actionevent in jcombobox of jtable

[Massimo Perelli]

Hi,
I'm not able to use actionlistener in selecting value of jcombobox with arrow keys. This jcombobox is in a jtable.
The actionlistener works fine only if an enter key is pressed, but not for every select with arow.

/*
 * NewJFrame.java
 *
 * Created on 3 giugno 2008, 8.23
 */
 
package javaapplication5;
 
import javax.swing.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.table.TableColumn;
import javax.swing.event.TableModelListener;
import javax.swing.event.TableModelEvent;
import javax.swing.table.TableModel;
/**
 *
 */
public class NewJFrame extends javax.swing.JFrame {
 
private void CambiojComboBox(){   
    System.out.println("Passed");
}
 
    /** Creates new form NewJFrame */
    public NewJFrame() {
        initComponents();
        TableColumn ModeColumn1 = jTable1.getColumnModel().getColumn(0);
        comboBox.removeAllItems();
        comboBox.addItem("1");
        comboBox.addItem("2");
        comboBox.addItem("3");
        ModeColumn1.setCellEditor(new DefaultCellEditor(comboBox));
        
        comboBox.addActionListener(actionListenerComboBox);
    }
    
    /** This method is called from within the constructor to
     * initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is
     * always regenerated by the Form Editor.
     */
    // <editor-fold defaultstate="collapsed" desc=" Generated Code ">                          
    private void initComponents() {
        jScrollPane1 = new javax.swing.JScrollPane();
        jTable1 = new javax.swing.JTable();
 
        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        jTable1.setModel(new javax.swing.table.DefaultTableModel(
            new Object [][] {
                {null},
                {null},
                {null},
                {null}
            },
            new String [] {
                "Title 1"
            }
        ));
        jScrollPane1.setViewportView(jTable1);
 
        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 380, Short.MAX_VALUE)
                .addContainerGap())
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 225, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(64, Short.MAX_VALUE))
        );
        pack();
    }// </editor-fold>                        
    
    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new NewJFrame().setVisible(true);
            }
        });
    }
    
    // Variables declaration - do not modify                     
    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JTable jTable1;
    // End of variables declaration                   
    JComboBox comboBox = new JComboBox();
    
    ActionListener actionListenerComboBox = new ActionListener() {
      public void actionPerformed(ActionEvent actionEvent) {
        CambiojComboBox();
      }
    };
}

[Rob Spoor]

That's because the selection does not change yet. You could try to get a hold of the JList that is actually used, and add a ListSelectionListener to that.

Some investigation has lead me to interface javax.swing.plaf.basic.ComboPopup which has a getList method, but that's as far as I got at the moment. I haven't been able to find out how to get a reference to this from a JComboBox reference. Perhaps you can get a bit further now you have a start where to look.

[Campbell Ritchie]

. . . and Massimo, welcome to JavaRanch

[Massimo Perelli]

Now I use the code:

    
class comboBoxCellRenderer extends DefaultListCellRenderer {
    public Component getListCellRendererComponent(JList list, 
                                                  Object value, 
                                                  int index, 
                                                  boolean isSelected, 
                                                  boolean cellHasFocus) {
        super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);
        if (isSelected == true) {
            SelezionecomboBox = Integer.valueOf(value.toString().substring(0,3)).intValue();
            logger.debug(SelezionecomboBox);     
            CambiojComboBox(SelezionecomboBox);
        }
        return this;
    }
}

setting the renderer:

    
comboBox.setRenderer(new comboBoxCellRenderer());

and It's work fine.
Thanks Massimo

[Rob Spoor]

It could cause problems though. That will be triggered anytime any element of your list is painted. That includes when opening the drop down list. It might cause the wrong element to be set.