Moving array of objects

[Alaric Mustoe]

so I have an array

package jforumanimationjunk;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.*;

/**
 *
 * @author mustoeal
 */
public class JForumAnimationJunk implements ActionListener, KeyListener {

    static final int FPS = 60;
    static final int TIMER = 1000 / FPS;
    static final int P_WIDTH = 500;
    static final int P_HEIGHT = 500;
    static final int O_WIDTH = 60;
    static final int O_HEIGHT = O_WIDTH / 3;
    int playerx = 400;
    int playery = 400;
    
   
    
    char key = 'g';
    Timer timer = null;
    JFrame f = null;
    MyJPanel p = null;

    JForumAnimationJunk() {
        timer = new Timer(TIMER, this);
        f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setTitle("SpaceInvaders");
        p = new MyJPanel();
        f.add(p);
        f.addKeyListener(this);

    }

    public void readimage(Graphics g) {

        int width = 50;    //width of the image
        int height = 50;   //height of the image

        Enemy[] enemies = new Enemy[6];
        Enemy[] enemies1 = new Enemy[6];

        for (int c = 0; c < enemies.length; c++) {
            enemies[c] = new Enemy("enemy 1.png");
            enemies1[c] = new Enemy("enemy 1.png");
        }
        
        

        Barrier[] barriers = new Barrier[3];

        for (int c = 0; c < barriers.length; c++) {

        }

        int barx = 30;
        int bary = 250;
        int barx1 = 200;
        int bary1 = 250;
        int barx2 = 350;
        int bary2 = 250;

        for (int c = 0; c < enemies.length; c++) {
            enemies[c].setPosition(50 * c, 0);
        }

        for (int d = 0; d < enemies.length; d++) {
            enemies1[d].setPosition(50 * d, 75);
        }
        for (int c = 0; c < enemies.length; c++) {
            drawImage(g, enemies[c].imageName, enemies[c].x, enemies[c].y);

            for (int d = 0; d < enemies1.length; d++) {
                drawImage(g, enemies1[d].imageName, enemies1[d].x, enemies1[d].y);
            }
        }
        BufferedImage image13 = null;
        File l = null;
        try {
            l = new File("barrier.png"); //image file path
            image13 = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
            image13 = ImageIO.read(l);

            g.drawImage(image13, barx, bary, null);
        } catch (IOException e) {
            System.out.println("Error: " + e);
        }
        BufferedImage image14 = null;
        File p = null;
        try {
            p = new File("barrier.png"); //image file path
            image14 = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
            image14 = ImageIO.read(p);

            g.drawImage(image14, barx1, bary1, null);
        } catch (IOException e) {
            System.out.println("Error: " + e);
        }
        BufferedImage image15 = null;
        File q = null;
        try {
            q = new File("barrier.png"); //image file path
            image15 = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
            image15 = ImageIO.read(q);

            g.drawImage(image15, barx2, bary2, null);
        } catch (IOException e) {
            System.out.println("Error: " + e);

        }
    }

    public static void main(String args[]) throws IOException {

        JForumAnimationJunk jfaj = new JForumAnimationJunk();
        jfaj.f.pack();
        jfaj.f.setVisible(true);
        jfaj.timer.start();

    }
 


 
 

    public static void drawImage(Graphics g, String imageName, int x, int y) {
        BufferedImage image = null;
        try {
            image = ImageIO.read(new File(imageName));
        } catch (IOException e) {
            System.out.println("Image with name " + imageName + "not found!");
        }
        g.drawImage(image, x, y, null);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        switch (key) {

            case 'a':
                playerx--;    //key for left movement;

                break;
            case 'd':
                playerx++;    // key for right movement;
                break;

            default:
                break;

        }
        //boundary checking
        if (playerx < 0) {
            playerx = 0;
        } else if (playerx > (P_WIDTH - O_WIDTH)) {
            playerx = P_WIDTH - O_WIDTH;
        }
        if (playery < 0) {
            playery = 0;
        } else if (playery > (P_HEIGHT - O_HEIGHT)) {
            playery = P_HEIGHT - O_HEIGHT;
        }
        p.repaint();
    }

    @Override
    public void keyPressed(KeyEvent k) {
        key = k.getKeyChar();  //read key for movement;
    }

    @Override
    public void keyReleased(KeyEvent k) {
        key = 'g'; //clears key to something not in the actionPerformed;

    }

    @Override
    public void keyTyped(KeyEvent k) {
        //intentionally left blank;
    }

    class MyJPanel extends JPanel {

        MyJPanel() {
            this.setPreferredSize(new Dimension(P_WIDTH, P_HEIGHT));
            this.setBackground(Color.BLACK);
        }

        @Override
        public void paintComponent(Graphics g) {

            g.setColor(Color.GREEN);
            super.paintComponent(g);
            g.fillOval(playerx, playery, O_WIDTH, O_HEIGHT);
            readimage(g);//read image
        }

    }

}

and have defined Entity

public abstract class Entity {

    public int x;
    public int y;
    public final String imageName;

    public Entity(String imageName) {
        this.imageName = imageName;
    }

    public void setPosition(int x, int y) {
        this.x = x;
        this.y = y;
    }

    
}   

and also said enemy

public class Enemy extends Entity {

    public Enemy(String imageName) {
        super(imageName);
    }
  }

can you help me to move these 2 lines of enemies over to the right 10 down 10 then over to the left 10 and then down 10 in that chronological order
Please I need help SOS

[Stefan Evans]

Well do you have any ideas?

I can see code in there where you loop through an array. That would be a start.

How would you affect the position of the "enemy" entities?

[Alaric Mustoe]

Stefan Evans wrote:Well do you have any ideas?

I can see code in there where you loop through an array. That would be a start.

How would you affect the position of the "enemy" entities?

Well I have a move method such as
for(int c =0;c<3;c++){
x = x+10;
etc

[Alaric Mustoe]

 public void move() {
   for(int c = 0; c<3;c++){
    x = x + 20;
  if(x == x +20){ 
    y = y -10;
 if(y == y -10){   
    x = x -20;
  if(x == x +20){ 
    y = y -10; 

[Stefan Evans]

Hmmm.
Ok, we've got some code there. But that is just x's and y's. I presume that they relate to location somehow.
But what does "c" refer to?
Can you explain what this code is meant to do using PseudoCode - i.e english?

Something along the lines of:
if (the enemy just moved to the right) then (move the enemy down)

[Alaric Mustoe]

so
if(boolean is set to true)
then move to the right this many times
then move down
then move left
then move down and loop
x is referring to entity class which defines entity x position and same with the y

[Paweł Baczyński]

if(x == x +20)
This condition will never be true.

[Winston Gutkowski]

Alaric Mustoe wrote:so
if(boolean is set to true)...

No, you're still trying to program it.

Describe the problem to us; don't tell us how you want to solve it - because that clearly isn't working.

Something along the lines that you did earlier: "Can you help me to move these 2 lines of enemies over to the right 10 down 10 then over to the left 10 and then down 10".

But we need to know ALL the rules before we can help you much.
If you already have a formal explanation of the game written out, show it to us - and if not, I suggest you start on it before you write one more line of code.

Also, a few questions:
1. If your battlefield is restricted, what do you want to happen if the rightmost enemy in the line can't move right 10?
2. You also appear to have some obstacles. How to they affect your line movement?

Winston

[Carey Brown]

When you move to the right (or left, or up, or down) what back fills the places vacated by the pieces that are moved?
What happens if the location you are about to move to is already occupied?
What happens when you get to the edge of the playing area and can't move?