'If double click, expand/collapse the row.'

def _doubleClick(self, widg, event):

    if (event.type == gtk.gdk._2BUTTON_PRESS):
        path = self.get_cursor()[0]
        if path:
            if self.row_expanded(path):
                self.collapse_row(path)
            else:
                self.expand_row(path, False)
