Windows: UWP ViewController accepts a CoreApplicationView and exposes to plugins

shell/platform/windows/client_wrapper/flutter_view_controller.cc

@@ -11,12 +11,12 @@ namespace flutter {
 
 #ifdef WINUWP
 FlutterViewController::FlutterViewController(
-    ABI::Windows::UI::Core::CoreWindow* window,
+    ABI::Windows::ApplicationModel::Core::CoreApplicationView* applicationview,
     ABI::Windows::ApplicationModel::Activation::IActivatedEventArgs* args,
     const DartProject& project) {
   engine_ = std::make_unique<FlutterEngine>(project);
-  controller_ = FlutterDesktopViewControllerCreateFromCoreWindow(
-      window, args, engine_->RelinquishEngine());
+  controller_ = FlutterDesktopViewControllerCreateFromCoreApplicationView(
+      applicationview, args, engine_->RelinquishEngine());
   if (!controller_) {
     std::cerr << "Failed to create view controller." << std::endl;
     return;

shell/platform/windows/client_wrapper/include/flutter/flutter_view.h

@@ -20,7 +20,12 @@ class FlutterView {
   FlutterView(FlutterView const&) = delete;
   FlutterView& operator=(FlutterView const&) = delete;
 
-#ifndef WINUWP
+#ifdef WINUWP
+  // Returns the backing CoreApplicationView for the view.
+  ABI::Windows::ApplicationModel::Core::CoreApplicationView* GetNativeWindow() {
+    return FlutterDesktopViewGetCoreApplicationView(view_);
+  }
+#else
   // Returns the backing HWND for the view.
   HWND GetNativeWindow() { return FlutterDesktopViewGetHWND(view_); }
 #endif

shell/platform/windows/client_wrapper/include/flutter/flutter_view_controller.h

@@ -47,7 +47,8 @@ class FlutterViewController {
   // |IActivatedEventArgs| will be used to configure the engine switches.  Can
   // be set to nullptr.
   explicit FlutterViewController(
-      ABI::Windows::UI::Core::CoreWindow* window,
+      ABI::Windows::ApplicationModel::Core::CoreApplicationView*
+          applicationview,
       ABI::Windows::ApplicationModel::Activation::IActivatedEventArgs* args,
       const DartProject& project);
 #endif

shell/platform/windows/flutter_window_win32.cc

@@ -81,6 +81,10 @@ WindowsRenderTarget FlutterWindowWin32::GetRenderTarget() {
   return WindowsRenderTarget(GetWindowHandle());
 }
 
+PlatformWindow FlutterWindowWin32::GetPlatformWindow() {
+  return GetWindowHandle();
+}
+
 float FlutterWindowWin32::GetDpiScale() {
   return static_cast<float>(GetCurrentDPI()) / static_cast<float>(base_dpi);
 }

shell/platform/windows/flutter_window_win32.h

@@ -86,6 +86,9 @@ class FlutterWindowWin32 : public WindowWin32, public WindowBindingHandler {
   // |FlutterWindowBindingHandler|
   WindowsRenderTarget GetRenderTarget() override;
 
+  // |FlutterWindowBindingHandler|
+  PlatformWindow GetPlatformWindow() override;
+
   // |FlutterWindowBindingHandler|
   float GetDpiScale() override;
 

shell/platform/windows/flutter_window_winuwp.cc

@@ -10,10 +10,13 @@ namespace flutter {
 static constexpr double kControllerScrollMultiplier = 3;
 
 FlutterWindowWinUWP::FlutterWindowWinUWP(
-    ABI::Windows::UI::Core::CoreWindow* window) {
-  winrt::Windows::UI::Core::CoreWindow cw{nullptr};
-  winrt::copy_from_abi(cw, window);
-  window_ = cw;
+    ABI::Windows::ApplicationModel::Core::CoreApplicationView*
+        applicationview) {
+  winrt::Windows::ApplicationModel::Core::CoreApplicationView cav{nullptr};
+  winrt::copy_from_abi(cav, applicationview);
+
+  application_view_ = cav;
+  window_ = application_view_.CoreWindow();
 
   SetEventHandlers();
 
@@ -46,6 +49,10 @@ WindowsRenderTarget FlutterWindowWinUWP::GetRenderTarget() {
 #endif
 }
 
+PlatformWindow FlutterWindowWinUWP::GetPlatformWindow() {
+  return application_view_;
+}
+
 void FlutterWindowWinUWP::ApplyInverseDpiScalingTransform() {
   // Apply inverse transform to negate built in DPI scaling in order to render
   // at native scale.

shell/platform/windows/flutter_window_winuwp.h

@@ -5,12 +5,13 @@
 #ifndef FLUTTER_SHELL_PLATFORM_WINDOWS_UWP_FLUTTER_WINDOW_H_
 #define FLUTTER_SHELL_PLATFORM_WINDOWS_UWP_FLUTTER_WINDOW_H_
 
-#include <winrt/Windows.Devices.Input.h>
-#include <winrt/Windows.UI.Composition.h>
-#include <winrt/Windows.UI.Input.h>
-#include <winrt/Windows.UI.Text.Core.h>
-#include <winrt/Windows.UI.ViewManagement.Core.h>
-#include <winrt/Windows.UI.ViewManagement.h>
+#include <third_party/cppwinrt/generated/winrt/Windows.ApplicationModel.Core.h>
+#include <third_party/cppwinrt/generated/winrt/Windows.Devices.Input.h>
+#include <third_party/cppwinrt/generated/winrt/Windows.UI.Composition.h>
+#include <third_party/cppwinrt/generated/winrt/Windows.UI.Input.h>
+#include <third_party/cppwinrt/generated/winrt/Windows.UI.Text.Core.h>
+#include <third_party/cppwinrt/generated/winrt/Windows.UI.ViewManagement.Core.h>
+#include <third_party/cppwinrt/generated/winrt/Windows.UI.ViewManagement.h>
 
 #include "flutter/shell/platform/embedder/embedder.h"
 #include "flutter/shell/platform/windows/display_helper_winuwp.h"
@@ -25,7 +26,8 @@ namespace flutter {
 // Specifically handles window events within windows.
 class FlutterWindowWinUWP : public WindowBindingHandler {
  public:
-  explicit FlutterWindowWinUWP(ABI::Windows::UI::Core::CoreWindow* window);
+  explicit FlutterWindowWinUWP(
+      ABI::Windows::ApplicationModel::Core::CoreApplicationView* window);
 
   virtual ~FlutterWindowWinUWP();
 
@@ -35,6 +37,9 @@ class FlutterWindowWinUWP : public WindowBindingHandler {
   // |WindowBindingHandler|
   WindowsRenderTarget GetRenderTarget() override;
 
+  // |FlutterWindowBindingHandler|
+  PlatformWindow GetPlatformWindow() override;
+
   // |WindowBindingHandler|
   float GetDpiScale() override;
 
@@ -119,6 +124,10 @@ class FlutterWindowWinUWP : public WindowBindingHandler {
   // Backing CoreWindow. nullptr if not set.
   winrt::Windows::UI::Core::CoreWindow window_{nullptr};
 
+  // CoreApplicationView that owns window_. nullptr if not set.
+  winrt::Windows::ApplicationModel::Core::CoreApplicationView application_view_{
+      nullptr};
+
   // Pointer to a FlutterWindowsView that can be
   // used to update engine windowing and input state.
   WindowBindingHandlerDelegate* binding_handler_delegate_;

shell/platform/windows/flutter_windows.cc

@@ -128,9 +128,20 @@ FlutterDesktopTextureRegistrarRef FlutterDesktopEngineGetTextureRegistrar(
       EngineFromHandle(engine)->texture_registrar());
 }
 
+#ifdef WINUWP
+ABI::Windows::ApplicationModel::Core::CoreApplicationView*
+FlutterDesktopViewGetCoreApplicationView(FlutterDesktopViewRef view) {
+  return static_cast<
+      ABI::Windows::ApplicationModel::Core::CoreApplicationView*>(
+      winrt::get_abi(ViewFromHandle(view)->GetPlatformWindow()));
+}
+#endif
+
+#ifndef WINUWP
 HWND FlutterDesktopViewGetHWND(FlutterDesktopViewRef view) {
-  return std::get<HWND>(*ViewFromHandle(view)->GetRenderTarget());
+  return ViewFromHandle(view)->GetPlatformWindow();
 }
+#endif
 
 FlutterDesktopViewRef FlutterDesktopPluginRegistrarGetView(
     FlutterDesktopPluginRegistrarRef registrar) {

shell/platform/windows/flutter_windows_view.cc

@@ -487,6 +487,10 @@ WindowsRenderTarget* FlutterWindowsView::GetRenderTarget() const {
   return render_target_.get();
 }
 
+PlatformWindow FlutterWindowsView::GetPlatformWindow() const {
+  return binding_handler_->GetPlatformWindow();
+}
+
 FlutterWindowsEngine* FlutterWindowsView::GetEngine() {
   return engine_.get();
 }

shell/platform/windows/flutter_windows_view.h

@@ -59,6 +59,9 @@ class FlutterWindowsView : public WindowBindingHandlerDelegate,
   // Return the currently configured WindowsRenderTarget.
   WindowsRenderTarget* GetRenderTarget() const;
 
+  // Return the currently configured PlatformWindow.
+  PlatformWindow GetPlatformWindow() const;
+
   // Returns the engine backing this view.
   FlutterWindowsEngine* GetEngine();
 

shell/platform/windows/flutter_windows_winuwp.cc

@@ -41,12 +41,12 @@ std::vector<std::string> SplitCommaSeparatedString(const std::string& s) {
 }
 
 FlutterDesktopViewControllerRef
-FlutterDesktopViewControllerCreateFromCoreWindow(
-    ABI::Windows::UI::Core::CoreWindow* window,
+FlutterDesktopViewControllerCreateFromCoreApplicationView(
+    ABI::Windows::ApplicationModel::Core::CoreApplicationView* application_view,
     ABI::Windows::ApplicationModel::Activation::IActivatedEventArgs* args,
     FlutterDesktopEngineRef engine) {
   std::unique_ptr<flutter::WindowBindingHandler> window_wrapper =
-      std::make_unique<flutter::FlutterWindowWinUWP>(window);
+      std::make_unique<flutter::FlutterWindowWinUWP>(application_view);
 
   auto state = std::make_unique<FlutterDesktopViewControllerState>();
   state->view =

shell/platform/windows/public/flutter_windows.h

@@ -77,11 +77,11 @@ typedef struct {
 // FlutterDesktopViewControllerDestroy. Returns a null pointer in the event of
 // an error.
 #ifdef WINUWP
-// The CoreWindow implementation accepts a pointer to the host CoreWindow
-// and view hookup is performed in the construction path.
+// The CoreApplicationView implementation accepts a pointer to the host
+// CoreApplicationView and view hookup is performed in the construction path.
 FLUTTER_EXPORT FlutterDesktopViewControllerRef
-FlutterDesktopViewControllerCreateFromCoreWindow(
-    ABI::Windows::UI::Core::CoreWindow* window,
+FlutterDesktopViewControllerCreateFromCoreApplicationView(
+    ABI::Windows::ApplicationModel::Core::CoreApplicationView* window,
     ABI::Windows::ApplicationModel::Activation::IActivatedEventArgs* args,
     FlutterDesktopEngineRef engine);
 #else  //! WINUWP
@@ -192,7 +192,12 @@ FlutterDesktopEngineGetTextureRegistrar(
 
 // ========== View ==========
 
-#ifndef WINUWP
+#ifdef WINUWP
+// Return backing CoreApplicationView for manipulation of CoreWindow and
+// CoreTitleBar in host application.
+FLUTTER_EXPORT ABI::Windows::ApplicationModel::Core::CoreApplicationView*
+FlutterDesktopViewGetCoreApplicationView(FlutterDesktopViewRef view);
+#else
 // Return backing HWND for manipulation in host application.
 FLUTTER_EXPORT HWND FlutterDesktopViewGetHWND(FlutterDesktopViewRef view);
 #endif

shell/platform/windows/testing/mock_window_binding_handler.h

@@ -25,6 +25,7 @@ class MockWindowBindingHandler : public WindowBindingHandler {
 
   MOCK_METHOD1(SetView, void(WindowBindingHandlerDelegate* view));
   MOCK_METHOD0(GetRenderTarget, WindowsRenderTarget());
+  MOCK_METHOD0(GetPlatformWindow, PlatformWindow());
   MOCK_METHOD0(GetDpiScale, float());
   MOCK_METHOD0(OnWindowResized, void());
   MOCK_METHOD0(GetPhysicalWindowBounds, PhysicalWindowBounds());

shell/platform/windows/window_binding_handler.h

@@ -15,6 +15,7 @@
 #include "flutter/shell/platform/windows/window_binding_handler_delegate.h"
 
 #ifdef WINUWP
+#include <third_party/cppwinrt/generated/winrt/Windows.ApplicationModel.Activation.h>
 #include <third_party/cppwinrt/generated/winrt/Windows.UI.Composition.h>
 #endif
 
@@ -28,6 +29,16 @@ struct PhysicalWindowBounds {
   size_t height;
 };
 
+// Type representing an underlying platform window.
+#ifdef WINUWP
+using PlatformWindow =
+    winrt::Windows::ApplicationModel::Core::CoreApplicationView;
+#else
+using PlatformWindow = HWND;
+#endif
+
+// Type representing a platform object that can be accepted by the Angle
+// rendering layer to bind to and render pixels into.
 #ifdef WINUWP
 using WindowsRenderTarget =
     std::variant<winrt::Windows::UI::Composition::SpriteVisual,
@@ -46,10 +57,14 @@ class WindowBindingHandler {
   // such as key presses, mouse position updates etc.
   virtual void SetView(WindowBindingHandlerDelegate* view) = 0;
 
-  // Returns a valid WindowsRenderTarget representing the backing
-  // window.
+  // Returns a valid WindowsRenderTarget representing the platform object that
+  // rendering can be bound to by ANGLE rendering backend.
   virtual WindowsRenderTarget GetRenderTarget() = 0;
 
+  // Returns a valid PlatformWindow representing the backing
+  // window.
+  virtual PlatformWindow GetPlatformWindow() = 0;
+
   // Returns the scale factor for the backing window.
   virtual float GetDpiScale() = 0;