1 /* GObject - GLib Type, Object, Parameter and Signal Library
2 * Copyright (C) 2006 Imendio AB
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
9 * This library 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 GNU
12 * Lesser General Public License for more details.
14 * You should have received a copy of the GNU Lesser General
15 * Public License along with this library; if not, write to the
16 * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
17 * Boston, MA 02111-1307, USA.
20 #define G_LOG_DOMAIN "TestSingleton"
21 #include <glib-object.h>
24 /* --- MySingleton class --- */
26 GObject parent_instance;
29 GObjectClass parent_class;
32 #define MY_TYPE_SINGLETON (my_singleton_get_type ())
33 #define MY_SINGLETON(o) (G_TYPE_CHECK_INSTANCE_CAST ((o), MY_TYPE_SINGLETON, MySingleton))
34 #define MY_IS_SINGLETON(o) (G_TYPE_CHECK_INSTANCE_TYPE ((o), MY_TYPE_SINGLETON))
35 #define MY_SINGLETON_CLASS(c) (G_TYPE_CHECK_CLASS_CAST ((c), MY_TYPE_SINGLETON, MySingletonClass))
36 #define MY_IS_SINGLETON_CLASS(c) (G_TYPE_CHECK_CLASS_TYPE ((c), MY_TYPE_SINGLETON))
37 #define MY_SINGLETON_GET_CLASS(o) (G_TYPE_INSTANCE_GET_CLASS ((o), MY_TYPE_SINGLETON, MySingletonClass))
39 G_DEFINE_TYPE (MySingleton, my_singleton, G_TYPE_OBJECT);
41 static MySingleton *the_one_and_only = NULL;
45 my_singleton_constructor (GType type,
46 guint n_construct_properties,
47 GObjectConstructParam *construct_properties)
50 return g_object_ref (the_one_and_only);
52 return G_OBJECT_CLASS (my_singleton_parent_class)->constructor (type, n_construct_properties, construct_properties);
56 my_singleton_init (MySingleton *self)
58 g_assert (the_one_and_only == NULL);
59 the_one_and_only = self;
63 my_singleton_class_init (MySingletonClass *klass)
65 G_OBJECT_CLASS (klass)->constructor = my_singleton_constructor;
68 /* --- test program --- */
73 MySingleton *singleton, *obj;
75 /* create the singleton */
76 singleton = g_object_new (MY_TYPE_SINGLETON, NULL);
77 g_assert (singleton != NULL);
78 /* assert _singleton_ creation */
79 obj = g_object_new (MY_TYPE_SINGLETON, NULL);
80 g_assert (singleton == obj);
83 g_object_unref (singleton);