private void initUI(){
JPanel mainPanel = getIContentPane();
mainPanel.setBackground(Color.WHITE);
mainPanel.setLayout(new BorderLayout());
elementList = new JList(listModel = new DefaultListModel());
elementList.setCellRenderer(new PreferenceListCellRenderer());
JScrollPane scrollPanel = new JScrollPane(elementList);
scrollPanel.setBorder(BorderFactory.createEmptyBorder());
scrollPanel.setPreferredSize(new Dimension(100, scrollPanel.getHeight()));
mainPanel.add(scrollPanel, BorderLayout.WEST);