[evolution] Make EMailPart and its subclasses extensible.

[Matthew Barnes <mbarnes src gnome org>]

commit bcfd1a92572941ebbcc503bb11461506a05416dc
Author: Matthew Barnes <mbarnes redhat com>
Date:   Sat May 25 15:36:25 2013 -0400

    Make EMailPart and its subclasses extensible.

 em-format/e-mail-part.c |   16 ++++++++++++++--
 1 files changed, 14 insertions(+), 2 deletions(-)
---
diff --git a/em-format/e-mail-part.c b/em-format/e-mail-part.c
index b4ba2b3..c7b0745 100644
--- a/em-format/e-mail-part.c
+++ b/em-format/e-mail-part.c
@@ -58,10 +58,12 @@ enum {
        PROP_PART_LIST
 };
 
-G_DEFINE_TYPE (
+G_DEFINE_TYPE_WITH_CODE (
        EMailPart,
        e_mail_part,
-       G_TYPE_OBJECT)
+       G_TYPE_OBJECT,
+       G_IMPLEMENT_INTERFACE (
+               E_TYPE_EXTENSIBLE, NULL))
 
 static void
 mail_part_validity_pair_free (gpointer ptr)
@@ -228,6 +230,15 @@ mail_part_finalize (GObject *object)
 }
 
 static void
+mail_part_constructed (GObject *object)
+{
+       /* Chain up to parent's constructed() method. */
+       G_OBJECT_CLASS (e_mail_part_parent_class)->constructed (object);
+
+       e_extensible_load_extensions (E_EXTENSIBLE (object));
+}
+
+static void
 e_mail_part_class_init (EMailPartClass *class)
 {
        GObjectClass *object_class;
@@ -239,6 +250,7 @@ e_mail_part_class_init (EMailPartClass *class)
        object_class->get_property = mail_part_get_property;
        object_class->dispose = mail_part_dispose;
        object_class->finalize = mail_part_finalize;
+       object_class->constructed = mail_part_constructed;
 
        g_object_class_install_property (
                object_class,