1 /*
2 * Copyright © 2010 Codethink Limited
3 *
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 2.1 of the License, or (at your option) any later version.
8 *
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.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
16 *
17 * Author: Ryan Lortie <desrt@desrt.ca>
18 */
19
20 #include "config.h"
21
22 #include "gsettingsbackendinternal.h"
23 #include "giomodule.h"
24 #include "gsimplepermission.h"
25
26
27 #define G_TYPE_NULL_SETTINGS_BACKEND (g_null_settings_backend_get_type ())
28 #define G_NULL_SETTINGS_BACKEND(inst) (G_TYPE_CHECK_INSTANCE_CAST ((inst), \
29 G_TYPE_NULL_SETTINGS_BACKEND, \
30 GNullSettingsBackend))
31
32
33 typedef GSettingsBackendClass GNullSettingsBackendClass;
34 typedef GSettingsBackend GNullSettingsBackend;
35
36 G_DEFINE_TYPE_WITH_CODE (GNullSettingsBackend,
37 g_null_settings_backend,
38 G_TYPE_SETTINGS_BACKEND,
39 g_io_extension_point_implement (G_SETTINGS_BACKEND_EXTENSION_POINT_NAME,
40 g_define_type_id, "null", 10))
41
42 static GVariant *
g_null_settings_backend_read(GSettingsBackend * backend,const gchar * key,const GVariantType * expected_type,gboolean default_value)43 g_null_settings_backend_read (GSettingsBackend *backend,
44 const gchar *key,
45 const GVariantType *expected_type,
46 gboolean default_value)
47 {
48 return NULL;
49 }
50
51 static gboolean
g_null_settings_backend_write(GSettingsBackend * backend,const gchar * key,GVariant * value,gpointer origin_tag)52 g_null_settings_backend_write (GSettingsBackend *backend,
53 const gchar *key,
54 GVariant *value,
55 gpointer origin_tag)
56 {
57 if (value)
58 g_variant_unref (g_variant_ref_sink (value));
59 return FALSE;
60 }
61
62 static gboolean
g_null_settings_backend_write_one(gpointer key,gpointer value,gpointer data)63 g_null_settings_backend_write_one (gpointer key,
64 gpointer value,
65 gpointer data)
66 {
67 if (value)
68 g_variant_unref (g_variant_ref_sink (value));
69 return FALSE;
70 }
71
72 static gboolean
g_null_settings_backend_write_tree(GSettingsBackend * backend,GTree * tree,gpointer origin_tag)73 g_null_settings_backend_write_tree (GSettingsBackend *backend,
74 GTree *tree,
75 gpointer origin_tag)
76 {
77 g_tree_foreach (tree, g_null_settings_backend_write_one, backend);
78 return FALSE;
79 }
80
81 static void
g_null_settings_backend_reset(GSettingsBackend * backend,const gchar * key,gpointer origin_tag)82 g_null_settings_backend_reset (GSettingsBackend *backend,
83 const gchar *key,
84 gpointer origin_tag)
85 {
86 }
87
88 static gboolean
g_null_settings_backend_get_writable(GSettingsBackend * backend,const gchar * name)89 g_null_settings_backend_get_writable (GSettingsBackend *backend,
90 const gchar *name)
91 {
92 return FALSE;
93 }
94
95 static GPermission *
g_null_settings_backend_get_permission(GSettingsBackend * backend,const gchar * path)96 g_null_settings_backend_get_permission (GSettingsBackend *backend,
97 const gchar *path)
98 {
99 return g_simple_permission_new (FALSE);
100 }
101
102 static void
g_null_settings_backend_init(GNullSettingsBackend * memory)103 g_null_settings_backend_init (GNullSettingsBackend *memory)
104 {
105 }
106
107 static void
g_null_settings_backend_class_init(GNullSettingsBackendClass * class)108 g_null_settings_backend_class_init (GNullSettingsBackendClass *class)
109 {
110 GSettingsBackendClass *backend_class = G_SETTINGS_BACKEND_CLASS (class);
111
112 backend_class->read = g_null_settings_backend_read;
113 backend_class->write = g_null_settings_backend_write;
114 backend_class->write_tree = g_null_settings_backend_write_tree;
115 backend_class->reset = g_null_settings_backend_reset;
116 backend_class->get_writable = g_null_settings_backend_get_writable;
117 backend_class->get_permission = g_null_settings_backend_get_permission;
118 }
119
120 /**
121 * g_null_settings_backend_new:
122 *
123 *
124 * Creates a readonly #GSettingsBackend.
125 *
126 * This backend does not allow changes to settings, so all settings
127 * will always have their default values.
128 *
129 * Returns: (transfer full): a newly created #GSettingsBackend
130 *
131 * Since: 2.28
132 */
133 GSettingsBackend *
g_null_settings_backend_new(void)134 g_null_settings_backend_new (void)
135 {
136 return g_object_new (G_TYPE_NULL_SETTINGS_BACKEND, NULL);
137 }
138