ShadowNinja.java

import greenfoot.*; // import every greefoot function, object and more

public class ShadowNinja extends NinjaEnemys
{
    private int invisibleTimer = 0;
    private boolean isInvisible = false; // if ninja is visible or not

    public ShadowNinja()
    {
        super(3);  // set speed
        GreenfootImage image = new GreenfootImage("./images/shadow_ninja.png");
        this.setImage(image);
    }
    
    public void moving()
    {
        this.move(-this.speed);
    }
    
    public void skills() {
        this.invisible();
    }
    
    private void invisible() {
        this.invisibleTimer++;
        
        // set the ninja invisible after a ceratin time
        if (this.invisibleTimer > 50) {
            this.isInvisible = !isInvisible;
            
            if (this.isInvisible) {
                this.getImage().setTransparency(0);
            } else {
                this.getImage().setTransparency(255);
            }
        
            this.invisibleTimer = 0;
        }
    }
    
    @Override
    public int getDamage() {
        return 2;
    }
}