I am trying to make thumbnail viewer and having problem putting the thumbnail in the proper place.

All I am trying to do is this:

iconPanel.add(iconBar, BorderLayout.NORTH);
        for (int x = 0; x < 4; x++) {

Ant then whenever I scroll,

for (k = index; k < indexLimit; k++) {
            JButton bt = new JButton(new ImageIcon(tmpImg));
            //Add action listener to button
            iconBar.add(bt, BorderLayout.CENTER);

But its not working, I dont see only one empty thumbnail at the start and on scroll i see 4 at time(which is fine!). But can you suggest a better layout strategy?


Yes the empty thumbnails are place holders.
And here is the code.(lets forget about the mouseWheel stuff for now)

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 * and open the template in the editor.
package desktopapplication2;

import java.awt.*;
import javax.swing.*;

/* FrameDemo.java requires no other files. */
public class imageLoad {

     * Create the GUI and show it.  For thread safety,
     * this method should be invoked from the
     * event-dispatching thread.
    private static JPanel iconPanel = new JPanel();
    private static JPanel iconBar = new JPanel();
    private static JButton emptyThumbnail = new JButton();

    private static void createAndShowGUI() {
        //Create and set up the window.
        JFrame frame = new JFrame("FrameDemo");

        //Add the two basic panels to the main panel
        iconPanel.setBorder(BorderFactory.createMatteBorder(5, 5, 5, 5, (new Color(169, 218, 146))));
        iconPanel.setBackground(new Color(218, 235, 201));

        // Lets set the empty icon thumbnails.
        emptyThumbnail.setPreferredSize(new Dimension(160, 120));
        emptyThumbnail.setBackground(new Color(207, 207, 207));
        emptyThumbnail.setBorder(BorderFactory.createLineBorder(new Color(156, 156, 156)));

        // We add two glue components. Later in process() we will add thumbnail buttons
        // to the toolbar inbetween thease glue compoents. This will center the
        // buttons in the toolbar.
        iconBar.setBackground(new Color(218, 235, 201));
        iconBar.setPreferredSize(new Dimension(788, 140));

        for (int x = 0; x < 4; x++) {
        // 1.Add buttonbar
        iconPanel.add(iconBar, BorderLayout.NORTH);

        frame.getContentPane().add(iconPanel, BorderLayout.CENTER);

        //Display the window.

    public static void main(String[] args) {
        //Schedule a job for the event-dispatching thread:
        //creating and showing this application's GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable() {

            public void run() {