TimerManager.cs

using Microsoft.Xna.Framework;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace notContra
{
    /// <summary>
    /// A class to manage Timers. Puts timers into a list. Ticks every timer in the list every game update.
    /// When the timer reaches it's time limit it gets added to the toRemove list and then removed from timers.
    /// The toRemove list is cleared after.
    /// </summary>
    class TimerManager
    {
        List<Timer> timers = new List<Timer>();
        List<Timer> toRemove = new List<Timer>();
        int nrToRemove = 0;
        int nrOfTimers = 0;

        public int NrOfTimers
        {
            get
            {
                return nrOfTimers;
            }
        }

        public TimerManager() { }

        public void Wait(int timeToWait)
        {
            Add(new Timer(timeToWait));
        }
        public void Wait(float timeToWait)
        {
            Add(new Timer(timeToWait));
        }

        void Add(Timer timer)
        {
            timers.Add(timer);
            nrOfTimers++;
        }

        public void Update(GameTime gameTime)
        {
            foreach(Timer element in timers)
            {
                element.Tick(gameTime);
                if(element.HasFinished)
                {
                    toRemove.Add(element);
                    nrToRemove++;
                }
            }
            if(nrToRemove != 0)
            {
                foreach(Timer element in toRemove)
                {
                    timers.Remove(element);
                    nrToRemove--;
                    nrOfTimers--;
                }
                toRemove.Clear();
            }
        }
    }
}