I'm working with on one of the little crab scenarios, and I am trying to have it add another lobster and more worms after you eat a set amount of worms. The problem is that I can't get my crab class to call my method "nextLevel();" from my CrabWorld class to add more worms and another lobster. Instead I keep getting an error message saying "non-static method nextLevel() cannot be referenced from a static context. Thanks in advance.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 | //CRAB CLASS 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; /** * 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(); } public Crab() { image1 = new GreenfootImage( "crab.png" ); image2 = new GreenfootImage( "crab2.png" ); setImage(image1); } public void switchImage() { if ( getImage() == image1 ) { setImage(image2); } else { setImage(image1); } } /** * Check whether a control key on the keyboard has been pressed. * If it has, react accordingly. */ public void checkKeypress() { if (Greenfoot.isKeyDown( "left" )) { turn(- 15 ); } if (Greenfoot.isKeyDown( "right" )) { turn( 15 ); } } /** * 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 (wormsEaten == 8 ) { CrabWorld.nextLevel(); wormsEaten = 0 ; } } } } |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 | //CrabWorld Class import greenfoot.*; // imports Actor, World, Greenfoot, GreenfootImage import java.util.Random; import java.awt.Color; public class CrabWorld extends World { // public static final Color pathColor = new Color(227, 202, 148); /** * Create the crab world (the beach). Our world has a size * of 560x560 cells, where every cell is just 1 pixel. */ public CrabWorld() { super ( 560 , 560 , 1 ); populateWorld(); } /** * Create the objects for the start of the game. */ public void populateWorld() { addObject( new Crab(), 300 , 300 ); addObject( new Lobster(), 90 , 70 ); addObject( new Lobster(), 390 , 200 ); addObject( new Lobster(), 360 , 500 ); addObject( new Worm(), Greenfoot.getRandomNumber( 560 ), Greenfoot.getRandomNumber( 560 )); addObject( new Worm(), Greenfoot.getRandomNumber( 560 ), Greenfoot.getRandomNumber( 560 )); addObject( new Worm(), Greenfoot.getRandomNumber( 560 ), Greenfoot.getRandomNumber( 560 )); addObject( new Worm(), Greenfoot.getRandomNumber( 560 ), Greenfoot.getRandomNumber( 560 )); addObject( new Worm(), Greenfoot.getRandomNumber( 560 ), Greenfoot.getRandomNumber( 560 )); addObject( new Worm(), Greenfoot.getRandomNumber( 560 ), Greenfoot.getRandomNumber( 560 )); addObject( new Worm(), Greenfoot.getRandomNumber( 560 ), Greenfoot.getRandomNumber( 560 )); addObject( new Worm(), Greenfoot.getRandomNumber( 560 ), Greenfoot.getRandomNumber( 560 )); addObject( new Worm(), Greenfoot.getRandomNumber( 560 ), Greenfoot.getRandomNumber( 560 )); addObject( new Worm(), Greenfoot.getRandomNumber( 560 ), Greenfoot.getRandomNumber( 560 )); } public void nextLevel() { addObject( new Lobster(), Greenfoot.getRandomNumber( 560 ), Greenfoot.getRandomNumber( 560 )); addObject( new Worm(), Greenfoot.getRandomNumber( 560 ), Greenfoot.getRandomNumber( 560 )); addObject( new Worm(), Greenfoot.getRandomNumber( 560 ), Greenfoot.getRandomNumber( 560 )); addObject( new Worm(), Greenfoot.getRandomNumber( 560 ), Greenfoot.getRandomNumber( 560 )); addObject( new Worm(), Greenfoot.getRandomNumber( 560 ), Greenfoot.getRandomNumber( 560 )); addObject( new Worm(), Greenfoot.getRandomNumber( 560 ), Greenfoot.getRandomNumber( 560 )); addObject( new Worm(), Greenfoot.getRandomNumber( 560 ), Greenfoot.getRandomNumber( 560 )); addObject( new Worm(), Greenfoot.getRandomNumber( 560 ), Greenfoot.getRandomNumber( 560 )); addObject( new Worm(), Greenfoot.getRandomNumber( 560 ), Greenfoot.getRandomNumber( 560 )); addObject( new Worm(), Greenfoot.getRandomNumber( 560 ), Greenfoot.getRandomNumber( 560 )); addObject( new Worm(), Greenfoot.getRandomNumber( 560 ), Greenfoot.getRandomNumber( 560 )); addAnimals = false ; } } |