Re: Need time waster code or something.

From:
Knute Johnson <nospam@rabbitbrush.frazmtn.com>
Newsgroups:
comp.lang.java.gui
Date:
Sat, 29 Apr 2006 22:16:26 -0700
Message-ID:
<MKX4g.1691$oz1.1472@newsfe06.phx>
Taunto wrote:

I'm trying to "flash" a button, by changing its icon from one color to
another.

It works with the mouse events (on when clicked, off when released), but
when I try to run the following code, I don't see a change. I see
something happen to the button (the color square gets ever so slightly
smaller), but the color doesn't change. If I comment out the code where
it sets the color back off, it stays on, so I know its executing.

I'm assuming my for-loop wait mechanism is the problem, and might be
going by so fast I can't see it. I've tried larger numbers and the same
problem.

Is there a better wait mechanism?

public void flashButton()
{
    button.setIcon(onIcon);
    for (long i = 0; i < 1000000; i++)
    {

    }
    button.setIcon(offIcon);
}


You can't do it that way. You need a timer or a thread that sleeps.
Here is an example of a JLabel that I wrote that displays the time. You
should be able to get where you want to go from this.

package com.knutejohnson.components;

import java.awt.*;
import java.awt.event.*;
import java.text.*;
import java.util.*;
import javax.swing.*;

public class JTimeLabel extends JLabel implements ActionListener {
     private SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss");
     private javax.swing.Timer timer = new javax.swing.Timer(250,this);

     public JTimeLabel() {
         super();
         timer.start();
     }

     public JTimeLabel(String text) {
         super(text);
         timer.start();
     }

     public JTimeLabel(String text, int horizontalAlignment) {
         super(text,horizontalAlignment);
         timer.start();
     }

     public JTimeLabel(String text, int horizontalAlignment, String
pattern) {
         super(text, horizontalAlignment);
         this.sdf = new SimpleDateFormat(pattern);
         timer.start();
     }

     public void actionPerformed(ActionEvent ae) {
         setText(sdf.format(new Date()));
     }

     public static void main(String[] args) {
         JFrame f = new JFrame();
         f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         f.add(new JTimeLabel("24:00:00",JLabel.CENTER));
         f.pack();
         f.setVisible(true);
     }
}

--

Knute Johnson
email s/nospam/knute/

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