Re: JSpinners as JTable cells - a solution

I've been writing an application for the past several weeks that has a
JTable that uses JSpinners in one column.
I discovered that I was having problems with the TableModel not updating
whenever a spinner was edited using only the buttons.
Editing with the text field was not a problem - but if you changed a value
using the buttons, you had to click in a different cell of the table
before the model would update.
Evidently, this was a focus problem. JSpinner buttons do not ordinarily
seem to get focus within a table - the text part can, but the buttons
don't.

After following numerous posts on forums etc. I stumbled across one
suggestion to use a custom UI for the spinner - however, this relied on
the plaf.basic look and feel, which means that if you change the UI in
order to add focuslisteners as you build it, the buttons may become a
different look and feel whilst you edit the values.
This wasn't very nice on the Mac, I can tell you!

I didn't really have much of a clue as to what I was doing - but I
definately didn't want to rebuild the UI from scratch, so I dug down into
the JSpinner's component list and applied focuslisteners to each. This
appears to fix the problem completely - something which no other solution
on the net had seemed to do without requiring a total program rewrite.

class SpinnerEditor extends AbstractCellEditor
         implements TableCellEditor {

     final JSpinner spinner;
     private JTable currentTable;
     private int selectedRow;
     private int selectedColumn;
     // Initializes the spinner.
     public SpinnerEditor(int min, int max) {
         spinner = new JSpinner(
             new SpinnerNumberModel(min, min, max, 1));
         //This alone does not fix the issue
         spinner.setFocusable(true);

         //List all of the components and make them focusable
         //then add an empty focuslistener to each
         for(Component tmpComponent:spinner.getComponents()){
             tmpComponent.setFocusable(true);
             tmpComponent.addFocusListener(new FocusAdapter(){
                 @Override
                 public void focusLost(FocusEvent fe){}
             });
         }
     }

     public Component getTableCellEditorComponent(JTable table,
         Object value, boolean isSelected, int row, int column) {
         spinner.setValue(value);
         currentTable = table;
         selectedRow = row;
         selectedColumn = column;
         return spinner;
     }

     public Object getCellEditorValue() {
         return spinner.getValue();
     }
 }