2 * Copyright (C) 2009-2010 Andy Spencer <andy753421@gmail.com>
4 * This program is free software: you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation, either version 3 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
19 * SECTION:gis-callback
20 * @short_description: Custom callback objects
22 * #GisCallback objects are used for custom drawing functions. A common example
23 * of this would be to render something which does not easily fit into a normal
24 * object. For instance, a Heads-Up-Display overlay.
26 * Callbacks are an alternate to extending GisObject with a new class and
27 * should be used when only once instance of the object will be needed.
31 #include "gis-callback.h"
35 * @callback: the function to call to draw the object
36 * @user_data: user data to pass to the drawing function
38 * Create a #GisCallback object with an associated function and user data.
40 * Returns: the new #GisCallback
42 GisCallback *gis_callback_new(GisCallbackFunc draw_cb, gpointer user_data)
44 GisCallback *cb = g_object_new(GIS_TYPE_CALLBACK, NULL);
46 cb->user_data = user_data;
50 /* Proxy class methods to per-object methods */
51 static void proxy_draw(GisObject *_cb, GisOpenGL *opengl)
53 GisCallback *cb = GIS_CALLBACK(_cb);
55 cb->draw(cb, opengl, cb->user_data);
59 G_DEFINE_TYPE(GisCallback, gis_callback, GIS_TYPE_OBJECT);
60 static void gis_callback_init(GisCallback *cb)
64 static void gis_callback_class_init(GisCallbackClass *klass)
66 GisObjectClass *object_class = GIS_OBJECT_CLASS(klass);
67 object_class->draw = proxy_draw;