.NET Scheduled Timer

/***************************************************************************
 * Copyright Andy Brummer 2004-2005
 * 
 * This code is provided "as is", with absolutely no warranty expressed
 * or implied. Any use is at your own risk.
 *
 * This code may be used in compiled form in any way you desire. This
 * file may be redistributed unmodified by any means provided it is
 * not sold for profit without the authors written consent, and
 * providing that this notice and the authors name is included. If
 * the source code in  this file is used in any commercial application
 * then a simple email would be nice.
 * 
 **************************************************************************/

using System;
using System.Collections;
using System.Reflection;
using System.Timers;

namespace Schedule
{
	/// <summary>
	/// Timer job groups a schedule, syncronization data, a result filter, method information and an enabled state so that multiple jobs
	/// can be managed by the same timer.  Each one operating independently of the others with different syncronization and recovery settings.
	/// </summary>
	public class TimerJob
	{
		public TimerJob(IScheduledItem schedule, IMethodCall method)
		{
			Schedule = schedule;
			Method = method;
			_ExecuteHandler = new ExecuteHandler(ExecuteInternal);
		}
		public IScheduledItem Schedule;
		public bool SyncronizedEvent = true;
		public IResultFilter Filter;
		public IMethodCall Method;
//		public IJobLog Log;
		public bool Enabled = true;

		public DateTime NextRunTime(DateTime time, bool IncludeStartTime)
		{
			if (!Enabled)
				return DateTime.MaxValue;
			return Schedule.NextRunTime(time, IncludeStartTime);
		}

		public void Execute(object sender, DateTime Begin, DateTime End, ExceptionEventHandler Error)
		{
			if (!Enabled)
				return;

			ArrayList EventList = new ArrayList();
			Schedule.AddEventsInInterval(Begin, End, EventList);

			if (Filter != null)
				Filter.FilterResultsInInterval(Begin, End, EventList);

			foreach(DateTime EventTime in EventList)
			{
				if (SyncronizedEvent)
                    _ExecuteHandler(sender, EventTime, Error);
				else
					_ExecuteHandler.BeginInvoke(sender, EventTime, Error, null, null);
			}
		}

		private void ExecuteInternal(object sender, DateTime EventTime, ExceptionEventHandler Error)
		{
			try 
			{
				TimerParameterSetter Setter = new TimerParameterSetter(EventTime, sender);
				Method.Execute(Setter);
			}
			catch (Exception ex)
			{
				if (Error != null)
					try { Error(this, new ExceptionEventArgs(EventTime, ex)); } catch {}
			}
		}

		private delegate void ExecuteHandler(object sender, DateTime EventTime, ExceptionEventHandler Error);

		private ExecuteHandler _ExecuteHandler;
	}

	/// <summary>
	/// Timer job manages a group of timer jobs.
	/// </summary>
	public class TimerJobList
	{
		public TimerJobList()
		{
			_List = new ArrayList();
		}

		public void Add(TimerJob Event)
		{
			_List.Add(Event);
		}

		public void Clear()
		{
			_List.Clear();
		}

		/// <summary>
		/// Gets the next time any of the jobs in the list will run.  Allows matching the exact start time.  If no matches are found the return
		/// is DateTime.MaxValue;
		/// </summary>
		/// <param name="time">The starting time for the interval being queried.  This time is included in the interval</param>
		/// <returns>The first absolute date one of the jobs will execute on.  If none of the jobs needs to run DateTime.MaxValue is returned.</returns>
		public DateTime NextRunTime(DateTime time)
		{
			DateTime next = DateTime.MaxValue;
			//Get minimum datetime from the list.
			foreach(TimerJob Job in _List)
			{
				DateTime Proposed = Job.NextRunTime(time, true);
				next = (Proposed < next) ? Proposed : next;
			}
			return next;
		}

		public TimerJob[] Jobs
		{
			get { return (TimerJob[])_List.ToArray(typeof(TimerJob)); }
		}

		private ArrayList _List;
	}

	/// <summary>
	/// The timer job allows delegates to be specified with unbound parameters.  This ParameterSetter assigns all unbound datetime parameters
	/// with the specified time and all unbound object parameters with the calling object.
	/// </summary>
	public class TimerParameterSetter : IParameterSetter
	{
		/// <summary>
		/// Initalize the ParameterSetter with the time to pass to unbound time parameters and object to pass to unbound object parameters.
		/// </summary>
		/// <param name="time">The time to pass to the unbound DateTime parameters</param>
		/// <param name="sender">The object to pass to the unbound object parameters</param>
		public TimerParameterSetter(DateTime time, object sender)
		{
			_time = time;
			_sender = sender;
		}
		public void reset()
		{
		}
		public bool GetParameterValue(ParameterInfo pi, int ParameterLoc, ref object parameter)
		{
			switch(pi.ParameterType.Name.ToLower())
			{
				case "datetime":
					parameter = _time;
					return true;
				case "object":
					parameter = _sender;
					return true;
				case "scheduledeventargs":
					parameter = new ScheduledEventArgs(_time);
					return true;
				case "eventargs":
					parameter = new ScheduledEventArgs(_time);
					return true;
			}
			return false;
		}
		DateTime _time;
		object _sender;
	}
}