public void setOutlineStroke(Stroke stroke) {
        if (stroke == null) {
            if (this.outlineStroke != null) {
                this.outlineStroke = null;
                fireChangeEvent();
            }
        }
        else {
            if (this.outlineStroke != null) {
                if (this.outlineStroke.equals(stroke)) {
                    return;  // nothing to do
                }
            }
            this.outlineStroke = stroke;
            fireChangeEvent();