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.