InputVerifier for JTextArea problem

Question

Hello,
I am having a problem with using an InputVerifier to check a max character limit on a JTextArea. It seems that occasionally after the verify of the JTextArea fails, I lose the next character I type into it! Here is the code, followed by a description of how to reproduce the problem. Note this code is copied from the Java 1.4.2 API documentation of the InputVerifier class, with the first JTextField changed to a JTextArea and the verify method modified:
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Frame;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
import javax.swing.InputVerifier;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JTextArea;
import javax.swing.JTextField;
public class TestJTextArea  extends JFrame {
    public TestJTextArea () {
       JTextArea ta = new JTextArea ("");
       ta.setPreferredSize(new Dimension(100, 50));
       getContentPane().add (ta, BorderLayout.NORTH);
       ta.setInputVerifier(new PassVerifier());
       JTextField tf2 = new JTextField ("TextField2");
       getContentPane().add (tf2, BorderLayout.SOUTH);
       WindowListener l = new WindowAdapter() {
           public void windowClosing(WindowEvent e) {
               System.exit(0);
       addWindowListener(l);
    class PassVerifier extends InputVerifier {
        public boolean verify(JComponent input) {
            JTextArea jText = (JTextArea)input;
            boolean retValue = jText.getText().length() < 5;
            if (!retValue) {
                System.out.println("MAX CHARS");
            return retValue;
    public static void main(String[] args) {
        Frame f = new TestJTextArea ();
       f.pack();
       f.setVisible(true);
}A way to reproduce the problem is type in the TextArea: "123455", then Ctrl+Tab and the verify will fail. Then backspace twice to delete the "55" and Ctrl+Tab to move to the TextField. Then Tab again to go back to the TextArea and type any charachter over than 5. About 80% of the time, the character that you type will be lost and not appear in the TextArea. It doesn't always happen, but if you try it a few times it will come up. Also, occasionally the backspace keystroke is also lost in the TextArea. Note this only happens when I use Tab. I am not able to reproduce it by using the mouse to change focus.
I have searched for a bug report on this, but have found nothing. Am I doing something wrong? I am simply using the sample code from the InputVerifier JavaDoc, but with a JTextArea... This is on a WinXP Pro machine with Java Std. Ed. 1.4.2.
Thank you for your help.
Angel

Answer 1

JTextField jtf = (JTextField)comboBox.getEditor().getEditorComponent();
jtf.setInputVerifier(new YourInputVerifier());