JProgressBar in JTable overwrites cell bounds

Question

Problem: When the user resizes the table (during a update) so that the entire JProgressBar will no longer fit in the cell, the text of the JProgressBar will overwrite its surrounding controls.
Sample code:
import javax.swing.table.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
import java.awt.*;
public class Main extends JFrame {
public Main() {
super("TableModel JProgressBar Demonstration");
// create our own custom TableModel
DownloadTableModel downloadModel = new DownloadTableModel();
JTable table = new JTable(downloadModel);
// add rows to our TableModel, each row is represented as a Download object
downloadModel.addDownload(new Download("linuxmandrake.zip", 1234567));
downloadModel.addDownload(new Download("flash5.exe", 56450000));
downloadModel.addDownload(new Download("jdk1.2.2-007.zip", 20000000));
// render the columns with class JProgressBar as such
ProgressBarRenderer pbr = new ProgressBarRenderer(0, 100);
pbr.setStringPainted(true);
table.setDefaultRenderer(JProgressBar.class, pbr);
// increase the height of the rows a bit
table.setRowHeight((int) pbr.getPreferredSize().getHeight());
// create the scroll pane and add the table to it.
JScrollPane scrollPane = new JScrollPane(table);
// add the scroll pane to this window.
getContentPane().add(scrollPane, BorderLayout.CENTER);
getContentPane().add(new JButton("Spacer"), BorderLayout.SOUTH);
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
public static void main(String[] args) {
Main main = new Main();
main.pack();
main.setVisible(true);
// a simple object that holds data about a particular download
// it starts a thread and increases the progress of "downloading"
// in a random manner
class Download extends Observable implements Runnable {
private Thread thisThread;
private String filename;
private int filesize;
private float progress;
public Download(String filename, int filesize) {
this.filename = filename;
this.filesize = filesize;
progress = 0.0f;
thisThread = new Thread(this);
thisThread.start();
public String getFilename() { return filename; }
public int getFilesize() { return filesize; }
public float getProgress() { return progress; }
public String toString() {
return "[" + filename + ", " + filesize + ", " + progress + "]"; }
public void run() {
Random r = new Random();
int count = 0;
while (count < filesize) {
int random = Math.abs(r.nextInt() % 100000);
count += random;
if (count > filesize) count = filesize;
progress = ((float) count / filesize) * 100;
// notify table model (and all other observers)
setChanged();
notifyObservers(this);
try { thisThread.sleep(500); } catch(InterruptedException e) { }
class DownloadTableModel extends AbstractTableModel implements Observer {
// holds the strings to be displayed in the column headers of our table
final String[] columnNames = {"Filename", "Filesize", "Progress"};
// holds the data types for all our columns
final Class[] columnClasses = {String.class, Integer.class, JProgressBar.class};
// holds our data
final Vector data = new Vector();
// adds a row
public void addDownload(Download d) {
data.addElement(d);
// the table model is interested in changes of the rows
d.addObserver(this);
fireTableRowsInserted(data.size()-1, data.size()-1);
// is called by a download object when its state changes
public void update(Observable observable, Object o) {
int index = data.indexOf(o);
if (index != -1)
fireTableRowsUpdated(index, index);
public int getColumnCount() {
return columnNames.length;
public int getRowCount() {
return data.size();
public String getColumnName(int col) {
return columnNames[col];
public Class getColumnClass(int c) {
return columnClasses[c];
public Object getValueAt(int row, int col) {
Download download = (Download) data.elementAt(row);
if (col == 0) return download.getFilename();
else if (col == 1) return new Integer(download.getFilesize());
else if (col == 2) return new Float(download.getProgress());
else return null;
public boolean isCellEditable(int row, int col) {
return false;
// a table cell renderer that displays a JProgressBar
class ProgressBarRenderer extends JProgressBar implements TableCellRenderer {
public ProgressBarRenderer() {
super();
public ProgressBarRenderer(BoundedRangeModel newModel) {
super(newModel);
public ProgressBarRenderer(int orient) {
super(orient);
public ProgressBarRenderer(int min, int max) {
super(min, max);
public ProgressBarRenderer(int orient, int min, int max) {
super(orient, min, max);
public Component getTableCellRendererComponent(
JTable table, Object value, boolean isSelected, boolean hasFocus,
int row, int column) {
setValue((int) ((Float) value).floatValue());
return this;
}

Answer 1

I do not have an answer for you.
However, I did skim through a solution to your problem. Since it didn't solve my problem at the time, I didn't try out the code.
In the book "Core Web Programming", Second Edition, Marty Hall and Larry Brown, Sun Microsystems Press, they do discuss making a progress bar synchronize with a file download and why you have to make it multi-threaded.
If you can head over to your bookstore, it's Chapter 15.6 and consists of about two and a half pages. Even better, the example's source code is available for free on their web site at:
http://www.corewebprogramming.com
Click on the hypertext link to Chapter 15, then scroll down and grab FileTransfer.java near the bottom of the page.
Hope this at least points you in the right direction, but I admit I wouldn't even allow the user to resize the table containing the progress bar to begin with. If I absolutely had to, I'd force the progress bar thread to reset itself each time it received a window-resizing event.