setLayout(new GridBagLayout());
setBorder(BorderFactory.createEmptyBorder(0, 0, 0, 5));
categoryComboBox = new JComboBox();
categoryComboBox.addActionListener(new CategorySelectionAction());
categoryComboBox.setRenderer(new FunctionCategoryCellRenderer());
formulaList = new JList();
formulaList.setCellRenderer(new FunctionDescriptionCellRenderer());
formulaList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
formulaList.addMouseListener(new FormulaListMouseHandler());