1 files changed, 70 insertions, 0 deletions
diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Xml/MergedCollection.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Xml/MergedCollection.cs
new file mode 100644
index 000000000..79574053b
--- /dev/null
+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Xml/MergedCollection.cs
@@ -0,0 +1,70 @@
+// Copyright (c) AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
+// This code is distributed under the GNU LGPL (for details please see \doc\license.txt)
+
+using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Collections.Specialized;
+
+namespace Tango.Scripting.Editors.Xml
+{
+	/// <summary>
+	/// Two collections in sequence
+	/// </summary>
+	public class MergedCollection<T, TCollection> : ObservableCollection<T> where TCollection : INotifyCollectionChanged, IList<T>
+	{
+		TCollection a;
+		TCollection b;
+		
+		/// <summary> Create a wrapper containing elements of 'a' and then 'b' </summary>
+		[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly")]
+		public MergedCollection(TCollection a, TCollection b)
+		{
+			this.a = a;
+			this.b = b;
+			
+			this.a.CollectionChanged += SourceCollectionAChanged;
+			this.b.CollectionChanged += SourceCollectionBChanged;
+			
+			Reset();
+		}
+		
+		void Reset()
+		{
+			this.Clear();
+			foreach(T item in a) this.Add(item);
+			foreach(T item in b) this.Add(item);
+		}
+
+		void SourceCollectionAChanged(object sender, NotifyCollectionChangedEventArgs e)
+		{
+			SourceCollectionChanged(0, e);
+		}
+		
+		void SourceCollectionBChanged(object sender, NotifyCollectionChangedEventArgs e)
+		{
+			SourceCollectionChanged(a.Count, e);
+		}
+		
+		void SourceCollectionChanged(int collectionStart, NotifyCollectionChangedEventArgs e)
+		{
+			switch(e.Action) {
+				case NotifyCollectionChangedAction.Add:
+					for (int i = 0; i < e.NewItems.Count; i++) {
+						this.InsertItem(collectionStart + e.NewStartingIndex + i, (T)e.NewItems[i]);
+					}
+					break;
+				case NotifyCollectionChangedAction.Remove:
+					for (int i = 0; i < e.OldItems.Count; i++) {
+						this.RemoveAt(collectionStart + e.OldStartingIndex);
+					}
+					break;
+				case NotifyCollectionChangedAction.Reset:
+					Reset();
+					break;
+				default:
+					throw new NotSupportedException(e.Action.ToString());
+			}
+		}
+	}
+}