
 #include "flutter/shell/platform/windows/testing/windows_test.h"
 #include "gmock/gmock.h"
@@ -56,36 +57,13 @@ const impeller::ProcTableGLES::Resolver kMockResolver = [](const char* name) {
   }
 };
 
-class MockAngleSurfaceManager : public AngleSurfaceManager {
- public:
-  MockAngleSurfaceManager() : AngleSurfaceManager(false) {}
-
-  MOCK_METHOD(bool, MakeCurrent, (), (override));
-
- private:
-  FML_DISALLOW_COPY_AND_ASSIGN(MockAngleSurfaceManager);
-};
-
-class MockFlutterWindowsView : public FlutterWindowsView {
- public:
-  MockFlutterWindowsView(std::unique_ptr<WindowBindingHandler> window)
-      : FlutterWindowsView(std::move(window)) {}
-  virtual ~MockFlutterWindowsView() = default;
-
-  MOCK_METHOD(bool, SwapBuffers, (), (override));
-
- private:
-  FML_DISALLOW_COPY_AND_ASSIGN(MockFlutterWindowsView);
-};
-
 class CompositorOpenGLTest : public WindowsTest {
  public:
   CompositorOpenGLTest() = default;
   virtual ~CompositorOpenGLTest() = default;
 
  protected:
   FlutterWindowsEngine* engine() { return engine_.get(); }
-  MockFlutterWindowsView* view() { return view_.get(); }
   MockAngleSurfaceManager* surface_manager() { return surface_manager_; }
 
   void UseHeadlessEngine() {
@@ -106,14 +84,14 @@ class CompositorOpenGLTest : public WindowsTest {
     EXPECT_CALL(*window.get(), SetView).Times(1);
     EXPECT_CALL(*window.get(), GetWindowHandle).WillRepeatedly(Return(nullptr));
 
-    view_ = std::make_unique<MockFlutterWindowsView>(std::move(window));
+    view_ = std::make_unique<FlutterWindowsView>(std::move(window));
 
     engine_->SetView(view_.get());
   }
 
  private:
   std::unique_ptr<FlutterWindowsEngine> engine_;
-  std::unique_ptr<MockFlutterWindowsView> view_;
+  std::unique_ptr<FlutterWindowsView> view_;
   MockAngleSurfaceManager* surface_manager_;
 
   FML_DISALLOW_COPY_AND_ASSIGN(CompositorOpenGLTest);
@@ -163,7 +141,7 @@ TEST_F(CompositorOpenGLTest, Present) {
   const FlutterLayer* layer_ptr = &layer;
 
   EXPECT_CALL(*surface_manager(), MakeCurrent).WillOnce(Return(true));
-  EXPECT_CALL(*view(), SwapBuffers).WillOnce(Return(true));
+  EXPECT_CALL(*surface_manager(), SwapBuffers).WillOnce(Return(true));
   EXPECT_TRUE(compositor.Present(&layer_ptr, 1));
 
   ASSERT_TRUE(compositor.CollectBackingStore(&backing_store));
@@ -179,7 +157,7 @@ TEST_F(CompositorOpenGLTest, PresentEmpty) {
   EXPECT_CALL(*surface_manager(), MakeCurrent)
       .Times(2)
       .WillRepeatedly(Return(true));
-  EXPECT_CALL(*view(), SwapBuffers).WillOnce(Return(true));
+  EXPECT_CALL(*surface_manager(), SwapBuffers).WillOnce(Return(true));
   EXPECT_TRUE(compositor.Present(nullptr, 0));
 }
 

shell/platform/windows/flutter_window.cc

@@ -168,10 +168,6 @@ float FlutterWindow::GetDpiScale() {
   return static_cast<float>(GetCurrentDPI()) / static_cast<float>(base_dpi);
 }
 
-bool FlutterWindow::IsVisible() {
-  return IsWindowVisible(GetWindowHandle());
-}
-
 PhysicalWindowBounds FlutterWindow::GetPhysicalWindowBounds() {
   return {GetCurrentWidth(), GetCurrentHeight()};
 }

shell/platform/windows/flutter_window.h

@@ -158,9 +158,6 @@ class FlutterWindow : public KeyboardManager::WindowDelegate,
   // |FlutterWindowBindingHandler|
   virtual float GetDpiScale() override;
 
-  // |FlutterWindowBindingHandler|
-  virtual bool IsVisible() override;
-
   // |FlutterWindowBindingHandler|
   virtual PhysicalWindowBounds GetPhysicalWindowBounds() override;
 

shell/platform/windows/flutter_window_unittests.cc

@@ -66,7 +66,6 @@ class MockFlutterWindow : public FlutterWindow {
   MOCK_METHOD(void, OnSetCursor, (), (override));
   MOCK_METHOD(float, GetScrollOffsetMultiplier, (), (override));
   MOCK_METHOD(float, GetDpiScale, (), (override));
-  MOCK_METHOD(bool, IsVisible, (), (override));
   MOCK_METHOD(void, UpdateCursorRect, (const Rect&), (override));
   MOCK_METHOD(void, OnResetImeComposing, (), (override));
   MOCK_METHOD(UINT, Win32DispatchMessage, (UINT, WPARAM, LPARAM), (override));

shell/platform/windows/flutter_windows_view.cc

@@ -590,42 +590,30 @@ void FlutterWindowsView::SendPointerEventWithData(
   }
 }
 
-bool FlutterWindowsView::SwapBuffers() {
-  // Called on an engine-controlled (non-platform) thread.
+void FlutterWindowsView::OnFramePresented() {
+  // Called on the engine's raster thread.
   std::unique_lock<std::mutex> lock(resize_mutex_);
 
   switch (resize_status_) {
-    // SwapBuffer requests during resize are ignored until the frame with the
-    // right dimensions has been generated. This is marked with
-    // kFrameGenerated resize status.
     case ResizeState::kResizeStarted:
-      return false;
+      // The caller must first call |OnFrameGenerated| or
+      // |OnEmptyFrameGenerated| before calling this method. This status
+      // indicates the caller did not call these methods or ignored their
+      // result.
+      FML_UNREACHABLE();
     case ResizeState::kFrameGenerated: {
-      bool visible = binding_handler_->IsVisible();
-      bool swap_buffers_result;
-      // For visible windows swap the buffers while resize handler is waiting.
-      // For invisible windows unblock the handler first and then swap buffers.
-      // SwapBuffers waits for vsync and there's no point doing that for
-      // invisible windows.
-      if (visible) {
-        swap_buffers_result = engine_->surface_manager()->SwapBuffers();
-      }
+      // A frame was generated for a pending resize.
+      // Unblock the platform thread.
       resize_status_ = ResizeState::kDone;
       lock.unlock();
       resize_cv_.notify_all();
 
       // Blocking the raster thread until DWM flushes alleviates glitches where
       // previous size surface is stretched over current size view.
       windows_proc_table_->DwmFlush();
-
-      if (!visible) {
-        swap_buffers_result = engine_->surface_manager()->SwapBuffers();
-      }
-      return swap_buffers_result;
     }
     case ResizeState::kDone:
-    default:
-      return engine_->surface_manager()->SwapBuffers();
+      return;
   }
 }
 

shell/platform/windows/flutter_windows_view.h

@@ -62,17 +62,6 @@ class FlutterWindowsView : public WindowBindingHandlerDelegate {
   // Tells the engine to generate a new frame
   void ForceRedraw();
 
-  // Swap the view's surface buffers. Must be called on the engine's raster
-  // thread. Returns true if the buffers were swapped.
-  //
-  // |OnFrameGenerated| or |OnEmptyFrameGenerated| must be called before this
-  // method.
-  //
-  // If the view is resizing, this returns false if the frame is not the target
-  // size. Otherwise, it unblocks the platform thread and blocks the raster
-  // thread until the v-blank.
-  virtual bool SwapBuffers();
-
   // Callback to clear a previously presented software bitmap.
   virtual bool ClearSoftwareBitmap();
 
@@ -103,6 +92,11 @@ class FlutterWindowsView : public WindowBindingHandlerDelegate {
   // |height| match the target size.
   bool OnFrameGenerated(size_t width, size_t height);
 
+  // Called on the raster thread after |CompositorOpenGL| presents a frame.
+  //
+  // 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);

shell/platform/windows/testing/mock_angle_surface_manager.h

@@ -25,6 +25,8 @@ class MockAngleSurfaceManager : public AngleSurfaceManager {
   MOCK_METHOD(bool, ClearCurrent, (), (override));
   MOCK_METHOD(void, SetVSyncEnabled, (bool), (override));
 
+  MOCK_METHOD(bool, SwapBuffers, (), (override));
+
  private:
   FML_DISALLOW_COPY_AND_ASSIGN(MockAngleSurfaceManager);
 };

shell/platform/windows/testing/mock_window_binding_handler.h

@@ -22,7 +22,6 @@ class MockWindowBindingHandler : public WindowBindingHandler {
   MOCK_METHOD(void, SetView, (WindowBindingHandlerDelegate * view), (override));
   MOCK_METHOD(HWND, GetWindowHandle, (), (override));
   MOCK_METHOD(float, GetDpiScale, (), (override));
-  MOCK_METHOD(bool, IsVisible, (), (override));
   MOCK_METHOD(PhysicalWindowBounds, GetPhysicalWindowBounds, (), (override));
   MOCK_METHOD(void,
               UpdateFlutterCursor,

shell/platform/windows/window_binding_handler.h

@@ -51,9 +51,6 @@ class WindowBindingHandler {
   // Returns the scale factor for the backing window.
   virtual float GetDpiScale() = 0;
 
-  // Returns whether the HWND is currently visible.
-  virtual bool IsVisible() = 0;
-
   // Returns the bounds of the backing window in physical pixels.
   virtual PhysicalWindowBounds GetPhysicalWindowBounds() = 0;