/*
 * This tiny class operates the SensorListeners for MazeNav.
 * This is looking for a significant change in light values, which signify that
 * it has come to something interesting navigationally.  It should then throw an
 * exception to MazeNav.explore(), but maybe it wonÕt.
 * 
 * **********************
 * Julie Powers-Boyle
 * 20060228, Tues; Programming WS
 * $id
 * **********************
 */
 
 import josx.platform.rcx.*;
 
 public class LightWatcher implements SensorListener{
 	
 	public void stateChanged(Sensor whichSensor, int lastValue, int newValue) {
        
        if (Math.abs(lastValue - newValue) > 2) { //this sig value prototypical
        	// this will interrupt exploreÕs while loop
			MazeNav.chrono.stop();
			MazeNav.different = true;
        }
    }
}