using System;

using System.Collections.Generic;

using System.Text;

namespace ActiveObject

{

    public class DelayedTyper : ICommand

    {

        private long itsDelay;

        private char itsChar;

        private static bool stop = false;

        private static ActiveObjectEngine engin =

            new ActiveObjectEngine();

        private class StopCommand : ICommand

        {

            public void Execute()

            {

                DelayedTyper.stop = true;

            }

        }

        public static void Main(string[] args)

        {

            engin.AddCommand(new DelayedTyper(100, ’A’));

            engin.AddCommand(new DelayedTyper(300, ’B’));

            engin.AddCommand(new DelayedTyper(500, ’C’));

            engin.AddCommand(new DelayedTyper(700, ’D’));

            ICommand stopCommand = new StopCommand();

            engin.AddCommand(new SleepCommand(2000, engin, stopCommand));

            engin.Run();

            Console.ReadLine();

        }

        public DelayedTyper(long delay, char c)

        {

            this.itsDelay = delay;

            this.itsChar = c;

        }

        public void Execute()

        {

            Console.Write(itsChar);

            if (!stop)

            {

                DelayAndRepeat();

            }

        }

        private void DelayAndRepeat()

        {

            engin.AddCommand(new SleepCommand(itsDelay, engin, this));

        }

    }

}