Re: Incorrect and permanent loss of keyboard focus

James L. Terman wrote:
I have a small sample problem that replicates my problem. The program creates a window with a text field that has keyboard focus.

The window has a menu item that I use to create another window of that type that correctly gets the keyboard focus.

I then click on the old window, bring it to front. It does not get the keyboard focus like it should in Linux. It will work correctly in windows.

I tried adding the call requestFocusInWindow which did not help and led to unpredictable behavior. The problem seems to be that I am in the situation where the call

KeyboardFocusManager.getCurrentKeyboardFocusManager
().getPermanentFocusOwner()

is returning the expected Component. The problem is that the KeyListener class that is registered with the Component is not being called when a key is being pressed.

The issue is that I have a component that has the keyboard focus, but the KeyListener class
is not responding.

This seems to be a linux only problem which makes it only more mysterious.

uname -a
Linux watson 2.6.20-1.2933.fc6 #1 SMP Mon Mar 19 11:38:26 EDT 2007 i686 i686 i386 GNU/Linux
java -version
java version "1.5.0_11"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_11-b03)
Java HotSpot(TM) Client VM (build 1.5.0_11-b03, mixed mode, sharing)
javac -version
javac 1.5.0_11
import java.awt.event.*;
import javax.swing.*;
class SwingWindow extends JFrame {
SwingWindow() {
super("SwingWindow");
JMenuBar menuBar = new JMenuBar(); JMenu fileMenu = new JMenu("File");
JMenuItem newItem = new JMenuItem("New");
newItem.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent event) {
SwingWindow.createAndShowGUI();
}
});
fileMenu.add(newItem);
menuBar.add(fileMenu);
setJMenuBar(menuBar);
setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE); JTextField text = new JTextField(200);
getContentPane().add(text);
pack();
setSize(700, 275);
}
public static void createAndShowGUI() {
JFrame frame = new SwingWindow();
frame.setVisible(true);
}
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}

I tried your program and I'm not seeing the problem you describe although I have seen it with one of my own programs. You can see mine at:

http://www.knutejohnson.com/chat.html

Press the 'Connect' button and a JOptionPane input dialog is opened. When closed the focus never returns to the JTextField where it belongs even with a call to requestFocus(). It does however return if you minimize the browser window and then maximise it. Just for my curiosity, try minimizing your program window and then maximize it to see if the focus goes where it belongs.

I'm not sure why your program doesn't fail for me but I was not able to make a test program that failed at all. I thought it might be Applet related but apparently it isn't.

There is something fishy in Linux I think.

--

Knute Johnson
email s/nospam/knute/
.