#if defined(GDK_WINDOWING_X11)
	#include <gdk/gdkx.h>
	#define GDK_NATIVE_WINDOW(wnd) GDK_WINDOW_XID((wnd))
#elif defined(GDK_WINDOWING_WIN32)
	#include <gdk/gdkwin32.h>
	#define GDK_NATIVE_WINDOW(wnd) GDK_WINDOW_HWND((wnd))
#else
	#define GDK_NATIVE_WINDOW(wnd) (wnd)
#endif /* kind of windowing system */