JList ListCellRenderer Help

Question

Hello All,
I have a small query in regards to a ListCellRenderer implementation.
I have my own ListCellRenderer implementation, and it is working fine in regards to bolding text, colors and so on. But I was wondering about how I would go making a nice "glowing" effect on the mouseover event of the List item.
I have been a web programmer for a while, and have had many nice experiences with JavaScript and using timing events, to slowly change the color of an HTML element, to give it that glowing effect.
I was kind of hoping to do the same for a JList, is there anyone out there that has had experiences with this kind of thing?
Any help is appreciated, I will also post if I find anything on my own.
Cheers,
Mark

Answer 1

I've no idea of what glowing effect you are after, but I was bored and have been playing with timers and colors and came up with this effect. If you develop your glow effect, please post your code so we can play with it.
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
class GlowSwing2 extends JPanel
    private static final int TIMER_PERIOD = 60;
    private static final int DIMEN = 400;
    private static final int GRID_SIZE = 5;
    private static final int COLOR_STEPS = 16;
    private Color currentColor = Color.black;
    private Color originalColor = Color.black;
    private int colorIndex = 0;
    private JLabel[][] labels = new JLabel[GRID_SIZE][GRID_SIZE];
    private JLabel currentLabel = null;
    private Timer timer = new Timer(TIMER_PERIOD, new MyTimerAction());
    private Color[] colors;
    GlowSwing2()
        setPreferredSize(new Dimension(DIMEN, DIMEN));
        int ebGap = 10;
        setBorder(BorderFactory.createEmptyBorder(ebGap, ebGap, ebGap, ebGap));
        setLayout(new GridLayout(GRID_SIZE, GRID_SIZE));
        for (int i = 0; i < GRID_SIZE; i++)
            for (int j = 0; j < GRID_SIZE; j++)
                JLabel jl = new JLabel("Hello");
                jl.setFont(new Font(Font.SANS_SERIF, Font.BOLD, 24));
                jl.addMouseListener(new LabelMouseListener());
                add(jl);
                labels[i][j] = jl;
        initColors();
        timer.start();
     * creates a nice sin wave of blue color
    private void initColors()
        colors = new Color[COLOR_STEPS];
        double periodStep = 2 * Math.PI / COLOR_STEPS;
        for (int i = 0; i < colors.length; i++)
            int c = (int)(256 * (Math.sin(i * periodStep) + 1)/2);
            if (c == 256)
                c = 255;
            colors[i] = new Color(c, c, 255);
    private class LabelMouseListener extends MouseAdapter
        @Override
        public void mouseEntered(MouseEvent mEvent)
            JLabel source = (JLabel)mEvent.getSource();
            originalColor = source.getForeground();
            currentLabel = source;
            super.mouseEntered(mEvent);
        @Override
        public void mouseExited(MouseEvent mEvent)
            currentLabel = null;
            ((JLabel)mEvent.getSource()).setForeground(originalColor);
            super.mouseExited(mEvent);
    private class MyTimerAction implements ActionListener
        public void actionPerformed(ActionEvent arg0)
            myTimerAction(arg0);
     * changes the colors of the labels
     * @param arg0
    private void myTimerAction(ActionEvent arg0)
        if (currentLabel != null)
            colorIndex++;
            colorIndex %= colors.length;
            currentColor = colors[colorIndex];
            currentLabel.setForeground(currentColor);
            currentLabel.repaint();
    private static void createAndShowGUI()
        JFrame frame = new JFrame("GlowSwing Application");
        frame.getContentPane().add(new GlowSwing2());
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    public static void main(String[] args)
        SwingUtilities.invokeLater(new Runnable()
            public void run()
                createAndShowGUI();
}