/**
* Overrides TPoint setXY method.
*
* @param x the x coordinate
* @param y the y coordinate
*/
public void setXY(double x, double y) {
if (track.isLocked()) return;
super.setXY(x, y);
repaint();
((PointMass) track).updateDerivatives(n);
track.support.firePropertyChange("step", null, new Integer(n)); // $NON-NLS-1$
}
