[gtkmm] Fullscreen with gtkmm-1.2

[Maurizio Umberto Puxeddu <umbpux tin it>]

Hello.

My application need to resize its main window to fullscreen and back to
the original size. Going fullscreen works but when I try to get to the
original size the windows hides (or maybe resizes) and then goes
fullscreen again I'm using gtkmm-1.2 and would like to keep this version
until the application is completed. My code is

void MetaControlWindow::fullscreen_changed_cb(bool value) {
  Gdk_Window window = get_window();
  if (value) {
    gint depth;
    window.get_geometry(xpos, ypos, xsize, ysize, depth);
    window.set_decorations(GdkWMDecoration(0));
    window.move_resize(0, 0, gdk_screen_width(), gdk_screen_height());
  } else {
    window.set_decorations(GDK_DECOR_ALL);
    window.move_resize(xpos, ypos, xsize, ysize);
  }
}

Where's the problem: me, gtkmm, gtk or the WM (Gnome's default coming
with RH 8.0)?
The code above appears to be called the right number of times with the
right value of the argument.

I guess Gtk (or Gtkmm) 2 has specific calls for fullscreen, so I guess
there may be some problem but I've not been able to understand where is
the point.

Maurizio Umberto Puxeddu.