How to dispose in Newest Java/LibGDX ApplicationListener?

Question

What I'm wondering:

How do you dispose of textures / spritebatches and the things you normally need to dispose of now?

Why I'm asking:

Because theirs no automatic dispose() function upon creation of the Main libGDX class. I don't remember details but there used to of been an @override dispose

I don't want a memory leak or whatever it's called when you don't dispose.

Answer 1

Make sure that you implement ApplicationListener in your main class in order to override dispose().

For example if MyGame is my main class then:

public class MyGame implements ApplicationListener {
    // put your Logic
}

Also libGDX provides the Game class that already implements ApplicationListener, so you can extend the Game class as follows:

public class MyGame extends Game {
    // Logic 
}

Once you follow one of the above approaches you are able to override dispose().

Answer 2

Some resources are not cleaned by the garbage collector. You need to dispose them manually, in order to save memory. You just need to call .dispose() You can find more information about libGDX memory management here. There is also a list with all resources that implement a disposable interface.

For example, you can dispose a Polygon Shape after using it to create your Fixture:

public void create() {
    FixtureDef fDef = new FixtureDef();
    Fixture fixture;
    PolygonShape shape = new PolygonShape();
    shape.setAsBox(w, h, position, angle);
    fDef.isSensor = true;
    fDef.shape = shape;
    fixture = body.createFixture(fDef);
    shape.dispose(); //You can dispose the shape.No longer needed.
}

However, you have to pay attention before disposing something that is still needed in your code:

public void setWalkLeftAnimation() {
    assetManager.load("walk_left.pack", TextureAtlas.class);
    assetManager.finishLoading();
    atlas = assetManager.get("walk_left.pack");
    walkingLeft =  new Animation(1/12f, atlas.getRegions());
    // Don't dispose it,you won't be able to render the animation.
    //assetManager.dispose();
    //atlas.dispose(); 
}

Dispose the Asset Manager and Atlas in the proper dispose method:

@Override
public void dispose(){
    assetManager.dispose();
    atlas.dispose();

    //Dispose it here with other resources.
}