:- object(event_registry,
	implements(event_registryp)).


	:- info([
		version is 1.0,
		author is 'Paulo Moura',
		date is 2000/7/24,
		comment is 'Before and after events registry predicates.']).


	monitors(Monitors) :-
		findall(
			Monitor,
			(current_event(before, _, _, _, Monitor),
			 current_event(after, _, _, _, Monitor)),
			List),
		{sort(List, Monitors)}.


	monitored(Objects) :-
		findall(
			Object,
			(current_event(before, Object, _, _, _),
			 current_event(after, Object, _, _, _)),
			List),
		{sort(List, Objects)}.


	monitor(Object, Message, Sender, Monitor) :-
		current_event(before, Object, Message, Sender, Monitor),
		current_event(after, Object, Message, Sender, Monitor).


	set_monitor(Object, Message, Sender, Monitor) :-
		define_events(before, Object, Message, Sender, Monitor),
		define_events(after, Object, Message, Sender, Monitor).


	del_monitors(Object, Message, Sender, Monitor) :-
		abolish_events(before, Object, Message, Sender, Monitor),
		abolish_events(after, Object, Message, Sender, Monitor).


	del_monitors :-
		abolish_events(before, _, _, _, _),
		abolish_events(after, _, _, _, _).


:- end_object.