public void actionPerformed(ActionEvent e) {
				if (ModelerUtilities.stopFiring(e))
					return;
				Object o = e.getSource();
				if (o instanceof JToggleButton) {
					// call the force routine once to build the neighbor list for the first time
					refreshForces();
					showChargeLines(((JToggleButton) o).isSelected());
				}
			}