1 files changed, 119 insertions, 0 deletions
diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Xml/AXmlAttributeCollection.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Xml/AXmlAttributeCollection.cs
new file mode 100644
index 000000000..95fa83cd0
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+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Xml/AXmlAttributeCollection.cs
@@ -0,0 +1,119 @@
+// 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;
+
+namespace Tango.Scripting.Editors.Xml
+{
+	/// <summary>
+	/// Specailized attribute collection with attribute name caching
+	/// </summary>
+	public class AXmlAttributeCollection: FilteredCollection<AXmlAttribute, AXmlObjectCollection<AXmlObject>>
+	{
+		/// <summary> Empty unbound collection </summary>
+		[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Security", "CA2104:DoNotDeclareReadOnlyMutableReferenceTypes",
+		                                                 Justification = "InsertItem prevents modifying the Empty collection")]
+		public static readonly AXmlAttributeCollection Empty = new AXmlAttributeCollection();
+		
+		/// <summary> Create unbound collection </summary>
+		protected AXmlAttributeCollection() {}
+		
+		/// <summary> Wrap the given collection.  Non-attributes are filtered </summary>
+		public AXmlAttributeCollection(AXmlObjectCollection<AXmlObject> source): base(source) {}
+		
+		/// <summary> Wrap the given collection.  Non-attributes are filtered.  Items not matching the condition are filtered. </summary>
+		public AXmlAttributeCollection(AXmlObjectCollection<AXmlObject> source, Predicate<object> condition): base(source, condition) {}
+		
+		Dictionary<string, List<AXmlAttribute>> hashtable = new Dictionary<string, List<AXmlAttribute>>();
+		
+		void AddToHashtable(AXmlAttribute attr)
+		{
+			string localName = attr.LocalName;
+			if (!hashtable.ContainsKey(localName)) {
+				hashtable[localName] = new List<AXmlAttribute>(1);
+			}
+			hashtable[localName].Add(attr);
+		}
+		
+		void RemoveFromHashtable(AXmlAttribute attr)
+		{
+			string localName = attr.LocalName;
+			hashtable[localName].Remove(attr);
+		}
+		
+		static List<AXmlAttribute> NoAttributes = new List<AXmlAttribute>();
+		
+		/// <summary>
+		/// Get all attributes with given local name.
+		/// Hash table is used for lookup so this is cheap.
+		/// </summary>
+		public IEnumerable<AXmlAttribute> GetByLocalName(string localName)
+		{
+			if (hashtable.ContainsKey(localName)) {
+				return hashtable[localName];
+			} else {
+				return NoAttributes;
+			}
+		}
+		
+		/// <inheritdoc/>
+		protected override void ClearItems()
+		{
+			foreach(AXmlAttribute item in this) {
+				RemoveFromHashtable(item);
+				item.Changing -= item_Changing;
+				item.Changed  -= item_Changed;
+			}
+			base.ClearItems();
+		}
+		
+		/// <inheritdoc/>
+		protected override void InsertItem(int index, AXmlAttribute item)
+		{
+			// prevent insertions into the static 'Empty' instance
+			if (this == Empty)
+				throw new NotSupportedException("Cannot insert into AXmlAttributeCollection.Empty");
+			
+			AddToHashtable(item);
+			item.Changing += item_Changing;
+			item.Changed  += item_Changed;
+			base.InsertItem(index, item);
+		}
+		
+		/// <inheritdoc/>
+		protected override void RemoveItem(int index)
+		{
+			RemoveFromHashtable(this[index]);
+			this[index].Changing -= item_Changing;
+			this[index].Changed  -= item_Changed;
+			base.RemoveItem(index);
+		}
+		
+		/// <inheritdoc/>
+		protected override void SetItem(int index, AXmlAttribute item)
+		{
+			RemoveFromHashtable(this[index]);
+			this[index].Changing -= item_Changing;
+			this[index].Changed  -= item_Changed;
+			
+			AddToHashtable(item);
+			item.Changing += item_Changing;
+			item.Changed  += item_Changed;
+			base.SetItem(index, item);
+		}
+		
+		// Every item in the collection should be registered to these handlers
+		// so that we can handle renames
+		
+		void item_Changing(object sender, AXmlObjectEventArgs e)
+		{
+			RemoveFromHashtable((AXmlAttribute)e.Object);
+		}
+		
+		void item_Changed(object sender, AXmlObjectEventArgs e)
+		{
+			AddToHashtable((AXmlAttribute)e.Object);
+		}
+	}
+}