protected void mouseLocationChanged(MouseEvent e) {
try {
if ((e.getModifiersEx() & InputEvent.BUTTON1_DOWN_MASK)
== InputEvent.BUTTON1_DOWN_MASK) {
Coordinate newCoord = toModelCoordinate(e.getPoint());
if (newCoord.distance(lastCoordinate()) < gridSize())
return;
//add(toModelSnapped(e.getPoint()));
add(newCoord);
}