Trying to make the window title string configurable, but having issues

with ConfigOpt trying to save it back.

mitterlib/ui/ui_pygtk.py

@@ -418,12 +418,14 @@ class Interface(object):
         self._main_tabs.set_tab_label_text(child, message)
 
         replies = self._main_tabs.get_nth_page(1)
-        messages_title = ('%d ' + 
-                N_('message', 'messages', data)) % (data)
-        replies_title = ('%d ' + 
-                N_('reply', 'replies', replies.count)) % (replies.count)
-
-        title = 'Mitter (%s, %s)' % (messages_title, replies_title)
+        title_info = {
+                'message_count': data,
+                'message': N_('message', 'messages', data),
+                'replies_count': replies.count,
+                'replies': N_('reply', 'replies', replies.count)
+                }
+
+        title = self._options[self.NAMESPACE]['window_title'] % (title_info)
         self._main_window.set_title(title)
 
         if (data + replies.count) > 0:
@@ -441,12 +443,14 @@ class Interface(object):
         self._main_tabs.set_tab_label_text(child, message)
 
         messages = self._main_tabs.get_nth_page(0)
-        messages_title = ('%d ' + 
-                N_('message', 'messages', messages.count)) % (messages.count)
-        replies_title = ('%d ' + 
-                N_('reply', 'replies', data)) % (data)
-
-        title = 'Mitter (%s, %s)' % (messages_title, replies_title)
+        title_info = {
+                'message_count': messages.count,
+                'message': N_('message', 'messages', messages.count),
+                'replies_count': data,
+                'replies': N_('reply', 'replies', data)
+                }
+
+        title = self._options[self.NAMESPACE]['window_title'] % (title_info)
         self._main_window.set_title(title)
         if (data + messages.count) > 0:
             self._statusicon.set_from_pixbuf(self._images['new-messages'])
@@ -1102,3 +1106,18 @@ class Interface(object):
                 metavar='CHAR',
                 default=_('<small>(protected)</small>'),
                 is_cmd_option=False)
+        options.add_option(
+                group=self.NAMESPACE,
+                option='window_title',
+                help='Format string to be used in the title, following ' \
+                        "Python's string formatting rules. Mitter will " \
+                        'pass a dictionary with:\n' \
+                        '"message_count": the number of unread messages,\n' \
+                        '"message": the translatable word for ' \
+                        '"message(s)",\n' \
+                        '"replies_count": the number of unread replies,\n' \
+                        '"replies": the translatable word for "replies"',
+                metavar='STRING',
+                default='Mitter (%(message_count)d %(message)s, ' \
+                        '%(replies_count)d %(replies)s)',
+                is_cmd_option=False)