this.x = x;
        this.y = y;
        this.x1 = x1;
        this.y1 = y1;

        line.setStartX(x);
        line.setStartY(y);
        line.setEndX(x1);
        line.setEndY(y1);
        line.getStrokeDashArray().addAll(4d, 8d);


        double sx = line.getStartX();
        double sy = line.getStartY();
        double ex = line.getEndX();
        double ey = line.getEndY();

        arrow1.setEndX(ex);
        arrow1.setEndY(ey);
        arrow2.setEndX(ex);
        arrow2.setEndY(ey);

        double factor = arrowLength / Math.hypot(sx-ex, sy-ey);
        double factorO = arrowWidth / Math.hypot(sx-ex, sy-ey);

        // part in direction of main line
        double dx = (sx - ex) * factor;
        double dy = (sy - ey) * factor;

        // part ortogonal to main line
        double ox = (sx - ex) * factorO;
        double oy = (sy - ey) * factorO;





            arrow1.setStartX(ex + dx - oy);
            arrow1.setStartY(ey + dy + ox);
            arrow2.setStartX(ex + dx + oy);
            arrow2.setStartY(ey + dy - ox);

            setColor();



        this.getChildren().addAll(arrow1,arrow2, line);