| #include "win32_window.h" |
| |
| #include <flutter_windows.h> |
| |
| #include "resource.h" |
| |
| namespace { |
| |
| // The Windows DPI system is based on this |
| // constant for machines running at 100% scaling. |
| constexpr int kBaseDpi = 96; |
| |
| constexpr const wchar_t kClassName[] = L"CLASSNAME"; |
| |
| using EnableNonClientDpiScaling = BOOL __stdcall(HWND hwnd); |
| |
| // Scale helper to convert logical scaler values to physical using passed in |
| // scale factor |
| int Scale(int source, double scale_factor) { |
| return static_cast<int>(source * scale_factor); |
| } |
| |
| // Dynamically loads the |EnableNonClientDpiScaling| from the User32 module. |
| // This API is only needed for PerMonitor V1 awareness mode. |
| void EnableFullDpiSupportIfAvailable(HWND hwnd) { |
| HMODULE user32_module = LoadLibraryA("User32.dll"); |
| if (!user32_module) { |
| return; |
| } |
| auto enable_non_client_dpi_scaling = |
| reinterpret_cast<EnableNonClientDpiScaling *>( |
| GetProcAddress(user32_module, "EnableNonClientDpiScaling")); |
| if (enable_non_client_dpi_scaling != nullptr) { |
| enable_non_client_dpi_scaling(hwnd); |
| FreeLibrary(user32_module); |
| } |
| } |
| } // namespace |
| |
| Win32Window::Win32Window() {} |
| |
| Win32Window::~Win32Window() { Destroy(); } |
| |
| bool Win32Window::CreateAndShow(const std::wstring &title, const Point &origin, |
| const Size &size) { |
| Destroy(); |
| |
| WNDCLASS window_class = RegisterWindowClass(); |
| |
| const POINT target_point = {static_cast<LONG>(origin.x), |
| static_cast<LONG>(origin.y)}; |
| HMONITOR monitor = MonitorFromPoint(target_point, MONITOR_DEFAULTTONEAREST); |
| UINT dpi = FlutterDesktopGetDpiForMonitor(monitor); |
| double scale_factor = dpi / kBaseDpi; |
| |
| HWND window = CreateWindow( |
| window_class.lpszClassName, title.c_str(), |
| WS_OVERLAPPEDWINDOW | WS_VISIBLE, Scale(origin.x, scale_factor), |
| Scale(origin.y, scale_factor), Scale(size.width, scale_factor), |
| Scale(size.height, scale_factor), nullptr, nullptr, |
| window_class.hInstance, this); |
| return window != nullptr; |
| } |
| |
| WNDCLASS Win32Window::RegisterWindowClass() { |
| WNDCLASS window_class{}; |
| window_class.hCursor = LoadCursor(nullptr, IDC_ARROW); |
| window_class.lpszClassName = kClassName; |
| window_class.style = CS_HREDRAW | CS_VREDRAW; |
| window_class.cbClsExtra = 0; |
| window_class.cbWndExtra = 0; |
| window_class.hInstance = GetModuleHandle(nullptr); |
| window_class.hIcon = |
| LoadIcon(window_class.hInstance, MAKEINTRESOURCE(IDI_APP_ICON)); |
| window_class.hbrBackground = 0; |
| window_class.lpszMenuName = nullptr; |
| window_class.lpfnWndProc = WndProc; |
| RegisterClass(&window_class); |
| return window_class; |
| } |
| |
| LRESULT CALLBACK Win32Window::WndProc(HWND const window, UINT const message, |
| WPARAM const wparam, |
| LPARAM const lparam) noexcept { |
| if (message == WM_NCCREATE) { |
| auto window_struct = reinterpret_cast<CREATESTRUCT *>(lparam); |
| SetWindowLongPtr(window, GWLP_USERDATA, |
| reinterpret_cast<LONG_PTR>(window_struct->lpCreateParams)); |
| |
| auto that = static_cast<Win32Window *>(window_struct->lpCreateParams); |
| EnableFullDpiSupportIfAvailable(window); |
| that->window_handle_ = window; |
| } else if (Win32Window *that = GetThisFromHandle(window)) { |
| return that->MessageHandler(window, message, wparam, lparam); |
| } |
| |
| return DefWindowProc(window, message, wparam, lparam); |
| } |
| |
| LRESULT |
| Win32Window::MessageHandler(HWND hwnd, UINT const message, WPARAM const wparam, |
| LPARAM const lparam) noexcept { |
| auto window = |
| reinterpret_cast<Win32Window *>(GetWindowLongPtr(hwnd, GWLP_USERDATA)); |
| |
| if (window == nullptr) { |
| return 0; |
| } |
| |
| switch (message) { |
| case WM_DESTROY: |
| window_handle_ = nullptr; |
| Destroy(); |
| return 0; |
| |
| case WM_DPICHANGED: { |
| auto newRectSize = reinterpret_cast<RECT *>(lparam); |
| LONG newWidth = newRectSize->right - newRectSize->left; |
| LONG newHeight = newRectSize->bottom - newRectSize->top; |
| |
| SetWindowPos(hwnd, nullptr, newRectSize->left, newRectSize->top, newWidth, |
| newHeight, SWP_NOZORDER | SWP_NOACTIVATE); |
| |
| return 0; |
| } |
| case WM_SIZE: |
| RECT rect; |
| GetClientRect(hwnd, &rect); |
| if (child_content_ != nullptr) { |
| // Size and position the child window. |
| MoveWindow(child_content_, rect.left, rect.top, rect.right - rect.left, |
| rect.bottom - rect.top, TRUE); |
| } |
| return 0; |
| |
| case WM_ACTIVATE: |
| if (child_content_ != nullptr) { |
| SetFocus(child_content_); |
| } |
| return 0; |
| |
| // Messages that are directly forwarded to embedding. |
| case WM_FONTCHANGE: |
| SendMessage(child_content_, WM_FONTCHANGE, NULL, NULL); |
| return 0; |
| } |
| |
| return DefWindowProc(window_handle_, message, wparam, lparam); |
| } |
| |
| void Win32Window::Destroy() { |
| if (window_handle_) { |
| DestroyWindow(window_handle_); |
| window_handle_ = nullptr; |
| } |
| |
| UnregisterClass(kClassName, nullptr); |
| } |
| |
| Win32Window *Win32Window::GetThisFromHandle(HWND const window) noexcept { |
| return reinterpret_cast<Win32Window *>( |
| GetWindowLongPtr(window, GWLP_USERDATA)); |
| } |
| |
| void Win32Window::SetChildContent(HWND content) { |
| child_content_ = content; |
| SetParent(content, window_handle_); |
| RECT frame; |
| GetClientRect(window_handle_, &frame); |
| |
| MoveWindow(content, frame.left, frame.top, frame.right - frame.left, |
| frame.bottom - frame.top, true); |
| |
| SetFocus(child_content_); |
| } |
| |
| HWND Win32Window::GetHandle() { return window_handle_; } |