single screen, multiple monitor window

[Wesley Smith <wesley hoke gmail com>]

hi,
I'm trying to get a toplevel window to span a screen fully.  The
screen (as reported by GdkScreen) is 3360x1050.  However, this single
screen is across 2 discrete outputs from 1 graphics card and thus
spans 2 physical monitors.  Currently, the GtkWindow will clamp its
size to 1 of the monitors (1680x1050) instead of going across both
even when I set its size to do so.  Is there a way to do this?  I can
get bare X windows to do this, but I'm not sure what the appropriate
Gtk function would be.

thanks,
wes