Modify cell editor for different rows in a JTable

Question

I have a JTable with the following columns:

rowNumber | Element | Quantity

And a JButton that adds rows every time it's clicked. The column Element has a custom JComboBox cell editor that gets filled with elements from a database. However i need to do the following:

Suppose i have these elements in the JComboBox of the first row in my table: Element1 Element2 Element3

I select Element2 from the JComboBox in the first row and then I proceed to add another row. This new row must not show Element2 any more in its JComboBox . And the previous (first) row must not show the Element selected in the second row and so on.

Answer 1

Create a custom CustomCellEditor like this.

final JComboBox<String> comboBox = new JComboBox<String>();
table.getColumnModel().getColumn(1).setCellEditor(new CustomCellEditor(comboBox){
    @Override
    public Component getTableCellEditorComponent(JTable table, Object value, boolean isSelected, int row, int column) {
         DefaultComboBoxModel<String> model = (DefaultComboBoxModel<String>) comboBox.getModel();
         model.removeAllElements();
         {//Add what you need according the row.
             model.addElement("X");
             model.addElement("Y");
             model.addElement("Z");
         }
         return super.getTableCellEditorComponent(table, value, isSelected, row, column);
   }
});

Answer 2

I think it may help to know the expected cardinality of the Set<Element> . Accordingly, @mKorbel raises the important question of scalability, citing this related discussion . In that case, the question proposes a List<DefaultCellEditor> , when a much simpler renderer will do.

Here, a CellEditor can manage a List<DefaultComboBoxModel<Element>> , selecting the correct combo model for the row currently being edited and invoking setModel() on the editor component. As each new table row is added, the editor would add a new element to the List and adjust existing elements as required. I would expect the complexity to grow as O(n ² ) , where n is the cardinality of the Set .