'populate the combo box'

def show(self):

    self._updateson = False
    cbox = self.cbox_lineprops
    for i in range((self._lastcnt - 1), (-1), (-1)):
        cbox.remove_text(i)
    for line in self.lines:
        cbox.append_text(line.get_label())
    cbox.set_active(0)
    self._updateson = True
    self._lastcnt = len(self.lines)
    self.dlg.show()
