Flutter Windows Desktop - Client Area Adjustment :: by Simon Lightfoot - 25th September 2024 :: https://www.youtube.com/watch?v=QiLPSsD9kRc

win32_window.cpp

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;

  RECT windowRect = {
      0,
      0,
      static_cast<LONG>(size.width),
      static_cast<LONG>(size.height),
  };

  AdjustWindowRectEx(&windowRect, WS_OVERLAPPEDWINDOW, FALSE, WS_EX_APPWINDOW);

  HWND window = CreateWindowEx(
      WS_EX_APPWINDOW,
      window_class,
      title.c_str(),
      WS_OVERLAPPEDWINDOW,
      Scale(origin.x, scale_factor),
      Scale(origin.y, scale_factor),
      Scale((windowRect.right - windowRect.left), scale_factor),
      Scale((windowRect.bottom - windowRect.top), scale_factor),
      nullptr,
      nullptr,
      GetModuleHandle(nullptr),
      this
  );

  if (!window) {
    return false;
  }

  UpdateTheme(window);

  return OnCreate();
}