Name: yyT116575 Date: 11/28/2000


java -version
java version "1.3.0"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.0-C)
Java HotSpot(TM) Client VM (build 1.3.0-C, mixed mode)


If the maximum value for a JProgressBar is very large (close to
Integer.MAX_VALUE), then setValue on the JProgessBar does not cause a repaint.
This can be seen in the following example code. When it is run the progress
bar should go up in increments of 10% each second, but it does not. That
adjoining JLabel displying the value actually supplied to the progress bar
*does* correctly update.

If the value of the constant MAXIMUM is reduced to, say, Integer.MAX_Value / 2,
then all works as it should. Alternatively, calling setMaximum on a small number
and then again on the large value before calling setValue also causes it to
repaint correctly. Or simply calling repaint() explicitly fixes it, too.

Note that while it sounds similar, the symptoms of this bug are different than
those of #4106139 already in the database, which is closed as fixed.

Besides Windows, I have also seen identical behavior under linux.

Sample code:

import java.util.Timer;
import java.util.TimerTask;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class ProgressBug extends JFrame {

    private static final int MAXIMUM = Integer.MAX_VALUE - 100;
    private static final int GRANULARITY = MAXIMUM / 10;

    private JProgressBar progressBar = new JProgressBar(0, MAXIMUM);
    private JLabel progressLabel
        = new JLabel(Integer.toString(MAXIMUM));
    private Timer progressTimer = new Timer();
    
    private ProgressBug() {
        getContentPane().add(progressBar, BorderLayout.WEST);
        progressBar.setStringPainted(true);
        getContentPane().add(progressLabel, BorderLayout.EAST);
        addWindowListener(new WindowAdapter() {
                public void windowClosing(WindowEvent evt) {
                    System.exit(0);
                }
            });
        setLocation(400, 300);
        pack();
        progressLabel.setText("");
    }

    public static void main(String[] args) {
        (new ProgressBug()).run();
    }

    private class UpdateTask extends TimerTask {

        final int value;

        UpdateTask(int v) {
            value = v;
        }

        public void run() {
            EventQueue.invokeLater(new Runnable() {
                    public void run() {
                        // Adding the following two lines here will
                        // make this work.
                        // progressBar.setMaximum(1);
                        // progressBar.setMaximum(MAXIMUM);
                        progressBar.setValue(value);
// Or adding the following one line here will also
// make this work.
// progressBar.repaint(100);
                        progressLabel.setText(Integer.toString(value));
                    }
                });
        }
    }

    private void run() {
        setVisible(true);
        for (int i = 0; i <= 10; ++i) {
            progressTimer.schedule(new UpdateTask(i * GRANULARITY), i * 1000);
        }
    }

}
(Review ID: 112864)
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