I have a table with a text column. I would like to ensure that the
values in that column remain unique when edited. I have created the
following class

class NameTextField extends JFormattedTextField {
 Set currentNames = null;
   
 public void setCurrentNames(Set currentNames) {
   this.currentNames = currentNames;
 }

 public boolean isEditValid() {
   String val = getFormatter().toString();
   System.out.println("isEditValid called with '"+val+"'");
   if (val == null || val.length() == 0 ||
       currentNames.contains(val)) {
     return false;
   }
   else {
     return super.isEditValid();
   }
 }
}

I then set the CellEditor for the column with

TableColumn nameColumn =
getColumnModel().getColumn(AttributeTableModel.NAME_COL);
text = new NameTextField();
nameColumn.setCellEditor(new DefaultCellEditor(text));

I expect isEditValid() to be called each time I press 'Enter' after
editing the field. I would also expect that if I returned false, the
field would retain focus and force the user to correct the problem.

What I get is the method is not getting called at all. What am I doing
wrong? Do I need to define a Formatter? FormatterFactory?