feat: ScrollQueue - added OnItemTrimmed event

CHANGELOG.md

@@ -5,6 +5,9 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Added
+ - ScrollQueue - Added OnItemTrimmed event
+ - ScrollQueueTests - Added OnItemTrimmed event test
 
 ## [11.0.0] - 2020-03-20
 ### Added

ICD.Common.Utils.Tests/Collections/ScrollQueueTest.cs

@@ -2,6 +2,7 @@
 using ICD.Common.Properties;
 using NUnit.Framework;
 using ICD.Common.Utils.Collections;
+using ICD.Common.Utils.EventArguments;
 
 namespace ICD.Common.Utils.Tests.Collections
 {
@@ -76,5 +77,43 @@ namespace ICD.Common.Utils.Tests.Collections
 
 			Assert.AreEqual(0, test.Peek());
 		}
+
+		[Test, UsedImplicitly]
+		public void OnItemTrimmedTest()
+		{
+			ScrollQueue<int> test = new ScrollQueue<int>(3);
+
+			int? removedItem = null;
+
+			test.OnItemTrimmed += (sender, args) => removedItem = args.Data;
+
+			test.Enqueue(1);
+			test.Enqueue(2);
+			test.Enqueue(3);
+
+			Assert.IsNull(removedItem, "Raised Early");
+
+			test.Enqueue(4);
+
+			Assert.True(removedItem.HasValue, "Not Raised");
+			if (removedItem.HasValue)
+				Assert.AreEqual(1, removedItem.Value, "Incorrect Value");
+
+			removedItem = null;
+
+			test.Enqueue(5);
+
+			Assert.True(removedItem.HasValue, "Not Raised");
+			if (removedItem.HasValue)
+				Assert.AreEqual(2, removedItem.Value, "Incorrect Value");
+
+			removedItem = null;
+
+			test.MaxSize = 4;
+
+			test.Enqueue(6);
+
+			Assert.False(removedItem.HasValue, "Raised Early");
+		}
 	}
 }

ICD.Common.Utils/Collections/ScrollQueue.cs

@@ -2,6 +2,8 @@
 using System.Collections;
 using System.Collections.Generic;
 using ICD.Common.Properties;
+using ICD.Common.Utils.EventArguments;
+using ICD.Common.Utils.Extensions;
 
 namespace ICD.Common.Utils.Collections
 {
@@ -15,6 +17,8 @@ namespace ICD.Common.Utils.Collections
 		private readonly LinkedList<TContents> m_Collection;
 		private int m_MaxSize;
 
+		public event EventHandler<GenericEventArgs<TContents>> OnItemTrimmed;
+
 		#region Properties
 
 		/// <summary>
@@ -141,7 +145,11 @@ namespace ICD.Common.Utils.Collections
 		private void Trim()
 		{
 			while (Count > MaxSize)
+			{
+				TContents removed = m_Collection.First.Value;
 				m_Collection.RemoveFirst();
+				OnItemTrimmed.Raise(this, new GenericEventArgs<TContents>(removed));
+			}
 		}
 
 		#endregion