/src/wrappers/gdk/library/gdk_event.e

  1indexing
  2	description: "union GdkEvent"
  3	copyright: "[
  4					Copyright (C) 2006 eiffel-libraries team, GTK+ team
  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 GDK_EVENT
 26
 27inherit 
 28	C_STRUCT 
 29		redefine from_external_pointer end
 30
 31insert
 32	GDK_EVENT_EXTERNALS
 33	GDK_EVENT_ANY_EXTERNALS
 34		-- The GdkEvent struct contains a union of all of the event
 35		-- structs, and allows access to the data fields in a number of
 36		-- ways.
 37		
 38		-- The event type is always the first field in all of the event
 39		-- structs, and can always be accessed with the following code, no
 40		-- matter what type of event it is:
 41		
 42		--  GdkEvent *event;
 43		--  GdkEventType type;
 44		--  type = event->type;
 45		
 46		-- To access other fields of the event structs, the pointer to
 47		-- the event can be cast to the appropriate event struct pointer,
 48		-- or the union member name can be used. For example if the event
 49		-- type is GDK_BUTTON_PRESS then the x coordinate of the button
 50		-- press can be accessed with:
 51		
 52		--  GdkEvent *event;
 53		--  gdouble x;
 54		--  x = ((GdkEventButton*)event)->x;
 55		--or:
 56		--  GdkEvent *event;
 57		--  gdouble x;
 58		--  x = event->button.x;
 59
 60		--union GdkEvent
 61		--{
 62		--  GdkEventType		    type;
 63		--  GdkEventAny		    any;
 64		--  GdkEventExpose	    expose;
 65		--  GdkEventNoExpose	    no_expose;
 66		--  GdkEventVisibility	    visibility;
 67		--  GdkEventMotion	    motion;
 68		--  GdkEventButton	    button;
 69		--  GdkEventScroll            scroll;
 70		--  GdkEventKey		    key;
 71		--  GdkEventCrossing	    crossing;
 72		--  GdkEventFocus		    focus_change;
 73		--  GdkEventConfigure	    configure;
 74		--  GdkEventProperty	    property;
 75		--  GdkEventSelection	    selection;
 76		--  GdkEventOwnerChange  	    owner_change;
 77		--  GdkEventProximity	    proximity;
 78		--  GdkEventClient	    client;
 79		--  GdkEventDND               dnd;
 80		--  GdkEventWindowState       window_state;
 81		--  GdkEventSetting           setting;
 82		--  GdkEventGrabBroken        grab_broken;
 83		--};
 84
 85creation {WRAPPER_HANDLER} from_external_pointer
 86
 87feature 
 88	from_external_pointer (a_pointer: POINTER) is
 89		do
 90			Precursor(a_pointer)
 91			debug
 92				std_error.put_string("GDK_EVENT.from_external_pointer: creating a generic GDK_EVENT of type "+type.out)
 93				if     is_event_motion then std_error.put_string(" motion ") 
 94				elseif is_event_button then std_error.put_string(" button ") 
 95				elseif is_event_scroll then std_error.put_string(" scroll ") 
 96				elseif is_event_key then std_error.put_string(" key ") 
 97				elseif is_event_focus then std_error.put_string(" focus ") 
 98				elseif is_event_crossing then std_error.put_string(" crossing ") 
 99				elseif is_event_expose then std_error.put_string(" expose ") 
100				end
101				std_error.put_line("from pointer "+a_pointer.out)
102			end
103		end
104feature
105	
106	type, event_type: INTEGER is
107		do
108			Result := gdk_event_type (handle)
109		ensure
110			is_valid_gdk_event_type (Result)
111		end
112	
113	is_event_motion: BOOLEAN is
114		do
115			Result := event_type = gdk_event_motion_notify
116		end
117
118	is_event_button: BOOLEAN is
119		do
120			Result := (event_type = gdk_event_button_press) or else
121						 (event_type = gdk_event_2button_press) or else
122						 (event_type = gdk_event_3button_press) or else
123						 (event_type = gdk_event_button_release)
124		end
125
126	is_event_scroll: BOOLEAN is
127		do
128			Result := event_type = gdk_event_scroll
129		end
130
131	is_event_key: BOOLEAN is
132		do
133			Result := (event_type = gdk_event_key_press) or else
134						 (event_type = gdk_event_key_release)
135		end
136
137	is_event_focus: BOOLEAN is
138		do
139			Result := (event_type = gdk_event_focus_change)
140		end
141
142	is_event_crossing: BOOLEAN is
143		do
144			Result := (event_type = gdk_event_enter_notify) or else
145						 (event_type = gdk_event_leave_notify)
146		end
147
148	is_event_expose: BOOLEAN is
149		do
150			Result := (event_type = gdk_event_expose)
151		end
152
153feature -- Common fields 
154	window: GDK_WINDOW is
155			-- the window which received the event.
156		local
157			 factory: G_OBJECT_EXPANDED_FACTORY[GDK_WINDOW]
158		do
159			if internal_window=Void then
160				internal_window := factory.existant_wrapper (gdk_event_any_get_window (handle))
161			end
162			Result:=internal_window
163		end
164
165	send_event: BOOLEAN is
166			-- 	TRUE if the event was sent explicitly (e.g. using XSendEvent).
167		do
168			Result := gdk_event_any_get_send_event (handle).to_boolean
169		end
170
171feature -- Memory handling
172
173	dispose is
174		do
175			-- TODO: See if this class could be an EIFFEL_OWNED heir.
176
177			-- Note that dispose is public for this class. This is
178			-- because it can be called when knowing that the event will
179			-- no longer be valid (i.e, deallocated by C)
180			if handle.is_not_null then
181				gdk_event_free (handle)
182				handle:= default_pointer
183			end
184		end
185
186	struct_size: INTEGER is
187		external "C inline use <gdk/gdk.h>"
188		alias "sizeof(GdkEvent)"
189		end
190
191	internal_window: GDK_WINDOW
192
193	invariant handle_is_not_null: is_not_null
194end -- class GDK_EVENT