/*
 * This tiny class operates the SensorListeners for PrimitiveNav.
 * This is looking for a significant change in light values, which signify that
 * its environment has varied.  It then switches the bool variable in
 * PrimitiveNav that interrupts the loop that keeps the motors running.
 * 
 * **********************
 * Julie Powers-Boyle
 * 20060301, Wed; Programming WS
 * $id
 * **********************
 */
 
 import josx.platform.rcx.*;
 
 public class PrimitiveWatcher implements SensorListener{
 	
 	public void stateChanged(Sensor whichSensor, int lastValue, int newValue) {
        
        if (PrimitiveNav.goingBackward == false){
			if (Math.abs(lastValue - newValue) > 2) { 
				// this will interrupt explore's while loop
				PrimitiveNav.different = true;
			}
		} else if (whichSensor != Sensor.S2) {
			if (Math.abs(lastValue - newValue) > 2) { 
				// this will interrupt explore's while loop
				PrimitiveNav.different = true;
			}
		}
    }
}