boolean old = contentAreaFilled; contentAreaFilled = b; firePropertyChange(CONTENT_AREA_FILLED_CHANGED_PROPERTY, old, b);
  public void setContentAreaFilled(boolean b)            {    if (contentAreaFilled == b)      return;        boolean old = contentAreaFilled;    contentAreaFilled = b;        firePropertyChange(CONTENT_AREA_FILLED_CHANGED_PROPERTY, old, b);    // The JDK sets the opaque property to the value of the contentAreaFilled    // property, so should we do.    setOpaque(b);            }