KeyEvent.consume() problem for BACKSPACE

Question

Hi!
I have the following problem - I want to disable the BACKSPACE key input for a JTextArea. I�ve done it like this:
private class MyKeyAdapter extends KeyAdapter {
public void keyPressed (KeyEvent e) {
if (e.getKeyCode()==KeyEvent.VK_BACK_SPACE) e.consume();
This method works for other keys but why not for BACKSPACE? Checking if the event has been consumed with KeyEvent.isConsumed() returns "true" like it should, but the event still gets processed in JTextArea.
Thanx in advance,
bbruno

Answer 1

Here, try the following with a document filter that filters out VK_DELETE and VK_BACK_SPACE:
import javax.swing.*;
import javax.swing.text.*;
import java.awt.event.*;
public class TxtDemo extends JFrame {
   public static void main(String[] args) {
      JFrame F=new TxtDemo("Test Window");
      F.pack();
      F.setVisible(true);
      F.addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent e) {
            System.exit(0);
   TxtDemo(String title) {
      super(title);
      JTextArea textArea = new JTextArea(5, 20);
      DocumentFilter filter = new DocumentFilter() {
         public void insertString(DocumentFilter.FilterBypass fb,int offset, String string, AttributeSet attr) throws BadLocationException {
            super.insertString(fb,offset,string,attr);
         public void remove(DocumentFilter.FilterBypass fb, int offset, int length) {  
            // do nothing
         public void replace(DocumentFilter.FilterBypass fb, int offset, int length, String text, AttributeSet attrs) throws BadLocationException {
            super.replace(fb,offset,length,text,attrs);
      ((AbstractDocument) textArea.getDocument()).setDocumentFilter(filter);
      getContentPane().add(textArea);
}Here is the same version that can be cut-n-paste:
import javax.swing.*;
import javax.swing.text.*;
import java.awt.event.*;
public class TxtDemo extends JFrame {
public static void main(String[] args) {
JFrame F=new TxtDemo("Test Window");
F.pack();
F.setVisible(true);
F.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
TxtDemo(String title) {
super(title);
JTextArea textArea = new JTextArea(5, 20);
DocumentFilter filter = new DocumentFilter() {
public void insertString(DocumentFilter.FilterBypass fb,int offset, String string, AttributeSet attr) throws BadLocationException {
super.insertString(fb,offset,string,attr);
public void remove(DocumentFilter.FilterBypass fb, int offset, int length) {  
// do nothing
public void replace(DocumentFilter.FilterBypass fb, int offset, int length, String text, AttributeSet attrs) throws BadLocationException {
super.replace(fb,offset,length,text,attrs);
((AbstractDocument) textArea.getDocument()).setDocumentFilter(filter);
getContentPane().add(textArea);
;o)
V.V.