1 files changed, 112 insertions, 0 deletions
diff --git a/e-util/e-extensible.c b/e-util/e-extensible.c
new file mode 100644
index 0000000000..9960d31d9f
--- /dev/null
+++ b/e-util/e-extensible.c
@@ -0,0 +1,112 @@
+/*
+ * e-extensible.c
+ *
+ * This program 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 License, or (at your option) version 3.
+ *
+ * This program 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 the program; if not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+#include "e-extensible.h"
+
+#include <e-util/e-util.h>
+#include <e-util/e-extension.h>
+
+static GQuark extensible_quark;
+
+static GPtrArray *
+extensible_get_extensions (EExtensible *extensible)
+{
+	return g_object_get_qdata (G_OBJECT (extensible), extensible_quark);
+}
+
+static void
+extensible_load_extension (GType extension_type,
+                           EExtensible *extensible)
+{
+	EExtensionClass *extension_class;
+	GType extensible_type;
+	GPtrArray *extensions;
+	EExtension *extension;
+
+	extensible_type = G_OBJECT_TYPE (extensible);
+	extension_class = g_type_class_ref (extension_type);
+
+	/* Only load extensions that extend the given extensible object. */
+	if (!g_type_is_a (extensible_type, extension_class->extensible_type))
+		goto exit;
+
+	extension = g_object_new (
+		extension_type, "extensible", extensible, NULL);
+
+	extensions = extensible_get_extensions (extensible);
+	g_ptr_array_add (extensions, extension);
+
+exit:
+	g_type_class_unref (extension_class);
+}
+
+static void
+extensible_interface_init (EExtensibleInterface *interface)
+{
+	extensible_quark = g_quark_from_static_string ("e-extensible-quark");
+}
+
+GType
+e_extensible_get_type (void)
+{
+	static GType type = 0;
+
+	if (G_UNLIKELY (type == 0)) {
+		static const GTypeInfo type_info = {
+			sizeof (EExtensibleInterface),
+			(GBaseInitFunc) NULL,
+			(GBaseFinalizeFunc) NULL,
+			(GClassInitFunc) extensible_interface_init,
+			(GClassFinalizeFunc) NULL,
+			NULL,  /* class_data */
+			0,     /* instance_size */
+			0,     /* n_preallocs */
+			(GInstanceInitFunc) NULL,
+			NULL   /* value_table */
+		};
+
+		type = g_type_register_static (
+			G_TYPE_INTERFACE, "EExtensible", &type_info, 0);
+
+		g_type_interface_add_prerequisite (type, G_TYPE_OBJECT);
+	}
+
+	return type;
+}
+
+void
+e_extensible_load_extensions (EExtensible *extensible)
+{
+	GPtrArray *extensions;
+
+	g_return_if_fail (E_IS_EXTENSIBLE (extensible));
+
+	if (extensible_get_extensions (extensible) != NULL)
+		return;
+
+	extensions = g_ptr_array_new_with_free_func (
+		(GDestroyNotify) g_object_unref);
+
+	g_object_set_qdata_full (
+		G_OBJECT (extensible), extensible_quark,
+		extensions, (GDestroyNotify) g_ptr_array_unref);
+
+	e_type_traverse (
+		E_TYPE_EXTENSION, (ETypeFunc)
+		extensible_load_extension, extensible);
+}