[glib] add 'null' GSettings backend

[Ryan Lortie <ryanl src gnome org>]

commit 3e36ee34269273df6a8d56fee7e7ee10eb913379
Author: Ryan Lortie <desrt desrt ca>
Date:   Thu Apr 15 18:22:14 2010 -0400

    add 'null' GSettings backend

 gio/Makefile.am            |    2 +
 gio/gnullsettingsbackend.c |  107 ++++++++++++++++++++++++++++++++++++++++++++
 gio/gnullsettingsbackend.h |   30 ++++++++++++
 3 files changed, 139 insertions(+), 0 deletions(-)
---
diff --git a/gio/Makefile.am b/gio/Makefile.am
index e0c2090..2bd0bec 100644
--- a/gio/Makefile.am
+++ b/gio/Makefile.am
@@ -81,6 +81,8 @@ gio-marshal.c: gio-marshal.h gio-marshal.list
 
 settings_sources = \
 	gsettingsbackendinternal.h	\
+	gnullsettingsbackend.h		\
+	gnullsettingsbackend.c		\
 	gsettingsbackend.c
 
 settings_headers = \
diff --git a/gio/gnullsettingsbackend.c b/gio/gnullsettingsbackend.c
new file mode 100644
index 0000000..e09ed9f
--- /dev/null
+++ b/gio/gnullsettingsbackend.c
@@ -0,0 +1,107 @@
+/*
+ * Copyright © 2010 Codethink Limited
+ *
+ * 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 of the licence, 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, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ * Author: Ryan Lortie <desrt desrt ca>
+ */
+
+#include "config.h"
+
+#include "gnullsettingsbackend.h"
+
+#define G_TYPE_NULL_SETTINGS_BACKEND    (g_null_settings_backend_get_type ())
+#define G_NULL_SETTINGS_BACKEND(inst)   (G_TYPE_CHECK_INSTANCE_CAST ((inst), \
+                                         G_TYPE_NULL_SETTINGS_BACKEND,       \
+                                         GNullSettingsBackend))
+
+
+typedef GSettingsBackendClass GNullSettingsBackendClass;
+typedef GSettingsBackend      GNullSettingsBackend;
+
+G_DEFINE_TYPE (GNullSettingsBackend,
+               g_null_settings_backend,
+               G_TYPE_SETTINGS_BACKEND)
+
+static GVariant *
+g_null_settings_backend_read (GSettingsBackend   *backend,
+                              const gchar        *key,
+                              const GVariantType *expected_type)
+{
+  return NULL;
+}
+
+static gboolean
+g_null_settings_backend_write (GSettingsBackend *backend,
+                               const gchar      *key,
+                               GVariant         *value,
+                               gpointer          origin_tag)
+{
+  return FALSE;
+}
+
+static gboolean
+g_null_settings_backend_write_keys (GSettingsBackend *backend,
+                                    GTree            *tree,
+                                    gpointer          origin_tag)
+{
+  return FALSE;
+}
+
+static void
+g_null_settings_backend_reset (GSettingsBackend *backend,
+                               const gchar      *key,
+                               gpointer          origin_tag)
+{
+}
+
+static void
+g_null_settings_backend_reset_path (GSettingsBackend *backend,
+                                    const gchar      *path,
+                                    gpointer          origin_tag)
+{
+}
+
+static gboolean
+g_null_settings_backend_get_writable (GSettingsBackend *backend,
+                                        const gchar      *name)
+{
+  return FALSE;
+}
+
+static void
+g_null_settings_backend_init (GNullSettingsBackend *memory)
+{
+}
+
+static void
+g_null_settings_backend_class_init (GNullSettingsBackendClass *class)
+{
+  GSettingsBackendClass *backend_class = G_SETTINGS_BACKEND_CLASS (class);
+
+  backend_class->read = g_null_settings_backend_read;
+  backend_class->write = g_null_settings_backend_write;
+  backend_class->write_keys = g_null_settings_backend_write_keys;
+  backend_class->reset = g_null_settings_backend_reset;
+  backend_class->reset_path = g_null_settings_backend_reset_path;
+  backend_class->get_writable = g_null_settings_backend_get_writable;
+}
+
+GSettingsBackend *
+g_null_settings_backend_new (void)
+{
+  return g_object_new (G_TYPE_NULL_SETTINGS_BACKEND, NULL);
+}
diff --git a/gio/gnullsettingsbackend.h b/gio/gnullsettingsbackend.h
new file mode 100644
index 0000000..ea07f52
--- /dev/null
+++ b/gio/gnullsettingsbackend.h
@@ -0,0 +1,30 @@
+/*
+ * Copyright © 2010 Codethink Limited
+ *
+ * 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 of the licence, 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, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ * Author: Ryan Lortie <desrt desrt ca>
+ */
+
+#ifndef __G_NULL_SETTINGS_BACKEND_H__
+#define __G_NULL_SETTINGS_BACKEND_H__
+
+#include <gio/gsettingsbackend.h>
+
+G_GNUC_INTERNAL
+GSettingsBackend * g_null_settings_backend_new (void);
+
+#endif /* __G_NULL_SETTINGS_BACKEND_H__ */