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Hi, all
I created a class "JoeTable" that extends JTable. It has 3 columns the first 2 columns use JComboBox editor. I meant for JoeTable to behave like this:
When the user clicks on one of the cells in the first 2 columns and change the value of the cell by using JComboBox, the TableModelListener added to JoeTable's TableModel will clear the 3rd cell out. My code went as below:
joeTableModel.addTableModelListener(new TableModelListener(){
public void tableChanged(TableModelEvent e)
if (getSelectedRow() == -1 || getSelectedColumn() == -1)
return;
if (e.getType() == e.UPDATE)
if (e.getColumn() == FIRSTCOLUMN
|| e.getColumn() == SECONDCOLUMN)
FilterTable.this.setValueAt(null, getSelectedRow(), THIRDCOLUMN);
return;
Now, when the user changes the value of one of the first 2 columns , the 3rd cell is cleared all right. The problem is, when the user click on one of the cells in the first 2 columns without changing its content, the tableChanged() method also catches an "UPDATE" event and clear the corresponding cell in the 3rd collumn. Does anyone know why? Any help would be highly appreciated.
Thanks
JimorJoe

Answer 1

this code block realy works
public class ThreeColumnTable extends JTable{
     public ThreeColumnTable(){
          super(5,3);
          int cols = getColumnCount();
          for(int i = 0; i < cols; i++){
               TableColumn col = getColumn(getColumnName(i));
               col.setPreferredWidth(30);
               if (i != 2)
                    col.setCellEditor(new ComboCellEditor());
               else
                    col.setCellEditor(new DefaultCellEditor(new JTextField()));
public class ComboCellEditor extends JComboBox implements ItemListener,
          TableCellEditor{
     private JTable table;
     private int row;
     private int col;
     public ComboCellEditor(){
          super();
          addItem("first item");
          addItem("second item");
          addItem("third item");
          addItemListener(this);
     public void itemStateChanged(ItemEvent e){
          if (e.getStateChange() == e.DESELECTED){
               table.setValueAt("",  row, 2);
               table.setValueAt(getSelectedItem(), row, col);
     public Object getCellEditorValue(){
          return getSelectedItem();
     public boolean isCellEditable(EventObject anEvent){
          return true;
     public boolean shouldSelectCell(EventObject anEvent){
          return true;
     public boolean stopCellEditing(){
          return true;
     public void cancelCellEditing(){
    public void addCellEditorListener(CellEditorListener l){
     public void removeCellEditorListener(CellEditorListener l){          
     public Component getTableCellEditorComponent(JTable table, Object value,
               boolean isSelected,
               int row, int col){
          this.row = row;
          this.col = col;
          this.table = table;
          return this;
}