GameComponent Manager class

// Component manager base class
// <typeparam name="T">Type of component to manage</typeparam>
public abstract class ComponentManager<T> : DrawableGameComponent where T : IGameComponent, IUpdateable
{
    // List of managed components
    protected List<T> components;

    // True, if T implements IDrawable
    private bool isDrawable;

    public ComponentManager(Game game)
        : base(game)
    {
        components = new List<T>();

        // Examine type interfaces
        Type[] interfaces = typeof(T).GetInterfaces();
        isDrawable = interfaces.Contains(typeof(IDrawable));
    }


    public override void Initialize()
    {
        base.Initialize();

        foreach (T item in this.components)
        {
            item.Initialize();
        }
    }

    public override void Update(GameTime gameTime)
    {
        foreach (T item in this.components)
            item.Update(gameTime);
    }

    public override void Draw(GameTime gameTime)
    {
        // Only call draw if the type implements IDrawable
        if (!isDrawable) return;

        foreach (T item in this.components)
            ((IDrawable)item).Draw(gameTime);
    }
}