How to put a JFrame on the top of all other applications

Question

when some message is received, I want to put an existing JFrame on the top of all other applications. So that the user knows that some message has arrived.
I tried toFront(), but it blinks the JFrame on the taskbar never comes on the top of other application.
Any ideas.
Rajesh

Answer 1

On Windows 98 the toFront() method works, but maybe not exactly how you expected.
There seems to be a delay of about 20 seconds.
If your frame has not been active within the last twenty seconds then the frame is displayed when the toFront() is used.
If the frame has been active within the last 20 seconds then the icon will flash.
I believe this behaviour is to prevent frames from poping up all the time. Here is a simple program that shows this behaviour:
import java.awt.*;
import java.awt.event.*;
import java.util.Date;
import javax.swing.*;
public class FrameToFront
    public static void main(String[] args)
        final JFrame frame = new JFrame();
        frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
        frame.setSize(200, 200);
        frame.setLocationRelativeTo( null );
        frame.setVisible(true);
        int delay = Integer.parseInt(args[0]);
        final Timer timer = new Timer(delay, new ActionListener()
            public void actionPerformed(ActionEvent e)
                System.out.println(new Date());
                frame.toFront();
        timer.start();
}After you start the program click on the dos window to hide the frame. Try the following two cases:
java FrameToFront 5000
java FrameToFront 20000