Re: Glade, Libglade, and using user_data in callbacks

[Tristan Van Berkom <tristan van berkom gmail com>]

On Fri, 14 Jan 2005 16:09:02 -0500, Matthew Yaconis <myaconis nycap rr com> 
[...]
> In the Glade Object box for the toggled event callback I've placed:
> "&GLOBAL_VAR.MY_GBOOLEAN"
>
> What am I missing?  I'm using libglade to load the interface, so I'm not
> sure if that can actually link up the global variable when the callback
> routine is connected to the widget's toggled signal.

The object parameter in glade is the name of the widget in the glade-ui
(the string that you would pass to `glade_xml_get_widget ()' ) 

I've implemented something similar though in glade-3 (which is not really
available yet) which allows you to check "lookup" checkbox and a patched
libglade will g_module_lookup() the user_data string in that case 
(you would still need "&GLOBAL_VAR.MY_GBOOLEAN" to be a valid 
symbol to lookup).

I also do some very black magic in order to use the same generic callback
for every signal's signature (we use this to genericly feed events to a finite
state machine engine):
==========================================
void object_event (GObject *object, ...)
{
    GSignalInvocationHint *ihint;
    GSignalQuery           query;
    fsm_event              event;
    gint                   i;
    va_list                ap;

    if ((ihint = g_signal_get_invocation_hint (object)) != NULL) {
        g_signal_query (ihint->signal_id, &query);  

        va_start (ap, object);
        for (i = 0; i < query.n_params; i++) {
            /* pop stack */
            va_arg (ap, gpointer);
        }
        event = va_arg (ap, fsm_event);
        va_end (ap);

        /* XXX execute filtered event XXX */
        fsm_run (state_machine, object, event);
    }
}
==========================================

It works, but like I said; its not really readily available software :-)

Cheers,
                                                                    -Tristan