Question

I have a JTable using a custom DefaultTableModel which has some Booleans in the last column (displayed as tick boxes).

When I add a MouseListener to retrieve the value of what’s been clicked it appears that the toggling of tick boxes no longer takes place.

// As soon as this is used in the component
// that is using the JTable, the toggling stops
table.addMouseListener(new MouseAdapter() {  
            public void mouseClicked(MouseEvent evt) {  
                int col = table.getSelectedColumn();  
                int row = table.getSelectedRow();

                Object o = table.getModel().getValueAt(row, col);

I assume that the event is being consumed by the listener. What can I add to the MouseListener code to restore the toggling behaviour?

Edit:

Oops, it appears that the issue lies with my override:

@Override
public void setValueAt(Object aValue, int row, int column) {

    // Attempt at mutually exclusive checkboxes
    if( column == 2 ){ // Starts at 0. Seek an alternative solution to avoid hardcoding?
        // Algorithm: cycle through List to set other Booleans to false

        // Uses entities. Is there another way of getting the number of rows from model?
        List<MyEntity> myEntities = this.getDatas();

        for( int i = 0; i < myEntities.size(); i++ ){
            if( i != row ){
                // Make sure this calls parent
                super.setValueAt( false , i, 2);
            }
        }

    } else {
        super.setValueAt(aValue, row, column); // Call parent class
    }

}  

Answer 1

Don’t add your own MouseListener. Instead override setValueAt() in the TableModel to see the new value set by the default editor for Boolean.class.

Addendum: Here’s an sscce. For expedience, it simply clears all entries in CHECK_COL, sets the new value and conditions the button accordingly.

import java.awt.*;
import javax.swing.*;
import javax.swing.table.DefaultTableModel;

/**
 * @see http://stackoverflow.com/questions/7920068
 * @see http://stackoverflow.com/questions/4526779
 */
public class CheckOne extends JPanel {

    private static final int CHECK_COL = 1;
    private static final Object[][] DATA = {
        {"One", Boolean.FALSE}, {"Two", Boolean.FALSE},
        {"Three", Boolean.FALSE}, {"Four", Boolean.FALSE},
        {"Five", Boolean.FALSE}, {"Six", Boolean.FALSE},
        {"Seven", Boolean.FALSE}, {"Eight", Boolean.FALSE},
        {"Nine", Boolean.FALSE}, {"Ten", Boolean.FALSE}};
    private static final String[] COLUMNS = {"Number", "CheckBox"};
    private DataModel dataModel = new DataModel(DATA, COLUMNS);
    private JTable table = new JTable(dataModel);
    private ControlPanel cp = new ControlPanel();

    public CheckOne() {
        super(new BorderLayout());
        this.add(new JScrollPane(table));
        this.add(cp, BorderLayout.SOUTH);
        table.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        table.setPreferredScrollableViewportSize(new Dimension(250, 175));
    }

    private class DataModel extends DefaultTableModel {

        public DataModel(Object[][] data, Object[] columnNames) {
            super(data, columnNames);
        }

        @Override
        public void setValueAt(Object aValue, int row, int col) {
            if (col == CHECK_COL) {
                for (int r = 0; r < getRowCount(); r++) {
                    super.setValueAt(false, r, CHECK_COL);
                }
            }
            super.setValueAt(aValue, row, col);
            cp.button.setEnabled(any());
        }

        private boolean any() {
            boolean result = false;
            for (int r = 0; r < getRowCount(); r++) {
                Boolean b = (Boolean) getValueAt(r, CHECK_COL);
                result |= b;
            }
            return result;
        }

        @Override
        public Class<?> getColumnClass(int col) {
            if (col == CHECK_COL) {
                return getValueAt(0, CHECK_COL).getClass();
            }
            return super.getColumnClass(col);
        }

        @Override
        public boolean isCellEditable(int row, int col) {
            return col == CHECK_COL;
        }
    }

    private class ControlPanel extends JPanel {

        JButton button = new JButton("Button");

        public ControlPanel() {
            button.setEnabled(false);
            this.add(new JLabel("Selection:"));
            this.add(button);
        }
    }

    private static void createAndShowUI() {
        JFrame frame = new JFrame("CheckOne");
        frame.add(new CheckOne());
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        java.awt.EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                createAndShowUI();
            }
        });
    }
}