bonobo-event-source
An Event Source where clients can connect to listen to events.
An event source object is responsible for channeling the emission
of signals on an object to the appropriate attached listeners.
The API is extremely simple and allows implementations to notify
their listeners of a new event occuring.
To notify a listener, you need to construct a textual string,
this is done by the bonobo_event functions
( see #BonoboListener ) ':' delimiting the fields. It is reccommended
that the IDL module path of the interface be used as the first
part of the string. This is because many interfaces can be aggregated
together and need to share the same event namespace without conflicts.
So for example the bonobo property bag notification code
uses the IDL path "Bonobo/Property" the "change" kind and sets the
sub-type to the property name:
An example event source notification
static void
notify_listeners (BonoboPropertyBag *pb,
BonoboProperty *prop,
const BonoboArg *new_value,
CORBA_Environment *opt_ev)
{
if (prop->flags & BONOBO_PROPERTY_NO_LISTENING)
return;
bonobo_event_source_notify_listeners_full (pb->es,
"Bonobo/Property",
"change", prop->name,
new_value, opt_ev);
}
Of course, you need to notify the listener with a valid
BonoboArg containing the event data, this could easily contain
a structure. eg.
Passing a structure in an event
module GNOME {
module Foo {
struct BaaEvent {
double a;
string b;
long c;
};
};
};
static void
fire_event (BonoboEventSource *on_source,
double a_double,
char *a_string,
long a_float,
CORBA_Environment *opt_ev)
{
CORBA_any any;
GNOME_Foo_BaaEvent e;
e.a = a_double;
e.b = a_string;
e.c = a_float;
any->_type = TC_GNOME_Foo_BaaEvent;
any->_data = &e;
bonobo_event_source_notify_listeners_full (
on_source, "GNOME/Foo", "event", NULL,
&any, opt_ev);
}
NB. it is reccommended that you make it clear that the event
structure is intended for use with the #BonoboEventSource /
#BonoboListener by naming it XYZEvent, ie. with the 'Event'
suffix.
#BonoboListener #BonoboArg
@Returns:
@event_source:
@event_name:
@opt_value:
@opt_ev:
@event_source:
@path:
@type:
@subtype:
@opt_value:
@opt_ev:
@object:
@listener:
@opt_ev:
@object:
@event_callback:
@opt_mask:
@opt_ev:
@user_data:
@event_source:
@event_name:
@Returns:
@object:
@callback:
@opt_mask:
@opt_ev:
@object:
@callback:
@opt_mask:
@opt_ev:
@Returns:
@event_source: