JTable bug?

Question

My program has a JTable in a TabbedPane, a menu bar, and a toolbar with icons representing menu bar shortcuts.
One menu/toolbar item is to clear all cells. When this is selected, my program first stops editing on the current cell, so that any cell currently being edited gets cleared too. I do it this way:
int row = myJTable.getEditingRow();
int col = myJTable.getEditingColumn();
if (row != -1 && col != -1)
myJTable.getCellEditor(row,col).stopCellEditing();
I then clear all table cells. There are similar menu/toolbar items for setting all cells to 0, filling them with random values, etc.
The problem is this: When I use the a Menu item to change table cells, the next cell I click in will not allow me to edit it! It will become selected, and have a blinking cursor, and look exactly like a cell normally looks when you can edit it, but when you type, nothing happens! I instead have to click in a different cell to be able to edit again. This happens every time I use a menu item to change all table cells.
HOWEVER, if I use a toolbar button to change all table cells, this does NOT happen! I'm baffled... Both the menu listener and toolbar listener call the exact same method to change all table cells. The code is identical.
Any ideas? If no one has any ideas, I can try to put together a small program to demonstrate the problem, but figured I would see if anyone has thoughts before taking the time to do that.
-Vern

Answer 1

Okay, here is source code. Sorry it's so long -- I tried to trim it down to the bare essentials necessary to reproduce the problem. [On a side note: anyone know how to post source code wihout all leading tabs/spaces getting trimmed?]
The problem may have something to do with my funky table cell editor -- MyCellEditor. I did not write this editor -- it was part of an existing project I have been assigned to modify. But if you remove the editor, it works correctly. I'm not sure if it's this particular editor causing the problem somehow, or just the fact that a custom editor is being used that helps trigger the problem.
In any case, run this program, type a number into a field, then choose "Clear table" from the menu. Then click once in a new field, and type in a number. It won't! Click in another field, and you can type again. Any ideas about this will be greatly appreciated!
import javax.swing.*;
import javax.swing.table.*;
import javax.swing.text.*;
import java.awt.event.*;
import java.awt.*;
public class JTableBugDemo
     protected JMenuItem clearMenuItem;
     protected MyTableModel tableModel;
     protected JTable table;
     public JTableBugDemo()
          JFrame frame = new JFrame("JTable Bug Demo");
          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          JMenuBar menuBar = new JMenuBar();
          JMenu fileMenu = new JMenu();
          clearMenuItem = new JMenuItem();
          fileMenu.setText( "File" );
          clearMenuItem.setText( "Clear table" );
          fileMenu.add(clearMenuItem);
          menuBar.add(fileMenu);
          frame.setJMenuBar(menuBar);
          clearMenuItem.addActionListener(new MyActionListener());
          JPanel newContentPane = createTable();
          newContentPane.setOpaque(true);
          frame.setContentPane(newContentPane);
          frame.pack();
          frame.setVisible(true);
     public JPanel createTable()
          JPanel myPanel = new JPanel( new GridLayout(1,0) );
          tableModel = new MyTableModel(5,5);
          table = new JTable();
          table.setPreferredScrollableViewportSize(new Dimension(500, 150) );
          table.setDefaultEditor(String.class, new MyCellEditor());
          table.setModel( tableModel );
          JScrollPane scrollPane = new JScrollPane(table);
          myPanel.add(scrollPane);
          return myPanel;
     public void finishTablesEditing()
          int row = table.getEditingRow();
          int col = table.getEditingColumn();
          if (row != -1 && col != -1) // if anything is being editing
               table.getCellEditor(row,col).stopCellEditing();
     public static void main(String[] args)
          new JTableBugDemo();
     class MyActionListener implements ActionListener
public void actionPerformed( ActionEvent e )
               if ( e.getSource().equals( clearMenuItem ) )
                    finishTablesEditing();
                    clearTable( );
                    return;
          // Put empty string in all table cells
     public void clearTable()
          for (int row = 0; row < tableModel.getRowCount(); row++)
               for (int col = 0; col < tableModel.getColumnCount(); col++)
                    tableModel.setValueAt("", row, col);
     class MyTableModel extends AbstractTableModel
          protected Object[][] data;
          public MyTableModel(int numRows, int numCols)
               data = new Object[numRows][numCols];
               for (int row = 0; row < numRows; row++)
                    for (int col = 0; col < numCols; col++)
                         data[row][col] = "" + (row * col);
          public int getColumnCount()
               return data[0].length;
          public int getRowCount()
               return data.length;
          public Object getValueAt(int row, int col)
               return data[row][col];
          public void setValueAt(Object value, int row, int col)
               data[row][col] = (Object)value;
               fireTableCellUpdated(row, col);
          public boolean isCellEditable(int row, int col)
               return true;
          public Class getColumnClass(int col)
               return getValueAt(0, col).getClass();
     class MyCellEditor extends DefaultCellEditor
          public MyCellEditor()
               super( new MyRealNumberOrBlankField(5) );
               setClickCountToStart(1);
     class MyRealNumberOrBlankField extends JTextField
          public MyRealNumberOrBlankField(int columns)
               super(columns);
          protected Document createDefaultModel()
               return new MyRealNumberOrBlankDocument();
          protected class MyRealNumberOrBlankDocument extends PlainDocument
               public void insertString(int offs, String str, AttributeSet a) throws BadLocationException
                    if(str == "")
                         super.insertString(offs, str, a);
                         return;
                    char[] source = str.toCharArray();
                    char[] result = new char[source.length];
                    int j = 0;
                    for (int i = 0; i < result.length; i++)
                         if (Character.isDigit(source) || source[i] == '.' || source[i] == 'E' || source[i] == '-' )
                              result[j++] = source[i];
                    super.insertString(offs, new String(result, 0, j), a);