| /* GObject - GLib Type, Object, Parameter and Signal Library |
| * Copyright (C) 2006 Imendio AB |
| * |
| * This library is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * This library is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General |
| * Public License along with this library; if not, see <http://www.gnu.org/licenses/>. |
| */ |
| #undef G_LOG_DOMAIN |
| #define G_LOG_DOMAIN "TestSingleton" |
| #include <glib-object.h> |
| #include <string.h> |
| |
| /* --- MySingleton class --- */ |
| typedef struct { |
| GObject parent_instance; |
| } MySingleton; |
| typedef struct { |
| GObjectClass parent_class; |
| } MySingletonClass; |
| |
| static GType my_singleton_get_type (void); |
| #define MY_TYPE_SINGLETON (my_singleton_get_type ()) |
| #define MY_SINGLETON(o) (G_TYPE_CHECK_INSTANCE_CAST ((o), MY_TYPE_SINGLETON, MySingleton)) |
| #define MY_IS_SINGLETON(o) (G_TYPE_CHECK_INSTANCE_TYPE ((o), MY_TYPE_SINGLETON)) |
| #define MY_SINGLETON_CLASS(c) (G_TYPE_CHECK_CLASS_CAST ((c), MY_TYPE_SINGLETON, MySingletonClass)) |
| #define MY_IS_SINGLETON_CLASS(c) (G_TYPE_CHECK_CLASS_TYPE ((c), MY_TYPE_SINGLETON)) |
| #define MY_SINGLETON_GET_CLASS(o) (G_TYPE_INSTANCE_GET_CLASS ((o), MY_TYPE_SINGLETON, MySingletonClass)) |
| |
| G_DEFINE_TYPE (MySingleton, my_singleton, G_TYPE_OBJECT) |
| |
| static MySingleton *the_one_and_only = NULL; |
| |
| /* --- methods --- */ |
| static GObject* |
| my_singleton_constructor (GType type, |
| guint n_construct_properties, |
| GObjectConstructParam *construct_properties) |
| { |
| if (the_one_and_only) |
| return g_object_ref (G_OBJECT (the_one_and_only)); |
| else |
| return G_OBJECT_CLASS (my_singleton_parent_class)->constructor (type, n_construct_properties, construct_properties); |
| } |
| |
| static void |
| my_singleton_init (MySingleton *self) |
| { |
| g_assert (the_one_and_only == NULL); |
| the_one_and_only = self; |
| } |
| |
| static void |
| my_singleton_class_init (MySingletonClass *klass) |
| { |
| G_OBJECT_CLASS (klass)->constructor = my_singleton_constructor; |
| } |
| |
| /* --- test program --- */ |
| int |
| main (int argc, |
| char *argv[]) |
| { |
| MySingleton *singleton, *obj; |
| |
| /* create the singleton */ |
| singleton = g_object_new (MY_TYPE_SINGLETON, NULL); |
| g_assert (singleton != NULL); |
| /* assert _singleton_ creation */ |
| obj = g_object_new (MY_TYPE_SINGLETON, NULL); |
| g_assert (singleton == obj); |
| g_object_unref (obj); |
| /* shutdown */ |
| g_object_unref (singleton); |
| return 0; |
| } |