/src/wrappers/gtk/library/motion_notify_event_callback.e

 1indexing
 2	description: "Generic callback for the motion-notify-event signal"
 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 MOTION_NOTIFY_EVENT_CALLBACK
26
27inherit CALLBACK redefine object end
28
29insert G_OBJECT_FACTORY [GTK_WIDGET]
30
31creation make
32
33feature
34	object: GTK_WIDGET
35
36feature
37	callback (motion_event_ptr: POINTER; instance: POINTER): INTEGER is
38		local
39			motion_event: GDK_EVENT_MOTION
40		do
41			debug
42				print ("Callback: instance=") print (instance.to_string) print ("%N")
43			end
44			-- The following is written with the implicit requirement 
45			-- that the object is actually created by the Eiffel 
46			object := wrapper(instance)
47			create motion_event.from_external_pointer (motion_event_ptr)
48			Result := function.item ([motion_event, object]).to_integer
49			-- GTK is about to release this event, detach it from Eiffel
50			motion_event.dispose
51		end
52
53	callback_pointer: POINTER is
54		do
55			Result := get_callback_pointer ($callback)
56		ensure
57			Result.is_not_null
58		end
59
60	connect (an_object: GTK_WIDGET; a_function: FUNCTION [ANY, TUPLE [GDK_EVENT_MOTION, GTK_WIDGET], BOOLEAN]) is
61		do
62			debug
63				print ("MOTION_NOTIFY_EVENT_CALLBACK.connect (an_object=") print (an_object.to_pointer.to_string)
64				print (" an_object.handle=") print (an_object.handle.to_string)
65				print (") Current=") print (to_pointer.to_string)
66				print (" Current.handle=") print (handle.to_string)
67				print ("%N")
68			end
69			
70			handler_id := g_signal_connect_closure (an_object.handle,
71																 signal_name.to_external,
72																 handle,
73																 0 -- i.e. call it before default handler
74																)
75			function:=a_function
76		end
77
78		signal_name: STRING is "motion-notify-event"
79
80	function: FUNCTION [ANY, TUPLE [GDK_EVENT_MOTION, GTK_WIDGET], BOOLEAN]
81
82end