Thread: Declaring a winner in a Race Car Program

Hello All!

I have the following code:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.Random;
 
public class RacingCar extends JFrame {
 
    public RacingCar() {
        int x = (int)(Math.random() * 3) + 2;
        setLayout(new GridLayout(x, 1, 5,5));
        for (int i = 0; i < x; i++){
                add(new CarImage());
        }
    }
 
    public static void main(String[] args) {
        JFrame frame = new RacingCar();
        frame.setTitle("Racing Car");
        frame.setSize(1200, 350);
        frame.setLocationRelativeTo(null);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }
 
    class CarImage extends JPanel {
        protected int x = 0;
        protected int y = 150;
        protected int z = 300;
        protected int c = 0;
        protected int k = 0;
 
        public CarImage() {
            int j = (int)(Math.random() * 1000) + 2;
                Timer timer1 = new Timer(j, new ActionListener(){
                public void actionPerformed(ActionEvent e) {
                x += 10;
                c ++;
                if (k < 341) {
                repaint();
                k++;
                }
                }
            });
            timer1.start();
        }
 
        @Override
        public void paintComponent(Graphics g) {
            super.paintComponent(g);
                // x = 0;
                y = getHeight();
                z = getWidth();
                g.setColor(Color.WHITE);
                g.fillRect(0, 0, z, y);
                Polygon polygon = new Polygon();
                polygon.addPoint(x + 10, y - 21);
                polygon.addPoint(x + 20, y - 31);
                polygon.addPoint(x + 30, y - 31);
                polygon.addPoint(x + 40, y - 21);
 
                if (x < z - 50) {
                    g.setColor(Color.BLACK);
                    g.fillOval(x + 10, y - 11, 10, 10);
                    g.fillOval(x + 30, y - 11, 10, 10);
                    g.setColor(Color.BLUE);
                    g.fillRect(x, y - 21, 50, 10);
                    g.setColor(Color.GRAY);
                    g.fillPolygon(polygon);
                    g.setColor(Color.RED);
                }
                else {
                    x = 0;
 
                }
        }
 
    }
}

I'm stuck for the time being. How would I declare a winner? What I mean is, there are 2 - 4 random cars being "generated." Each cars speed is randomly "generated." I am trying to figure out a way for a winner to be declared after 3 "laps."

Would someone please show me what I can do? I appreciate it and thank you in advance?

Originally Posted by Norm

Where do you count the laps each car has made?

 
if (k < 341) {
                        repaint();
                        k++;

Is where I will get 3 "laps" based on the panel width of 1200.

[QUOTE=Where do you record the x location of each car so that you know which car is in front?[/QUOTE]

I do not


[QUOTE=Most of the variables have poor non-descriptive names making the code hard to read and understand. j, c, k, y , z ???[/QUOTE]
Thanks

Originally Posted by Norm

Your code is very hard to read and understand. There are no comments and the variable names are not descriptive of what data they hold. The 341 is a complete mystery and will cause problems when the size of the JFrame is set to a different size to make for faster testing by making the laps shorter.
If you want to stop the race after so many laps, you need to count the number of laps that the car has made so you know when the race is over.


I suggest that you fix the code so that it is more easily understood.

Thank You.

Ok so here is some updated code But I am not see the flaw. It doesn't seem to stop after 3 laps. Can someone point out what might be wrong? I really appreciate it.
Here is the updated code:

import java.awt.Color;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.Polygon;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.Timer;
 
public class RacingCar extends JFrame {
 
    private static boolean stopTheRace = false;
 
    public static void stopRace(){
        stopTheRace = true;
    }
 
    public static void startRace(){
        stopTheRace = false;
    }
 
    public static boolean isStopTheRace(){
        return stopTheRace;
    }
 
    public RacingCar() {
        int x = (int)(Math.random() * 3) + 2;
        setLayout(new GridLayout(x, 1, 5,5));
        for (int i = 0; i < x; i++){
                add(new CarImage(i));
        }
    }
 
    public static void main(String[] args) {
        JFrame frame = new RacingCar();
        frame.setTitle("Racing Car");
        frame.setSize(1200, 350);
        frame.setLocationRelativeTo(null);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }
 
    class CarImage extends JPanel {
        protected int x = 0;
        protected int y = 350;
        protected int z = 1200;
        protected int c = 0;
        protected int carId;
        protected int laps = 0;
 
        public CarImage(int id) {
            int j = (int)(Math.random() * 70) + 2;
                this.carId = id;
                final Timer timer1 = new Timer(j, new ActionListener(){
 
                    @Override
                    public void actionPerformed(ActionEvent e) {
                        x += 10;
                        c ++;
                        String CarLane = (carId + 1)+"";
                        if (laps == 3){
                            RacingCar.stopRace();
                            JOptionPane.showMessageDialog(null, "Winner in Lane "
                             + CarLane + " ", "Winner winner chicken dinner", 
                             JOptionPane.INFORMATION_MESSAGE);
                        }
                        if (RacingCar.isStopTheRace()){
                            ((Timer)e.getSource()).stop();
                        }
                        repaint();
                    }
            });
 
            timer1.start();
 
        }
 
        @Override
        public void paintComponent(Graphics g) {
            super.paintComponent(g);
                //x = 0;
                y = getHeight();
                z = getWidth();
                g.setColor(Color.WHITE);
                g.fillRect(0, 0, z, y);
                Polygon polygon = new Polygon();
                polygon.addPoint(x + 10, y - 21);
                polygon.addPoint(x + 20, y - 31);
                polygon.addPoint(x + 30, y - 31);
                polygon.addPoint(x + 40, y - 21);
 
                if (x < z - 50) {
                    g.setColor(Color.BLACK);
                    g.fillOval(x + 10, y - 11, 10, 10);
                    g.fillOval(x + 30, y - 11, 10, 10);
                    g.setColor(Color.BLUE);
                    g.fillRect(x, y - 21, 50, 10);
                    g.setColor(Color.GRAY);
                    g.fillPolygon(polygon);
                    g.setColor(Color.RED);
                }
                else {
                    x = 0;
 
                }
        }
 
    }
}

Originally Posted by Norm

Where are the laps counted?

Yah good call. Gotta figure out how to count the laps. Not really sure how to go about it efficiently. I did have a loop with repaint() in it and it really did not seem efficient enough.
It was:

if (k < 341) {
     repaint();
     k++;
}

but that did not take into account if the window was resized. Any ideas?

Originally Posted by Norm

Where is the car when it completes a lap? Can you use its position to determine when it has completed a lap?

Yes. Since the panel width is "z = 1200", I assume one lap would roughly be less than a panel width. Is that not correct?

Originally Posted by Norm

Sorry, I don't know what the variable z contains or what the meaning of 1200 is.
A better name for the variable would explain what data z contains.
The length of the race track should be held in a variable and not hardcoded as 1200.

Perhaps something like this:
carsPosition >= trackLength

Ok so we can go along those lines, but then that begs the question, if a user desides to change the size of the frame, how does one know the size of the frame? What would be a value of that or better yet, how do I determine the value of that?