Default button being clicked multiple times when enter key is pressed

Question

Hello,
There seems to be a strange difference in how the default button behaves in JRE 1.4.X versus 1.3.X.
In 1.3.X, when the enter key was pressed, the default button would be "pressed down" when the key was pressed, but wouldn't be fully clicked until the enter key was released. This means that only one event would be fired, even if the enter key was held down for a long time.
In 1.4.X however, if the enter key is pressed and held for more than a second, then the default button is clicked multiple times until the enter key is released.
Consider the following code (which is just a dialog with a button on it):
public class SimpleDialog extends JDialog implements java.awt.event.ActionListener
private JButton jButton1 = new JButton("button");
public SimpleDialog()
this.getContentPane().add(jButton1);
this.getRootPane().setDefaultButton(jButton1);
jButton1.addActionListener(this);
this.pack();
public void actionPerformed(ActionEvent e)
if (e.getSource() == jButton1)
System.out.println("button pressed");
public static void main(String[] args)
new SimpleDialog().show();
When you compile and run this code under 1.3.1, and hold the enter key down for 10 seconds, you will only see one print line statement.
However, if you compile and run this code under 1.4.1, and then hold the enter key down for 10 seconds, you will see about 100 print line statements.
Is this a bug in 1.4.X or was this desired functionality (e.g. was it fixing some other bug)?
Does anyone know how I can make it behave the "old way" (when the default button was only clicked once)?
Thanks in advance if you have any advice.
Dave

Answer 1

Hello all,
I think I have found a solution. The behaviour of the how the default button is triggered is contained withing the RootPaneUI. So, if I override the default RootPaneUI used by the UIDefaults with my own RootPaneUI, I can define that behaviour for myself.
Here is my simple dialog with a button and a textfield (when the focus is NOT on the button, and the enter key is pressed, I don't want the actionPerformed method to be called until the enter key is released):
package focustests;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.util.*;
public class SimpleDialog extends JDialog implements java.awt.event.ActionListener
private JButton jButton1 = new JButton("button");
public SimpleDialog()
this.getContentPane().add(new JTextField("a text field"), BorderLayout.NORTH);
this.getContentPane().add(jButton1, BorderLayout.SOUTH);
this.getRootPane().setDefaultButton(jButton1);
jButton1.addActionListener(this);
this.pack();
public void actionPerformed(ActionEvent e)
if (e.getSource() == jButton1)
System.out.println("button pressed");
public static void main(String[] args)
javax.swing.UIManager.getDefaults().put("RootPaneUI", "focustests.MyRootPaneUI");
new SimpleDialog().show();
and the MyRootPaneUI class controls the behaviour for how the default button is handled:
package focustests;
import javax.swing.*;
* Since we are using the Windows look and feel in our product, we should extend from the
* Windows laf RootPaneUI
public class MyRootPaneUI extends com.sun.java.swing.plaf.windows.WindowsRootPaneUI
private final static MyRootPaneUI myRootPaneUI = new MyRootPaneUI();
public static javax.swing.plaf.ComponentUI createUI(JComponent c) {
return myRootPaneUI;
protected void installKeyboardActions(JRootPane root) {
super.installKeyboardActions(root);
InputMap km = SwingUtilities.getUIInputMap(root,
JComponent.WHEN_IN_FOCUSED_WINDOW);
if (km == null) {
km = new javax.swing.plaf.InputMapUIResource();
SwingUtilities.replaceUIInputMap(root,
JComponent.WHEN_IN_FOCUSED_WINDOW, km);
//when the Enter key is pressed (with no modifiers), trigger a "pressed" event
km.put(KeyStroke.getKeyStroke(java.awt.event.KeyEvent.VK_ENTER,
0, false), "pressed");
//when the Enter key is released (with no modifiers), trigger a "release" event
km.put(KeyStroke.getKeyStroke(java.awt.event.KeyEvent.VK_ENTER,
0, true), "released");
ActionMap am = SwingUtilities.getUIActionMap(root);
if (am == null) {
am = new javax.swing.plaf.ActionMapUIResource();
SwingUtilities.replaceUIActionMap(root, am);
am.put("press", new HoldDefaultButtonAction(root, true));
am.put("release", new HoldDefaultButtonAction(root, false));
* This is a copy of the static nested class DefaultAction which was
* contained in the JRootPane class in Java 1.3.1. Since we are
* using Java 1.4.1, and we don't like the way the new JRE handles
* the default button, we will replace it with the old (1.3.1) way of
* doing things.
static class HoldDefaultButtonAction extends AbstractAction {
JRootPane root;
boolean press;
HoldDefaultButtonAction(JRootPane root, boolean press) {
this.root = root;
this.press = press;
public void actionPerformed(java.awt.event.ActionEvent e) {
JButton owner = root.getDefaultButton();
if (owner != null && SwingUtilities.getRootPane(owner) == root) {
ButtonModel model = owner.getModel();
if (press) {
model.setArmed(true);
model.setPressed(true);
} else {
model.setPressed(false);
public boolean isEnabled() {
JButton owner = root.getDefaultButton();
return (owner != null && owner.getModel().isEnabled());
This seems to work. Does anyone have any comments on this solution?
Tjacobs, I still don't see how adding a key listeners or overriding the processKeyEvent method on my button would help. The button won't receive the key event unless the focus is on the button. There is no method "enableEvents(...)" in the AWTEventMulticaster. Perhaps you have some code examples? Thanks anyway for your help.
Dave