Tabbing between cells in a JTable

[Jonathan Moore]

I'm trying to create a JTable that acts like a set of JTextFields, with the top row and left column rendered as JLabels. The code below works fine, but I'd like to be able to tab between cells and the cell to immediately go into edit mode (so it's invisible to the user that this is actually a table). Additionally I'd like it to skip uneditable cells, so tabbing on a far right cell doesn't move to the label on the next row, but to the next editable cell. I've spent quite a while trying to figure this one out but with no luck, so does anyone have any pointers?

If you run the code below you will see that clicking in an editable cell automatically puts it into edit mode (with cursor and changed text position) but tabbing doesn't give any visual indications, though if you start typing it starts editing.

Thanks for any help, and here;s the code:

  import javax.swing.*;
import javax.swing.border.Border;
import javax.swing.border.EmptyBorder;
import javax.swing.table.TableCellRenderer;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.table.DefaultTableModel;
import java.awt.*;
 
public class TableTest extends JFrame {
 
public TableTest()
    {
getContentPane().add(new MyTable());
}
 

public static void main(String[] args)
    {
TableTest frame = new TableTest();
frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
}
 
    public class MyTable extends JTable
    {
        public MyTable()
        {
            super(new MyTableModel());
            putClientProperty("terminateEditOnFocusLost", Boolean.TRUE);
            setDefaultRenderer(String.class, new Renderer());
            DefaultCellEditor dce = new DefaultCellEditor(new JTextField());
            dce.setClickCountToStart(1);
            setDefaultEditor(String.class, dce);
            setOpaque(false);
            setShowGrid(false);
        }
 
        private class Renderer implements TableCellRenderer
        {
            DefaultTableCellRenderer renderer;
            JTextField textField;
            protected Border border = new EmptyBorder(1, 1, 1, 1);
 
            public Renderer()
            {
                renderer = new DefaultTableCellRenderer();
                textField = new JTextField();
                textField.setHorizontalAlignment(SwingConstants.RIGHT);
            }
 
            public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column)
            {
                if (!isCellEditable(row, column))
                {
                    renderer.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column);
                    renderer.setHorizontalAlignment(column == 0 ? SwingConstants.LEFT : SwingConstants.RIGHT);
                    renderer.setBackground(Color.GRAY.brighter());
                    renderer.setOpaque(false);
                    renderer.setFont(table.getFont().deriveFont(9f).deriveFont(Font.BOLD));
                    renderer.setForeground(Color.BLACK);
                    renderer.setBorder(border);
                    return renderer;
                }
                textField.setText(value.toString());
                return textField;
            }
        }
    }
 
    class MyTableModel extends DefaultTableModel
    {
        String[][] data = new String[][]
                {
                        {"", "col 1", "col 2"},
                        {"row 1", "1", "2"},
                        {"row 2", "3", "4"},
                        {"row 3", "5", "6"},
                };
 
        public MyTableModel()
        {
 
        }
 
        public int getRowCount()
        {
            return 4;
        }
        public int getColumnCount()
        {
            return 3;
        }
 
        public Object getValueAt(int row, int column)
        {
            return data[row][column];
        }
 

        public boolean isCellEditable(int row, int column)
        {
            return row != 0 && column != 0;
        }
 
        public Class getColumnClass(int column)
        {
            return String.class;
        }
    }
}
 
  

[Craig Wood]

I'd like to be able to tab between cells and the cell to immediately go into edit mode
(so it's invisible to the user that this is actually a table). Additionally I'd like it to
skip uneditable cells, so tabbing on a far right cell doesn't move to the label on the
next row, but to the next editable cell.
I got your code to work (as described above) with only the following additions:

import javax.swing.event.*;
...
            // Add this to the MyTable constructor.
            configure();
...
        // Add this method to the body of MyTable class.
        private void configure()
        {
            setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
            setCellSelectionEnabled(true);
            // Add SelectionListeners to track selection changes
            // across columns.
            getColumnModel().getSelectionModel().addListSelectionListener(
                        new ExploreSelectionListener());
        }
 
        // Add this class to the body of MyTable class.
        private class ExploreSelectionListener implements ListSelectionListener
        {
            public void valueChanged(ListSelectionEvent e)
            {
                if(!e.getValueIsAdjusting())
                {
                    int row = getSelectedRow();
                    int col = getSelectedColumn();
                    // Make sure we start with legal values.
                    while(col < 0) col++;
                    while(row < 0) row++;
                    // Find the next editable cell.
                    while(!isCellEditable(row, col))
                    {
                        col++;
                        if(col > getColumnCount()-1)
                        {
                            col = 1;
                            row = (row == getRowCount()-1) ? 1 : row+1;
                        }
                    }
                    // Select the cell in the table.
                    final int r = row, c = col;
                    EventQueue.invokeLater(new Runnable()
                    {
                        public void run()
                        {
                            changeSelection(r, c, false, false);
                        }
                    });
                    // Edit.
                    if(isCellEditable(row, col))
                    {
                        editCellAt(row, col);
                        ((JTextField)editorComp).selectAll();
                        editorComp.requestFocusInWindow();
                    }
                }
            }
        }
...
        // Add this method to the body of MyTableModel class.
        public void setValueAt(Object value, int row, int column)
        {
            data[row][column] = value.toString();
        }

[Jonathan Moore]

That's great - thanks for your help Craig.

Jon