/src/wrappers/gtk/library/button_event_callback.e

 1indexing
 2	description: "Generic callback for the button-release-event and button-pressed-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
25deferred class BUTTON_EVENT_CALLBACK
26	-- You want to use one of BUTTON_EVENT_RELEASE_CALLBACK or BUTTON_EVENT_PRESS_CALLBACK
27
28inherit CALLBACK redefine object end
29
30insert G_OBJECT_FACTORY [GTK_WIDGET]
31
32feature
33	object: GTK_WIDGET
34
35feature
36
37	callback (event_button_ptr: POINTER; instance: POINTER): INTEGER is
38		local
39			button_event: GDK_EVENT_BUTTON
40		do
41			debug print ("Callback: instance=") print (instance.to_string) print ("%N") end
42			-- The following is written with the implicit requirement 
43			-- that object actually has an Eiffel wrapper
44			object := wrapper(instance)
45			create button_event.from_external_pointer (event_button_ptr)
46			Result := function.item ([button_event, object]).to_integer
47			-- GTK is about to release this event, detach it from Eiffel
48			button_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_BUTTON, 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_BUTTON, GTK_WIDGET], BOOLEAN]
69
70end -- class BUTTON_EVENT_CALLBACK