@Override public void handleMousePressed(ChartCanvas canvas,MouseEvent e){
  this.mousePressedPoint=new Point2D.Double(e.getX(),e.getY());
}

@ Override public void handleMousePressed ( ChartCanvas canvas , MouseEvent e ) { this . mousePressedPoint = new Point2D . Double ( e . getX ( ) , e . getY ( ) ) ; }
handles a mouse pressed event by recording the location of the mouse pointer ( so that later we can check that the click isn ' t part of a drag ) .
