use G_DEFINE_TYPE_WITH_PRIVATE to replace g_type_class_add_private

gnc_tree_model_owner_get_type is being replaced by
that provided by G_DEFINE_TYPE_WITH_PRIVATE and G_ADD_PRIVATE.
Replace g_type_add_interface_static by G_IMPLEMENT_INTERFACE.

gnucash/gnome-utils/gnc-tree-model-commodity.c

@@ -106,44 +106,10 @@ typedef struct GncTreeModelCommodityPrivate
 /** A pointer to the parent class of a commodity tree model. */
 static GObjectClass *parent_class = NULL;
 
-GType
-gnc_tree_model_commodity_get_type (void)
-{
-    static GType gnc_tree_model_commodity_type = 0;
-
-    if (gnc_tree_model_commodity_type == 0)
-    {
-        static const GTypeInfo our_info =
-        {
-            sizeof (GncTreeModelCommodityClass),
-            NULL,
-            NULL,
-            (GClassInitFunc) gnc_tree_model_commodity_class_init,
-            NULL,
-            NULL,
-            sizeof (GncTreeModelCommodity),
-            0,
-            (GInstanceInitFunc) gnc_tree_model_commodity_init
-        };
-
-        static const GInterfaceInfo tree_model_info =
-        {
-            (GInterfaceInitFunc) gnc_tree_model_commodity_tree_model_init,
-            NULL,
-            NULL
-        };
-
-        gnc_tree_model_commodity_type = g_type_register_static (GNC_TYPE_TREE_MODEL,
-                                        GNC_TREE_MODEL_COMMODITY_NAME,
-                                        &our_info, 0);
-
-        g_type_add_interface_static (gnc_tree_model_commodity_type,
-                                     GTK_TYPE_TREE_MODEL,
-                                     &tree_model_info);
-    }
-
-    return gnc_tree_model_commodity_type;
-}
+G_DEFINE_TYPE_WITH_CODE(GncTreeModelCommodity, gnc_tree_model_commodity, GNC_TYPE_TREE_MODEL,
+                        G_ADD_PRIVATE(GncTreeModelCommodity)
+                        G_IMPLEMENT_INTERFACE(GTK_TYPE_TREE_MODEL,
+                                              gnc_tree_model_commodity_tree_model_init))
 
 static void
 gnc_tree_model_commodity_class_init (GncTreeModelCommodityClass *klass)
@@ -154,8 +120,6 @@ gnc_tree_model_commodity_class_init (GncTreeModelCommodityClass *klass)
 
     o_class->finalize = gnc_tree_model_commodity_finalize;
     o_class->dispose = gnc_tree_model_commodity_dispose;
-
-    g_type_class_add_private(klass, sizeof(GncTreeModelCommodityPrivate));
 }
 
 static void