Show or hide each TableColumn added to the JTableHeader

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

Code

class TableHeaderPopupMenu extends JPopupMenu {
  protected TableHeaderPopupMenu(JTable table) {
    super();
    TableColumnModel columnModel = table.getColumnModel();
    List>TableColumn> list = Collections.list(columnModel.getColumns());
    list.forEach(tableColumn -> {
      String name = Objects.toString(tableColumn.getHeaderValue());
      // System.out.format("%s - %s%n", name, tableColumn.getIdentifier());
      JCheckBoxMenuItem item = new JCheckBoxMenuItem(name, true);
      item.addItemListener(e -> {
        if (((AbstractButton) e.getItemSelectable()).isSelected()) {
          columnModel.addColumn(tableColumn);
        } else {
          columnModel.removeColumn(tableColumn);
        }
        updateMenuItems(columnModel);
      });
      add(item);
    });
  }

  @Override public void show(Component c, int x, int y) {
    if (c instanceof JTableHeader) {
      JTableHeader header = (JTableHeader) c;
      JTable table = header.getTable();
      header.setDraggedColumn(null);
      header.repaint();
      table.repaint();
      updateMenuItems(header.getColumnModel());
      super.show(c, x, y);
    }
  }

  private void updateMenuItems(TableColumnModel columnModel) {
    boolean isOnlyOneMenu = columnModel.getColumnCount() == 1;
    if (isOnlyOneMenu) {
      stream(this).map(MenuElement::getComponent).forEach(mi ->
          mi.setEnabled(!(mi instanceof AbstractButton)
                        || !((AbstractButton) mi).isSelected()));
    } else {
      stream(this).forEach(me -> me.getComponent().setEnabled(true));
    }
  }

  private static Stream>MenuElement> stream(MenuElement me) {
    return Stream.of(me.getSubElements())
      .flatMap(m -> Stream.concat(Stream.of(m), stream(m)));
  }
}

Explanation

• Initially shows all TableColumns generated from a TableModel
• All JCheckBoxMenuItems are also selected
• TableColumn hidden with TableColumnModel#removeColumn(TableColumn) method when deselected with JCheckBoxMenuItem
• The column is removed from TableColumnModel and hidden from JTableHeader, but the column remains in TableModel
• Check the number of TableColumn columns to enable/disable the JCheckBoxMenuItem, e.g. when opening a JPopupMenu, so that all TableColumns are not hidden
• Show TableColumn with TableColumnModel#addColumn(TableColumn) method when selected and set with JCheckBoxMenuItem
• Columns are added to TableColumnModel and appear in JTableHeader, but TableModel is unchanged from its initial state

---

• UIManager.put("CheckBoxMenuItem.doNotCloseOnMouseClick", true) in Java 9 or higher; If set to and the currently selected TableColumn is hidden with JCheckBoxMenuItem while JPopupMenu is open, an ArrayIndexOutOfBoundsException will occur
• Add PopupMenuListener to JPopupMenu or override the JPopupMenu#show(...) method to JTableHeader.setDraggedColumn(null) can be avoided by clearing the selection state in the scene view

References

• Show or hide each TableColumn added to the JTableHeader(Japanese)
• Table Column Manager « Java Tips Weblog

Save and load the state of a JTable and TableColumn(name, width, position and sortKey)

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

Code

class DefaultTableModelPersistenceDelegate extends DefaultPersistenceDelegate {
  @Override protected void initialize(
        Class<?> type, Object oldInstance, Object newInstance, Encoder encoder) {
    super.initialize(type, oldInstance,  newInstance, encoder);
    DefaultTableModel m = (DefaultTableModel) oldInstance;
    for (int row = 0; row < m.getRowCount(); row++) {
      for (int col = 0; col < m.getColumnCount(); col++) {
        Object[] o = new Object[] {m.getValueAt(row, col), row, col};
        encoder.writeStatement(new Statement(oldInstance, "setValueAt", o));
      }
    }
  }
}

File file = File.createTempFile("output", ".xml");
try (XMLEncoder xe = new XMLEncoder(new BufferedOutputStream(new FileOutputStream(file)))) {
  xe.setPersistenceDelegate(
    RowSorter.SortKey.class,
    new DefaultPersistenceDelegate(new String[] {"column", "sortOrder"}));
  xe.writeObject(table.getRowSorter().getSortKeys());
//...

class TableColumnModelPersistenceDelegate extends DefaultPersistenceDelegate {
  @Override protected void initialize(
      Class<?> type, Object oldInstance, Object newInstance, Encoder encoder) {
    super.initialize(type, oldInstance, newInstance, encoder);
    DefaultTableColumnModel m = (DefaultTableColumnModel) oldInstance;
    for (int col = 0; col < m.getColumnCount(); col++) {
      Object[] o = {m.getColumn(col)};
      encoder.writeStatement(new Statement(oldInstance, "addColumn", o));
    }
  }
}

References

• Save and load the state of a JTable and TableColumn(name, width, position and sortKey)(Japanese)