[hardwired]

Now we can slide up and down.

Code:

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

public class SlidingDown extends JPanel implements Runnable {
    Image[] images;
    int[] yLocs;

    public SlidingDown() {
        String prefix = "images/geek/geek";
        String[] ids = { "-c---", "--g--", "---h-", "----t" };
        images = new Image[ids.length];
        for(int i = 0; i < images.length; i++) {
            String path = prefix + ids[i] + ".gif";
            images[i] = new ImageIcon(path).getImage();
        }
        yLocs = new int[images.length];
        for(int i = 0; i < yLocs.length; i++) {
            yLocs[i] = -images[i].getHeight(this);
        }
    }

    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        for(int i = 0; i < images.length; i++) {
            int x = (getWidth() - images[i].getWidth(this))/2;
            g.drawImage(images[i], x, yLocs[i], this);
        }
    }

    public Dimension getPreferredSize() {
        return new Dimension(300,400);
    }

    public void run() {
        int height = getPreferredSize().height;
        int index = 0;
        do {
            yLocs[index]++;
            repaint();
            if(yLocs[index] > height) {
                index++;
            }
            try {
                Thread.sleep(100);
            } catch(InterruptedException e) {
                break;
            }
        } while(index < images.length);
        System.out.println("all done");
    }

    private void start() {
        Thread thread = new Thread(this);
        thread.setPriority(Thread.NORM_PRIORITY);
        thread.start();
    }

    public static void main(String[] args) {
        SlidingDown test = new SlidingDown();
        JFrame f = new JFrame();
        f.add(test);
        f.pack();
        f.setLocation(200,200);
        f.setVisible(true);
        test.start();
    }
}