def _prev_index(self, s):
        self.set_index(max(0, self.index - 1))
def __init__(self, backendsdialog):
        """
        Constructor, just initializes the gtk widgets

        @param backends: a reference to the dialog in which this is
        loaded
        """
        super().__init__()
        self.dialog = backendsdialog
        self.req = backendsdialog.get_requester()
        self._init_liststore()
        self._init_renderers()
        self._init_signals()
        self.refresh()