namespace TeamPlatformer
{
   abstract class GameScreen
    {
        public enum ScreenStatus { Activ, Inactiv, inTransition}

        abstract public event ScreenHandler ScreenChanged;

        abstract public void LoadContent(ContentManager content);

        abstract public void Update(GameTime gameTime);

        abstract public void Draw(SpriteBatch spriteBatch);
    }
}

#################################################################

namespace TeamPlatformer
{
    public delegate void ScreenHandler();

    class ScreenManager : DrawableGameComponent
    {
        SpriteBatch spriteBatch;
        ContentManager content;

        List<GameScreen> screenList;
        GameScreen currentScreen;

        public ScreenManager(Game game): base(game)
        {
            content = new ContentManager(game.Content.ServiceProvider, game.Content.RootDirectory);

            screenList = new List<GameScreen>();
            screenList.Add(new MenuScreen());
            screenList.Add(new PauseScreen());
            screenList.Add(new IntroScreen());

            screenList[2].ScreenChanged += IntroEndHandler;

            currentScreen = screenList[2];
        }


        protected override void LoadContent()
        {
            spriteBatch = new SpriteBatch(GraphicsDevice);

            //foreach (GameScreen screen in screenList)
            //{
            //    screen.LoadContent(content);
            //}

            currentScreen.LoadContent(content);

            base.LoadContent();
        }

        public override void Update(GameTime gameTime)
        {
            currentScreen.Update(gameTime);
            base.Update(gameTime);
        }

        private void IntroEndHandler()
        {
            currentScreen = screenList[0];
        }

        public override void Draw(GameTime gameTime)
        {
            GraphicsDevice.Clear(Color.CornflowerBlue);
            currentScreen.Draw(spriteBatch);
            base.Draw(gameTime);
        }
    }
}

######################################################################

namespace TeamPlatformer
{
    class IntroScreen : GameScreen
    {
        //Intro Länge hier einstellen

        private const int introDuration = 5;
        private double elapsedTime = 0f;

        //Screen Switch Event

        public override event ScreenHandler ScreenChanged;

        private Texture2D Intro;
        private Rectangle BackgroundRectangle;

        public IntroScreen()
        {
            BackgroundRectangle = new Rectangle(0, 0, 800, 600);
        }

        public override void LoadContent(ContentManager content)
        {
            Intro = content.Load<Texture2D>("Logo");
        }

        public override void Update(GameTime gameTime)
        {
            elapsedTime += gameTime.ElapsedGameTime.TotalSeconds;

            if(elapsedTime >= introDuration)
            {
                if(ScreenChanged != null)
                OnIntroEnd();
            }
        }

        protected void OnIntroEnd()
        {
            elapsedTime = 0;
            ScreenChanged();
        }

        public override void Draw(SpriteBatch spriteBatch)
        {
            spriteBatch.Begin();
            spriteBatch.Draw(Intro, BackgroundRectangle, Color.White);
            spriteBatch.End();
        }
    }
}