java - LibGdx:Tween Callback on Tween Engine -

i following following tutorial have created button when write tweencallback should display button @ end of animation. not working , ends splash screen fading in , out. code splash screen.

public class splash implements screen{ private sprite splash; private spritebatch batch; private tweenmanager tweenmanager;  @override public void render(float delta) {     gdx.gl.glclearcolor(0, 0, 0, 1);     gdx.gl.glclear(gl20.gl_color_buffer_bit);     tweenmanager.update(delta);     batch.begin();     splash.draw(batch);     batch.end();  }  @override public void resize(int width, int height) {  }  @override public void show() {     tweenmanager = new tweenmanager();     tween.registeraccessor(sprite.class, new spriteaccessor());     batch = new spritebatch();     texture splashtexture = new texture ("backgrounds/openingscreen.png");     splash = new sprite(splashtexture);     splash.setsize(gdx.graphics.getwidth(), gdx.graphics.getheight());     tween.set(splash, spriteaccessor.alpha).target(0).start(tweenmanager);     tween.to(splash, spriteaccessor.alpha, 3f).target(1).repeatyoyo(1, 0f).setcallback(new tweencallback() {          @override         public void onevent(int type, basetween<?> source) {             ((game)gdx.app.getapplicationlistener()).setscreen(new mainmenu());         }     }).start(tweenmanager); } 

i know problem not button have in main class tried use setscreen (new mainmenu()); , button shows up. here dont understand why wont show up. tutorial works fine , checked code against source code tutorial. ideas? thanks

answer: turns out had commented out initial draw screen in mainmenu class , thats why didn't work