1  /* GObject - GLib Type, Object, Parameter and Signal Library
       2   * Copyright (C) 2006 Imendio AB
       3   *
       4   * SPDX-License-Identifier: LGPL-2.1-or-later
       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
       8   * License as published by the Free Software Foundation; either
       9   * version 2.1 of the License, or (at your option) any later version.
      10   *
      11   * This library is distributed in the hope that it will be useful,
      12   * but 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
      17   * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
      18   */
      19  
      20  #include <glib-object.h>
      21  
      22  /* --- MySingleton class --- */
      23  
      24  struct _MySingleton {
      25    GObject parent_instance;
      26    int myint;
      27  };
      28  
      29  #define MY_TYPE_SINGLETON my_singleton_get_type ()
      30  G_DECLARE_FINAL_TYPE (MySingleton, my_singleton, MY, SINGLETON, GObject)
      31  G_DEFINE_FINAL_TYPE (MySingleton, my_singleton, G_TYPE_OBJECT)
      32  
      33  static MySingleton *the_one_and_only = NULL;
      34  
      35  /* --- methods --- */
      36  static GObject*
      37  my_singleton_constructor (GType                  type,
      38                            guint                  n_construct_properties,
      39                            GObjectConstructParam *construct_properties)
      40  {
      41    if (the_one_and_only)
      42      return g_object_ref (G_OBJECT (the_one_and_only));
      43    else
      44      return G_OBJECT_CLASS (my_singleton_parent_class)->constructor (type, n_construct_properties, construct_properties);
      45  }
      46  
      47  static void
      48  my_singleton_finalize (GObject *object)
      49  {
      50    g_assert ((GObject *) the_one_and_only == object);
      51    the_one_and_only = NULL;
      52  
      53    G_OBJECT_CLASS (my_singleton_parent_class)->finalize (object);
      54  }
      55  
      56  static void
      57  my_singleton_init (MySingleton *self)
      58  {
      59    g_assert_null (the_one_and_only);
      60    the_one_and_only = self;
      61  }
      62  
      63  static void
      64  my_singleton_set_property (GObject      *gobject,
      65                             guint         prop_id,
      66                             const GValue *value,
      67                             GParamSpec   *pspec)
      68  {
      69    MySingleton *self = (MySingleton *) gobject;
      70  
      71    g_assert (prop_id == 1);
      72  
      73    self->myint = g_value_get_int (value);
      74  }
      75  
      76  static void
      77  my_singleton_get_property (GObject    *gobject,
      78                             guint       prop_id,
      79                             GValue     *value,
      80                             GParamSpec *pspec)
      81  {
      82    MySingleton *self = (MySingleton *) gobject;
      83  
      84    g_assert (prop_id == 1);
      85  
      86    g_value_set_int (value, self->myint);
      87  }
      88  
      89  static void
      90  my_singleton_class_init (MySingletonClass *klass)
      91  {
      92    GObjectClass *object_class = G_OBJECT_CLASS (klass);
      93  
      94    object_class->constructor = my_singleton_constructor;
      95    object_class->finalize = my_singleton_finalize;
      96    object_class->set_property = my_singleton_set_property;
      97    object_class->get_property = my_singleton_get_property;
      98  
      99    g_object_class_install_property (G_OBJECT_CLASS (klass), 1,
     100                                     g_param_spec_int ("foo", NULL, NULL,
     101                                                       0, G_MAXINT, 0,
     102                                                       G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_STATIC_STRINGS));
     103  }
     104  
     105  static void
     106  test_singleton_construction (void)
     107  {
     108    MySingleton *singleton, *obj;
     109  
     110    /* create the singleton */
     111    singleton = g_object_new (MY_TYPE_SINGLETON, NULL);
     112    g_assert_nonnull (singleton);
     113  
     114    /* assert _singleton_ creation */
     115    obj = g_object_new (MY_TYPE_SINGLETON, NULL);
     116    g_assert_true (singleton == obj);
     117    g_object_unref (obj);
     118  
     119    /* shutdown */
     120    g_object_unref (singleton);
     121  }
     122  
     123  static void
     124  test_singleton_construct_property (void)
     125  {
     126    MySingleton *singleton;
     127  
     128    g_test_summary ("Test that creating a singleton with a construct-time property works");
     129    g_test_bug ("https://gitlab.gnome.org/GNOME/glib/-/issues/2666");
     130  
     131    /* create the singleton and set a property at construction time */
     132    singleton = g_object_new (MY_TYPE_SINGLETON, "foo", 1, NULL);
     133    g_assert_nonnull (singleton);
     134  
     135    /* shutdown */
     136    g_object_unref (singleton);
     137  }
     138  
     139  int
     140  main (int   argc,
     141        char *argv[])
     142  {
     143    g_test_init (&argc, &argv, NULL);
     144  
     145    g_test_add_func ("/gobject/singleton/construction", test_singleton_construction);
     146    g_test_add_func ("/gobject/singleton/construct-property", test_singleton_construct_property);
     147  
     148    return g_test_run ();
     149  }