libgdx-application-lifecycle

libGDX Application Lifecycle

Reference for ApplicationListener, ApplicationAdapter, lifecycle method order, frame-independent updates, resource disposal, and platform-specific pause/resume behavior.

ApplicationListener Interface

public interface ApplicationListener {
    void create();             // App created — OpenGL context now available
    void resize(int w, int h); // Window/viewport resized
    void render();             // Called every frame (update + draw combined)
    void pause();              // App losing focus / going to background
    void resume();             // App regaining focus / returning to foreground
    void dispose();            // App shutting down — release all resources
}

There is no update() method. All game logic and drawing happen in render().

ApplicationAdapter (Use This)

ApplicationAdapter implements ApplicationListener with empty defaults. Extend it and override only what you need — avoids boilerplate empty methods.

// YES — extend ApplicationAdapter
public class MyGame extends ApplicationAdapter { ... }

// NO — don't implement ApplicationListener directly unless you need all 6 methods
public class MyGame implements ApplicationListener { ... }

Lifecycle Order

create() → resize(w,h) → [render() loop] → pause() → dispose()
                          ↕
                   pause() ↔ resume()

Startup: create() → resize(w, h) → render() ... Exit: pause() → dispose()

On Android, dispose() may not be called if the OS kills the process while backgrounded. Save critical state in pause(), not dispose().

Initialization: create(), Not the Constructor

All GPU/audio/file initialization must happen inside create(). The OpenGL context and libGDX subsystems (Gdx.graphics, Gdx.audio, Gdx.files, etc.) do not exist until create() is called. Constructing a Texture, SpriteBatch, or any GL-dependent object as a field initializer or in the constructor will crash.