code: def scrollbar_toggled(self, settings, key, user_data):
          
          for term in self.guake.notebook_manager.iter_terminals():
              # There is an hbox in each tab of the main notebook and it
              # contains a Terminal and a Scrollbar. Since only have the
              # Terminal here, we're going to use this to get the
              # scrollbar and hide/show it.
              hbox = term.get_parent()
              if hbox is None:
                  continue
              terminal, scrollbar = hbox.get_children()
              if settings.get_boolean(key):
                  scrollbar.show()
              else:
                  scrollbar.hide()
docs: If the gconf var use_scrollbar be changed, this method will
          be called and will show/hide scrollbars of all terminals open.