Name: jk109818 Date: 05/03/2002


FULL PRODUCT VERSION :
java version "1.4.0"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.0-b92)
Java HotSpot(TM) Client VM (build 1.4.0-b92, mixed mode)

FULL OPERATING SYSTEM VERSION :
Microsoft Windows 2000 [Version 5.00.2195]

A DESCRIPTION OF THE PROBLEM :
Calling setSelectedFiles() with a large array of files
(e.g. 475) on a JFileChooser configured with
setMultiSelectionEnabled(true) is extremely slow (i.e. 3.5
minutes). Selecting all files by typing Ctrl-A in the file
list takes a second or two.

The bulk of the time is taken by
MetalFileChooserUI.setFileSelected(). It walks through the
selectedFiles array comparing it to the array of selected
values in the JList, then adjusts the JList selection which
fires a selection property change which starts the whole
process over again. It's very inefficient.

It would also be nice if JFileChooser exposed a selectAll()
method that efficiently selected all files in the list.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. Run the attached SelectAllChooser program
2. Navigate to a directory containing a lot of files (you
can see the slowness with only 30 files or so, but the more
files the more obvious)
3. Press the Select All button in the chooser accessory

EXPECTED VERSUS ACTUAL BEHAVIOR :
It takes a very long time to select all the files. The
program prints how long it took to stdout.

This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.awt.event.*;
import java.io.*;
import javax.swing.*;
public class SelectAllChooser {
public static void main(String args[]) {
final JFileChooser fc = new JFileChooser();
fc.setMultiSelectionEnabled(true);
JButton btnSelectAll = new JButton("Select All");
btnSelectAll.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
long lStart = System.currentTimeMillis();
File[] files = fc.getCurrentDirectory
().listFiles();
fc.setSelectedFiles(files);
System.out.println("time " +
(System.currentTimeMillis() - lStart) + "ms");
}
});
fc.setAccessory(btnSelectAll);
fc.showOpenDialog(null);
System.exit(0);
}
}
---------- END SOURCE ----------

CUSTOMER WORKAROUND :
You can type Ctrl-A in the list to select all files, but
users do not know this which is why I am providing a
button. It would be nice if there was some way to have the
button programmatically invoke the "selectAll" Action on
the JList.
(Review ID: 146137)
======================================================================