def activate(self, event):
        """Change the value."""
        self._index += 1
        if self._index >= len(self._values):
            self._index = 0

        self._selection = self._values[self._index]
        self.ao2.speak(self._selection)
def activate ( self , event ) : self . _index += 1 if self . _index >= len ( self . _values ) : self . _index = 0 self . _selection = self . _values [ self . _index ] self . ao2 . speak ( self . _selection )
Change the value.