TestScreen

public class TestScreen implements Screen {
    protected Stage stage;
    private ClipTest ct;

    public TestScreen() {
        this.stage = new Stage(G.GAME_WIDTH, G.GAME_HEIGHT, true);

        Gdx.input.setInputProcessor(this.stage);
        Gdx.input.setCatchBackKey(true);
        Gdx.input.setCatchMenuKey(true);
    }

    @Override
    public void render(float delta) {
        Gdx.gl.glClearColor(1.0f, 0, 0, 0); // Black
        Gdx.graphics.getGL20().glClear(GL20.GL_COLOR_BUFFER_BIT | GL20.GL_DEPTH_BUFFER_BIT); // Clear the screen

        // update and draw the stage actors
        stage.act(delta);
        stage.draw();
    }

    @Override
    public void resize(int width, int height) {
        stage.setViewport(G.GAME_WIDTH, G.GAME_HEIGHT, true);
        stage.getCamera().translate(-stage.getGutterWidth(), -stage.getGutterHeight(), 0);
    }

    @Override
    public void show() {
        Gdx.input.setInputProcessor(this.stage);

        ct = new ClipTest();
        ct.setPosition(100, 200);
        stage.addActor(ct);
    }

    @Override
    public void dispose() {
        this.stage.dispose();
    }

    @Override public void hide() { }
    @Override public void pause() { }
    @Override public void resume() { }
}