public void translateSelectedPoint (double deltaX, double deltaY)
{
if (getModifyPoint() == null)
return;
WhiteboardPoint point;
for (int i = 0; i < points.size (); i++)
{
point = points.get (i);
if(getModifyPoint().equals(point))
{
WhiteboardPoint newPoint
= new WhiteboardPoint (
point.getX () + deltaX, point.getY () + deltaY);
points.set (i, newPoint);
this.setModifyPoint(newPoint);