| // Copyright 2014 The Flutter Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "win32_window.h" |
| |
| #include <dwmapi.h> |
| #include <flutter_windows.h> |
| |
| #include "resource.h" |
| |
| namespace { |
| |
| /// Window attribute that enables dark mode window decorations. |
| /// |
| /// Redefined in case the developer's machine has a Windows SDK older than |
| /// version 10.0.22000.0. |
| /// See: https://docs.microsoft.com/windows/win32/api/dwmapi/ne-dwmapi-dwmwindowattribute |
| #ifndef DWMWA_USE_IMMERSIVE_DARK_MODE |
| #define DWMWA_USE_IMMERSIVE_DARK_MODE 20 |
| #endif |
| |
| constexpr const wchar_t kWindowClassName[] = L"FLUTTER_RUNNER_WIN32_WINDOW"; |
| |
| /// Registry key for app theme preference. |
| /// |
| /// A value of 0 indicates apps should use dark mode. A non-zero or missing |
| /// value indicates apps should use light mode. |
| constexpr const wchar_t kGetPreferredBrightnessRegKey[] = |
| L"Software\\Microsoft\\Windows\\CurrentVersion\\Themes\\Personalize"; |
| constexpr const wchar_t kGetPreferredBrightnessRegValue[] = L"AppsUseLightTheme"; |
| |
| // The number of Win32Window objects that currently exist. |
| static int g_active_window_count = 0; |
| |
| 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 |
| |
| // Manages the Win32Window's window class registration. |
| class WindowClassRegistrar { |
| public: |
| ~WindowClassRegistrar() = default; |
| |
| // Returns the singleton registar instance. |
| static WindowClassRegistrar* GetInstance() { |
| if (!instance_) { |
| instance_ = new WindowClassRegistrar(); |
| } |
| return instance_; |
| } |
| |
| // Returns the name of the window class, registering the class if it hasn't |
| // previously been registered. |
| const wchar_t* GetWindowClass(); |
| |
| // Unregisters the window class. Should only be called if there are no |
| // instances of the window. |
| void UnregisterWindowClass(); |
| |
| private: |
| WindowClassRegistrar() = default; |
| |
| static WindowClassRegistrar* instance_; |
| |
| bool class_registered_ = false; |
| }; |
| |
| WindowClassRegistrar* WindowClassRegistrar::instance_ = nullptr; |
| |
| const wchar_t* WindowClassRegistrar::GetWindowClass() { |
| if (!class_registered_) { |
| WNDCLASS window_class{}; |
| window_class.hCursor = LoadCursor(nullptr, IDC_ARROW); |
| window_class.lpszClassName = kWindowClassName; |
| 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 = Win32Window::WndProc; |
| RegisterClass(&window_class); |
| class_registered_ = true; |
| } |
| return kWindowClassName; |
| } |
| |
| void WindowClassRegistrar::UnregisterWindowClass() { |
| UnregisterClass(kWindowClassName, nullptr); |
| class_registered_ = false; |
| } |
| |
| Win32Window::Win32Window() { |
| ++g_active_window_count; |
| } |
| |
| Win32Window::~Win32Window() { |
| --g_active_window_count; |
| Destroy(); |
| } |
| |
| bool Win32Window::Create(const std::wstring& title, |
| const Point& origin, |
| const Size& size) { |
| Destroy(); |
| |
| const wchar_t* window_class = |
| WindowClassRegistrar::GetInstance()->GetWindowClass(); |
| |
| 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 / 96.0; |
| |
| HWND window = CreateWindow( |
| window_class, title.c_str(), WS_OVERLAPPEDWINDOW, |
| Scale(origin.x, scale_factor), Scale(origin.y, scale_factor), |
| Scale(size.width, scale_factor), Scale(size.height, scale_factor), |
| nullptr, nullptr, GetModuleHandle(nullptr), this); |
| |
| if (!window) { |
| return false; |
| } |
| |
| UpdateTheme(window); |
| |
| return OnCreate(); |
| } |
| |
| bool Win32Window::Show() { |
| return ShowWindow(window_handle_, SW_SHOWNORMAL); |
| } |
| |
| // static |
| 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 { |
| switch (message) { |
| case WM_DESTROY: |
| window_handle_ = nullptr; |
| Destroy(); |
| if (quit_on_close_) { |
| PostQuitMessage(0); |
| } |
| 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 = GetClientArea(); |
| 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; |
| |
| case WM_DWMCOLORIZATIONCOLORCHANGED: |
| UpdateTheme(hwnd); |
| return 0; |
| } |
| |
| return DefWindowProc(window_handle_, message, wparam, lparam); |
| } |
| |
| void Win32Window::Destroy() { |
| OnDestroy(); |
| |
| if (window_handle_) { |
| DestroyWindow(window_handle_); |
| window_handle_ = nullptr; |
| } |
| if (g_active_window_count == 0) { |
| WindowClassRegistrar::GetInstance()->UnregisterWindowClass(); |
| } |
| } |
| |
| 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 = GetClientArea(); |
| |
| MoveWindow(content, frame.left, frame.top, frame.right - frame.left, |
| frame.bottom - frame.top, true); |
| |
| SetFocus(child_content_); |
| } |
| |
| RECT Win32Window::GetClientArea() { |
| RECT frame; |
| GetClientRect(window_handle_, &frame); |
| return frame; |
| } |
| |
| HWND Win32Window::GetHandle() { |
| return window_handle_; |
| } |
| |
| void Win32Window::SetQuitOnClose(bool quit_on_close) { |
| quit_on_close_ = quit_on_close; |
| } |
| |
| bool Win32Window::OnCreate() { |
| // No-op; provided for subclasses. |
| return true; |
| } |
| |
| void Win32Window::OnDestroy() { |
| // No-op; provided for subclasses. |
| } |
| |
| void Win32Window::UpdateTheme(HWND const window) { |
| DWORD light_mode; |
| DWORD light_mode_size = sizeof(light_mode); |
| LSTATUS result = RegGetValue(HKEY_CURRENT_USER, kGetPreferredBrightnessRegKey, |
| kGetPreferredBrightnessRegValue, |
| RRF_RT_REG_DWORD, nullptr, &light_mode, |
| &light_mode_size); |
| |
| if (result == ERROR_SUCCESS) { |
| BOOL enable_dark_mode = light_mode == 0; |
| DwmSetWindowAttribute(window, DWMWA_USE_IMMERSIVE_DARK_MODE, |
| &enable_dark_mode, sizeof(enable_dark_mode)); |
| } |
| } |