protected void notifyPotentiometerListeners(double previous) {
for (int i = 0; i < potentiometerListeners.size(); i++) {
((PotentiometerListener)
potentiometerListeners.elementAt(i)).didReceivePosition(
new PotentiometerEvent(
this,
PotentiometerEvent.DEFAULT,
getState("Value"), previous
));
}