Loading TextureAtlases using AssetManager in LibGdx

Question

I want to use AssetManager in LibGDX to load my TextureAtlas. But I am not getting it. I have actually one large 2048 x 2048 px image, that I am creating in Predator. and then I am using the regions. Should I need to load the atlas once using AssetManager or what?

This is my current code

public class Assets {
private final static String FILE_SPRITE_ATLAS = "data/sprite_sheet.txt";

private final static String FILE_UI_SKIN = "skin/uiskin.json";
private final static String FILE_UI_SKIN_OTHER = "otherskin/uiskin.json";

public static TextureAtlas spriteAtlas;
public static Skin skin;
public static Skin other_skin;

//
public static TextureRegion bg;
public static TextureRegion dark_bg;

public static TextureRegion button_bg;
public static TextureRegion dracus;
public static TextureRegion egg;
public static TextureRegion egg_icon,play_icon,settings_icon,fb_icon,back_icon,credits_icon,sound_off,sound_on;
public static TextureRegion hunter_shooting;
public static TextureRegion hunter_walking;
public static TextureRegion button_pause;
public static TextureRegion dragon_icon;
public static TextureRegion arrow;
public static TextureRegion transparent_credits;
public static TextureRegion transparent_box;
public static TextureRegion transparent,mat,high_scores,tooltip,player_icon;
public static TextureRegion logo,egg_bucket,audio_icon,lock_icon,star;


public static Animation dragonLeft, dragonRight,dragonUp,dragonFront;
public static Animation anim_hunter_shooting;
public static Animation anim_hunter_walking;
public static Animation hunter_ready_shooting;
//
public static BitmapFont smallFont;
public static BitmapFont bigFont;

// TEST OBJECT
public static TextureRegion imgTest;
public static BitmapFont font3_1;

public static Texture loadTexture(String file) {
    return new Texture(Gdx.files.internal(file));
}

public static TextureAtlas getSpriteAtlas() {
    if (spriteAtlas == null) {
        spriteAtlas = new TextureAtlas(
                Gdx.files.internal(FILE_SPRITE_ATLAS));
    }
    return spriteAtlas;
}

public static Skin getSkin() {
    if (skin == null) {
        FileHandle skinFile = Gdx.files.internal(FILE_UI_SKIN);
        skin = new Skin(skinFile);
    }
    return skin;
}

public static Skin getOtherSkin() {
    if (other_skin == null) {
        FileHandle skinFile = Gdx.files.internal(FILE_UI_SKIN_OTHER);
        other_skin = new Skin(skinFile);
    }
    return other_skin;
}

public static void loadAll() {
    relaseResources();
    loadImages();
    loadButtons();
    loadFonts();
    loadAnimations();
    loadSoundsAndMusics();
}

private static void relaseResources() {
    skin = null;
}

public static void loadImages() {

    //REGIONS FROM SPRITE ATLAS
    bg = getSpriteAtlas().findRegion("bg");
    dark_bg = new TextureRegion(bg.getTexture(),0,0,960,300);
    button_bg = getSpriteAtlas().findRegion("button_bg");
    dracus = getSpriteAtlas().findRegion("dracus");
    egg = getSpriteAtlas().findRegion("egg");
    egg_icon = getSpriteAtlas().findRegion("egg_icon");
    sound_on = getSpriteAtlas().findRegion("sound_on");
    sound_off = getSpriteAtlas().findRegion("sound_off");
    credits_icon = getSpriteAtlas().findRegion("credits_icon");
    back_icon = getSpriteAtlas().findRegion("back");
    fb_icon = getSpriteAtlas().findRegion("fb_icon");
    settings_icon = getSpriteAtlas().findRegion("settings_icon");
    play_icon = getSpriteAtlas().findRegion("play_icon");
    transparent = getSpriteAtlas().findRegion("transparent");

    hunter_walking =getSpriteAtlas().findRegion("hunter_walking");
    hunter_shooting =getSpriteAtlas().findRegion("hunter_shooting");

    button_pause =getSpriteAtlas().findRegion("button_pause");
    arrow =getSpriteAtlas().findRegion("arrow");
    dragon_icon =getSpriteAtlas().findRegion("dragon_icon");

    transparent_credits =getSpriteAtlas().findRegion("transparent_credits");
    transparent_box =getSpriteAtlas().findRegion("transparent_box");
    egg_bucket =getSpriteAtlas().findRegion("egg_bucket");
    logo =getSpriteAtlas().findRegion("logo");
    mat =getSpriteAtlas().findRegion("mat");

    audio_icon=getSpriteAtlas().findRegion("audio_icon");
    lock_icon =getSpriteAtlas().findRegion("lock_icon");
    //howtoplay_icon =getSpriteAtlas().findRegion("howtoplay_icon");
    high_scores =getSpriteAtlas().findRegion("high_scores");
    star = getSpriteAtlas().findRegion("star");
    tooltip = getSpriteAtlas().findRegion("tooltip");
    player_icon = getSpriteAtlas().findRegion("player_icon");

    }

public static void loadButtons() {
    //img_btn_home = getAtlas().findRegion("img_btn_home");
    //img_btn_home_pressed = getAtlas().findRegion("img_btn_home_pressed");
}

public static void loadFonts() {
    //
    smallFont = new BitmapFont(Gdx.files.internal("data/smallFont.fnt"),
            Gdx.files.internal("data/smallFont.png"), false);
    bigFont = new BitmapFont(Gdx.files.internal("data/bigFont.fnt"),
            Gdx.files.internal("data/bigFont.png"), false);
    font3_1 = new BitmapFont(Gdx.files.internal("data/font3.fnt"),
            Gdx.files.internal("data/font3.png"), false);
}

public static void loadAnimations() {
    //Loading the Dragon

    TextureRegion[][] regions2 = Assets.dracus.split(96, 96);

    dragonLeft = new Animation(0.15f, regions2[1][0],regions2[1][1], regions2[1][2],regions2[1][3]);
    dragonLeft.setPlayMode(Animation.LOOP_PINGPONG);    

    dragonRight = new Animation(0.15f, regions2[2][0],regions2[2][1], regions2[2][2],regions2[2][3]);
    dragonRight.setPlayMode(Animation.LOOP_PINGPONG);

    dragonUp = new Animation(0.15f, regions2[3][0],regions2[3][1], regions2[3][2],regions2[3][3]);
    dragonUp.setPlayMode(Animation.LOOP_PINGPONG);  

    dragonFront = new Animation(0.15f, regions2[0][0],regions2[0][1], regions2[0][2],regions2[0][3]);
    dragonFront.setPlayMode(Animation.LOOP_PINGPONG);   


    TextureRegion[][] hunter_shoot_regions = hunter_shooting.split(110, 143);
    anim_hunter_shooting = new Animation(0.25f, hunter_shoot_regions[0][0],hunter_shoot_regions[0][1], 
            hunter_shoot_regions[0][2],hunter_shoot_regions[0][3]);
    //anim_hunter_shooting.setPlayMode(Animation.LOOP_PINGPONG);

    hunter_ready_shooting = new Animation(1.0f, hunter_shoot_regions[0][0],hunter_shoot_regions[0][1]);

    TextureRegion[][] hunter_walk_regions = hunter_walking.split(86, 132);
    anim_hunter_walking = new Animation(0.20f, hunter_walk_regions[0][0],hunter_walk_regions[0][1], 
            hunter_walk_regions[0][2],hunter_walk_regions[0][3]);
    anim_hunter_walking.setPlayMode(Animation.LOOP_PINGPONG);   
}

public static void loadSoundsAndMusics() {
}
}

Answer 1

Create an AssetManager:

AssetManager manager = new AssetManager();

This to begin the loading:

manager.load(FILE_SPRITE_ATLAS, TextureAtlas.class);

This getting called continously for asynchronous loading:

manager.update();

Or this called once for synchronous loading:

manager.finishLoading();

and then this saves the spriteAtlas (when update() returns 1):

spriteAtlas = manager.get(FILE_SPRITE_ATLAS, TextureAtlas.class);

Next time, do not post that much code. Post only the relevant parts. In this case there wasn't actually any relevant parts. You don't even have an AssetManager declared...

Useful Link: Libgdx Wiki.