Added HandlerList.cs so that we can have prioritized event handlers also so you can easily register a handler and not have to put 'if (e.Handled) return;' at the top.

TShockAPI/HandlerList.cs

@@ -0,0 +1,79 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Linq;
+using System.Text;
+
+namespace TShockAPI
+{
+	public class HandlerList : HandlerList<EventArgs>
+	{
+	}
+	public class HandlerList<T> where T : EventArgs
+	{
+		protected class HandlerObject
+		{
+			public EventHandler<T> Handler { get; set; }
+			public HandlerPriority Priority { get; set; }
+			public bool GetHandled { get; set; }
+		}
+
+		protected object HandlerLock = new object();
+		protected List<HandlerObject> Handlers { get; set; }
+		public HandlerList()
+		{
+			Handlers = new List<HandlerObject>();
+		}
+
+		/// <summary>
+		/// Register a handler
+		/// </summary>
+		/// <param name="handler">Delegate to be called</param>
+		/// <param name="priority">Priority of the delegate</param>
+		/// <param name="gethandled">Should the handler receive a call even if it has been handled</param>
+		public void Register(EventHandler<T> handler, HandlerPriority priority = HandlerPriority.Normal, bool gethandled = false)
+		{
+			lock (HandlerLock)
+			{
+				Handlers.Add(new HandlerObject { Handler = handler, Priority = priority, GetHandled = gethandled });
+				Handlers = Handlers.OrderBy(h => (int)h.Priority).ToList();
+			}
+		}
+
+		public void UnRegister(EventHandler<T> handler)
+		{
+			lock (HandlerLock)
+			{
+				Handlers.RemoveAll(h => h.Handler.Equals(handler));
+			}
+		}
+
+		public void Invoke(object sender, T e)
+		{
+			List<HandlerObject> handlers;
+			lock (HandlerLock)
+			{
+				//Copy the list for invoking as to not keep it locked during the invokes
+				handlers = new List<HandlerObject>(Handlers);
+			}
+
+			var hargs = e as HandledEventArgs;
+			for (int i = 0; i < handlers.Count; i++)
+			{
+				if (hargs == null || !hargs.Handled || (hargs.Handled && handlers[i].GetHandled))
+				{
+					handlers[i].Handler(sender, e);
+				}
+			}
+		}
+	}
+
+	public enum HandlerPriority
+	{
+		Highest = 1,
+		High = 2,
+		Normal = 3,
+		Low = 4,
+		Lowest = 5,
+	}
+}