Use JTable instead of JList as a drop down list of JComboBox

• download example.jar
• download src.zip
• repository

Code

class DropdownTableComboBox<E extends List<Object>> extends JComboBox<E> {
  protected final transient HighlightListener highlighter = new HighlightListener();
  protected final JTable table = new JTable() {
    @Override public Component prepareRenderer(
          TableCellRenderer renderer, int row, int column) {
      Component c = super.prepareRenderer(renderer, row, column);
      c.setForeground(Color.BLACK);
      if (highlighter.isHighlightableRow(row)) {
        c.setBackground(new Color(255, 200, 200));
      } else if (isRowSelected(row)) {
        c.setBackground(Color.CYAN);
      } else {
        c.setBackground(Color.WHITE);
      }
      return c;
    }
    @Override public void updateUI() {
      removeMouseListener(highlighter);
      removeMouseMotionListener(highlighter);
      super.updateUI();
      addMouseListener(highlighter);
      addMouseMotionListener(highlighter);
      getTableHeader().setReorderingAllowed(false);
    }
  };
  protected final List<E> list;

  protected DropdownTableComboBox(List<E> list, DefaultTableModel model) {
    super();
    this.list = list;
    table.setModel(model);
    list.forEach(this::addItem);
    // list.forEach(model::addRow);
    list.forEach(v -> model.addRow(v.toArray(new Object[0])));
  }

  @Override public void updateUI() {
    super.updateUI();
    EventQueue.invokeLater(() -> {
      setUI(new MetalComboBoxUI() {
        @Override protected ComboPopup createPopup() {
          return new ComboTablePopup(comboBox, table);
        }
      });
      setEditable(false);
    });
  }
  public List<Object> getSelectedRow() {
    return list.get(getSelectedIndex());
  }
}

References

• Use JTable instead of JList as a drop down list of JComboBox(Japanese)