FocusTraversalKeys challenge

[Med Shabe]

I need to navigate through the components using the tab key and also want to perform some kind of computations once the user has pressed the tab key. I can do the calculation but he tab stays in the current field.

I�m not sure how to set the focus to the next available component.

Any help is appreciated.

  import java.awt.event.*;
import javax.swing.*;
 

class TabNavTest extends JPanel implements KeyListener {
    JTextField tf1 = new JTextField(8);
    JTextField tf2 = new JTextField(8);
    JTextField tf3 = new JTextField(8);
    JTextField tf4 = new JTextField(8);
    JPanel jp;
    
 
    public TabNavTest() {
        setSize(300, 75);
        jp = new JPanel();
        tf1.addKeyListener(this);
        tf2.addKeyListener(this);
//            tf2.setFocusTraversalKeys(
//                KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS,
//                Collections.EMPTY_SET);
//            tf2.processComponentKeyEvent(this);
        tf2.setFocusTraversalKeysEnabled(false);
        
        jp.add(tf1);
        jp.add(tf2);
        jp.add(tf3);
        jp.add(tf4);
    }
  
    public JPanel getJP() {
        return jp;
    }
 
    public void keyPressed(KeyEvent ke) {
        if ( ke.getKeyCode() == KeyEvent.VK_TAB ) {
            String s1 = tf1.getText();
            String s2 = tf2.getText();
            int i1 = Integer.valueOf(s1).intValue();
            int i2 = Integer.valueOf(s2).intValue();
            int res = i1 * i2;
            
            tf3.setText(Integer.toString(res));
//            JOptionPane.showMessageDialog(null, res);
            
        }
    }
 
    public void keyTyped(KeyEvent ke) {
    }
 
    public void keyReleased(KeyEvent ke) {
    }
 
    public static void main(String args[]) {
 
        JFrame f = new JFrame("TabNavTest");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setContentPane(new TabNavTest().getJP());
 
        f.setSize(600, 450);
        f.setVisible(true);
 
        f.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
    }
}

[Michael Dunn]

it might be simpler to use a focusListener, or a documentListener

here's your code as a focusListener:
as tf3 is for the 'result' - I've changed that to unfocusable,
not sure what tf4 is for

import java.awt.event.*;
import javax.swing.*;
class TabNavTest extends JPanel
{
  JTextField tf1 = new JTextField(8);
  JTextField tf2 = new JTextField(8);
  JTextField tf3 = new JTextField(8);
  JTextField tf4 = new JTextField(8);
  JPanel jp = new JPanel();
  public TabNavTest()
  {
    tf3.setFocusable(false);
    jp.add(tf1);
    jp.add(tf2);
    jp.add(tf3);
    jp.add(tf4);
    tf2.addFocusListener(new FocusAdapter(){
      public void focusLost(FocusEvent fe){
        multiply();}});
  }
  public JPanel getJP(){return jp;}
  public void multiply()
  {
    //error handling for non-int values
    tf3.setText(String.valueOf( (Integer.parseInt(tf1.getText()) * Integer.parseInt(tf2.getText()))));
  }
  public static void main(String args[])
  {
    JFrame f = new JFrame("TabNavTest");
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.setContentPane(new TabNavTest().getJP());
    f.setSize(600, 450);
    f.setVisible(true);
  }
}

[Mahesh x Bogadi]

Hey Meb,

In your code, implementation of keylistener methods.. call the super(parent) methods!!!

[Med Shabe]

Thank you both.