/src/wrappers/gtk/library/scroll_event_callback.e

 1indexing
 2	description: "Generic callback for the scroll-event signals"
 3	copyright: "[
 4					Copyright (C) 2006 Paolo redaelli, 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 SCROLL_EVENT_CALLBACK
26
27inherit CALLBACK redefine object end
28
29insert G_OBJECT_FACTORY [GTK_WIDGET]
30
31create
32	make
33
34feature
35	object: GTK_WIDGET
36
37feature
38
39	callback (scroll_event_ptr: POINTER; instance: POINTER): INTEGER is
40		local
41			scroll_event: GDK_EVENT_SCROLL
42		do
43			debug print ("Callback: instance=") print (instance.to_string) print ("%N") end
44			object := wrapper(instance)
45			create scroll_event.from_external_pointer(scroll_event_ptr)
46			
47			Result := function.item ([scroll_event, object]).to_integer
48			-- GTK is about to release this event, detach it from Eiffel
49			scroll_event.dispose
50		end
51
52	callback_pointer: POINTER is
53		do
54			Result := get_callback_pointer ($callback)
55		ensure
56			Result.is_not_null
57		end
58
59	connect (an_object: GTK_WIDGET; a_function: FUNCTION [ANY, TUPLE [GDK_EVENT_SCROLL, GTK_WIDGET], BOOLEAN]) is
60		do
61			handler_id := g_signal_connect_closure (an_object.handle,
62																 signal_name.to_external,
63																 handle,
64																 0 -- i.e. call it before default handler
65																)
66			function := a_function
67		end
68
69	function: FUNCTION [ANY, TUPLE [GDK_EVENT_SCROLL, GTK_WIDGET], BOOLEAN]
70
71	signal_name: STRING is "scroll-event"
72
73end -- class SCROLL_EVENT_CALLBACK