Hi newsgroups!

I have a scrolling-savvy component for viewing a large image
inside a JScrollPane. The JScrollPane reacts to the cursor keys
(Up, Down, PageUp, PageDown, Home, End, ...), so that I am able
to scroll through the image *without* using the mouse.
This works fine with Java 1.4.2.

But with Java 1.5.0 the JScrollPane doesn't react to these keys.
(I even retested with Java 1.3.1: The JScrollPane doesn't react
there, too)

What is wrong with my code? Did I rely on an undocumented
1.4-feature? Has Sun silently removed this fine feature in 1.5 ?
How can I get this feature in 1.5 ?

Below is a short compilable example for reproducing the problem:

// Begin SSCCE
import java.awt.*;
import java.awt.image.*;
import javax.swing.*;

public class ImageComponent extends JComponent implements Scrollable
{
    public static void main(String args[])
    {
        JFrame frame = new JFrame("Scroll Test");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JScrollPane scrollPane = new JScrollPane(new ImageComponent());
        frame.getContentPane().add(scrollPane, BorderLayout.CENTER);
        frame.pack();
        frame.setVisible(true);
    }

    private BufferedImage image =  // a meaningless large image
            new BufferedImage(850, 1100, BufferedImage.TYPE_BYTE_GRAY);

    public Dimension getPreferredSize()
    {
        return new Dimension(image.getWidth(), image.getHeight());
    }

    protected void paintComponent(Graphics g)
    {
        g.drawImage(image, 0, 0, this);
    }

    // Implementation of Scrollable interface:

    public Dimension getPreferredScrollableViewportSize()
    {
        return new Dimension(Math.min(image.getWidth(), 500),
                            Math.min(image.getHeight(), 500));
    }

    public int getScrollableUnitIncrement(Rectangle visibleRect,
            int orientation, int direction)
    {
        return getScrollableBlockIncrement(visibleRect, orientation,
                direction) / 10;
    }

    public int getScrollableBlockIncrement(Rectangle visibleRect,
            int orientation, int direction)
    {
        switch (orientation)
        {
            case SwingConstants.HORIZONTAL: return visibleRect.width;
            case SwingConstants.VERTICAL:   return visibleRect.height;
            default: throw new IllegalArgumentException();
        }
    }
}
// End SSCCE