protected void configurePopup ( ) { setLayout ( new BoxLayout ( this , BoxLayout . Y_AXIS ) ) ; setBorderPainted ( true ) ; setBorder ( LIST_BORDER ) ; setOpaque ( false ) ; add ( scroller ) ; setDoubleBuffered ( true ) ; setFocusable ( false ) ; }
Configures the popup portion of the combo box . This method is called when the UI class is created .