From 7651d5200767a339089dd4021bf77a86b6adcf80 Mon Sep 17 00:00:00 2001 From: Vidhu Kant Sharma Date: Mon, 11 Sep 2023 01:00:14 +0530 Subject: first commit --- windows/runner/win32_window.cpp | 288 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 288 insertions(+) create mode 100644 windows/runner/win32_window.cpp (limited to 'windows/runner/win32_window.cpp') diff --git a/windows/runner/win32_window.cpp b/windows/runner/win32_window.cpp new file mode 100644 index 0000000..60608d0 --- /dev/null +++ b/windows/runner/win32_window.cpp @@ -0,0 +1,288 @@ +#include "win32_window.h" + +#include +#include + +#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(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( + 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 registrar 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(origin.x), + static_cast(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(lparam); + SetWindowLongPtr(window, GWLP_USERDATA, + reinterpret_cast(window_struct->lpCreateParams)); + + auto that = static_cast(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(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( + 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)); + } +} -- cgit v1.2.3