JPanel center_panel = new JPanel();
center_panel.setLayout( new BoxLayout( center_panel,
BoxLayout.Y_AXIS ) );
/* The Time Ruler */
time_ruler = new RulerTime( time_model );
time_ruler_vport = new ViewportTime( time_model );
time_ruler_vport.setView( time_ruler );
time_ruler_panel = new ViewportTimePanel( time_ruler_vport );
if ( Parameters.HISTOGRAM_ZERO_ORIGIN )
time_ruler_panel.setBorderTitle( " Duration (seconds) ",