I'm following the Canyon Bunny example in making my own game and I'm at the point where I want to implement a level selection screen. The way the example code works is that there's a Level class whose constructor takes a string variable that contains the path of the level file to be loaded from WorldController class which contains the game logic. So far I have a LevelScreen with the various buttons for the various levels like so:
public class LevelScreen extends AbstractGameScreen { private Stage stage; private Skin levelSkin; private String currLevel; private Image imgBackground; private Button btnForest, btnDesert; private final float DEBUG_REBUILD_INTERVAL = 5.0f; private boolean debugEnabled = false; private float debugRebuildStage; private static final String TAG = LevelScreen.class.getName(); public LevelScreen(DirectedGame game) { super(game); } private void rebuildStage() { levelSkin = new Skin(Gdx.files.internal(Constants.SKIN_LEVEL_UI), new TextureAtlas(Constants.TEXTURE_ATLAS_LEVELS)); Table layerBackground = buildBackgroundLayer(); Table layerLevels = buildLevelsLayer(); stage.clear(); Stack stack = new Stack(); stage.addActor(stack); stack.setSize(Constants.VIEWPORT_GUI_WIDTH, Constants.VIEWPORT_GUI_HEIGHT); stack.add(layerBackground); stack.add(layerLevels); } private Table buildBackgroundLayer() { Table layer = new Table(); imgBackground = new Image(levelSkin, "wallpaper"); layer.add(imgBackground); return layer; } private Table buildLevelsLayer() { Table layer = new Table(); btnDesert = new Button(levelSkin, "desert"); layer.addActor(btnDesert); btnDesert.setPosition(50, 250); btnDesert.addListener(new ChangeListener() { @Override public void changed(ChangeEvent event, Actor actor) { onDesertClicked(); } private void onDesertClicked() { setCurrLevel(Constants.LEVEL_01); ScreenTransition transition = ScreenTransitionSlide.init(0.75f, ScreenTransitionSlide.LEFT, false, Interpolation.bounceOut); game.setScreen(new GameScreen(game), transition); } }); btnForest = new Button(levelSkin, "forest"); layer.addActor(btnForest); btnForest.setPosition(345, 150); btnForest.addListener(new ChangeListener() { @Override public void changed(ChangeEvent event, Actor actor) { onForestClicked(); } private void onForestClicked() { setCurrLevel(Constants.LEVEL_02); ScreenTransition transition = ScreenTransitionSlide.init(0.75f, ScreenTransitionSlide.LEFT, false, Interpolation.bounceOut); game.setScreen(new GameScreen(game), transition); } }); btnBack = new Button(levelSkin, "back"); layer.addActor(btnBack); btnBack.setPosition(640, 50); btnBack.addListener(new ChangeListener() { @Override public void changed(ChangeEvent event, Actor actor) { onBackClicked(); } }); return layer; } @Override public InputProcessor getInputProcessor() { return stage; } @Override public void render(float deltaTime) { Gdx.gl.glClearColor(0.0f, 0.0f, 0.0f, 1.0f); Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT); if (debugEnabled) { debugRebuildStage -= deltaTime; if (debugRebuildStage <= 0) { debugRebuildStage = DEBUG_REBUILD_INTERVAL; rebuildStage(); } } stage.act(deltaTime); stage.draw(); Table.drawDebug(stage); } private void onBackClicked() { ScreenTransition transition = ScreenTransitionSlide.init(1, ScreenTransitionSlide.RIGHT, false, Interpolation.bounceOut); game.setScreen(new MenuScreen(game), transition); } @Override public void resize(int width, int height) { stage.getViewport().update(width, height, true); } @Override public void show() { stage = new Stage(new StretchViewport(Constants.VIEWPORT_GUI_WIDTH, Constants.VIEWPORT_GUI_HEIGHT)); rebuildStage(); } @Override public void hide() { stage.dispose(); levelSkin.dispose(); } @Override public void pause() { } public String getCurrLevel() { return currLevel; } public void setCurrLevel(String currLevel) { this.currLevel = currLevel; } }
What I'm trying to achieve is for the initLevel() method in WorldController to receive currLevel and pass it to Level as shown
public class WorldController extends InputAdapter { private static final String TAG = WorldController.class.getName(); public Level level; public int lives; public int coinScore, keyScore; public CameraHelper cameraHelper; private DirectedGame game; private LevelScreen levScreen; private Rectangle r1 = new Rectangle(); private Rectangle r2 = new Rectangle(); public WorldController(DirectedGame game) { this.game = game; init(); } private void init() { cameraHelper = new CameraHelper(); lives = Constants.LIVES_START; initLevel(); } private void initLevel() { coinScore = 0; level = new Level(levScreen.getCurrLevel()); cameraHelper.setTarget(level.player); } // more code } I keep getting a NPE error with this. I'm still new to java and libgdx, what I'd like to know is how I can pass the String containing the path to the level file from LevelSelect to WorldController and specifically to this line level = new Level(levScreen.getCurrLevel()); Thanks.
