Crab

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

/**
 * This class defines a crab. Crabs live on the beach. They like sand worms
 * (very yummy, especially the green ones).
 *
 * Version: 5
 *
 * In this version, the crab behaves as before, but we add animation of the
 * image.
 */

public class Crab extends Animal
{
    private GreenfootImage image1;
    private GreenfootImage image2;
    private int wormsEaten;

    /**
     * Create a crab and initialize its two images.
     */
    public Crab()
    {
        image1 = new GreenfootImage("crab2.png");
        image2 = new GreenfootImage("crab.png");
        setImage(image1);
        wormsEaten = 0;
    }

    /**
     * Act - do whatever the crab wants to do. This method is called whenever
     *  the 'Act' or 'Run' button gets pressed in the environment.
     */
    public void act()
    {
        checkKeypress();
        move();
        lookForWorm();
        switchImage();
    }

    /**
     * Alternate the crab's image between image1 and image2.
     */
    public void switchImage()
    {
        if (getImage() == image1)
        {
            setImage(image1);
        }
        else
        {
            setImage(image2);
        }
    }

    /**
     * Check whether a control key on the keyboard has been pressed.
     * If it has, react accordingly.
     */
    public void checkKeypress()
    {
        if (Greenfoot.isKeyDown("left"))
        {
            turn(-4);
        }
        if (Greenfoot.isKeyDown("right"))
        {
            turn(4);
        }
        if (Greenfoot.isKeyDown("up"))
        {
            turn(4);
        }
        if (Greenfoot.isKeyDown("down"))
        {
            turn(-4);
        }
    }

    /**
     * Check whether we have stumbled upon a worm.
     * If we have, eat it. If not, do nothing. If we have
     * eaten eight worms, we win.
     */
    public void lookForWorm()
    {
        if ( canSee(Worm.class) )
        {
            eat(Worm.class);
            Greenfoot.playSound("slurp.wav");

            wormsEaten = wormsEaten + 1;
            if (CrabWorld.getWorm() == 0)
            {
                Greenfoot.playSound("fanfare.wav");
                Greenfoot.stop();
            }
        }
    }
}