Merge pull request #16 from alexmercerind/window-restore-fix-api-change

refactor: improve NativeViewContainer API & fix: window restore animation
alexmercerind · May 25, 2022 · 5e6360b · 5e6360b
2 parents af2374d + aac22da
commit 5e6360b
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,5 +1,6 @@
 ## 0.0.2
 
+- chore: switch to MIT license.
 - fix: window restore animation after clicking on taskbar icon (@alexmercerind).
 - refactor: plugin initialization (@alexmercerind).
 

diff --git a/README.md b/README.md
@@ -68,7 +68,7 @@ Add following lines to your `windows/runner/main.cpp` file:
 ```diff
   window.SetQuitOnClose(true);
 
-+ flutternativeview::CreateNativeViewContainer();
++ flutternativeview::NativeViewContainer::GetInstance()->Create();
 
   ::MSG msg;
   while (::GetMessage(&msg, nullptr, 0, 0)) {
@@ -155,11 +155,12 @@ controller.dispose();
 - Windows 10 & higher support.
 - Proper disposing of `HWND` and instances.
 - Semi transparent `Widget`s on top of `NativeView`.
-- Customizable hit-test i.e. optional interactability with the `NativeView`s.
 - Placement of `NativeView`s inside scrollables like `ListView`s.
+- [UNSTABLE] Customizable hit-test i.e. optional interactability with the `NativeView`s.
 
 #### Under Progress
 
+- Stable support for interactability with the `NativeView`s [maybe switching to programmatic approach].
 - Support for older Windows versions.
 - Defining z-order for each `NativeViewController`.
 - Finalized API.

diff --git a/core/native_view_container.cc b/core/native_view_container.cc
@@ -14,14 +14,58 @@
 
 namespace flutternativeview {
 
-constexpr const auto kClassName = L"FLUTTER_NATIVE_VIEW";
-constexpr const auto kWindowName = L"flutter_native_view";
+NativeViewContainer* NativeViewContainer::GetInstance() {
+  return instance_.get();
+}
+
+HWND NativeViewContainer::Create() {
+  auto window_class = WNDCLASSEX{};
+  ::SecureZeroMemory(&window_class, sizeof(window_class));
+  window_class.cbSize = sizeof(window_class);
+  window_class.style = CS_HREDRAW | CS_VREDRAW;
+  window_class.lpfnWndProc = WindowProc;
+  window_class.hInstance = 0;
+  window_class.lpszClassName = kClassName;
+  window_class.hCursor = ::LoadCursorW(nullptr, IDC_ARROW);
+  window_class.hbrBackground = ::CreateSolidBrush(0);
+  ::RegisterClassExW(&window_class);
+  handle_ =
+      ::CreateWindow(kClassName, kWindowName, WS_OVERLAPPEDWINDOW,
+                     CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT,
+                     nullptr, nullptr, GetModuleHandle(nullptr), nullptr);
+  // Disable DWM animations on |native_view_container|.
+  auto disable_window_transitions = TRUE;
+  DwmSetWindowAttribute(handle_, DWMWA_TRANSITIONS_FORCEDISABLED,
+                        &disable_window_transitions,
+                        sizeof(disable_window_transitions));
+  return handle_;
+}
 
-static HWND native_view_container = nullptr;
+HWND NativeViewContainer::Get(HWND window) {
+  RECT window_rect;
+  ::GetWindowRect(window, &window_rect);
+  ::SetWindowPos(handle_, window, window_rect.left, window_rect.top,
+                 window_rect.right - window_rect.left,
+                 window_rect.bottom - window_rect.top, SWP_NOACTIVATE);
+  ::SetWindowLongPtr(handle_, GWLP_USERDATA, reinterpret_cast<LONG>(window));
+  // Remove taskbar entry.
+  // Using |ITaskbarList3| available on Windows 7 or higher. Modification to
+  // |native_view_container|'s |GWL_STYLE| OR |GWL_EX_STYLE| made underlying
+  // |HWND| obvious to user.
+  ITaskbarList3* taskbar = nullptr;
+  ::CoCreateInstance(CLSID_TaskbarList, 0, CLSCTX_INPROC_SERVER,
+                     IID_PPV_ARGS(&taskbar));
+  taskbar->DeleteTab(handle_);
+  taskbar->Release();
+  ::ShowWindow(handle_, SW_SHOWNOACTIVATE);
+  ::SetFocus(window);
+  return handle_;
+}
 
-LRESULT CALLBACK NativeViewContainerProc(HWND const window, UINT const message,
-                                         WPARAM const wparam,
-                                         LPARAM const lparam) noexcept {
+LRESULT CALLBACK NativeViewContainer::WindowProc(HWND const window,
+                                                 UINT const message,
+                                                 WPARAM const wparam,
+                                                 LPARAM const lparam) noexcept {
   switch (message) {
     case WM_DESTROY: {
       ::PostQuitMessage(0);
@@ -63,49 +107,7 @@ LRESULT CALLBACK NativeViewContainerProc(HWND const window, UINT const message,
   return ::DefWindowProc(window, message, wparam, lparam);
 }
 
-HWND CreateNativeViewContainer() {
-  auto window_class = WNDCLASSEX{};
-  ::SecureZeroMemory(&window_class, sizeof(window_class));
-  window_class.cbSize = sizeof(window_class);
-  window_class.style = CS_HREDRAW | CS_VREDRAW;
-  window_class.lpfnWndProc = NativeViewContainerProc;
-  window_class.hInstance = 0;
-  window_class.lpszClassName = kClassName;
-  window_class.hCursor = ::LoadCursorW(nullptr, IDC_ARROW);
-  window_class.hbrBackground = ::CreateSolidBrush(0);
-  ::RegisterClassExW(&window_class);
-  native_view_container =
-      ::CreateWindow(kClassName, kWindowName, WS_OVERLAPPEDWINDOW,
-                     CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT,
-                     nullptr, nullptr, GetModuleHandle(nullptr), nullptr);
-  // Disable DWM animations on |native_view_container|.
-  auto disable_window_transitions = TRUE;
-  DwmSetWindowAttribute(native_view_container, DWMWA_TRANSITIONS_FORCEDISABLED,
-                        &disable_window_transitions,
-                        sizeof(disable_window_transitions));
-  return native_view_container;
-}
-
-HWND GetNativeViewContainer(HWND window) {
-  RECT window_rect;
-  ::GetWindowRect(window, &window_rect);
-  ::SetWindowPos(native_view_container, window, window_rect.left,
-                 window_rect.top, window_rect.right - window_rect.left,
-                 window_rect.bottom - window_rect.top, SWP_NOACTIVATE);
-  ::SetWindowLongPtr(native_view_container, GWLP_USERDATA,
-                     reinterpret_cast<LONG>(window));
-  // Remove taskbar entry.
-  // Using |ITaskbarList3| available on Windows 7 or higher. Modification to
-  // |native_view_container|'s |GWL_STYLE| OR |GWL_EX_STYLE| made underlying
-  // |HWND| obvious to user.
-  ITaskbarList3* taskbar = nullptr;
-  ::CoCreateInstance(CLSID_TaskbarList, 0, CLSCTX_INPROC_SERVER,
-                     IID_PPV_ARGS(&taskbar));
-  taskbar->DeleteTab(native_view_container);
-  taskbar->Release();
-  ::ShowWindow(native_view_container, SW_SHOWNOACTIVATE);
-  ::SetFocus(window);
-  return native_view_container;
-}
+std::unique_ptr<NativeViewContainer> NativeViewContainer::instance_ =
+    std::make_unique<NativeViewContainer>();
 
 }  // namespace flutternativeview
diff --git a/core/native_view_container.h b/core/native_view_container.h
@@ -23,9 +23,32 @@ namespace flutternativeview {
 extern "C" {
 #endif
 
-DLLEXPORT HWND CreateNativeViewContainer();
-
-DLLEXPORT HWND GetNativeViewContainer(HWND window);
+class NativeViewContainer {
+ public:
+  DLLEXPORT static NativeViewContainer* GetInstance();
+
+  // Creates a new |NativeViewContainer| to hold various native views.
+  // Transitions on this window are disabled using
+  // |DWMWA_TRANSITIONS_FORCEDISABLED|.
+  DLLEXPORT HWND NativeViewContainer::Create();
+
+  // Returns the |NativeViewContainer|'s window handle for the given parent
+  // |window|. The method also removes the taskbar entry of |handle_| & returns
+  // focus back to |window| (if lost).
+  // |window| is stored on |NativeViewContainer|'s window as |GWLP_USERDATA|.
+  DLLEXPORT HWND NativeViewContainer::Get(HWND window);
+
+ private:
+  static std::unique_ptr<NativeViewContainer> NativeViewContainer::instance_;
+  static constexpr auto kClassName = L"FLUTTER_NATIVE_VIEW";
+  static constexpr auto kWindowName = L"flutter_native_view";
+
+  static LRESULT CALLBACK NativeViewContainer::WindowProc(
+      HWND const window, UINT const message, WPARAM const wparam,
+      LPARAM const lparam) noexcept;
+
+  HWND handle_;
+};
 
 #ifdef __cplusplus
 }

diff --git a/core/native_view_core.cc b/core/native_view_core.cc
@@ -27,7 +27,8 @@ NativeViewCore::NativeViewCore(HWND window, HWND child_window)
 
 void NativeViewCore::EnsureInitialized() {
   flutternativeview::SetWindowComposition(window_, 6, 0);
-  native_view_container_ = flutternativeview::GetNativeViewContainer(window_);
+  native_view_container_ =
+      flutternativeview::NativeViewContainer::GetInstance()->Get(window_);
 }
 
 void NativeViewCore::CreateNativeView(HWND native_view, RECT rect,
@@ -101,13 +102,15 @@ std::optional<HRESULT> NativeViewCore::WindowProc(HWND hwnd, UINT message,
     case WM_SIZE: {
       // Keeping the |native_view_container_| hidden when minimizing the app &
       // showing it again only when the app is restored.
-      if (last_wm_size_wparam_ == SIZE_MINIMIZED) {
-        std::thread([=]() {
-          std::this_thread::sleep_for(
-              std::chrono::milliseconds(kNativeViewPositionAndShowDelay));
-          ::ShowWindow(native_view_container_, SW_SHOWNOACTIVATE);
-        }).detach();
-      }
+      // ---- INTENTIONALLY COMMENTED OUT ----
+      // if (last_wm_size_wparam_ == SIZE_MINIMIZED) {
+      //   std::thread([=]() {
+      //     std::this_thread::sleep_for(
+      //         std::chrono::milliseconds(kNativeViewPositionAndShowDelay));
+      //     ::ShowWindow(native_view_container_, SW_SHOWNOACTIVATE);
+      //   }).detach();
+      // }
+
       // Handle Windows's minimize & maximize animations properly.
       // Since |SetWindowPos| & other Win32 APIs on |native_view_container_|
       // do not re-produce the same DWM animations like  actual user

diff --git a/example/windows/runner/main.cpp b/example/windows/runner/main.cpp
@@ -32,7 +32,7 @@ int APIENTRY wWinMain(_In_ HINSTANCE instance, _In_opt_ HINSTANCE prev,
   }
   window.SetQuitOnClose(true);
 
-  flutternativeview::CreateNativeViewContainer();
+  flutternativeview::NativeViewContainer::GetInstance()->Create();
 
   ::MSG msg;
   while (::GetMessage(&msg, nullptr, 0, 0)) {