void gdk_window_move ( GdkWindow* window, gint x, gint y )
Repositions a window relative to its parent window.
For toplevel windows, window managers may ignore or modify the move;
you should probably use
gtk_window_move() on a
anyway, instead of using GDK functions. For child windows,
the move will reliably succeed.
If you’re also planning to resize the window, use
to both move and resize simultaneously, for a nicer visual effect.