1 files changed, 282 insertions, 0 deletions
diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Xml/AXmlContainer.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Xml/AXmlContainer.cs
new file mode 100644
index 000000000..3cc716de5
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+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Xml/AXmlContainer.cs
@@ -0,0 +1,282 @@
+// 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;
+using System.Diagnostics;
+using System.Linq;
+
+using Tango.Scripting.Editors.Document;
+
+namespace Tango.Scripting.Editors.Xml
+{
+	/// <summary>
+	/// Abstact base class for all types that can contain child nodes
+	/// </summary>
+	public abstract class AXmlContainer: AXmlObject
+	{
+		/// <summary>
+		/// Children of the node.  It is read-only.
+		/// Note that is has CollectionChanged event.
+		/// </summary>
+		public AXmlObjectCollection<AXmlObject> Children { get; private set; }
+		
+		/// <summary> Create new container </summary>
+		protected  AXmlContainer()
+		{
+			this.Children = new AXmlObjectCollection<AXmlObject>();
+		}
+		
+		#region Helpper methods
+		
+		ObservableCollection<AXmlElement> elements;
+		
+		/// <summary> Gets direcly nested elements (non-recursive) </summary>
+		public ObservableCollection<AXmlElement> Elements {
+			get {
+				if (elements == null) {
+					elements = new FilteredCollection<AXmlElement, AXmlObjectCollection<AXmlObject>>(this.Children);
+				}
+				return elements;
+			}
+		}
+		
+		internal AXmlObject FirstChild {
+			get {
+				return this.Children[0];
+			}
+		}
+		
+		internal AXmlObject LastChild {
+			get {
+				return this.Children[this.Children.Count - 1];
+			}
+		}
+		
+		#endregion
+		
+		/// <inheritdoc/>
+		public override IEnumerable<AXmlObject> GetSelfAndAllChildren()
+		{
+			return (new AXmlObject[] { this }).Flatten(
+				delegate(AXmlObject i) {
+					AXmlContainer container = i as AXmlContainer;
+					if (container != null)
+						return container.Children;
+					else
+						return null;
+				}
+			);
+		}
+		
+		/// <summary>
+		/// Gets a child fully containg the given offset.
+		/// Goes recursively down the tree.
+		/// Specail case if at the end of attribute or text
+		/// </summary>
+		public AXmlObject GetChildAtOffset(int offset)
+		{
+			foreach(AXmlObject child in this.Children) {
+				if ((child is AXmlAttribute || child is AXmlText) && offset == child.EndOffset) return child;
+				if (child.StartOffset < offset && offset < child.EndOffset) {
+					AXmlContainer container = child as AXmlContainer;
+					if (container != null) {
+						return container.GetChildAtOffset(offset);
+					} else {
+						return child;
+					}
+				}
+			}
+			return this; // No childs at offset
+		}
+		
+		// Only these four methods should be used to modify the collection
+		
+		/// <summary> To be used exlucively by the parser </summary>
+		internal void AddChild(AXmlObject item)
+		{
+			// Childs can be only added to newly parsed items
+			Assert(this.Parent == null, "I have to be new");
+			Assert(item.IsCached, "Added item must be in cache");
+			// Do not set parent pointer
+			this.Children.InsertItemAt(this.Children.Count, item);
+		}
+		
+		/// <summary> To be used exlucively by the parser </summary>
+		internal void AddChildren(IEnumerable<AXmlObject> items)
+		{
+			// Childs can be only added to newly parsed items
+			Assert(this.Parent == null, "I have to be new");
+			// Do not set parent pointer
+			this.Children.InsertItemsAt(this.Children.Count, items.ToList());
+		}
+		
+		/// <summary>
+		/// To be used exclusively by the children update algorithm.
+		/// Insert child and keep links consistent.
+		/// </summary>
+		void InsertChild(int index, AXmlObject item)
+		{
+			AXmlParser.Log("Inserting {0} at index {1}", item, index);
+			
+			Assert(this.Document != null, "Can not insert to dangling object");
+			Assert(item.Parent != this, "Can not own item twice");
+			
+			SetParentPointersInTree(item);
+			
+			this.Children.InsertItemAt(index, item);
+			
+			this.Document.OnObjectInserted(index, item);
+		}
+		
+		/// <summary> Recursively fix all parent pointer in a tree </summary>
+		/// <remarks>
+		/// Cache constraint:
+		///    If cached item has parent set, then the whole subtree must be consistent and document set
+		/// </remarks>
+		void SetParentPointersInTree(AXmlObject item)
+		{
+			// All items come from the parser cache
+			
+			if (item.Parent == null) {
+				// Dangling object - either a new parser object or removed tree (still cached)
+				item.Parent = this;
+				item.Document = this.Document;
+				AXmlContainer container = item as AXmlContainer;
+				if (container != null) {
+					foreach(AXmlObject child in container.Children) {
+						container.SetParentPointersInTree(child);
+					}
+				}
+			} else if (item.Parent == this) {
+				// If node is attached and then deattached, it will have null parent pointer
+				//   but valid subtree - so its children will alredy have correct parent pointer
+				//   like in this case
+				// item.DebugCheckConsistency(false);
+				// Rest of the tree is consistent - do not recurse
+			} else {
+				// From cache & parent set => consitent subtree
+				// item.DebugCheckConsistency(false);
+				// The parent (or any futher parents) can not be part of parsed document
+				//   becuase otherwise this item would be included twice => safe to change parents
+				// Maintain cache constraint by setting parents to null
+				foreach(AXmlObject ancest in item.GetAncestors().ToList()) {
+					ancest.Parent = null;
+				}
+				item.Parent = this;
+				// Rest of the tree is consistent - do not recurse
+			}
+		}
+		
+		/// <summary>
+		/// To be used exclusively by the children update algorithm.
+		/// Remove child, set parent to null and notify the document
+		/// </summary>
+		void RemoveChild(int index)
+		{
+			AXmlObject removed = this.Children[index];
+			AXmlParser.Log("Removing {0} at index {1}", removed, index);
+			
+			// Stop tracking if the object can not be used again
+			if (!removed.IsCached)
+				this.Document.Parser.TrackedSegments.RemoveParsedObject(removed);
+			
+			// Null parent pointer
+			Assert(removed.Parent == this, "Inconsistent child");
+			removed.Parent = null;
+			
+			this.Children.RemoveItemAt(index);
+			
+			this.Document.OnObjectRemoved(index, removed);
+		}
+		
+		/// <summary> Verify that the subtree is consistent.  Only in debug build. </summary>
+		/// <remarks> Parent pointers might be null or pointing somewhere else in parse tree </remarks>
+		internal override void DebugCheckConsistency(bool checkParentPointers)
+		{
+			base.DebugCheckConsistency(checkParentPointers);
+			AXmlObject prevChild = null;
+			int myStartOffset = this.StartOffset;
+			int myEndOffset = this.EndOffset;
+			foreach(AXmlObject child in this.Children) {
+				Assert(child.Length != 0, "Empty child");
+				if (checkParentPointers) {
+					Assert(child.Parent != null, "Null parent reference");
+					Assert(child.Parent == this, "Inccorect parent reference");
+				}
+				if (this.Document != null) {
+					Assert(child.Document != null, "Child has null document");
+					Assert(child.Document == this.Document, "Child is in different document");
+				}
+				if (this.IsCached)
+					Assert(child.IsCached, "Child not in cache");
+				Assert(myStartOffset <= child.StartOffset && child.EndOffset <= myEndOffset, "Child not within parent text range");
+				if (prevChild != null)
+					Assert(prevChild.EndOffset <= child.StartOffset, "Overlaping childs");
+				child.DebugCheckConsistency(checkParentPointers);
+				prevChild = child;
+			}
+		}
+		
+		/// <remarks>
+		/// Note the the method is not called recuively.
+		/// Only the helper methods are recursive.
+		/// </remarks>
+		internal void UpdateTreeFrom(AXmlContainer srcContainer)
+		{
+			this.StartOffset = srcContainer.StartOffset; // Force the update
+			this.UpdateDataFrom(srcContainer);
+			RemoveChildrenNotIn(srcContainer.Children);
+			InsertAndUpdateChildrenFrom(srcContainer.Children);
+		}
+		
+		void RemoveChildrenNotIn(IList<AXmlObject> srcList)
+		{
+			Dictionary<int, AXmlObject> srcChildren = srcList.ToDictionary(i => i.StartOffset);
+			for(int i = 0; i < this.Children.Count;) {
+				AXmlObject child = this.Children[i];
+				AXmlObject srcChild;
+				
+				if (srcChildren.TryGetValue(child.StartOffset, out srcChild) && child.CanUpdateDataFrom(srcChild)) {
+					// Keep only one item with given offset (we might have several due to deletion)
+					srcChildren.Remove(child.StartOffset);
+					// If contaner that needs updating
+					AXmlContainer childAsContainer = child as AXmlContainer;
+					if (childAsContainer != null && child.LastUpdatedFrom != srcChild)
+						childAsContainer.RemoveChildrenNotIn(((AXmlContainer)srcChild).Children);
+					i++;
+				} else {
+					RemoveChild(i);
+				}
+			}
+		}
+		
+		void InsertAndUpdateChildrenFrom(IList<AXmlObject> srcList)
+		{
+			for(int i = 0; i < srcList.Count; i++) {
+				// End of our list?
+				if (i == this.Children.Count) {
+					InsertChild(i, srcList[i]);
+					continue;
+				}
+				AXmlObject child = this.Children[i];
+				AXmlObject srcChild = srcList[i];
+				
+				if (child.CanUpdateDataFrom(srcChild)) { // includes offset test
+					// Does it need updating?
+					if (child.LastUpdatedFrom != srcChild) {
+						child.UpdateDataFrom(srcChild);
+						AXmlContainer childAsContainer = child as AXmlContainer;
+						if (childAsContainer != null)
+							childAsContainer.InsertAndUpdateChildrenFrom(((AXmlContainer)srcChild).Children);
+					}
+				} else {
+					InsertChild(i, srcChild);
+				}
+			}
+			Assert(this.Children.Count == srcList.Count, "List lengths differ after update");
+		}
+	}
+}