SDL_WINDOWID implementation for Directfb Backend

Hi all,
I need to play a SDL application inside a GTK application over Directfb.
I checked in sdl/video/x11 that SDL is using “SDL_WINDOWID” environment
variable to draw within the gtk application. But there is no such
implementation in sdl/video/directfb.

Gtk applications over directfb are running fine and it is getting the
window id also. Could you please suggest me, How to use the window id over
directfb.!

Do you have any idea of implementing “SDL_WINDOWID” for Directfb.!?!

Thanks,
Karunakaran A.