where to add thread in the program

[amith]

in the above program, the main motive of the program is to keep one image fixed at the bottom (the fixed one is red) and start a thread for the image(the blue one) which u can see the code in the comment lines of the program given below .i just want to keep the fixed image and the other image(blue) in thread so that the two images should be visible to me , my program should look like one image(red) is fixed at the bottom and other image (blue) coming from top to bottom and both should be visible to me but they are not if one is fixed then i can see only that image i cant see the other image could u help out with this code and how to use thread in this program.


import java.util.*;
import java.awt.*;
import javax.swing.*;
class load extends JFrame
{

Image r;
Image b;

int y=329;
int floor=329;
int x=3;
load()
{

super("some name");
r=new ImageIcon("red.png").getImage();
b=new ImageIcon("blue.png").getImage();

getContentPane().add(new display());
setVisible(true);
setSize(175,400);
setResizable(false);
}

class display extends JPanel //implements Runnable
{
//Thread t=new Thread(this);
display()
{
repaint();
}

public void paintComponent(Graphics q)
{
Graphics2D n=(Graphics2D)q;
q.drawImage(r,x,y,this);
}
/*
i just want to place the red image fixed at the bottom
and start new blue image thread i,e
try
{
y=0;
while(y!=floor)
{
y++;
q.drawImage(b,x,y,this);
Thread.sleep(10);
}
}
catch(Exception e)
{
}
*/

}
}
class f
{
public static void main(String args[])
{
new load();
}
}

[Norm]

Suggestions:
Use CODE tags around code that you post to make for easier reading.
Use words for variable names instead of single letters
Naming conventions for Java classes is Uppercase first letter.

Re your logic - Following probably wrong because it is hard to read your code without the indentation showing nesting of {}.
Move the loop out of the paintComponent() method. You should only stay in this method long enough to do some drawing and then exit. Use repaint() to cause the system to call the paintComponent() method. Put the repaint() call following where you compute what/where to draw, probably in a loop inside a thread .

There are several examples of how to use Threads. Use a Search to find some and then put some code in your progam and post it using CODE tags.

[hardwired]

Didn't we just do this.

Code:

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

public class SlidingDownRevisited extends JPanel implements Runnable {
    Image[] images;
    int yLoc;

    public SlidingDownRevisited() {
        String prefix = "images/geek/geek";
        String[] ids = { "-c---", "--g--" };
        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();
        }
        yLoc = -images[1].getHeight(this);
    }

    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        int x = (getWidth() - images[0].getWidth(this))/2;
        int y = getHeight() - images[0].getHeight(this);
        g.drawImage(images[0], x, y, this);
        g.drawImage(images[1], x, yLoc, this);
    }

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

    public void run() {
        int height = getPreferredSize().height -
                     images[0].getHeight(this);
        do {
            yLoc++;
            repaint();
            try {
                Thread.sleep(100);
            } catch(InterruptedException e) {
                break;
            }
        } while(yLoc + images[1].getHeight(this) < height);
        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) {
        SlidingDownRevisited test = new SlidingDownRevisited();
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(test);
        f.pack();
        f.setLocation(200,200);
        f.setVisible(true);
        test.start();
    }
}