/src/wrappers/gtk/library/expose_event_callback.e

 1indexing
 2	description: "Callback for the expose-event signal."
 3	copyright: "[
 4					Copyright (C) 2007 eiffel-libraries team,  GTK+ team and others
 5					
 6					This library is free software; you can redistribute it and/or
 7					modify it under the terms of the GNU Lesser General Public License
 8					as published by the Free Software Foundation; either version 2.1 of
 9					the License, or (at your option) any later version.
10					
11					This library is distributed in the hope that it will be useful, but
12					WITHOUT ANY WARRANTY; without even the implied warranty of
13					MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14					Lesser General Public License for more details.
15
16					You should have received a copy of the GNU Lesser General Public
17					License along with this library; if not, write to the Free Software
18					Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
19					02110-1301 USA
20				]"
21	license: "LGPL v2 or later"
22	date: "$Date:$"
23	revision "$Revision:$"
24
25class EXPOSE_EVENT_CALLBACK
26
27inherit CALLBACK redefine object end
28
29insert G_OBJECT_FACTORY [GTK_WIDGET]
30
31creation
32	make
33
34feature
35	object: GTK_WIDGET
36
37feature
38
39	callback (event_expose_ptr: POINTER; instance: POINTER): INTEGER is
40		local
41			expose_event: GDK_EVENT_EXPOSE
42		do
43			check eiffel_created_the_widget: has_eiffel_wrapper_stored (instance) end
44			object := wrapper(instance)
45			create expose_event.from_external_pointer (event_expose_ptr)
46			Result := function.item ([expose_event, object]).to_integer
47			-- GTK is about to release this event, detach it from Eiffel
48			expose_event.dispose
49		end
50
51	callback_pointer: POINTER is
52		do
53			Result := get_callback_pointer ($callback)
54		ensure
55			Result.is_not_null
56		end
57
58	connect (an_object: GTK_WIDGET; a_function: FUNCTION [ANY, TUPLE [GDK_EVENT_EXPOSE, GTK_WIDGET], BOOLEAN]) is
59		do
60			handler_id := g_signal_connect_closure (an_object.handle,
61																 signal_name.to_external,
62																 handle,
63																 0 -- i.e. call it before default handler
64																)
65			function := a_function
66		end
67
68	function: FUNCTION [ANY, TUPLE [GDK_EVENT_EXPOSE, GTK_WIDGET], BOOLEAN]
69
70	signal_name: STRING is "expose-event"
71
72end -- class EXPOSE_EVENT_CALLBACK