Counter Problem

INSIDE Counter Class

import greenfoot.*;  // (World, Actor, GreenfootImage, Greenfoot and MouseInfo)

/**
 * Write a description of class Counter here.
 * 
 * @author (your name) 
 * @version (a version number or a date)
 */
public class Counter extends Actor

{
    private static final Color transparent = new Color(0,0,0,0);
    private GreenfootImage background;
    private int value;
    private int target;
    
    public Counter(){
    background = getImage();//gets the image from the class
    value = 0;
    target = 0;
    updateImage();
    }
    
    /**
     * Act - do whatever the Counter wants to do. This method is called whenever
     * the 'Act' or 'Run' button gets pressed in the environment.
     */
    public void act() 
    {
        if (value < target) {
        
            value ++;
            updateImage();
        }
        else if (value > target) {
        value --;
        updateImage();
        }
    }
    
    public void add(int score){

        target += score;
        
    }
    
    public int getValue(){
    return value;
    
    }
    
    public void setValue(int newValue)
    {
    target = newValue;
    value = newValue;
    updateImage();
    }
    
    public void updateImage()
    {
    GreenfootImage image = new GreenfootImage(background);
    GreenfootImage text = new GreenfootImage("" + value, 22, Color.YELLOW, transparent);
    image.drawImage(text, (image.getWidth()-text.getWidth())/2,
    (image.getHeight()-text.getHeight())/2);
    setImage(image);
    }
    
}



INSIDE Bullet Class

private Counter counter;

    
    public Bullet(Counter pointCounter){

        counter = pointCounter;
        
    }
    public void destroyEnemy(){

      
             
        if(collectItem(Enemy.class)){
            collect(Enemy.class);
            getWorld().removeObject(this);
           
            
        }
        else
        if(atWorldEdge()){getWorld().removeObject(this);}

        
    }

INSIDE PLAYER1 Class

import greenfoot.*;  //        collectToken (World, Actor, GreenfootImage, Greenfoot and MouseInfo)

/**
 * Write a description of class Player1 here.
 * 
 * @author (your name) 
 * @version (a version number or a date)
 */
public class Player1 extends Characters
{
    private int shotdelay;
    /**
     * Act - do whatever the Player1 wants to do. This method is called whenever
     * the 'Act' or 'Run' button gets pressed in the environment.
     */
    public void act() 
    {
        // Add your action code here.
        
        keyPress();
        fireBullet();
        turnAtEdge();
        
    }

    
    
    public void keyPress() {

        if(Greenfoot.isKeyDown("left")){
            turn(-5);
        }

        if (Greenfoot.isKeyDown("right")){
            turn(5);
        } 

        if (Greenfoot.isKeyDown("up")){
            move(5);    
        }
    }
private Counter counter;

    
    public Player1(Counter pointCounter){

        counter = pointCounter;
      
    }
    public void fireBullet(){
        if(shotdelay > 0) shotdelay --;

        if (shotdelay == 0 && Greenfoot.isKeyDown("space")){
            Bullet b = new Bullet(counter);
            b.setRotation(getRotation());
            getWorld().addObject(b, getX(), getY());
            b.move(20);
            shotdelay = 20;
            
            
        }

    }



    
    
    public void turnAtEdge()
    {
        if (atWorldEdge())
        {
            turn(5);
        }
    }
    public void checkKeys()
    {
        if (Greenfoot.isKeyDown("left"))
        {
            turn(-5);
        }
        
        if (Greenfoot.isKeyDown("right"))
        {
            turn(5);
        }
    }
    

        public Player1() {
        GreenfootImage image = getImage();
        image.scale(50,100);
        setImage(image);
    }
}