MERGE

24 files changed, 4071 insertions, 0 deletions

diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/Boxes.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/Boxes.cs
new file mode 100644
index 000000000..517948bae
--- /dev/null
+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/Boxes.cs
@@ -0,0 +1,21 @@
+// 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;
+
+namespace Tango.Scripting.Editors.Utils
+{
+	/// <summary>
+	/// Reuse the same instances for boxed booleans.
+	/// </summary>
+	static class Boxes
+	{
+		public static readonly object True = true;
+		public static readonly object False = false;
+		
+		public static object Box(bool value)
+		{
+			return value ? True : False;
+		}
+	}
+}
diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/BusyManager.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/BusyManager.cs
new file mode 100644
index 000000000..8551ff49e
--- /dev/null
+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/BusyManager.cs
@@ -0,0 +1,55 @@
+// 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.Utils
+{
+	/// <summary>
+	/// This class is used to prevent stack overflows by representing a 'busy' flag
+	/// that prevents reentrance when another call is running.
+	/// However, using a simple 'bool busy' is not thread-safe, so we use a
+	/// thread-static BusyManager.
+	/// </summary>
+	static class BusyManager
+	{
+		public struct BusyLock : IDisposable
+		{
+			public static readonly BusyLock Failed = new BusyLock(null);
+			
+			readonly List<object> objectList;
+			
+			public BusyLock(List<object> objectList)
+			{
+				this.objectList = objectList;
+			}
+			
+			public bool Success {
+				get { return objectList != null; }
+			}
+			
+			public void Dispose()
+			{
+				if (objectList != null) {
+					objectList.RemoveAt(objectList.Count - 1);
+				}
+			}
+		}
+		
+		[ThreadStatic] static List<object> _activeObjects;
+		
+		public static BusyLock Enter(object obj)
+		{
+			List<object> activeObjects = _activeObjects;
+			if (activeObjects == null)
+				activeObjects = _activeObjects = new List<object>();
+			for (int i = 0; i < activeObjects.Count; i++) {
+				if (activeObjects[i] == obj)
+					return BusyLock.Failed;
+			}
+			activeObjects.Add(obj);
+			return new BusyLock(activeObjects);
+		}
+	}
+}
diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/CallbackOnDispose.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/CallbackOnDispose.cs
new file mode 100644
index 000000000..a6eebf2f1
--- /dev/null
+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/CallbackOnDispose.cs
@@ -0,0 +1,35 @@
+// 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.Diagnostics;
+using System.Threading;
+
+namespace Tango.Scripting.Editors.Utils
+{
+	/// <summary>
+	/// Invokes an action when it is disposed.
+	/// </summary>
+	/// <remarks>
+	/// This class ensures the callback is invoked at most once,
+	/// even when Dispose is called on multiple threads.
+	/// </remarks>
+	sealed class CallbackOnDispose : IDisposable
+	{
+		Action action;
+		
+		public CallbackOnDispose(Action action)
+		{
+			Debug.Assert(action != null);
+			this.action = action;
+		}
+		
+		public void Dispose()
+		{
+			Action a = Interlocked.Exchange(ref action, null);
+			if (a != null) {
+				a();
+			}
+		}
+	}
+}
diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/CharRope.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/CharRope.cs
new file mode 100644
index 000000000..844ab9544
--- /dev/null
+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/CharRope.cs
@@ -0,0 +1,172 @@
+// 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.Globalization;
+using System.Text;
+
+namespace Tango.Scripting.Editors.Utils
+{
+	/// <summary>
+	/// Poor man's template specialization: extension methods for Rope&lt;char&gt;.
+	/// </summary>
+	public static class CharRope
+	{
+		/// <summary>
+		/// Creates a new rope from the specified text.
+		/// </summary>
+		public static Rope<char> Create(string text)
+		{
+			if (text == null)
+				throw new ArgumentNullException("text");
+			return new Rope<char>(InitFromString(text));
+		}
+		
+		/// <summary>
+		/// Retrieves the text for a portion of the rope.
+		/// Runs in O(lg N + M), where M=<paramref name="length"/>.
+		/// </summary>
+		/// <exception cref="ArgumentOutOfRangeException">offset or length is outside the valid range.</exception>
+		/// <remarks>
+		/// This method counts as a read access and may be called concurrently to other read accesses.
+		/// </remarks>
+		public static string ToString(this Rope<char> rope, int startIndex, int length)
+		{
+			if (rope == null)
+				throw new ArgumentNullException("rope");
+			if (length == 0)
+				return string.Empty;
+			char[] buffer = new char[length];
+			rope.CopyTo(startIndex, buffer, 0, length);
+			return new string(buffer);
+		}
+		
+		/// <summary>
+		/// Retrieves the text for a portion of the rope and writes it to the specified string builder.
+		/// Runs in O(lg N + M), where M=<paramref name="length"/>.
+		/// </summary>
+		/// <exception cref="ArgumentOutOfRangeException">offset or length is outside the valid range.</exception>
+		/// <remarks>
+		/// This method counts as a read access and may be called concurrently to other read accesses.
+		/// </remarks>
+		public static void WriteTo(this Rope<char> rope, StringBuilder output, int startIndex, int length)
+		{
+			if (rope == null)
+				throw new ArgumentNullException("rope");
+			if (output == null)
+				throw new ArgumentNullException("output");
+			rope.VerifyRange(startIndex, length);
+			rope.root.WriteTo(startIndex, output, length);
+		}
+		
+		/// <summary>
+		/// Appends text to this rope.
+		/// Runs in O(lg N + M).
+		/// </summary>
+		/// <exception cref="ArgumentNullException">newElements is null.</exception>
+		public static void AddText(this Rope<char> rope, string text)
+		{
+			InsertText(rope, rope.Length, text);
+		}
+		
+		/// <summary>
+		/// Inserts text into this rope.
+		/// Runs in O(lg N + M).
+		/// </summary>
+		/// <exception cref="ArgumentNullException">newElements is null.</exception>
+		/// <exception cref="ArgumentOutOfRangeException">index or length is outside the valid range.</exception>
+		public static void InsertText(this Rope<char> rope, int index, string text)
+		{
+			if (rope == null)
+				throw new ArgumentNullException("rope");
+			rope.InsertRange(index, text.ToCharArray(), 0, text.Length);
+			/*if (index < 0 || index > rope.Length) {
+				throw new ArgumentOutOfRangeException("index", index, "0 <= index <= " + rope.Length.ToString(CultureInfo.InvariantCulture));
+			}
+			if (text == null)
+				throw new ArgumentNullException("text");
+			if (text.Length == 0)
+				return;
+			rope.root = rope.root.Insert(index, text);
+			rope.OnChanged();*/
+		}
+		
+		internal static RopeNode<char> InitFromString(string text)
+		{
+			if (text.Length == 0) {
+				return RopeNode<char>.emptyRopeNode;
+			}
+			RopeNode<char> node = RopeNode<char>.CreateNodes(text.Length);
+			FillNode(node, text, 0);
+			return node;
+		}
+		
+		static void FillNode(RopeNode<char> node, string text, int start)
+		{
+			if (node.contents != null) {
+				text.CopyTo(start, node.contents, 0, node.length);
+			} else {
+				FillNode(node.left, text, start);
+				FillNode(node.right, text, start + node.left.length);
+			}
+		}
+		
+		internal static void WriteTo(this RopeNode<char> node, int index, StringBuilder output, int count)
+		{
+			if (node.height == 0) {
+				if (node.contents == null) {
+					// function node
+					node.GetContentNode().WriteTo(index, output, count);
+				} else {
+					// leaf node: append data
+					output.Append(node.contents, index, count);
+				}
+			} else {
+				// concat node: do recursive calls
+				if (index + count <= node.left.length) {
+					node.left.WriteTo(index, output, count);
+				} else if (index >= node.left.length) {
+					node.right.WriteTo(index - node.left.length, output, count);
+				} else {
+					int amountInLeft = node.left.length - index;
+					node.left.WriteTo(index, output, amountInLeft);
+					node.right.WriteTo(0, output, count - amountInLeft);
+				}
+			}
+		}
+		
+		/// <summary>
+		/// Gets the index of the first occurrence of any element in the specified array.
+		/// </summary>
+		/// <param name="rope">The target rope.</param>
+		/// <param name="anyOf">Array of characters being searched.</param>
+		/// <param name="startIndex">Start index of the search.</param>
+		/// <param name="length">Length of the area to search.</param>
+		/// <returns>The first index where any character was found; or -1 if no occurrence was found.</returns>
+		public static int IndexOfAny(this Rope<char> rope, char[] anyOf, int startIndex, int length)
+		{
+			if (rope == null)
+				throw new ArgumentNullException("rope");
+			if (anyOf == null)
+				throw new ArgumentNullException("anyOf");
+			rope.VerifyRange(startIndex, length);
+			
+			while (length > 0) {
+				var entry = rope.FindNodeUsingCache(startIndex).UnsafePeek();
+				char[] contents = entry.node.contents;
+				int startWithinNode = startIndex - entry.nodeStartIndex;
+				int nodeLength = Math.Min(entry.node.length, startWithinNode + length);
+				for (int i = startIndex - entry.nodeStartIndex; i < nodeLength; i++) {
+					char element = contents[i];
+					foreach (char needle in anyOf) {
+						if (element == needle)
+							return entry.nodeStartIndex + i;
+					}
+				}
+				length -= nodeLength - startWithinNode;
+				startIndex = entry.nodeStartIndex + nodeLength;
+			}
+			return -1;
+		}
+	}
+}
diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/CompressingTreeList.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/CompressingTreeList.cs
new file mode 100644
index 000000000..42f5007c9
--- /dev/null
+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/CompressingTreeList.cs
@@ -0,0 +1,882 @@
+// 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.Diagnostics;
+using System.Text;
+
+namespace Tango.Scripting.Editors.Utils
+{
+	/// <summary>
+	/// A IList{T} implementation that has efficient insertion and removal (in O(lg n) time)
+	/// and that saves memory by allocating only one node when a value is repeated in adjacent indices.
+	/// Based on this "compression", it also supports efficient InsertRange/SetRange/RemoveRange operations.
+	/// </summary>
+	/// <remarks>
+	/// Current memory usage: 5*IntPtr.Size + 12 + sizeof(T) per node.
+	/// Use this class only if lots of adjacent values are identical (can share one node).
+	/// </remarks>
+	[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1710:IdentifiersShouldHaveCorrectSuffix",
+	                                                 Justification = "It's an IList<T> implementation")]
+	public sealed class CompressingTreeList<T> : IList<T>
+	{
+		// Further memory optimization: this tree could work without parent pointers. But that
+		// requires changing most of tree manipulating logic.
+		// Also possible is to remove the count field and calculate it as totalCount-left.totalCount-right.totalCount
+		// - but that would make tree manipulations more difficult to handle.
+		
+		#region Node definition
+		sealed class Node
+		{
+			internal Node left, right, parent;
+			internal bool color;
+			internal int count, totalCount;
+			internal T value;
+			
+			public Node(T value, int count)
+			{
+				this.value = value;
+				this.count = count;
+				this.totalCount = count;
+			}
+			
+			internal Node LeftMost {
+				get {
+					Node node = this;
+					while (node.left != null)
+						node = node.left;
+					return node;
+				}
+			}
+			
+			internal Node RightMost {
+				get {
+					Node node = this;
+					while (node.right != null)
+						node = node.right;
+					return node;
+				}
+			}
+			
+			/// <summary>
+			/// Gets the inorder predecessor of the node.
+			/// </summary>
+			internal Node Predecessor {
+				get {
+					if (left != null) {
+						return left.RightMost;
+					} else {
+						Node node = this;
+						Node oldNode;
+						do {
+							oldNode = node;
+							node = node.parent;
+							// go up until we are coming out of a right subtree
+						} while (node != null && node.left == oldNode);
+						return node;
+					}
+				}
+			}
+			
+			/// <summary>
+			/// Gets the inorder successor of the node.
+			/// </summary>
+			internal Node Successor {
+				get {
+					if (right != null) {
+						return right.LeftMost;
+					} else {
+						Node node = this;
+						Node oldNode;
+						do {
+							oldNode = node;
+							node = node.parent;
+							// go up until we are coming out of a left subtree
+						} while (node != null && node.right == oldNode);
+						return node;
+					}
+				}
+			}
+			
+			public override string ToString()
+			{
+				return "[TotalCount=" + totalCount + " Count=" + count + " Value=" + value + "]";
+			}
+		}
+		#endregion
+		
+		#region Fields and Constructor
+		readonly Func<T, T, bool> comparisonFunc;
+		Node root;
+		
+		/// <summary>
+		/// Creates a new CompressingTreeList instance.
+		/// </summary>
+		/// <param name="comparisonFunc">A function that checks two values for equality. If this
+		/// function returns true, a single node may be used to store the two values.</param>
+		public CompressingTreeList(Func<T, T, bool> comparisonFunc)
+		{
+			if (comparisonFunc == null)
+				throw new ArgumentNullException("comparisonFunc");
+			this.comparisonFunc = comparisonFunc;
+		}
+		#endregion
+		
+		#region InsertRange
+		/// <summary>
+		/// Inserts <paramref name="item"/> <paramref name="count"/> times at position
+		/// <paramref name="index"/>.
+		/// </summary>
+		public void InsertRange(int index, int count, T item)
+		{
+			if (index < 0 || index > this.Count)
+				throw new ArgumentOutOfRangeException("index", index, "Value must be between 0 and " + this.Count);
+			if (count < 0)
+				throw new ArgumentOutOfRangeException("count", count, "Value must not be negative");
+			if (count == 0)
+				return;
+			unchecked {
+				if (this.Count + count < 0)
+					throw new OverflowException("Cannot insert elements: total number of elements must not exceed int.MaxValue.");
+			}
+			
+			if (root == null) {
+				root = new Node(item, count);
+			} else {
+				Node n = GetNode(ref index);
+				// check if we can put the value into the node n:
+				if (comparisonFunc(n.value, item)) {
+					n.count += count;
+					UpdateAugmentedData(n);
+				} else if (index == n.count) {
+					// this can only happen when appending at the end
+					Debug.Assert(n == root.RightMost);
+					InsertAsRight(n, new Node(item, count));
+				} else if (index == 0) {
+					// insert before:
+					// maybe we can put the value in the previous node?
+					Node p = n.Predecessor;
+					if (p != null && comparisonFunc(p.value, item)) {
+						p.count += count;
+						UpdateAugmentedData(p);
+					} else {
+						InsertBefore(n, new Node(item, count));
+					}
+				} else {
+					Debug.Assert(index > 0 && index < n.count);
+					// insert in the middle:
+					// split n into a new node and n
+					n.count -= index;
+					InsertBefore(n, new Node(n.value, index));
+					// then insert the new item in between
+					InsertBefore(n, new Node(item, count));
+					UpdateAugmentedData(n);
+				}
+			}
+			CheckProperties();
+		}
+		
+		void InsertBefore(Node node, Node newNode)
+		{
+			if (node.left == null) {
+				InsertAsLeft(node, newNode);
+			} else {
+				InsertAsRight(node.left.RightMost, newNode);
+			}
+		}
+		#endregion
+		
+		#region RemoveRange
+		/// <summary>
+		/// Removes <paramref name="count"/> items starting at position
+		/// <paramref name="index"/>.
+		/// </summary>
+		public void RemoveRange(int index, int count)
+		{
+			if (index < 0 || index > this.Count)
+				throw new ArgumentOutOfRangeException("index", index, "Value must be between 0 and " + this.Count);
+			if (count < 0 || index + count > this.Count)
+				throw new ArgumentOutOfRangeException("count", count, "0 <= length, index(" + index + ")+count <= " + this.Count);
+			if (count == 0)
+				return;
+			
+			Node n = GetNode(ref index);
+			if (index + count < n.count) {
+				// just remove inside a single node
+				n.count -= count;
+				UpdateAugmentedData(n);
+			} else {
+				// keep only the part of n from 0 to index
+				Node firstNodeBeforeDeletedRange;
+				if (index > 0) {
+					count -= (n.count - index);
+					n.count = index;
+					UpdateAugmentedData(n);
+					firstNodeBeforeDeletedRange = n;
+					n = n.Successor;
+				} else {
+					Debug.Assert(index == 0);
+					firstNodeBeforeDeletedRange = n.Predecessor;
+				}
+				while (n != null && count >= n.count) {
+					count -= n.count;
+					Node s = n.Successor;
+					RemoveNode(n);
+					n = s;
+				}
+				if (count > 0) {
+					Debug.Assert(n != null && count < n.count);
+					n.count -= count;
+					UpdateAugmentedData(n);
+				}
+				if (n != null) {
+					Debug.Assert(n.Predecessor == firstNodeBeforeDeletedRange);
+					if (firstNodeBeforeDeletedRange != null && comparisonFunc(firstNodeBeforeDeletedRange.value, n.value)) {
+						firstNodeBeforeDeletedRange.count += n.count;
+						RemoveNode(n);
+						UpdateAugmentedData(firstNodeBeforeDeletedRange);
+					}
+				}
+			}
+			
+			CheckProperties();
+		}
+		#endregion
+		
+		#region SetRange
+		/// <summary>
+		/// Sets <paramref name="count"/> indices starting at <paramref name="index"/> to
+		/// <paramref name="item"/>
+		/// </summary>
+		public void SetRange(int index, int count, T item)
+		{
+			RemoveRange(index, count);
+			InsertRange(index, count, item);
+		}
+		#endregion
+		
+		#region GetNode
+		Node GetNode(ref int index)
+		{
+			Node node = root;
+			while (true) {
+				if (node.left != null && index < node.left.totalCount) {
+					node = node.left;
+				} else {
+					if (node.left != null) {
+						index -= node.left.totalCount;
+					}
+					if (index < node.count || node.right == null)
+						return node;
+					index -= node.count;
+					node = node.right;
+				}
+			}
+		}
+		#endregion
+		
+		#region UpdateAugmentedData
+		void UpdateAugmentedData(Node node)
+		{
+			int totalCount = node.count;
+			if (node.left != null) totalCount += node.left.totalCount;
+			if (node.right != null) totalCount += node.right.totalCount;
+			if (node.totalCount != totalCount) {
+				node.totalCount = totalCount;
+				if (node.parent != null)
+					UpdateAugmentedData(node.parent);
+			}
+		}
+		#endregion
+		
+		#region IList<T> implementation
+		/// <summary>
+		/// Gets or sets an item by index.
+		/// </summary>
+		public T this[int index] {
+			get {
+				if (index < 0 || index >= this.Count)
+					throw new ArgumentOutOfRangeException("index", index, "Value must be between 0 and " + (this.Count - 1));
+				return GetNode(ref index).value;
+			}
+			set {
+				RemoveAt(index);
+				Insert(index, value);
+			}
+		}
+		
+		/// <summary>
+		/// Gets the number of items in the list.
+		/// </summary>
+		public int Count {
+			get {
+				if (root != null)
+					return root.totalCount;
+				else
+					return 0;
+			}
+		}
+		
+		bool ICollection<T>.IsReadOnly {
+			get {
+				return false;
+			}
+		}
+		
+		/// <summary>
+		/// Gets the index of the specified <paramref name="item"/>.
+		/// </summary>
+		public int IndexOf(T item)
+		{
+			int index = 0;
+			if (root != null) {
+				Node n = root.LeftMost;
+				while (n != null) {
+					if (comparisonFunc(n.value, item))
+						return index;
+					index += n.count;
+					n = n.Successor;
+				}
+			}
+			Debug.Assert(index == this.Count);
+			return -1;
+		}
+		
+		/// <summary>
+		/// Gets the the first index so that all values from the result index to <paramref name="index"/>
+		/// are equal.
+		/// </summary>
+		public int GetStartOfRun(int index)
+		{
+			if (index < 0 || index >= this.Count)
+				throw new ArgumentOutOfRangeException("index", index, "Value must be between 0 and " + (this.Count - 1));
+			int indexInRun = index;
+			GetNode(ref indexInRun);
+			return index - indexInRun;
+		}
+
+		/// <summary>
+		/// Gets the first index after <paramref name="index"/> so that the value at the result index is not
+		/// equal to the value at <paramref name="index"/>.
+		/// That is, this method returns the exclusive end index of the run of equal values.
+		/// </summary>
+		public int GetEndOfRun(int index)
+		{
+			if (index < 0 || index >= this.Count)
+				throw new ArgumentOutOfRangeException("index", index, "Value must be between 0 and " + (this.Count - 1));
+			int indexInRun = index;
+			int runLength = GetNode(ref indexInRun).count;
+			return index - indexInRun + runLength;
+		}
+
+		/// <summary>
+		/// Gets the number of elements after <paramref name="index"/> that have the same value as each other.
+		/// </summary>
+		[Obsolete("This method may be confusing as it returns only the remaining run length after index. " +
+		          "Use GetStartOfRun/GetEndOfRun instead.")]
+		public int GetRunLength(int index)
+		{
+			if (index < 0 || index >= this.Count)
+				throw new ArgumentOutOfRangeException("index", index, "Value must be between 0 and " + (this.Count - 1));
+			return GetNode(ref index).count - index;
+		}
+		
+		/// <summary>
+		/// Applies the conversion function to all elements in this CompressingTreeList.
+		/// </summary>
+		public void Transform(Func<T, T> converter)
+		{
+			if (root == null)
+				return;
+			Node prevNode = null;
+			for (Node n = root.LeftMost; n != null; n = n.Successor) {
+				n.value = converter(n.value);
+				if (prevNode != null && comparisonFunc(prevNode.value, n.value)) {
+					n.count += prevNode.count;
+					UpdateAugmentedData(n);
+					RemoveNode(prevNode);
+				}
+				prevNode = n;
+			}
+		}
+
+		
+		/// <summary>
+		/// Inserts the specified <paramref name="item"/> at <paramref name="index"/>
+		/// </summary>
+		public void Insert(int index, T item)
+		{
+			InsertRange(index, 1, item);
+		}
+		
+		/// <summary>
+		/// Removes one item at <paramref name="index"/>
+		/// </summary>
+		public void RemoveAt(int index)
+		{
+			RemoveRange(index, 1);
+		}
+		
+		/// <summary>
+		/// Adds the specified <paramref name="item"/> to the end of the list.
+		/// </summary>
+		public void Add(T item)
+		{
+			InsertRange(this.Count, 1, item);
+		}
+		
+		/// <summary>
+		/// Removes all items from this list.
+		/// </summary>
+		public void Clear()
+		{
+			root = null;
+		}
+		
+		/// <summary>
+		/// Gets whether this list contains the specified item.
+		/// </summary>
+		public bool Contains(T item)
+		{
+			return IndexOf(item) >= 0;
+		}
+		
+		/// <summary>
+		/// Copies all items in this list to the specified array.
+		/// </summary>
+		public void CopyTo(T[] array, int arrayIndex)
+		{
+			if (array == null)
+				throw new ArgumentNullException("array");
+			if (array.Length < this.Count)
+				throw new ArgumentException("The array is too small", "array");
+			if (arrayIndex < 0 || arrayIndex + this.Count > array.Length)
+				throw new ArgumentOutOfRangeException("arrayIndex", arrayIndex, "Value must be between 0 and " + (array.Length - this.Count));
+			foreach (T v in this) {
+				array[arrayIndex++] = v;
+			}
+		}
+		
+		/// <summary>
+		/// Removes the specified item from this list.
+		/// </summary>
+		public bool Remove(T item)
+		{
+			int index = IndexOf(item);
+			if (index >= 0) {
+				RemoveAt(index);
+				return true;
+			} else {
+				return false;
+			}
+		}
+		#endregion
+		
+		#region IEnumerable<T>
+		/// <summary>
+		/// Gets an enumerator for this list.
+		/// </summary>
+		public IEnumerator<T> GetEnumerator()
+		{
+			if (root != null) {
+				Node n = root.LeftMost;
+				while (n != null) {
+					for (int i = 0; i < n.count; i++) {
+						yield return n.value;
+					}
+					n = n.Successor;
+				}
+			}
+		}
+		
+		System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
+		{
+			return GetEnumerator();
+		}
+		#endregion
+		
+		#region Red/Black Tree
+		internal const bool RED = true;
+		internal const bool BLACK = false;
+		
+		void InsertAsLeft(Node parentNode, Node newNode)
+		{
+			Debug.Assert(parentNode.left == null);
+			parentNode.left = newNode;
+			newNode.parent = parentNode;
+			newNode.color = RED;
+			UpdateAugmentedData(parentNode);
+			FixTreeOnInsert(newNode);
+		}
+		
+		void InsertAsRight(Node parentNode, Node newNode)
+		{
+			Debug.Assert(parentNode.right == null);
+			parentNode.right = newNode;
+			newNode.parent = parentNode;
+			newNode.color = RED;
+			UpdateAugmentedData(parentNode);
+			FixTreeOnInsert(newNode);
+		}
+		
+		void FixTreeOnInsert(Node node)
+		{
+			Debug.Assert(node != null);
+			Debug.Assert(node.color == RED);
+			Debug.Assert(node.left == null || node.left.color == BLACK);
+			Debug.Assert(node.right == null || node.right.color == BLACK);
+			
+			Node parentNode = node.parent;
+			if (parentNode == null) {
+				// we inserted in the root -> the node must be black
+				// since this is a root node, making the node black increments the number of black nodes
+				// on all paths by one, so it is still the same for all paths.
+				node.color = BLACK;
+				return;
+			}
+			if (parentNode.color == BLACK) {
+				// if the parent node where we inserted was black, our red node is placed correctly.
+				// since we inserted a red node, the number of black nodes on each path is unchanged
+				// -> the tree is still balanced
+				return;
+			}
+			// parentNode is red, so there is a conflict here!
+			
+			// because the root is black, parentNode is not the root -> there is a grandparent node
+			Node grandparentNode = parentNode.parent;
+			Node uncleNode = Sibling(parentNode);
+			if (uncleNode != null && uncleNode.color == RED) {
+				parentNode.color = BLACK;
+				uncleNode.color = BLACK;
+				grandparentNode.color = RED;
+				FixTreeOnInsert(grandparentNode);
+				return;
+			}
+			// now we know: parent is red but uncle is black
+			// First rotation:
+			if (node == parentNode.right && parentNode == grandparentNode.left) {
+				RotateLeft(parentNode);
+				node = node.left;
+			} else if (node == parentNode.left && parentNode == grandparentNode.right) {
+				RotateRight(parentNode);
+				node = node.right;
+			}
+			// because node might have changed, reassign variables:
+			parentNode = node.parent;
+			grandparentNode = parentNode.parent;
+			
+			// Now recolor a bit:
+			parentNode.color = BLACK;
+			grandparentNode.color = RED;
+			// Second rotation:
+			if (node == parentNode.left && parentNode == grandparentNode.left) {
+				RotateRight(grandparentNode);
+			} else {
+				// because of the first rotation, this is guaranteed:
+				Debug.Assert(node == parentNode.right && parentNode == grandparentNode.right);
+				RotateLeft(grandparentNode);
+			}
+		}
+		
+		void RemoveNode(Node removedNode)
+		{
+			if (removedNode.left != null && removedNode.right != null) {
+				// replace removedNode with it's in-order successor
+				
+				Node leftMost = removedNode.right.LeftMost;
+				RemoveNode(leftMost); // remove leftMost from its current location
+				
+				// and overwrite the removedNode with it
+				ReplaceNode(removedNode, leftMost);
+				leftMost.left = removedNode.left;
+				if (leftMost.left != null) leftMost.left.parent = leftMost;
+				leftMost.right = removedNode.right;
+				if (leftMost.right != null) leftMost.right.parent = leftMost;
+				leftMost.color = removedNode.color;
+				
+				UpdateAugmentedData(leftMost);
+				if (leftMost.parent != null) UpdateAugmentedData(leftMost.parent);
+				return;
+			}
+			
+			// now either removedNode.left or removedNode.right is null
+			// get the remaining child
+			Node parentNode = removedNode.parent;
+			Node childNode = removedNode.left ?? removedNode.right;
+			ReplaceNode(removedNode, childNode);
+			if (parentNode != null) UpdateAugmentedData(parentNode);
+			if (removedNode.color == BLACK) {
+				if (childNode != null && childNode.color == RED) {
+					childNode.color = BLACK;
+				} else {
+					FixTreeOnDelete(childNode, parentNode);
+				}
+			}
+		}
+		
+		void FixTreeOnDelete(Node node, Node parentNode)
+		{
+			Debug.Assert(node == null || node.parent == parentNode);
+			if (parentNode == null)
+				return;
+			
+			// warning: node may be null
+			Node sibling = Sibling(node, parentNode);
+			if (sibling.color == RED) {
+				parentNode.color = RED;
+				sibling.color = BLACK;
+				if (node == parentNode.left) {
+					RotateLeft(parentNode);
+				} else {
+					RotateRight(parentNode);
+				}
+				
+				sibling = Sibling(node, parentNode); // update value of sibling after rotation
+			}
+			
+			if (parentNode.color == BLACK
+			    && sibling.color == BLACK
+			    && GetColor(sibling.left) == BLACK
+			    && GetColor(sibling.right) == BLACK)
+			{
+				sibling.color = RED;
+				FixTreeOnDelete(parentNode, parentNode.parent);
+				return;
+			}
+			
+			if (parentNode.color == RED
+			    && sibling.color == BLACK
+			    && GetColor(sibling.left) == BLACK
+			    && GetColor(sibling.right) == BLACK)
+			{
+				sibling.color = RED;
+				parentNode.color = BLACK;
+				return;
+			}
+			
+			if (node == parentNode.left &&
+			    sibling.color == BLACK &&
+			    GetColor(sibling.left) == RED &&
+			    GetColor(sibling.right) == BLACK)
+			{
+				sibling.color = RED;
+				sibling.left.color = BLACK;
+				RotateRight(sibling);
+			}
+			else if (node == parentNode.right &&
+			         sibling.color == BLACK &&
+			         GetColor(sibling.right) == RED &&
+			         GetColor(sibling.left) == BLACK)
+			{
+				sibling.color = RED;
+				sibling.right.color = BLACK;
+				RotateLeft(sibling);
+			}
+			sibling = Sibling(node, parentNode); // update value of sibling after rotation
+			
+			sibling.color = parentNode.color;
+			parentNode.color = BLACK;
+			if (node == parentNode.left) {
+				if (sibling.right != null) {
+					Debug.Assert(sibling.right.color == RED);
+					sibling.right.color = BLACK;
+				}
+				RotateLeft(parentNode);
+			} else {
+				if (sibling.left != null) {
+					Debug.Assert(sibling.left.color == RED);
+					sibling.left.color = BLACK;
+				}
+				RotateRight(parentNode);
+			}
+		}
+		
+		void ReplaceNode(Node replacedNode, Node newNode)
+		{
+			if (replacedNode.parent == null) {
+				Debug.Assert(replacedNode == root);
+				root = newNode;
+			} else {
+				if (replacedNode.parent.left == replacedNode)
+					replacedNode.parent.left = newNode;
+				else
+					replacedNode.parent.right = newNode;
+			}
+			if (newNode != null) {
+				newNode.parent = replacedNode.parent;
+			}
+			replacedNode.parent = null;
+		}
+		
+		void RotateLeft(Node p)
+		{
+			// let q be p's right child
+			Node q = p.right;
+			Debug.Assert(q != null);
+			Debug.Assert(q.parent == p);
+			// set q to be the new root
+			ReplaceNode(p, q);
+			
+			// set p's right child to be q's left child
+			p.right = q.left;
+			if (p.right != null) p.right.parent = p;
+			// set q's left child to be p
+			q.left = p;
+			p.parent = q;
+			UpdateAugmentedData(p);
+			UpdateAugmentedData(q);
+		}
+		
+		void RotateRight(Node p)
+		{
+			// let q be p's left child
+			Node q = p.left;
+			Debug.Assert(q != null);
+			Debug.Assert(q.parent == p);
+			// set q to be the new root
+			ReplaceNode(p, q);
+			
+			// set p's left child to be q's right child
+			p.left = q.right;
+			if (p.left != null) p.left.parent = p;
+			// set q's right child to be p
+			q.right = p;
+			p.parent = q;
+			UpdateAugmentedData(p);
+			UpdateAugmentedData(q);
+		}
+		
+		static Node Sibling(Node node)
+		{
+			if (node == node.parent.left)
+				return node.parent.right;
+			else
+				return node.parent.left;
+		}
+		
+		static Node Sibling(Node node, Node parentNode)
+		{
+			Debug.Assert(node == null || node.parent == parentNode);
+			if (node == parentNode.left)
+				return parentNode.right;
+			else
+				return parentNode.left;
+		}
+		
+		static bool GetColor(Node node)
+		{
+			return node != null ? node.color : BLACK;
+		}
+		#endregion
+		
+		#region CheckProperties
+		[Conditional("DATACONSISTENCYTEST")]
+		internal void CheckProperties()
+		{
+			#if DEBUG
+			if (root != null) {
+				CheckProperties(root);
+				
+				// check red-black property:
+				int blackCount = -1;
+				CheckNodeProperties(root, null, RED, 0, ref blackCount);
+				
+				// ensure that the tree is compressed:
+				Node p = root.LeftMost;
+				Node n = p.Successor;
+				while (n != null) {
+					Debug.Assert(!comparisonFunc(p.value, n.value));
+					p = n;
+					n = p.Successor;
+				}
+			}
+			#endif
+		}
+		
+		#if DEBUG
+		void CheckProperties(Node node)
+		{
+			Debug.Assert(node.count > 0);
+			int totalCount = node.count;
+			if (node.left != null) {
+				CheckProperties(node.left);
+				totalCount += node.left.totalCount;
+			}
+			if (node.right != null) {
+				CheckProperties(node.right);
+				totalCount += node.right.totalCount;
+			}
+			Debug.Assert(node.totalCount == totalCount);
+		}
+		
+		/*
+		1. A node is either red or black.
+		2. The root is black.
+		3. All leaves are black. (The leaves are the NIL children.)
+		4. Both children of every red node are black. (So every red node must have a black parent.)
+		5. Every simple path from a node to a descendant leaf contains the same number of black nodes. (Not counting the leaf node.)
+		 */
+		void CheckNodeProperties(Node node, Node parentNode, bool parentColor, int blackCount, ref int expectedBlackCount)
+		{
+			if (node == null) return;
+			
+			Debug.Assert(node.parent == parentNode);
+			
+			if (parentColor == RED) {
+				Debug.Assert(node.color == BLACK);
+			}
+			if (node.color == BLACK) {
+				blackCount++;
+			}
+			if (node.left == null && node.right == null) {
+				// node is a leaf node:
+				if (expectedBlackCount == -1)
+					expectedBlackCount = blackCount;
+				else
+					Debug.Assert(expectedBlackCount == blackCount);
+			}
+			CheckNodeProperties(node.left, node, node.color, blackCount, ref expectedBlackCount);
+			CheckNodeProperties(node.right, node, node.color, blackCount, ref expectedBlackCount);
+		}
+		#endif
+		#endregion
+		
+		#region GetTreeAsString
+		internal string GetTreeAsString()
+		{
+			#if DEBUG
+			if (root == null)
+				return "<empty tree>";
+			StringBuilder b = new StringBuilder();
+			AppendTreeToString(root, b, 0);
+			return b.ToString();
+			#else
+			return "Not available in release build.";
+			#endif
+		}
+		
+		#if DEBUG
+		static void AppendTreeToString(Node node, StringBuilder b, int indent)
+		{
+			if (node.color == RED)
+				b.Append("RED   ");
+			else
+				b.Append("BLACK ");
+			b.AppendLine(node.ToString());
+			indent += 2;
+			if (node.left != null) {
+				b.Append(' ', indent);
+				b.Append("L: ");
+				AppendTreeToString(node.left, b, indent);
+			}
+			if (node.right != null) {
+				b.Append(' ', indent);
+				b.Append("R: ");
+				AppendTreeToString(node.right, b, indent);
+			}
+		}
+		#endif
+		#endregion
+	}
+}
diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/Constants.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/Constants.cs
new file mode 100644
index 000000000..0344ada80
--- /dev/null
+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/Constants.cs
@@ -0,0 +1,15 @@
+// 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;
+
+namespace Tango.Scripting.Editors.Utils
+{
+	static class Constants
+	{
+		/// <summary>
+		/// Multiply with this constant to convert from points to device-independent pixels.
+		/// </summary>
+		public const double PixelPerPoint = 4 / 3.0;
+	}
+}
diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/DelayedEvents.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/DelayedEvents.cs
new file mode 100644
index 000000000..8afc9f2ee
--- /dev/null
+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/DelayedEvents.cs
@@ -0,0 +1,48 @@
+// 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.Utils
+{
+	/// <summary>
+	/// Maintains a list of delayed events to raise.
+	/// </summary>
+	sealed class DelayedEvents
+	{
+		struct EventCall
+		{
+			EventHandler handler;
+			object sender;
+			EventArgs e;
+			
+			public EventCall(EventHandler handler, object sender, EventArgs e)
+			{
+				this.handler = handler;
+				this.sender = sender;
+				this.e = e;
+			}
+			
+			public void Call()
+			{
+				handler(sender, e);
+			}
+		}
+		
+		Queue<EventCall> eventCalls = new Queue<EventCall>();
+		
+		public void DelayedRaise(EventHandler handler, object sender, EventArgs e)
+		{
+			if (handler != null) {
+				eventCalls.Enqueue(new EventCall(handler, sender, e));
+			}
+		}
+		
+		public void RaiseEvents()
+		{
+			while (eventCalls.Count > 0)
+				eventCalls.Dequeue().Call();
+		}
+	}
+}
diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/Deque.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/Deque.cs
new file mode 100644
index 000000000..66496d68f
--- /dev/null
+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/Deque.cs
@@ -0,0 +1,174 @@
+// 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.Diagnostics;
+
+namespace Tango.Scripting.Editors.Utils
+{
+	/// <summary>
+	/// Double-ended queue.
+	/// </summary>
+	[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1710:IdentifiersShouldHaveCorrectSuffix")]
+	[Serializable]
+	public sealed class Deque<T> : ICollection<T>
+	{
+		T[] arr = Empty<T>.Array;
+		int size, head, tail;
+		
+		/// <inheritdoc/>
+		public int Count {
+			get { return size; }
+		}
+		
+		/// <inheritdoc/>
+		public void Clear()
+		{
+			arr = Empty<T>.Array;
+			size = 0;
+			head = 0;
+			tail = 0;
+		}
+		
+		/// <summary>
+		/// Gets/Sets an element inside the deque.
+		/// </summary>
+		public T this[int index] {
+			get {
+				ThrowUtil.CheckInRangeInclusive(index, "index", 0, size - 1);
+				return arr[(head + index) % arr.Length];
+			}
+			set {
+				ThrowUtil.CheckInRangeInclusive(index, "index", 0, size - 1);
+				arr[(head + index) % arr.Length] = value;
+			}
+		}
+		
+		/// <summary>
+		/// Adds an element to the end of the deque.
+		/// </summary>
+		[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1702:CompoundWordsShouldBeCasedCorrectly", MessageId = "PushBack")]
+		public void PushBack(T item)
+		{
+			if (size == arr.Length)
+				SetCapacity(Math.Max(4, arr.Length * 2));
+			arr[tail++] = item;
+			if (tail == arr.Length) tail = 0;
+			size++;
+		}
+		
+		/// <summary>
+		/// Pops an element from the end of the deque.
+		/// </summary>
+		public T PopBack()
+		{
+			if (size == 0)
+				throw new InvalidOperationException();
+			if (tail == 0)
+				tail = arr.Length - 1;
+			else
+				tail--;
+			T val = arr[tail];
+			arr[tail] = default(T); // allow GC to collect the element
+			size--;
+			return val;
+		}
+		
+		/// <summary>
+		/// Adds an element to the front of the deque.
+		/// </summary>
+		public void PushFront(T item)
+		{
+			if (size == arr.Length)
+				SetCapacity(Math.Max(4, arr.Length * 2));
+			if (head == 0)
+				head = arr.Length - 1;
+			else
+				head--;
+			arr[head] = item;
+			size++;
+		}
+		
+		/// <summary>
+		/// Pops an element from the end of the deque.
+		/// </summary>
+		public T PopFront()
+		{
+			if (size == 0)
+				throw new InvalidOperationException();
+			T val = arr[head];
+			arr[head] = default(T); // allow GC to collect the element
+			head++;
+			if (head == arr.Length) head = 0;
+			size--;
+			return val;
+		}
+		
+		void SetCapacity(int capacity)
+		{
+			T[] newArr = new T[capacity];
+			CopyTo(newArr, 0);
+			head = 0;
+			tail = (size == capacity) ? 0 : size;
+			arr = newArr;
+		}
+		
+		/// <inheritdoc/>
+		public IEnumerator<T> GetEnumerator()
+		{
+			if (head < tail) {
+				for (int i = head; i < tail; i++)
+					yield return arr[i];
+			} else {
+				for (int i = head; i < arr.Length; i++)
+					yield return arr[i];
+				for (int i = 0; i < tail; i++)
+					yield return arr[i];
+			}
+		}
+		
+		System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
+		{
+			return this.GetEnumerator();
+		}
+		
+		bool ICollection<T>.IsReadOnly {
+			get { return false; }
+		}
+		
+		void ICollection<T>.Add(T item)
+		{
+			PushBack(item);
+		}
+		
+		/// <inheritdoc/>
+		public bool Contains(T item)
+		{
+			EqualityComparer<T> comparer = EqualityComparer<T>.Default;
+			foreach (T element in this)
+				if (comparer.Equals(item, element))
+					return true;
+			return false;
+		}
+		
+		/// <inheritdoc/>
+		public void CopyTo(T[] array, int arrayIndex)
+		{
+			if (array == null)
+				throw new ArgumentNullException("array");
+			if (head < tail) {
+				Array.Copy(arr, head, array, arrayIndex, tail - head);
+			} else {
+				int num1 = arr.Length - head;
+				Array.Copy(arr, head, array, arrayIndex, num1);
+				Array.Copy(arr, 0, array, arrayIndex + num1, tail);
+			}
+		}
+		
+		bool ICollection<T>.Remove(T item)
+		{
+			throw new NotSupportedException();
+		}
+	}
+}
diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/Empty.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/Empty.cs
new file mode 100644
index 000000000..1f890dd7a
--- /dev/null
+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/Empty.cs
@@ -0,0 +1,17 @@
+// 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.ObjectModel;
+
+namespace Tango.Scripting.Editors.Utils
+{
+	/// <summary>
+	/// Provides immutable empty list instances.
+	/// </summary>
+	static class Empty<T>
+	{
+		public static readonly T[] Array = new T[0];
+		//public static readonly ReadOnlyCollection<T> ReadOnlyCollection = new ReadOnlyCollection<T>(Array);
+	}
+}
diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/ExtensionMethods.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/ExtensionMethods.cs
new file mode 100644
index 000000000..d9b00ed33
--- /dev/null
+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/ExtensionMethods.cs
@@ -0,0 +1,214 @@
+// 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.Diagnostics;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Media;
+using System.Xml;
+
+namespace Tango.Scripting.Editors.Utils
+{
+	static class ExtensionMethods
+	{
+		#region Epsilon / IsClose / CoerceValue
+		/// <summary>
+		/// Epsilon used for <c>IsClose()</c> implementations.
+		/// We can use up quite a few digits in front of the decimal point (due to visual positions being relative to document origin),
+		/// and there's no need to be too accurate (we're dealing with pixels here),
+		/// so we will use the value 0.01.
+		/// Previosly we used 1e-8 but that was causing issues:
+		/// http://community.sharpdevelop.net/forums/t/16048.aspx
+		/// </summary>
+		public const double Epsilon = 0.01;
+		
+		/// <summary>
+		/// Returns true if the doubles are close (difference smaller than 0.01).
+		/// </summary>
+		public static bool IsClose(this double d1, double d2)
+		{
+			if (d1 == d2) // required for infinities
+				return true;
+			return Math.Abs(d1 - d2) < Epsilon;
+		}
+		
+		/// <summary>
+		/// Returns true if the doubles are close (difference smaller than 0.01).
+		/// </summary>
+		public static bool IsClose(this Size d1, Size d2)
+		{
+			return IsClose(d1.Width, d2.Width) && IsClose(d1.Height, d2.Height);
+		}
+		
+		/// <summary>
+		/// Returns true if the doubles are close (difference smaller than 0.01).
+		/// </summary>
+		public static bool IsClose(this Vector d1, Vector d2)
+		{
+			return IsClose(d1.X, d2.X) && IsClose(d1.Y, d2.Y);
+		}
+		
+		/// <summary>
+		/// Forces the value to stay between mininum and maximum.
+		/// </summary>
+		/// <returns>minimum, if value is less than minimum.
+		/// Maximum, if value is greater than maximum.
+		/// Otherwise, value.</returns>
+		public static double CoerceValue(this double value, double minimum, double maximum)
+		{
+			return Math.Max(Math.Min(value, maximum), minimum);
+		}
+		
+		/// <summary>
+		/// Forces the value to stay between mininum and maximum.
+		/// </summary>
+		/// <returns>minimum, if value is less than minimum.
+		/// Maximum, if value is greater than maximum.
+		/// Otherwise, value.</returns>
+		public static int CoerceValue(this int value, int minimum, int maximum)
+		{
+			return Math.Max(Math.Min(value, maximum), minimum);
+		}
+		#endregion
+		
+		#region CreateTypeface
+		/// <summary>
+		/// Creates typeface from the framework element.
+		/// </summary>
+		public static Typeface CreateTypeface(this FrameworkElement fe)
+		{
+			return new Typeface((FontFamily)fe.GetValue(TextBlock.FontFamilyProperty),
+			                    (FontStyle)fe.GetValue(TextBlock.FontStyleProperty),
+			                    (FontWeight)fe.GetValue(TextBlock.FontWeightProperty),
+			                    (FontStretch)fe.GetValue(TextBlock.FontStretchProperty));
+		}
+		#endregion
+		
+		#region AddRange / Sequence
+		public static void AddRange<T>(this ICollection<T> collection, IEnumerable<T> elements)
+		{
+			foreach (T e in elements)
+				collection.Add(e);
+		}
+		
+		/// <summary>
+		/// Creates an IEnumerable with a single value.
+		/// </summary>
+		public static IEnumerable<T> Sequence<T>(T value)
+		{
+			yield return value;
+		}
+		#endregion
+		
+		#region XML reading
+		/// <summary>
+		/// Gets the value of the attribute, or null if the attribute does not exist.
+		/// </summary>
+		public static string GetAttributeOrNull(this XmlElement element, string attributeName)
+		{
+			XmlAttribute attr = element.GetAttributeNode(attributeName);
+			return attr != null ? attr.Value : null;
+		}
+		
+		/// <summary>
+		/// Gets the value of the attribute as boolean, or null if the attribute does not exist.
+		/// </summary>
+		public static bool? GetBoolAttribute(this XmlElement element, string attributeName)
+		{
+			XmlAttribute attr = element.GetAttributeNode(attributeName);
+			return attr != null ? (bool?)XmlConvert.ToBoolean(attr.Value) : null;
+		}
+		
+		/// <summary>
+		/// Gets the value of the attribute as boolean, or null if the attribute does not exist.
+		/// </summary>
+		public static bool? GetBoolAttribute(this XmlReader reader, string attributeName)
+		{
+			string attributeValue = reader.GetAttribute(attributeName);
+			if (attributeValue == null)
+				return null;
+			else
+				return XmlConvert.ToBoolean(attributeValue);
+		}
+		#endregion
+		
+		#region DPI independence
+		public static Rect TransformToDevice(this Rect rect, Visual visual)
+		{
+			Matrix matrix = PresentationSource.FromVisual(visual).CompositionTarget.TransformToDevice;
+			return Rect.Transform(rect, matrix);
+		}
+		
+		public static Rect TransformFromDevice(this Rect rect, Visual visual)
+		{
+			Matrix matrix = PresentationSource.FromVisual(visual).CompositionTarget.TransformFromDevice;
+			return Rect.Transform(rect, matrix);
+		}
+		
+		public static Size TransformToDevice(this Size size, Visual visual)
+		{
+			Matrix matrix = PresentationSource.FromVisual(visual).CompositionTarget.TransformToDevice;
+			return new Size(size.Width * matrix.M11, size.Height * matrix.M22);
+		}
+		
+		public static Size TransformFromDevice(this Size size, Visual visual)
+		{
+			Matrix matrix = PresentationSource.FromVisual(visual).CompositionTarget.TransformFromDevice;
+			return new Size(size.Width * matrix.M11, size.Height * matrix.M22);
+		}
+		
+		public static Point TransformToDevice(this Point point, Visual visual)
+		{
+			Matrix matrix = PresentationSource.FromVisual(visual).CompositionTarget.TransformToDevice;
+			return new Point(point.X * matrix.M11, point.Y * matrix.M22);
+		}
+		
+		public static Point TransformFromDevice(this Point point, Visual visual)
+		{
+			Matrix matrix = PresentationSource.FromVisual(visual).CompositionTarget.TransformFromDevice;
+			return new Point(point.X * matrix.M11, point.Y * matrix.M22);
+		}
+		#endregion
+		
+		#region System.Drawing <-> WPF conversions
+		public static System.Drawing.Point ToSystemDrawing(this Point p)
+		{
+			return new System.Drawing.Point((int)p.X, (int)p.Y);
+		}
+		
+		public static Point ToWpf(this System.Drawing.Point p)
+		{
+			return new Point(p.X, p.Y);
+		}
+		
+		public static Size ToWpf(this System.Drawing.Size s)
+		{
+			return new Size(s.Width, s.Height);
+		}
+		
+		public static Rect ToWpf(this System.Drawing.Rectangle rect)
+		{
+			return new Rect(rect.Location.ToWpf(), rect.Size.ToWpf());
+		}
+		#endregion
+		
+		[Conditional("DEBUG")]
+		public static void CheckIsFrozen(Freezable f)
+		{
+			if (f != null && !f.IsFrozen)
+				Debug.WriteLine("Performance warning: Not frozen: " + f.ToString());
+		}
+		
+		[Conditional("DEBUG")]
+		public static void Log(bool condition, string format, params object[] args)
+		{
+			if (condition) {
+				string output = DateTime.Now.ToString("hh:MM:ss") + ": " + string.Format(format, args) + Environment.NewLine + Environment.StackTrace;
+				Console.WriteLine(output);
+				Debug.WriteLine(output);
+			}
+		}
+	}
+}
diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/FileReader.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/FileReader.cs
new file mode 100644
index 000000000..b44c589d7
--- /dev/null
+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/FileReader.cs
@@ -0,0 +1,208 @@
+// 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.IO;
+using System.Text;
+
+namespace Tango.Scripting.Editors.Utils
+{
+	/// <summary>
+	/// Class that can open text files with auto-detection of the encoding.
+	/// </summary>
+	public static class FileReader
+	{
+		/// <summary>
+		/// Gets if the given encoding is a Unicode encoding (UTF).
+		/// </summary>
+		/// <remarks>
+		/// Returns true for UTF-7, UTF-8, UTF-16 LE, UTF-16 BE, UTF-32 LE and UTF-32 BE.
+		/// Returns false for all other encodings.
+		/// </remarks>
+		public static bool IsUnicode(Encoding encoding)
+		{
+			if (encoding == null)
+				throw new ArgumentNullException("encoding");
+			switch (encoding.CodePage) {
+				case 65000: // UTF-7
+				case 65001: // UTF-8
+				case 1200: // UTF-16 LE
+				case 1201: // UTF-16 BE
+				case 12000: // UTF-32 LE
+				case 12001: // UTF-32 BE
+					return true;
+				default:
+					return false;
+			}
+		}
+		
+		/// <summary>
+		/// Reads the content of the given stream.
+		/// </summary>
+		/// <param name="stream">The stream to read.
+		/// The stream must support seeking and must be positioned at its beginning.</param>
+		/// <param name="defaultEncoding">The encoding to use if the encoding cannot be auto-detected.</param>
+		/// <returns>The file content as string.</returns>
+		public static string ReadFileContent(Stream stream, Encoding defaultEncoding)
+		{
+			using (StreamReader reader = OpenStream(stream, defaultEncoding)) {
+				return reader.ReadToEnd();
+			}
+		}
+		
+		/// <summary>
+		/// Reads the content of the file.
+		/// </summary>
+		/// <param name="fileName">The file name.</param>
+		/// <param name="defaultEncoding">The encoding to use if the encoding cannot be auto-detected.</param>
+		/// <returns>The file content as string.</returns>
+		public static string ReadFileContent(string fileName, Encoding defaultEncoding)
+		{
+			using (FileStream fs = new FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.Read)) {
+				return ReadFileContent(fs, defaultEncoding);
+			}
+		}
+		
+		/// <summary>
+		/// Opens the specified file for reading.
+		/// </summary>
+		/// <param name="fileName">The file to open.</param>
+		/// <param name="defaultEncoding">The encoding to use if the encoding cannot be auto-detected.</param>
+		/// <returns>Returns a StreamReader that reads from the stream. Use
+		/// <see cref="StreamReader.CurrentEncoding"/> to get the encoding that was used.</returns>
+		public static StreamReader OpenFile(string fileName, Encoding defaultEncoding)
+		{
+			if (fileName == null)
+				throw new ArgumentNullException("fileName");
+			FileStream fs = new FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.Read);
+			try {
+				return OpenStream(fs, defaultEncoding);
+				// don't use finally: the stream must be kept open until the StreamReader closes it
+			} catch {
+				fs.Dispose();
+				throw;
+			}
+		}
+		
+		/// <summary>
+		/// Opens the specified stream for reading.
+		/// </summary>
+		/// <param name="stream">The stream to open.</param>
+		/// <param name="defaultEncoding">The encoding to use if the encoding cannot be auto-detected.</param>
+		/// <returns>Returns a StreamReader that reads from the stream. Use
+		/// <see cref="StreamReader.CurrentEncoding"/> to get the encoding that was used.</returns>
+		public static StreamReader OpenStream(Stream stream, Encoding defaultEncoding)
+		{
+			if (stream == null)
+				throw new ArgumentNullException("stream");
+			if (stream.Position != 0)
+				throw new ArgumentException("stream is not positioned at beginning.", "stream");
+			if (defaultEncoding == null)
+				throw new ArgumentNullException("defaultEncoding");
+			
+			if (stream.Length >= 2) {
+				// the autodetection of StreamReader is not capable of detecting the difference
+				// between ISO-8859-1 and UTF-8 without BOM.
+				int firstByte = stream.ReadByte();
+				int secondByte = stream.ReadByte();
+				switch ((firstByte << 8) | secondByte) {
+					case 0x0000: // either UTF-32 Big Endian or a binary file; use StreamReader
+					case 0xfffe: // Unicode BOM (UTF-16 LE or UTF-32 LE)
+					case 0xfeff: // UTF-16 BE BOM
+					case 0xefbb: // start of UTF-8 BOM
+						// StreamReader autodetection works
+						stream.Position = 0;
+						return new StreamReader(stream);
+					default:
+						return AutoDetect(stream, (byte)firstByte, (byte)secondByte, defaultEncoding);
+				}
+			} else {
+				if (defaultEncoding != null) {
+					return new StreamReader(stream, defaultEncoding);
+				} else {
+					return new StreamReader(stream);
+				}
+			}
+		}
+		
+		static StreamReader AutoDetect(Stream fs, byte firstByte, byte secondByte, Encoding defaultEncoding)
+		{
+			int max = (int)Math.Min(fs.Length, 500000); // look at max. 500 KB
+			const int ASCII = 0;
+			const int Error = 1;
+			const int UTF8  = 2;
+			const int UTF8Sequence = 3;
+			int state = ASCII;
+			int sequenceLength = 0;
+			byte b;
+			for (int i = 0; i < max; i++) {
+				if (i == 0) {
+					b = firstByte;
+				} else if (i == 1) {
+					b = secondByte;
+				} else {
+					b = (byte)fs.ReadByte();
+				}
+				if (b < 0x80) {
+					// normal ASCII character
+					if (state == UTF8Sequence) {
+						state = Error;
+						break;
+					}
+				} else if (b < 0xc0) {
+					// 10xxxxxx : continues UTF8 byte sequence
+					if (state == UTF8Sequence) {
+						--sequenceLength;
+						if (sequenceLength < 0) {
+							state = Error;
+							break;
+						} else if (sequenceLength == 0) {
+							state = UTF8;
+						}
+					} else {
+						state = Error;
+						break;
+					}
+				} else if (b >= 0xc2 && b < 0xf5) {
+					// beginning of byte sequence
+					if (state == UTF8 || state == ASCII) {
+						state = UTF8Sequence;
+						if (b < 0xe0) {
+							sequenceLength = 1; // one more byte following
+						} else if (b < 0xf0) {
+							sequenceLength = 2; // two more bytes following
+						} else {
+							sequenceLength = 3; // three more bytes following
+						}
+					} else {
+						state = Error;
+						break;
+					}
+				} else {
+					// 0xc0, 0xc1, 0xf5 to 0xff are invalid in UTF-8 (see RFC 3629)
+					state = Error;
+					break;
+				}
+			}
+			fs.Position = 0;
+			switch (state) {
+				case ASCII:
+				case Error:
+					// when the file seems to be ASCII or non-UTF8,
+					// we read it using the user-specified encoding so it is saved again
+					// using that encoding.
+					if (IsUnicode(defaultEncoding)) {
+						// the file is not Unicode, so don't read it using Unicode even if the
+						// user has choosen Unicode as the default encoding.
+						
+						// If we don't do this, SD will end up always adding a Byte Order Mark
+						// to ASCII files.
+						defaultEncoding = Encoding.Default; // use system encoding instead
+					}
+					return new StreamReader(fs, defaultEncoding);
+				default:
+					return new StreamReader(fs);
+			}
+		}
+	}
+}
diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/ImmutableStack.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/ImmutableStack.cs
new file mode 100644
index 000000000..18a835fd2
--- /dev/null
+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/ImmutableStack.cs
@@ -0,0 +1,114 @@
+// 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.Diagnostics;
+using System.Text;
+
+namespace Tango.Scripting.Editors.Utils
+{
+	/// <summary>
+	/// An immutable stack.
+	/// 
+	/// Using 'foreach' on the stack will return the items from top to bottom (in the order they would be popped).
+	/// </summary>
+	[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1710:IdentifiersShouldHaveCorrectSuffix")]
+	[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1711:IdentifiersShouldNotHaveIncorrectSuffix")]
+	[Serializable]
+	public sealed class ImmutableStack<T> : IEnumerable<T>
+	{
+		/// <summary>
+		/// Gets the empty stack instance.
+		/// </summary>
+		[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Security", "CA2104:DoNotDeclareReadOnlyMutableReferenceTypes", Justification = "ImmutableStack is immutable")]
+		[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1000:DoNotDeclareStaticMembersOnGenericTypes")]
+		public static readonly ImmutableStack<T> Empty = new ImmutableStack<T>();
+		
+		readonly T value;
+		readonly ImmutableStack<T> next;
+		
+		private ImmutableStack()
+		{
+		}
+		
+		private ImmutableStack(T value, ImmutableStack<T> next)
+		{
+			this.value = value;
+			this.next = next;
+		}
+		
+		/// <summary>
+		/// Pushes an item on the stack. This does not modify the stack itself, but returns a new
+		/// one with the value pushed.
+		/// </summary>
+		public ImmutableStack<T> Push(T item)
+		{
+			return new ImmutableStack<T>(item, this);
+		}
+		
+		/// <summary>
+		/// Gets the item on the top of the stack.
+		/// </summary>
+		/// <exception cref="InvalidOperationException">The stack is empty.</exception>
+		public T Peek()
+		{
+			if (IsEmpty)
+				throw new InvalidOperationException("Operation not valid on empty stack.");
+			return value;
+		}
+		
+		internal T UnsafePeek()
+		{
+			Debug.Assert(!IsEmpty);
+			return value;
+		}
+		
+		/// <summary>
+		/// Gets the stack with the top item removed.
+		/// </summary>
+		/// <exception cref="InvalidOperationException">The stack is empty.</exception>
+		public ImmutableStack<T> Pop()
+		{
+			if (IsEmpty)
+				throw new InvalidOperationException("Operation not valid on empty stack.");
+			return next;
+		}
+		
+		/// <summary>
+		/// Gets if this stack is empty.
+		/// </summary>
+		public bool IsEmpty {
+			get { return next == null; }
+		}
+		
+		/// <summary>
+		/// Gets an enumerator that iterates through the stack top-to-bottom.
+		/// </summary>
+		public IEnumerator<T> GetEnumerator()
+		{
+			ImmutableStack<T> t = this;
+			while (!t.IsEmpty) {
+				yield return t.value;
+				t = t.next;
+			}
+		}
+		
+		System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
+		{
+			return this.GetEnumerator();
+		}
+		
+		/// <inheritdoc/>
+		public override string ToString()
+		{
+			StringBuilder b = new StringBuilder("[Stack");
+			foreach (T val in this) {
+				b.Append(' ');
+				b.Append(val);
+			}
+			b.Append(']');
+			return b.ToString();
+		}
+	}
+}
diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/NullSafeCollection.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/NullSafeCollection.cs
new file mode 100644
index 000000000..8a37c54ae
--- /dev/null
+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/NullSafeCollection.cs
@@ -0,0 +1,31 @@
+// 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.ObjectModel;
+
+namespace Tango.Scripting.Editors.Utils
+{
+	/// <summary>
+	/// A collection that cannot contain null values.
+	/// </summary>
+	[Serializable]
+	public class NullSafeCollection<T> : Collection<T> where T : class
+	{
+		/// <inheritdoc/>
+		protected override void InsertItem(int index, T item)
+		{
+			if (item == null)
+				throw new ArgumentNullException("item");
+			base.InsertItem(index, item);
+		}
+		
+		/// <inheritdoc/>
+		protected override void SetItem(int index, T item)
+		{
+			if (item == null)
+				throw new ArgumentNullException("item");
+			base.SetItem(index, item);
+		}
+	}
+}
diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/ObserveAddRemoveCollection.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/ObserveAddRemoveCollection.cs
new file mode 100644
index 000000000..091de0d91
--- /dev/null
+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/ObserveAddRemoveCollection.cs
@@ -0,0 +1,63 @@
+// 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.ObjectModel;
+
+namespace Tango.Scripting.Editors.Utils
+{
+	/// <summary>
+	/// A collection where adding and removing items causes a callback.
+	/// It is valid for the onAdd callback to throw an exception - this will prevent the new item from
+	/// being added to the collection.
+	/// </summary>
+	sealed class ObserveAddRemoveCollection<T> : Collection<T>
+	{
+		readonly Action<T> onAdd, onRemove;
+		
+		public ObserveAddRemoveCollection(Action<T> onAdd, Action<T> onRemove)
+		{
+			this.onAdd = onAdd;
+			this.onRemove = onRemove;
+		}
+		
+		protected override void ClearItems()
+		{
+			if (onRemove != null) {
+				foreach (T val in this)
+					onRemove(val);
+			}
+			base.ClearItems();
+		}
+		
+		protected override void InsertItem(int index, T item)
+		{
+			if (onAdd != null)
+				onAdd(item);
+			base.InsertItem(index, item);
+		}
+		
+		protected override void RemoveItem(int index)
+		{
+			if (onRemove != null)
+				onRemove(this[index]);
+			base.RemoveItem(index);
+		}
+		
+		protected override void SetItem(int index, T item)
+		{
+			if (onRemove != null)
+				onRemove(this[index]);
+			try {
+				if (onAdd != null)
+					onAdd(item);
+			} catch {
+				// When adding the new item fails, just remove the old one
+				// (we cannot keep the old item since we already successfully called onRemove for it)
+				base.RemoveAt(index);
+				throw;
+			}
+			base.SetItem(index, item);
+		}
+	}
+}
diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/PixelSnapHelpers.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/PixelSnapHelpers.cs
new file mode 100644
index 000000000..abd859533
--- /dev/null
+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/PixelSnapHelpers.cs
@@ -0,0 +1,92 @@
+// 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.Windows;
+using System.Windows.Media;
+
+namespace Tango.Scripting.Editors.Utils
+{
+	/// <summary>
+	/// Contains static helper methods for aligning stuff on a whole number of pixels.
+	/// </summary>
+	public static class PixelSnapHelpers
+	{
+		/// <summary>
+		/// Gets the pixel size on the screen containing visual.
+		/// This method does not take transforms on visual into account.
+		/// </summary>
+		public static Size GetPixelSize(Visual visual)
+		{
+			if (visual == null)
+				throw new ArgumentNullException("visual");
+			PresentationSource source = PresentationSource.FromVisual(visual);
+			if (source != null) {
+				Matrix matrix = source.CompositionTarget.TransformFromDevice;
+				return new Size(matrix.M11, matrix.M22);
+			} else {
+				return new Size(1, 1);
+			}
+		}
+		
+		/// <summary>
+		/// Aligns <paramref name="value"/> on the next middle of a pixel.
+		/// </summary>
+		/// <param name="value">The value that should be aligned</param>
+		/// <param name="pixelSize">The size of one pixel</param>
+		public static double PixelAlign(double value, double pixelSize)
+		{
+			// 0 -> 0.5
+			// 0.1 -> 0.5
+			// 0.5 -> 0.5
+			// 0.9 -> 0.5
+			// 1 -> 1.5
+			return pixelSize * (Math.Round((value / pixelSize) + 0.5) - 0.5);
+		}
+		
+		/// <summary>
+		/// Aligns the borders of rect on the middles of pixels.
+		/// </summary>
+		public static Rect PixelAlign(Rect rect, Size pixelSize)
+		{
+			rect.X = PixelAlign(rect.X, pixelSize.Width);
+			rect.Y = PixelAlign(rect.Y, pixelSize.Height);
+			rect.Width = Round(rect.Width, pixelSize.Width);
+			rect.Height = Round(rect.Height, pixelSize.Height);
+			return rect;
+		}
+		
+		/// <summary>
+		/// Rounds <paramref name="point"/> to whole number of pixels.
+		/// </summary>
+		public static Point Round(Point point, Size pixelSize)
+		{
+			return new Point(Round(point.X, pixelSize.Width), Round(point.Y, pixelSize.Height));
+		}
+		
+		/// <summary>
+		/// Rounds val to whole number of pixels.
+		/// </summary>
+		public static Rect Round(Rect rect, Size pixelSize)
+		{
+			return new Rect(Round(rect.X, pixelSize.Width), Round(rect.Y, pixelSize.Height),
+			                Round(rect.Width, pixelSize.Width), Round(rect.Height, pixelSize.Height));
+		}
+		
+		/// <summary>
+		/// Rounds <paramref name="value"/> to a whole number of pixels.
+		/// </summary>
+		public static double Round(double value, double pixelSize)
+		{
+			return pixelSize * Math.Round(value / pixelSize);
+		}
+		
+		/// <summary>
+		/// Rounds <paramref name="value"/> to an whole odd number of pixels.
+		/// </summary>
+		public static double RoundToOdd(double value, double pixelSize)
+		{
+			return Round(value - pixelSize, pixelSize * 2) + pixelSize;
+		}
+	}
+}
diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/PropertyChangedWeakEventManager.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/PropertyChangedWeakEventManager.cs
new file mode 100644
index 000000000..9b70c8f54
--- /dev/null
+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/PropertyChangedWeakEventManager.cs
@@ -0,0 +1,26 @@
+// 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.ComponentModel;
+
+namespace Tango.Scripting.Editors.Utils
+{
+	/// <summary>
+	/// WeakEventManager for INotifyPropertyChanged.PropertyChanged.
+	/// </summary>
+	public sealed class PropertyChangedWeakEventManager : WeakEventManagerBase<PropertyChangedWeakEventManager, INotifyPropertyChanged>
+	{
+		/// <inheritdoc/>
+		protected override void StartListening(INotifyPropertyChanged source)
+		{
+			source.PropertyChanged += DeliverEvent;
+		}
+		
+		/// <inheritdoc/>
+		protected override void StopListening(INotifyPropertyChanged source)
+		{
+			source.PropertyChanged -= DeliverEvent;
+		}
+	}
+}
diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/Rope.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/Rope.cs
new file mode 100644
index 000000000..d27edd199
--- /dev/null
+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/Rope.cs
@@ -0,0 +1,789 @@
+// 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.Linq;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Globalization;
+using System.Runtime.Serialization;
+using System.Text;
+
+namespace Tango.Scripting.Editors.Utils
+{
+	/// <summary>
+	/// A kind of List&lt;T&gt;, but more efficient for random insertions/removal.
+	/// Also has cheap Clone() and SubRope() implementations.
+	/// </summary>
+	/// <remarks>
+	/// This class is not thread-safe: multiple concurrent write operations or writes concurrent to reads have undefined behaviour.
+	/// Concurrent reads, however, are safe.
+	/// However, clones of a rope are safe to use on other threads even though they share data with the original rope.
+	/// </remarks>
+	[Serializable]
+	[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1710:IdentifiersShouldHaveCorrectSuffix")]
+	public sealed class Rope<T> : IList<T>, ICloneable
+	{
+		internal RopeNode<T> root;
+		
+		internal Rope(RopeNode<T> root)
+		{
+			this.root = root;
+			root.CheckInvariants();
+		}
+		
+		/// <summary>
+		/// Creates a new rope representing the empty string.
+		/// </summary>
+		public Rope()
+		{
+			// we'll construct the empty rope as a clone of an imaginary static empty rope
+			this.root = RopeNode<T>.emptyRopeNode;
+			root.CheckInvariants();
+		}
+		
+		/// <summary>
+		/// Creates a rope from the specified input.
+		/// This operation runs in O(N).
+		/// </summary>
+		/// <exception cref="ArgumentNullException">input is null.</exception>
+		public Rope(IEnumerable<T> input)
+		{
+			if (input == null)
+				throw new ArgumentNullException("input");
+			Rope<T> inputRope = input as Rope<T>;
+			if (inputRope != null) {
+				// clone ropes instead of copying them
+				inputRope.root.Publish();
+				this.root = inputRope.root;
+			} else {
+				string text = input as string;
+				if (text != null) {
+					// if a string is IEnumerable<T>, then T must be char
+					((Rope<char>)(object)this).root = CharRope.InitFromString(text);
+				} else {
+					T[] arr = ToArray(input);
+					this.root = RopeNode<T>.CreateFromArray(arr, 0, arr.Length);
+				}
+			}
+			this.root.CheckInvariants();
+		}
+		
+		/// <summary>
+		/// Creates a rope from a part of the array.
+		/// This operation runs in O(N).
+		/// </summary>
+		/// <exception cref="ArgumentNullException">input is null.</exception>
+		public Rope(T[] array, int arrayIndex, int count)
+		{
+			VerifyArrayWithRange(array, arrayIndex, count);
+			this.root = RopeNode<T>.CreateFromArray(array, arrayIndex, count);
+			this.root.CheckInvariants();
+		}
+		
+		/// <summary>
+		/// Creates a new rope that lazily initalizes its content.
+		/// </summary>
+		/// <param name="length">The length of the rope that will be lazily loaded.</param>
+		/// <param name="initializer">
+		/// The callback that provides the content for this rope.
+		/// <paramref name="initializer"/> will be called exactly once when the content of this rope is first requested.
+		/// It must return a rope with the specified length.
+		/// Because the initializer function is not called when a rope is cloned, and such clones may be used on another threads,
+		/// it is possible for the initializer callback to occur on any thread.
+		/// </param>
+		/// <remarks>
+		/// Any modifications inside the rope will also cause the content to be initialized.
+		/// However, insertions at the beginning and the end, as well as inserting this rope into another or
+		/// using the <see cref="Concat(Rope{T},Rope{T})"/> method, allows constructions of larger ropes where parts are
+		/// lazily loaded.
+		/// However, even methods like Concat may sometimes cause the initializer function to be called, e.g. when
+		/// two short ropes are concatenated.
+		/// </remarks>
+		[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1006:DoNotNestGenericTypesInMemberSignatures")]
+		public Rope(int length, Func<Rope<T>> initializer)
+		{
+			if (initializer == null)
+				throw new ArgumentNullException("initializer");
+			if (length < 0)
+				throw new ArgumentOutOfRangeException("length", length, "Length must not be negative");
+			if (length == 0) {
+				this.root = RopeNode<T>.emptyRopeNode;
+			} else {
+				this.root = new FunctionNode<T>(length, initializer);
+			}
+			this.root.CheckInvariants();
+		}
+		
+		static T[] ToArray(IEnumerable<T> input)
+		{
+			T[] arr = input as T[];
+			return arr ?? input.ToArray();
+		}
+		
+		/// <summary>
+		/// Clones the rope.
+		/// This operation runs in linear time to the number of rope nodes touched since the last clone was created.
+		/// If you count the per-node cost to the operation modifying the rope (doing this doesn't increase the complexity of the modification operations);
+		/// the remainder of Clone() runs in O(1).
+		/// </summary>
+		/// <remarks>
+		/// This method counts as a read access and may be called concurrently to other read accesses.
+		/// </remarks>
+		public Rope<T> Clone()
+		{
+			// The Publish() call actually modifies this rope instance; but this modification is thread-safe
+			// as long as the tree structure doesn't change during the operation.
+			root.Publish();
+			return new Rope<T>(root);
+		}
+		
+		object ICloneable.Clone()
+		{
+			return this.Clone();
+		}
+		
+		/// <summary>
+		/// Resets the rope to an empty list.
+		/// Runs in O(1).
+		/// </summary>
+		public void Clear()
+		{
+			root = RopeNode<T>.emptyRopeNode;
+			OnChanged();
+		}
+		
+		/// <summary>
+		/// Gets the length of the rope.
+		/// Runs in O(1).
+		/// </summary>
+		/// <remarks>
+		/// This method counts as a read access and may be called concurrently to other read accesses.
+		/// </remarks>
+		public int Length {
+			get { return root.length; }
+		}
+		
+		/// <summary>
+		/// Gets the length of the rope.
+		/// Runs in O(1).
+		/// </summary>
+		/// <remarks>
+		/// This method counts as a read access and may be called concurrently to other read accesses.
+		/// </remarks>
+		public int Count {
+			get { return root.length; }
+		}
+		
+		/// <summary>
+		/// Inserts another rope into this rope.
+		/// Runs in O(lg N + lg M), plus a per-node cost as if <c>newElements.Clone()</c> was called.
+		/// </summary>
+		/// <exception cref="ArgumentNullException">newElements is null.</exception>
+		/// <exception cref="ArgumentOutOfRangeException">index or length is outside the valid range.</exception>
+		public void InsertRange(int index, Rope<T> newElements)
+		{
+			if (index < 0 || index > this.Length) {
+				throw new ArgumentOutOfRangeException("index", index, "0 <= index <= " + this.Length.ToString(CultureInfo.InvariantCulture));
+			}
+			if (newElements == null)
+				throw new ArgumentNullException("newElements");
+			newElements.root.Publish();
+			root = root.Insert(index, newElements.root);
+			OnChanged();
+		}
+		
+		/// <summary>
+		/// Inserts new elemetns into this rope.
+		/// Runs in O(lg N + M), where N is the length of this rope and M is the number of new elements.
+		/// </summary>
+		/// <exception cref="ArgumentNullException">newElements is null.</exception>
+		/// <exception cref="ArgumentOutOfRangeException">index or length is outside the valid range.</exception>
+		public void InsertRange(int index, IEnumerable<T> newElements)
+		{
+			if (newElements == null)
+				throw new ArgumentNullException("newElements");
+			Rope<T> newElementsRope = newElements as Rope<T>;
+			if (newElementsRope != null) {
+				InsertRange(index, newElementsRope);
+			} else {
+				T[] arr = ToArray(newElements);
+				InsertRange(index, arr, 0, arr.Length);
+			}
+		}
+		
+		/// <summary>
+		/// Inserts new elements into this rope.
+		/// Runs in O(lg N + M), where N is the length of this rope and M is the number of new elements.
+		/// </summary>
+		/// <exception cref="ArgumentNullException">newElements is null.</exception>
+		/// <exception cref="ArgumentOutOfRangeException">index or length is outside the valid range.</exception>
+		public void InsertRange(int index, T[] array, int arrayIndex, int count)
+		{
+			if (index < 0 || index > this.Length) {
+				throw new ArgumentOutOfRangeException("index", index, "0 <= index <= " + this.Length.ToString(CultureInfo.InvariantCulture));
+			}
+			VerifyArrayWithRange(array, arrayIndex, count);
+			if (count > 0) {
+				root = root.Insert(index, array, arrayIndex, count);
+				OnChanged();
+			}
+		}
+		
+		/// <summary>
+		/// Appends multiple elements to the end of this rope.
+		/// Runs in O(lg N + M), where N is the length of this rope and M is the number of new elements.
+		/// </summary>
+		/// <exception cref="ArgumentNullException">newElements is null.</exception>
+		public void AddRange(IEnumerable<T> newElements)
+		{
+			InsertRange(this.Length, newElements);
+		}
+		
+		/// <summary>
+		/// Appends another rope to the end of this rope.
+		/// Runs in O(lg N + lg M), plus a per-node cost as if <c>newElements.Clone()</c> was called.
+		/// </summary>
+		/// <exception cref="ArgumentNullException">newElements is null.</exception>
+		public void AddRange(Rope<T> newElements)
+		{
+			InsertRange(this.Length, newElements);
+		}
+		
+		/// <summary>
+		/// Appends new elements to the end of this rope.
+		/// Runs in O(lg N + M), where N is the length of this rope and M is the number of new elements.
+		/// </summary>
+		/// <exception cref="ArgumentNullException">array is null.</exception>
+		public void AddRange(T[] array, int arrayIndex, int count)
+		{
+			InsertRange(this.Length, array, arrayIndex, count);
+		}
+		
+		/// <summary>
+		/// Removes a range of elements from the rope.
+		/// Runs in O(lg N).
+		/// </summary>
+		/// <exception cref="ArgumentOutOfRangeException">offset or length is outside the valid range.</exception>
+		public void RemoveRange(int index, int count)
+		{
+			VerifyRange(index, count);
+			if (count > 0) {
+				root = root.RemoveRange(index, count);
+				OnChanged();
+			}
+		}
+		
+		/// <summary>
+		/// Copies a range of the specified array into the rope, overwriting existing elements.
+		/// Runs in O(lg N + M).
+		/// </summary>
+		public void SetRange(int index, T[] array, int arrayIndex, int count)
+		{
+			VerifyRange(index, count);
+			VerifyArrayWithRange(array, arrayIndex, count);
+			if (count > 0) {
+				root = root.StoreElements(index, array, arrayIndex, count);
+				OnChanged();
+			}
+		}
+		
+		/// <summary>
+		/// Creates a new rope and initializes it with a part of this rope.
+		/// Runs in O(lg N) plus a per-node cost as if <c>this.Clone()</c> was called.
+		/// </summary>
+		/// <exception cref="ArgumentOutOfRangeException">offset or length is outside the valid range.</exception>
+		/// <remarks>
+		/// This method counts as a read access and may be called concurrently to other read accesses.
+		/// </remarks>
+		public Rope<T> GetRange(int index, int count)
+		{
+			VerifyRange(index, count);
+			Rope<T> newRope = Clone();
+			int endIndex = index + count;
+			newRope.RemoveRange(endIndex, newRope.Length - endIndex);
+			newRope.RemoveRange(0, index);
+			return newRope;
+		}
+		
+		/*
+		#region Equality
+		/// <summary>
+		/// Gets whether the two ropes have the same content.
+		/// Runs in O(N + M).
+		/// </summary>
+		/// <remarks>
+		/// This method counts as a read access and may be called concurrently to other read accesses.
+		/// </remarks>
+		public bool Equals(Rope other)
+		{
+			if (other == null)
+				return false;
+			// quick detection for ropes that are clones of each other:
+			if (other.root == this.root)
+				return true;
+			if (other.Length != this.Length)
+				return false;
+			using (RopeTextReader a = new RopeTextReader(this, false)) {
+				using (RopeTextReader b = new RopeTextReader(other, false)) {
+					int charA, charB;
+					do {
+						charA = a.Read();
+						charB = b.Read();
+						if (charA != charB)
+							return false;
+					} while (charA != -1);
+					return true;
+				}
+			}
+		}
+		
+		/// <summary>
+		/// Gets whether two ropes have the same content.
+		/// Runs in O(N + M).
+		/// </summary>
+		public override bool Equals(object obj)
+		{
+			return Equals(obj as Rope);
+		}
+		
+		/// <summary>
+		/// Calculates the hash code of the rope's content.
+		/// Runs in O(N).
+		/// </summary>
+		/// <remarks>
+		/// This method counts as a read access and may be called concurrently to other read accesses.
+		/// </remarks>
+		public override int GetHashCode()
+		{
+			int hashcode = 0;
+			using (RopeTextReader reader = new RopeTextReader(this, false)) {
+				unchecked {
+					int val;
+					while ((val = reader.Read()) != -1) {
+						hashcode = hashcode * 31 + val;
+					}
+				}
+			}
+			return hashcode;
+		}
+		#endregion
+		 */
+		
+		/// <summary>
+		/// Concatenates two ropes. The input ropes are not modified.
+		/// Runs in O(lg N + lg M).
+		/// </summary>
+		/// <remarks>
+		/// This method counts as a read access and may be called concurrently to other read accesses.
+		/// </remarks>
+		[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1000:DoNotDeclareStaticMembersOnGenericTypes")]
+		public static Rope<T> Concat(Rope<T> left, Rope<T> right)
+		{
+			if (left == null)
+				throw new ArgumentNullException("left");
+			if (right == null)
+				throw new ArgumentNullException("right");
+			left.root.Publish();
+			right.root.Publish();
+			return new Rope<T>(RopeNode<T>.Concat(left.root, right.root));
+		}
+		
+		/// <summary>
+		/// Concatenates multiple ropes. The input ropes are not modified.
+		/// </summary>
+		/// <remarks>
+		/// This method counts as a read access and may be called concurrently to other read accesses.
+		/// </remarks>
+		[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1000:DoNotDeclareStaticMembersOnGenericTypes")]
+		public static Rope<T> Concat(params Rope<T>[] ropes)
+		{
+			if (ropes == null)
+				throw new ArgumentNullException("ropes");
+			Rope<T> result = new Rope<T>();
+			foreach (Rope<T> r in ropes)
+				result.AddRange(r);
+			return result;
+		}
+		
+		#region Caches / Changed event
+		internal struct RopeCacheEntry
+		{
+			internal readonly RopeNode<T> node;
+			internal readonly int nodeStartIndex;
+			
+			internal RopeCacheEntry(RopeNode<T> node, int nodeStartOffset)
+			{
+				this.node = node;
+				this.nodeStartIndex = nodeStartOffset;
+			}
+			
+			internal bool IsInside(int offset)
+			{
+				return offset >= nodeStartIndex && offset < nodeStartIndex + node.length;
+			}
+		}
+		
+		// cached pointer to 'last used node', used to speed up accesses by index that are close together
+		[NonSerialized]
+		volatile ImmutableStack<RopeCacheEntry> lastUsedNodeStack;
+		
+		internal void OnChanged()
+		{
+			lastUsedNodeStack = null;
+			
+			root.CheckInvariants();
+		}
+		#endregion
+		
+		#region GetChar / SetChar
+		/// <summary>
+		/// Gets/Sets a single character.
+		/// Runs in O(lg N) for random access. Sequential read-only access benefits from a special optimization and runs in amortized O(1).
+		/// </summary>
+		/// <exception cref="ArgumentOutOfRangeException">Offset is outside the valid range (0 to Length-1).</exception>
+		/// <remarks>
+		/// The getter counts as a read access and may be called concurrently to other read accesses.
+		/// </remarks>
+		public T this[int index] {
+			get {
+				// use unsigned integers - this way negative values for index overflow and can be tested for with the same check
+				if (unchecked((uint)index >= (uint)this.Length)) {
+					throw new ArgumentOutOfRangeException("index", index, "0 <= index < " + this.Length.ToString(CultureInfo.InvariantCulture));
+				}
+				RopeCacheEntry entry = FindNodeUsingCache(index).UnsafePeek();
+				return entry.node.contents[index - entry.nodeStartIndex];
+			}
+			set {
+				if (index < 0 || index >= this.Length) {
+					throw new ArgumentOutOfRangeException("index", index, "0 <= index < " + this.Length.ToString(CultureInfo.InvariantCulture));
+				}
+				root = root.SetElement(index, value);
+				OnChanged();
+				/* Here's a try at implementing the setter using the cached node stack (UNTESTED code!).
+				 * However I don't use the code because it's complicated and doesn't integrate correctly with change notifications.
+				 * Instead, I'll use the much easier to understand recursive solution.
+				 * Oh, and it also doesn't work correctly with function nodes.
+				ImmutableStack<RopeCacheEntry> nodeStack = FindNodeUsingCache(offset);
+				RopeCacheEntry entry = nodeStack.Peek();
+				if (!entry.node.isShared) {
+					entry.node.contents[offset - entry.nodeStartOffset] = value;
+					// missing: clear the caches except for the node stack cache (e.g. ToString() cache?)
+				} else {
+					RopeNode oldNode = entry.node;
+					RopeNode newNode = oldNode.Clone();
+					newNode.contents[offset - entry.nodeStartOffset] = value;
+					for (nodeStack = nodeStack.Pop(); !nodeStack.IsEmpty; nodeStack = nodeStack.Pop()) {
+						RopeNode parentNode = nodeStack.Peek().node;
+						RopeNode newParentNode = parentNode.CloneIfShared();
+						if (newParentNode.left == oldNode) {
+							newParentNode.left = newNode;
+						} else {
+							Debug.Assert(newParentNode.right == oldNode);
+							newParentNode.right = newNode;
+						}
+						if (parentNode == newParentNode) {
+							// we were able to change the existing node (it was not shared);
+							// there's no reason to go further upwards
+							ClearCacheOnModification();
+							return;
+						} else {
+							oldNode = parentNode;
+							newNode = newParentNode;
+						}
+					}
+					// we reached the root of the rope.
+					Debug.Assert(root == oldNode);
+					root = newNode;
+					ClearCacheOnModification();
+				}*/
+			}
+		}
+		
+		internal ImmutableStack<RopeCacheEntry> FindNodeUsingCache(int index)
+		{
+			Debug.Assert(index >= 0 && index < this.Length);
+			
+			// thread safety: fetch stack into local variable
+			ImmutableStack<RopeCacheEntry> stack = lastUsedNodeStack;
+			ImmutableStack<RopeCacheEntry> oldStack = stack;
+			
+			if (stack == null) {
+				stack = ImmutableStack<RopeCacheEntry>.Empty.Push(new RopeCacheEntry(root, 0));
+			}
+			while (!stack.UnsafePeek().IsInside(index))
+				stack = stack.Pop();
+			while (true) {
+				RopeCacheEntry entry = stack.UnsafePeek();
+				// check if we've reached a leaf or function node
+				if (entry.node.height == 0) {
+					if (entry.node.contents == null) {
+						// this is a function node - go down into its subtree
+						entry = new RopeCacheEntry(entry.node.GetContentNode(), entry.nodeStartIndex);
+						// entry is now guaranteed NOT to be another function node
+					}
+					if (entry.node.contents != null) {
+						// this is a node containing actual content, so we're done
+						break;
+					}
+				}
+				// go down towards leaves
+				if (index - entry.nodeStartIndex >= entry.node.left.length)
+					stack = stack.Push(new RopeCacheEntry(entry.node.right, entry.nodeStartIndex + entry.node.left.length));
+				else
+					stack = stack.Push(new RopeCacheEntry(entry.node.left, entry.nodeStartIndex));
+			}
+			
+			// write back stack to volatile cache variable
+			// (in multithreaded access, it doesn't matter which of the threads wins - it's just a cache)
+			if (oldStack != stack) {
+				// no need to write when we the cache variable didn't change
+				lastUsedNodeStack = stack;
+			}
+			
+			// this method guarantees that it finds a leaf node
+			Debug.Assert(stack.Peek().node.contents != null);
+			return stack;
+		}
+		#endregion
+		
+		#region ToString / WriteTo
+		internal void VerifyRange(int startIndex, int length)
+		{
+			if (startIndex < 0 || startIndex > this.Length) {
+				throw new ArgumentOutOfRangeException("startIndex", startIndex, "0 <= startIndex <= " + this.Length.ToString(CultureInfo.InvariantCulture));
+			}
+			if (length < 0 || startIndex + length > this.Length) {
+				throw new ArgumentOutOfRangeException("length", length, "0 <= length, startIndex(" + startIndex + ")+length <= " + this.Length.ToString(CultureInfo.InvariantCulture));
+			}
+		}
+		
+		internal static void VerifyArrayWithRange(T[] array, int arrayIndex, int count)
+		{
+			if (array == null)
+				throw new ArgumentNullException("array");
+			if (arrayIndex < 0 || arrayIndex > array.Length) {
+				throw new ArgumentOutOfRangeException("startIndex", arrayIndex, "0 <= arrayIndex <= " + array.Length.ToString(CultureInfo.InvariantCulture));
+			}
+			if (count < 0 || arrayIndex + count > array.Length) {
+				throw new ArgumentOutOfRangeException("count", count, "0 <= length, arrayIndex(" + arrayIndex + ")+count <= " + array.Length.ToString(CultureInfo.InvariantCulture));
+			}
+		}
+		
+		/// <summary>
+		/// Creates a string from the rope. Runs in O(N).
+		/// </summary>
+		/// <returns>A string consisting of all elements in the rope as comma-separated list in {}.
+		/// As a special case, Rope&lt;char&gt; will return its contents as string without any additional separators or braces,
+		/// so it can be used like StringBuilder.ToString().</returns>
+		/// <remarks>
+		/// This method counts as a read access and may be called concurrently to other read accesses.
+		/// </remarks>
+		public override string ToString()
+		{
+			Rope<char> charRope = this as Rope<char>;
+			if (charRope != null) {
+				return charRope.ToString(0, this.Length);
+			} else {
+				StringBuilder b = new StringBuilder();
+				foreach (T element in this) {
+					if (b.Length == 0)
+						b.Append('{');
+					else
+						b.Append(", ");
+					b.Append(element.ToString());
+				}
+				b.Append('}');
+				return b.ToString();
+			}
+		}
+		
+		internal string GetTreeAsString()
+		{
+			#if DEBUG
+			return root.GetTreeAsString();
+			#else
+			return "Not available in release build.";
+			#endif
+		}
+		#endregion
+		
+		bool ICollection<T>.IsReadOnly {
+			get { return false; }
+		}
+		
+		/// <summary>
+		/// Finds the first occurance of item.
+		/// Runs in O(N).
+		/// </summary>
+		/// <returns>The index of the first occurance of item, or -1 if it cannot be found.</returns>
+		/// <remarks>
+		/// This method counts as a read access and may be called concurrently to other read accesses.
+		/// </remarks>
+		public int IndexOf(T item)
+		{
+			var comparer = EqualityComparer<T>.Default;
+			int index = 0;
+			foreach (T element in this) {
+				if (comparer.Equals(item, element))
+					return index;
+				index++;
+			}
+			return -1;
+		}
+		
+		/// <summary>
+		/// Inserts the item at the specified index in the rope.
+		/// Runs in O(lg N).
+		/// </summary>
+		public void Insert(int index, T item)
+		{
+			InsertRange(index, new[] { item }, 0, 1);
+		}
+		
+		/// <summary>
+		/// Removes a single item from the rope.
+		/// Runs in O(lg N).
+		/// </summary>
+		public void RemoveAt(int index)
+		{
+			RemoveRange(index, 1);
+		}
+		
+		/// <summary>
+		/// Appends the item at the end of the rope.
+		/// Runs in O(lg N).
+		/// </summary>
+		public void Add(T item)
+		{
+			InsertRange(this.Length, new[] { item }, 0, 1);
+		}
+		
+		/// <summary>
+		/// Searches the item in the rope.
+		/// Runs in O(N).
+		/// </summary>
+		/// <remarks>
+		/// This method counts as a read access and may be called concurrently to other read accesses.
+		/// </remarks>
+		public bool Contains(T item)
+		{
+			return IndexOf(item) >= 0;
+		}
+		
+		/// <summary>
+		/// Copies the whole content of the rope into the specified array.
+		/// Runs in O(N).
+		/// </summary>
+		/// <remarks>
+		/// This method counts as a read access and may be called concurrently to other read accesses.
+		/// </remarks>
+		public void CopyTo(T[] array, int arrayIndex)
+		{
+			CopyTo(0, array, arrayIndex, this.Length);
+		}
+		
+		/// <summary>
+		/// Copies the a part of the rope into the specified array.
+		/// Runs in O(lg N + M).
+		/// </summary>
+		/// <remarks>
+		/// This method counts as a read access and may be called concurrently to other read accesses.
+		/// </remarks>
+		public void CopyTo(int index, T[] array, int arrayIndex, int count)
+		{
+			VerifyRange(index, count);
+			VerifyArrayWithRange(array, arrayIndex, count);
+			this.root.CopyTo(index, array, arrayIndex, count);
+		}
+		
+		/// <summary>
+		/// Removes the first occurance of an item from the rope.
+		/// Runs in O(N).
+		/// </summary>
+		public bool Remove(T item)
+		{
+			int index = IndexOf(item);
+			if (index >= 0) {
+				RemoveAt(index);
+				return true;
+			}
+			return false;
+		}
+		
+		/// <summary>
+		/// Retrieves an enumerator to iterate through the rope.
+		/// The enumerator will reflect the state of the rope from the GetEnumerator() call, further modifications
+		/// to the rope will not be visible to the enumerator.
+		/// </summary>
+		/// <remarks>
+		/// This method counts as a read access and may be called concurrently to other read accesses.
+		/// </remarks>
+		public IEnumerator<T> GetEnumerator()
+		{
+			this.root.Publish();
+			return Enumerate(root);
+		}
+		
+		/// <summary>
+		/// Creates an array and copies the contents of the rope into it.
+		/// Runs in O(N).
+		/// </summary>
+		/// <remarks>
+		/// This method counts as a read access and may be called concurrently to other read accesses.
+		/// </remarks>
+		public T[] ToArray()
+		{
+			T[] arr = new T[this.Length];
+			CopyTo(arr, 0);
+			return arr;
+		}
+		
+		/// <summary>
+		/// Creates an array and copies the contents of the rope into it.
+		/// Runs in O(N).
+		/// </summary>
+		/// <remarks>
+		/// This method counts as a read access and may be called concurrently to other read accesses.
+		/// </remarks>
+		public T[] ToArray(int startIndex, int count)
+		{
+			VerifyRange(startIndex, count);
+			T[] arr = new T[count];
+			CopyTo(startIndex, arr, 0, count);
+			return arr;
+		}
+		
+		static IEnumerator<T> Enumerate(RopeNode<T> node)
+		{
+			Stack<RopeNode<T>> stack = new Stack<RopeNode<T>>();
+			while (node != null) {
+				// go to leftmost node, pushing the right parts that we'll have to visit later
+				while (node.contents == null) {
+					if (node.height == 0) {
+						// go down into function nodes
+						node = node.GetContentNode();
+						continue;
+					}
+					Debug.Assert(node.right != null);
+					stack.Push(node.right);
+					node = node.left;
+				}
+				// yield contents of leaf node
+				for (int i = 0; i < node.length; i++) {
+					yield return node.contents[i];
+				}
+				// go up to the next node not visited yet
+				if (stack.Count > 0)
+					node = stack.Pop();
+				else
+					node = null;
+			}
+		}
+		
+		System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
+		{
+			return this.GetEnumerator();
+		}
+	}
+}
diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/RopeNode.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/RopeNode.cs
new file mode 100644
index 000000000..87f060c1b
--- /dev/null
+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/RopeNode.cs
@@ -0,0 +1,605 @@
+// 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.Diagnostics;
+using System.Runtime.Serialization;
+
+using System.Text;
+
+namespace Tango.Scripting.Editors.Utils
+{
+	// Class used to represent a node in the tree.
+	// There are three types of nodes:
+	// Concat nodes: height>0, left!=null, right!=null, contents==null
+	// Leaf nodes: height==0, left==null, right==null, contents!=null
+	// Function nodes: height==0, left==null, right==null, contents==null, are of type FunctionNode<T>
+	
+	[Serializable]
+	class RopeNode<T>
+	{
+		internal const int NodeSize = 256;
+		
+		internal static readonly RopeNode<T> emptyRopeNode = new RopeNode<T> { isShared = true, contents = new T[RopeNode<T>.NodeSize] };
+		
+		// Fields for pointers to sub-nodes. Only non-null for concat nodes (height>=1)
+		internal RopeNode<T> left, right;
+		internal volatile bool isShared; // specifies whether this node is shared between multiple ropes
+		// the total length of all text in this subtree
+		internal int length;
+		// the height of this subtree: 0 for leaf nodes; 1+max(left.height,right.height) for concat nodes
+		internal byte height;
+		
+		// The character data. Only non-null for leaf nodes (height=0) that aren't function nodes.
+		internal T[] contents;
+		
+		internal int Balance {
+			get { return right.height - left.height; }
+		}
+		
+		[Conditional("DATACONSISTENCYTEST")]
+		internal void CheckInvariants()
+		{
+			if (height == 0) {
+				Debug.Assert(left == null && right == null);
+				if (contents == null) {
+					Debug.Assert(this is FunctionNode<T>);
+					Debug.Assert(length > 0);
+					Debug.Assert(isShared);
+				} else {
+					Debug.Assert(contents != null && contents.Length == NodeSize);
+					Debug.Assert(length >= 0 && length <= NodeSize);
+				}
+			} else {
+				Debug.Assert(left != null && right != null);
+				Debug.Assert(contents == null);
+				Debug.Assert(length == left.length + right.length);
+				Debug.Assert(height == 1 + Math.Max(left.height, right.height));
+				Debug.Assert(Math.Abs(this.Balance) <= 1);
+				
+				// this is an additional invariant that forces the tree to combine small leafs to prevent excessive memory usage:
+				Debug.Assert(length > NodeSize);
+				// note that this invariant ensures that all nodes except for the empty rope's single node have at least length 1
+				
+				if (isShared)
+					Debug.Assert(left.isShared && right.isShared);
+				left.CheckInvariants();
+				right.CheckInvariants();
+			}
+		}
+		
+		internal RopeNode<T> Clone()
+		{
+			if (height == 0) {
+				// If a function node needs cloning, we'll evaluate it.
+				if (contents == null)
+					return GetContentNode().Clone();
+				T[] newContents = new T[NodeSize];
+				contents.CopyTo(newContents, 0);
+				return new RopeNode<T> {
+					length = this.length,
+					contents = newContents
+				};
+			} else {
+				return new RopeNode<T> {
+					left = this.left,
+					right = this.right,
+					length = this.length,
+					height = this.height
+				};
+			}
+		}
+		
+		internal RopeNode<T> CloneIfShared()
+		{
+			if (isShared)
+				return Clone();
+			else
+				return this;
+		}
+		
+		internal void Publish()
+		{
+			if (!isShared) {
+				if (left != null)
+					left.Publish();
+				if (right != null)
+					right.Publish();
+				// it's important that isShared=true is set at the end:
+				// Publish() must not return until the whole subtree is marked as shared, even when
+				// Publish() is called concurrently.
+				isShared = true;
+			}
+		}
+		
+		internal static RopeNode<T> CreateFromArray(T[] arr, int index, int length)
+		{
+			if (length == 0) {
+				return emptyRopeNode;
+			}
+			RopeNode<T> node = CreateNodes(length);
+			return node.StoreElements(0, arr, index, length);
+		}
+		
+		internal static RopeNode<T> CreateNodes(int totalLength)
+		{
+			int leafCount = (totalLength + NodeSize - 1) / NodeSize;
+			return CreateNodes(leafCount, totalLength);
+		}
+		
+		static RopeNode<T> CreateNodes(int leafCount, int totalLength)
+		{
+			Debug.Assert(leafCount > 0);
+			Debug.Assert(totalLength > 0);
+			RopeNode<T> result = new RopeNode<T>();
+			result.length = totalLength;
+			if (leafCount == 1) {
+				result.contents = new T[NodeSize];
+			} else {
+				int rightSide = leafCount / 2;
+				int leftSide = leafCount - rightSide;
+				int leftLength = leftSide * NodeSize;
+				result.left = CreateNodes(leftSide, leftLength);
+				result.right = CreateNodes(rightSide, totalLength - leftLength);
+				result.height = (byte)(1 + Math.Max(result.left.height, result.right.height));
+			}
+			return result;
+		}
+		
+		/// <summary>
+		/// Balances this node and recomputes the 'height' field.
+		/// This method assumes that the children of this node are already balanced and have an up-to-date 'height' value.
+		/// </summary>
+		internal void Rebalance()
+		{
+			// Rebalance() shouldn't be called on shared nodes - it's only called after modifications!
+			Debug.Assert(!isShared);
+			// leaf nodes are always balanced (we don't use 'height' to detect leaf nodes here
+			// because Balance is supposed to recompute the height).
+			if (left == null)
+				return;
+			
+			// ensure we didn't miss a MergeIfPossible step
+			Debug.Assert(this.length > NodeSize);
+			
+			// We need to loop until it's balanced. Rotations might cause two small leaves to combine to a larger one,
+			// which changes the height and might mean we need additional balancing steps.
+			while (Math.Abs(this.Balance) > 1) {
+				// AVL balancing
+				// note: because we don't care about the identity of concat nodes, this works a little different than usual
+				// tree rotations: in our implementation, the "this" node will stay at the top, only its children are rearranged
+				if (this.Balance > 1) {
+					if (right.Balance < 0) {
+						right = right.CloneIfShared();
+						right.RotateRight();
+					}
+					this.RotateLeft();
+					// If 'this' was unbalanced by more than 2, we've shifted some of the inbalance to the left node; so rebalance that.
+					this.left.Rebalance();
+				} else if (this.Balance < -1) {
+					if (left.Balance > 0) {
+						left = left.CloneIfShared();
+						left.RotateLeft();
+					}
+					this.RotateRight();
+					// If 'this' was unbalanced by more than 2, we've shifted some of the inbalance to the right node; so rebalance that.
+					this.right.Rebalance();
+				}
+			}
+			
+			Debug.Assert(Math.Abs(this.Balance) <= 1);
+			this.height = (byte)(1 + Math.Max(left.height, right.height));
+		}
+		
+		void RotateLeft()
+		{
+			Debug.Assert(!isShared);
+			
+			/* Rotate tree to the left
+			 * 
+			 *       this               this
+			 *       /  \               /  \
+			 *      A   right   ===>  left  C
+			 *           / \          / \
+			 *          B   C        A   B
+			 */
+			RopeNode<T> a = left;
+			RopeNode<T> b = right.left;
+			RopeNode<T> c = right.right;
+			// reuse right concat node, if possible
+			this.left = right.isShared ? new RopeNode<T>() : right;
+			this.left.left = a;
+			this.left.right = b;
+			this.left.length = a.length + b.length;
+			this.left.height = (byte)(1 + Math.Max(a.height, b.height));
+			this.right = c;
+			
+			this.left.MergeIfPossible();
+		}
+		
+		void RotateRight()
+		{
+			Debug.Assert(!isShared);
+			
+			/* Rotate tree to the right
+			 * 
+			 *       this             this
+			 *       /  \             /  \
+			 *     left  C   ===>    A  right
+			 *     / \                   /  \
+			 *    A   B                 B    C
+			 */
+			RopeNode<T> a = left.left;
+			RopeNode<T> b = left.right;
+			RopeNode<T> c = right;
+			// reuse left concat node, if possible
+			this.right = left.isShared ? new RopeNode<T>() : left;
+			this.right.left = b;
+			this.right.right = c;
+			this.right.length = b.length + c.length;
+			this.right.height = (byte)(1 + Math.Max(b.height, c.height));
+			this.left = a;
+			
+			this.right.MergeIfPossible();
+		}
+		
+		void MergeIfPossible()
+		{
+			Debug.Assert(!isShared);
+			
+			if (this.length <= NodeSize) {
+				// Convert this concat node to leaf node.
+				// We know left and right cannot be concat nodes (they would have merged already),
+				// but they could be function nodes.
+				this.height = 0;
+				int lengthOnLeftSide = this.left.length;
+				if (this.left.isShared) {
+					this.contents = new T[NodeSize];
+					left.CopyTo(0, this.contents, 0, lengthOnLeftSide);
+				} else {
+					// must be a leaf node: function nodes are always marked shared
+					Debug.Assert(this.left.contents != null);
+					// steal buffer from left side
+					this.contents = this.left.contents;
+					#if DEBUG
+					// In debug builds, explicitly mark left node as 'damaged' - but no one else should be using it
+					// because it's not shared.
+					this.left.contents = Empty<T>.Array;
+					#endif
+				}
+				this.left = null;
+				right.CopyTo(0, this.contents, lengthOnLeftSide, this.right.length);
+				this.right = null;
+			}
+		}
+		
+		/// <summary>
+		/// Copies from the array to this node.
+		/// </summary>
+		internal RopeNode<T> StoreElements(int index, T[] array, int arrayIndex, int count)
+		{
+			RopeNode<T> result = this.CloneIfShared();
+			// result cannot be function node after a call to Clone()
+			if (result.height == 0) {
+				// leaf node:
+				Array.Copy(array, arrayIndex, result.contents, index, count);
+			} else {
+				// concat node:
+				if (index + count <= result.left.length) {
+					result.left = result.left.StoreElements(index, array, arrayIndex, count);
+				} else if (index >= this.left.length) {
+					result.right = result.right.StoreElements(index - result.left.length, array, arrayIndex, count);
+				} else {
+					int amountInLeft = result.left.length - index;
+					result.left = result.left.StoreElements(index, array, arrayIndex, amountInLeft);
+					result.right = result.right.StoreElements(0, array, arrayIndex + amountInLeft, count - amountInLeft);
+				}
+				result.Rebalance(); // tree layout might have changed if function nodes were replaced with their content
+			}
+			return result;
+		}
+		
+		/// <summary>
+		/// Copies from this node to the array.
+		/// </summary>
+		internal void CopyTo(int index, T[] array, int arrayIndex, int count)
+		{
+			if (height == 0) {
+				if (this.contents == null) {
+					// function node
+					this.GetContentNode().CopyTo(index, array, arrayIndex, count);
+				} else {
+					// leaf node
+					Array.Copy(this.contents, index, array, arrayIndex, count);
+				}
+			} else {
+				// concat node
+				if (index + count <= this.left.length) {
+					this.left.CopyTo(index, array, arrayIndex, count);
+				} else if (index >= this.left.length) {
+					this.right.CopyTo(index - this.left.length, array, arrayIndex, count);
+				} else {
+					int amountInLeft = this.left.length - index;
+					this.left.CopyTo(index, array, arrayIndex, amountInLeft);
+					this.right.CopyTo(0, array, arrayIndex + amountInLeft, count - amountInLeft);
+				}
+			}
+		}
+		
+		internal RopeNode<T> SetElement(int offset, T value)
+		{
+			RopeNode<T> result = CloneIfShared();
+			// result of CloneIfShared() is leaf or concat node
+			if (result.height == 0) {
+				result.contents[offset] = value;
+			} else {
+				if (offset < result.left.length) {
+					result.left = result.left.SetElement(offset, value);
+				} else {
+					result.right = result.right.SetElement(offset - result.left.length, value);
+				}
+				result.Rebalance(); // tree layout might have changed if function nodes were replaced with their content
+			}
+			return result;
+		}
+		
+		internal static RopeNode<T> Concat(RopeNode<T> left, RopeNode<T> right)
+		{
+			if (left.length == 0)
+				return right;
+			if (right.length == 0)
+				return left;
+			
+			if (left.length + right.length <= NodeSize) {
+				left = left.CloneIfShared();
+				// left is guaranteed to be leaf node after cloning:
+				// - it cannot be function node (due to clone)
+				// - it cannot be concat node (too short)
+				right.CopyTo(0, left.contents, left.length, right.length);
+				left.length += right.length;
+				return left;
+			} else {
+				RopeNode<T> concatNode = new RopeNode<T>();
+				concatNode.left = left;
+				concatNode.right = right;
+				concatNode.length = left.length + right.length;
+				concatNode.Rebalance();
+				return concatNode;
+			}
+		}
+		
+		/// <summary>
+		/// Splits this leaf node at offset and returns a new node with the part of the text after offset.
+		/// </summary>
+		RopeNode<T> SplitAfter(int offset)
+		{
+			Debug.Assert(!isShared && height == 0 && contents != null);
+			RopeNode<T> newPart = new RopeNode<T>();
+			newPart.contents = new T[NodeSize];
+			newPart.length = this.length - offset;
+			Array.Copy(this.contents, offset, newPart.contents, 0, newPart.length);
+			this.length = offset;
+			return newPart;
+		}
+		
+		internal RopeNode<T> Insert(int offset, RopeNode<T> newElements)
+		{
+			if (offset == 0) {
+				return Concat(newElements, this);
+			} else if (offset == this.length) {
+				return Concat(this, newElements);
+			}
+			
+			// first clone this node (converts function nodes to leaf or concat nodes)
+			RopeNode<T> result = CloneIfShared();
+			if (result.height == 0) {
+				// leaf node: we'll need to split this node
+				RopeNode<T> left = result;
+				RopeNode<T> right = left.SplitAfter(offset);
+				return Concat(Concat(left, newElements), right);
+			} else {
+				// concat node
+				if (offset < result.left.length) {
+					result.left = result.left.Insert(offset, newElements);
+				} else {
+					result.right = result.right.Insert(offset - result.left.length, newElements);
+				}
+				result.length += newElements.length;
+				result.Rebalance();
+				return result;
+			}
+		}
+		
+		internal RopeNode<T> Insert(int offset, T[] array, int arrayIndex, int count)
+		{
+			Debug.Assert(count > 0);
+			
+			if (this.length + count < RopeNode<char>.NodeSize) {
+				RopeNode<T> result = CloneIfShared();
+				// result must be leaf node (Clone never returns function nodes, too short for concat node)
+				int lengthAfterOffset = result.length - offset;
+				T[] resultContents = result.contents;
+				for (int i = lengthAfterOffset; i >= 0; i--) {
+					resultContents[i + offset + count] = resultContents[i + offset];
+				}
+				Array.Copy(array, arrayIndex, resultContents, offset, count);
+				result.length += count;
+				return result;
+			} else if (height == 0) {
+				// TODO: implement this more efficiently?
+				return Insert(offset, CreateFromArray(array, arrayIndex, count));
+			} else {
+				// this is a concat node (both leafs and function nodes are handled by the case above)
+				RopeNode<T> result = CloneIfShared();
+				if (offset < result.left.length) {
+					result.left = result.left.Insert(offset, array, arrayIndex, count);
+				} else {
+					result.right = result.right.Insert(offset - result.left.length, array, arrayIndex, count);
+				}
+				result.length += count;
+				result.Rebalance();
+				return result;
+			}
+		}
+		
+		internal RopeNode<T> RemoveRange(int index, int count)
+		{
+			Debug.Assert(count > 0);
+			
+			// produce empty node when one node is deleted completely
+			if (index == 0 && count == this.length)
+				return emptyRopeNode;
+			
+			int endIndex = index + count;
+			RopeNode<T> result = CloneIfShared(); // convert function node to concat/leaf
+			if (result.height == 0) {
+				int remainingAfterEnd = result.length - endIndex;
+				for (int i = 0; i < remainingAfterEnd; i++) {
+					result.contents[index + i] = result.contents[endIndex + i];
+				}
+				result.length -= count;
+			} else {
+				if (endIndex <= result.left.length) {
+					// deletion is only within the left part
+					result.left = result.left.RemoveRange(index, count);
+				} else if (index >= result.left.length) {
+					// deletion is only within the right part
+					result.right = result.right.RemoveRange(index - result.left.length, count);
+				} else {
+					// deletion overlaps both parts
+					int deletionAmountOnLeftSide = result.left.length - index;
+					result.left = result.left.RemoveRange(index, deletionAmountOnLeftSide);
+					result.right = result.right.RemoveRange(0, count - deletionAmountOnLeftSide);
+				}
+				// The deletion might have introduced empty nodes. Those must be removed.
+				if (result.left.length == 0)
+					return result.right;
+				if (result.right.length == 0)
+					return result.left;
+				
+				result.length -= count;
+				result.MergeIfPossible();
+				result.Rebalance();
+			}
+			return result;
+		}
+		
+		#region Debug Output
+		#if DEBUG
+		internal virtual void AppendTreeToString(StringBuilder b, int indent)
+		{
+			b.AppendLine(ToString());
+			indent += 2;
+			if (left != null) {
+				b.Append(' ', indent);
+				b.Append("L: ");
+				left.AppendTreeToString(b, indent);
+			}
+			if (right != null) {
+				b.Append(' ', indent);
+				b.Append("R: ");
+				right.AppendTreeToString(b, indent);
+			}
+		}
+		
+		public override string ToString()
+		{
+			if (contents != null) {
+				char[] charContents = contents as char[];
+				if (charContents != null)
+					return "[Leaf length=" + length + ", isShared=" + isShared + ", text=\"" + new string(charContents, 0, length) + "\"]";
+				else
+					return "[Leaf length=" + length + ", isShared=" + isShared + "\"]";
+			} else {
+				return "[Concat length=" + length + ", isShared=" + isShared + ", height=" + height + ", Balance=" + this.Balance + "]";
+			}
+		}
+		
+		internal string GetTreeAsString()
+		{
+			StringBuilder b = new StringBuilder();
+			AppendTreeToString(b, 0);
+			return b.ToString();
+		}
+		#endif
+		#endregion
+		
+		/// <summary>
+		/// Gets the root node of the subtree from a lazily evaluated function node.
+		/// Such nodes are always marked as shared.
+		/// GetContentNode() will return either a Concat or Leaf node, never another FunctionNode.
+		/// </summary>
+		internal virtual RopeNode<T> GetContentNode()
+		{
+			throw new InvalidOperationException("Called GetContentNode() on non-FunctionNode.");
+		}
+	}
+	
+	sealed class FunctionNode<T> : RopeNode<T>
+	{
+		Func<Rope<T>> initializer;
+		RopeNode<T> cachedResults;
+		
+		public FunctionNode(int length, Func<Rope<T>> initializer)
+		{
+			Debug.Assert(length > 0);
+			Debug.Assert(initializer != null);
+			
+			this.length = length;
+			this.initializer = initializer;
+			// Function nodes are immediately shared, but cannot be cloned.
+			// This ensures we evaluate every initializer only once.
+			this.isShared = true;
+		}
+		
+		internal override RopeNode<T> GetContentNode()
+		{
+			lock (this) {
+				if (this.cachedResults == null) {
+					if (this.initializer == null)
+						throw new InvalidOperationException("Trying to load this node recursively; or: a previous call to a rope initializer failed.");
+					Func<Rope<T>> initializerCopy = this.initializer;
+					this.initializer = null;
+					Rope<T> resultRope = initializerCopy();
+					if (resultRope == null)
+						throw new InvalidOperationException("Rope initializer returned null.");
+					RopeNode<T> resultNode = resultRope.root;
+					resultNode.Publish(); // result is shared between returned rope and the rope containing this function node
+					if (resultNode.length != this.length)
+						throw new InvalidOperationException("Rope initializer returned rope with incorrect length.");
+					if (resultNode.height == 0 && resultNode.contents == null) {
+						// ResultNode is another function node.
+						// We want to guarantee that GetContentNode() never returns function nodes, so we have to
+						// go down further in the tree.
+						this.cachedResults = resultNode.GetContentNode();
+					} else {
+						this.cachedResults = resultNode;
+					}
+				}
+				return this.cachedResults;
+			}
+		}
+		
+		#if DEBUG
+		internal override void AppendTreeToString(StringBuilder b, int indent)
+		{
+			RopeNode<T> resultNode;
+			lock (this) {
+				b.AppendLine(ToString());
+				resultNode = cachedResults;
+			}
+			indent += 2;
+			if (resultNode != null) {
+				b.Append(' ', indent);
+				b.Append("C: ");
+				resultNode.AppendTreeToString(b, indent);
+			}
+		}
+		
+		public override string ToString()
+		{
+			return "[FunctionNode length=" + length + " initializerRan=" + (initializer == null) + "]";
+		}
+		#endif
+	}
+}
diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/RopeTextReader.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/RopeTextReader.cs
new file mode 100644
index 000000000..43c8fc57b
--- /dev/null
+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/RopeTextReader.cs
@@ -0,0 +1,105 @@
+// 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.Diagnostics;
+using System.IO;
+
+namespace Tango.Scripting.Editors.Utils
+{
+	/// <summary>
+	/// TextReader implementation that reads text from a rope.
+	/// </summary>
+	public sealed class RopeTextReader : TextReader
+	{
+		Stack<RopeNode<char>> stack = new Stack<RopeNode<char>>();
+		RopeNode<char> currentNode;
+		int indexInsideNode;
+		
+		/// <summary>
+		/// Creates a new RopeTextReader.
+		/// Internally, this method creates a Clone of the rope; so the text reader will always read through the old
+		/// version of the rope if it is modified. <seealso cref="Rope{T}.Clone()"/>
+		/// </summary>
+		public RopeTextReader(Rope<char> rope)
+		{
+			if (rope == null)
+				throw new ArgumentNullException("rope");
+			
+			// We force the user to iterate through a clone of the rope to keep the API contract of RopeTextReader simple
+			// (what happens when a rope is modified while iterating through it?)
+			rope.root.Publish();
+			
+			// special case for the empty rope:
+			// leave currentNode initialized to null (RopeTextReader doesn't support empty nodes)
+			if (rope.Length != 0) {
+				currentNode = rope.root;
+				GoToLeftMostLeaf();
+			}
+		}
+		
+		void GoToLeftMostLeaf()
+		{
+			while (currentNode.contents == null) {
+				if (currentNode.height == 0) {
+					// this is a function node - move to its contained rope
+					currentNode = currentNode.GetContentNode();
+					continue;
+				}
+				Debug.Assert(currentNode.right != null);
+				stack.Push(currentNode.right);
+				currentNode = currentNode.left;
+			}
+			Debug.Assert(currentNode.height == 0);
+		}
+		
+		/// <inheritdoc/>
+		public override int Peek()
+		{
+			if (currentNode == null)
+				return -1;
+			return currentNode.contents[indexInsideNode];
+		}
+		
+		/// <inheritdoc/>
+		public override int Read()
+		{
+			if (currentNode == null)
+				return -1;
+			char result = currentNode.contents[indexInsideNode++];
+			if (indexInsideNode >= currentNode.length)
+				GoToNextNode();
+			return result;
+		}
+		
+		void GoToNextNode()
+		{
+			if (stack.Count == 0) {
+				currentNode = null;
+			} else {
+				indexInsideNode = 0;
+				currentNode = stack.Pop();
+				GoToLeftMostLeaf();
+			}
+		}
+		
+		/// <inheritdoc/>
+		public override int Read(char[] buffer, int index, int count)
+		{
+			if (currentNode == null)
+				return 0;
+			int amountInCurrentNode = currentNode.length - indexInsideNode;
+			if (count < amountInCurrentNode) {
+				Array.Copy(currentNode.contents, indexInsideNode, buffer, index, count);
+				indexInsideNode += count;
+				return count;
+			} else {
+				// read to end of current node
+				Array.Copy(currentNode.contents, indexInsideNode, buffer, index, amountInCurrentNode);
+				GoToNextNode();
+				return amountInCurrentNode;
+			}
+		}
+	}
+}
diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/StringSegment.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/StringSegment.cs
new file mode 100644
index 000000000..f2fad60cf
--- /dev/null
+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/StringSegment.cs
@@ -0,0 +1,107 @@
+// 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;
+
+namespace Tango.Scripting.Editors.Utils
+{
+	/// <summary>
+	/// Represents a string with a segment.
+	/// Similar to System.ArraySegment&lt;T&gt;, but for strings instead of arrays.
+	/// </summary>
+	public struct StringSegment : IEquatable<StringSegment>
+	{
+		readonly string text;
+		readonly int offset;
+		readonly int count;
+		
+		/// <summary>
+		/// Creates a new StringSegment.
+		/// </summary>
+		public StringSegment(string text, int offset, int count)
+		{
+			if (text == null)
+				throw new ArgumentNullException("text");
+			if (offset < 0 || offset > text.Length)
+				throw new ArgumentOutOfRangeException("offset");
+			if (offset + count > text.Length)
+				throw new ArgumentOutOfRangeException("count");
+			this.text = text;
+			this.offset = offset;
+			this.count = count;
+		}
+		
+		/// <summary>
+		/// Creates a new StringSegment.
+		/// </summary>
+		public StringSegment(string text)
+		{
+			if (text == null)
+				throw new ArgumentNullException("text");
+			this.text = text;
+			this.offset = 0;
+			this.count = text.Length;
+		}
+		
+		/// <summary>
+		/// Gets the string used for this segment.
+		/// </summary>
+		public string Text {
+			get { return text; }
+		}
+		
+		/// <summary>
+		/// Gets the start offset of the segment with the text.
+		/// </summary>
+		public int Offset {
+			get { return offset; }
+		}
+		
+		/// <summary>
+		/// Gets the length of the segment.
+		/// </summary>
+		public int Count {
+			get { return count; }
+		}
+		
+		#region Equals and GetHashCode implementation
+		/// <inheritdoc/>
+		public override bool Equals(object obj)
+		{
+			if (obj is StringSegment)
+				return Equals((StringSegment)obj); // use Equals method below
+			else
+				return false;
+		}
+		
+		/// <inheritdoc/>
+		public bool Equals(StringSegment other)
+		{
+			// add comparisions for all members here
+			return object.ReferenceEquals(this.text, other.text) && offset == other.offset && count == other.count;
+		}
+		
+		/// <inheritdoc/>
+		public override int GetHashCode()
+		{
+			return text.GetHashCode() ^ offset ^ count;
+		}
+		
+		/// <summary>
+		/// Equality operator.
+		/// </summary>
+		public static bool operator ==(StringSegment left, StringSegment right)
+		{
+			return left.Equals(right);
+		}
+		
+		/// <summary>
+		/// Inequality operator.
+		/// </summary>
+		public static bool operator !=(StringSegment left, StringSegment right)
+		{
+			return !left.Equals(right);
+		}
+		#endregion
+	}
+}
diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/TextFormatterFactory.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/TextFormatterFactory.cs
new file mode 100644
index 000000000..dd6fe8b9e
--- /dev/null
+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/TextFormatterFactory.cs
@@ -0,0 +1,71 @@
+// 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.Globalization;
+using System.Reflection;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Media;
+using System.Windows.Media.TextFormatting;
+
+namespace Tango.Scripting.Editors.Utils
+{
+	/// <summary>
+	/// Creates TextFormatter instances that with the correct TextFormattingMode, if running on .NET 4.0.
+	/// </summary>
+	static class TextFormatterFactory
+	{		
+		/// <summary>
+		/// Creates a <see cref="TextFormatter"/> using the formatting mode used by the specified owner object.
+		/// </summary>
+		public static TextFormatter Create(DependencyObject owner)
+		{
+			if (owner == null)
+				throw new ArgumentNullException("owner");
+			return TextFormatter.Create(TextOptions.GetTextFormattingMode(owner));
+		}
+		
+		/// <summary>
+		/// Returns whether the specified dependency property affects the text formatter creation.
+		/// Controls should re-create their text formatter for such property changes.
+		/// </summary>
+		public static bool PropertyChangeAffectsTextFormatter(DependencyProperty dp)
+		{
+			return dp == TextOptions.TextFormattingModeProperty;
+		}
+		
+		/// <summary>
+		/// Creates formatted text.
+		/// </summary>
+		/// <param name="element">The owner element. The text formatter setting are read from this element.</param>
+		/// <param name="text">The text.</param>
+		/// <param name="typeface">The typeface to use. If this parameter is null, the typeface of the <paramref name="element"/> will be used.</param>
+		/// <param name="emSize">The font size. If this parameter is null, the font size of the <paramref name="element"/> will be used.</param>
+		/// <param name="foreground">The foreground color. If this parameter is null, the foreground of the <paramref name="element"/> will be used.</param>
+		/// <returns>A FormattedText object using the specified settings.</returns>
+		public static FormattedText CreateFormattedText(FrameworkElement element, string text, Typeface typeface, double? emSize, Brush foreground)
+		{
+			if (element == null)
+				throw new ArgumentNullException("element");
+			if (text == null)
+				throw new ArgumentNullException("text");
+			if (typeface == null)
+				typeface = element.CreateTypeface();
+			if (emSize == null)
+				emSize = TextBlock.GetFontSize(element);
+			if (foreground == null)
+				foreground = TextBlock.GetForeground(element);
+			return new FormattedText(
+				text,
+				CultureInfo.CurrentCulture,
+				FlowDirection.LeftToRight,
+				typeface,
+				emSize.Value,
+				foreground,
+				null,
+				TextOptions.GetTextFormattingMode(element)
+			);
+		}
+	}
+}
diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/ThrowUtil.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/ThrowUtil.cs
new file mode 100644
index 000000000..69dbb5ad0
--- /dev/null
+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/ThrowUtil.cs
@@ -0,0 +1,56 @@
+// 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.Globalization;
+
+namespace Tango.Scripting.Editors.Utils
+{
+	/// <summary>
+	/// Contains exception-throwing helper methods.
+	/// </summary>
+	static class ThrowUtil
+	{
+		/// <summary>
+		/// Throws an ArgumentNullException if <paramref name="val"/> is null; otherwise
+		/// returns val.
+		/// </summary>
+		/// <example>
+		/// Use this method to throw an ArgumentNullException when using parameters for base
+		/// constructor calls.
+		/// <code>
+		/// public VisualLineText(string text) : base(ThrowUtil.CheckNotNull(text, "text").Length)
+		/// </code>
+		/// </example>
+		public static T CheckNotNull<T>(T val, string parameterName) where T : class
+		{
+			if (val == null)
+				throw new ArgumentNullException(parameterName);
+			return val;
+		}
+		
+		public static int CheckNotNegative(int val, string parameterName)
+		{
+			if (val < 0)
+				throw new ArgumentOutOfRangeException(parameterName, val, "value must not be negative");
+			return val;
+		}
+		
+		public static int CheckInRangeInclusive(int val, string parameterName, int lower, int upper)
+		{
+			if (val < lower || val > upper)
+				throw new ArgumentOutOfRangeException(parameterName, val, "Expected: " + lower.ToString(CultureInfo.InvariantCulture) + " <= " + parameterName + " <= " + upper.ToString(CultureInfo.InvariantCulture));
+			return val;
+		}
+		
+		public static InvalidOperationException NoDocumentAssigned()
+		{
+			return new InvalidOperationException("Document is null");
+		}
+		
+		public static InvalidOperationException NoValidCaretPosition()
+		{
+			return new InvalidOperationException("Could not find a valid caret position in the line");
+		}
+	}
+}
diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/WeakEventManagerBase.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/WeakEventManagerBase.cs
new file mode 100644
index 000000000..87e4de515
--- /dev/null
+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/WeakEventManagerBase.cs
@@ -0,0 +1,86 @@
+// 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.Diagnostics;
+using System.Windows;
+
+namespace Tango.Scripting.Editors.Utils
+{
+	/// <summary>
+	/// WeakEventManager with AddListener/RemoveListener and CurrentManager implementation.
+	/// Helps implementing the WeakEventManager pattern with less code.
+	/// </summary>
+	public abstract class WeakEventManagerBase<TManager, TEventSource> : WeakEventManager
+		where TManager : WeakEventManagerBase<TManager, TEventSource>, new()
+		where TEventSource : class
+	{
+		/// <summary>
+		/// Creates a new WeakEventManagerBase instance.
+		/// </summary>
+		protected WeakEventManagerBase()
+		{
+			Debug.Assert(GetType() == typeof(TManager));
+		}
+		
+		/// <summary>
+		/// Adds a weak event listener.
+		/// </summary>
+		[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1000:DoNotDeclareStaticMembersOnGenericTypes")]
+		public static void AddListener(TEventSource source, IWeakEventListener listener)
+		{
+			CurrentManager.ProtectedAddListener(source, listener);
+		}
+		
+		/// <summary>
+		/// Removes a weak event listener.
+		/// </summary>
+		[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1000:DoNotDeclareStaticMembersOnGenericTypes")]
+		public static void RemoveListener(TEventSource source, IWeakEventListener listener)
+		{
+			CurrentManager.ProtectedRemoveListener(source, listener);
+		}
+		
+		/// <inheritdoc/>
+		protected sealed override void StartListening(object source)
+		{
+			if (source == null)
+				throw new ArgumentNullException("source");
+			StartListening((TEventSource)source);
+		}
+		
+		/// <inheritdoc/>
+		protected sealed override void StopListening(object source)
+		{
+			if (source == null)
+				throw new ArgumentNullException("source");
+			StopListening((TEventSource)source);
+		}
+		
+		/// <summary>
+		/// Attaches the event handler.
+		/// </summary>
+		protected abstract void StartListening(TEventSource source);
+		
+		/// <summary>
+		/// Detaches the event handler.
+		/// </summary>
+		protected abstract void StopListening(TEventSource source);
+		
+		/// <summary>
+		/// Gets the current manager.
+		/// </summary>
+		[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1721:PropertyNamesShouldNotMatchGetMethods")]
+		protected static TManager CurrentManager {
+			get {
+				Type managerType = typeof(TManager);
+				TManager manager = (TManager)GetCurrentManager(managerType);
+				if (manager == null) {
+					manager = new TManager();
+					SetCurrentManager(managerType, manager);
+				}
+				return manager;
+			}
+		}
+	}
+}
diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/Win32.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/Win32.cs
new file mode 100644
index 000000000..421c35c5a
--- /dev/null
+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Utils/Win32.cs
@@ -0,0 +1,85 @@
+// 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.Runtime.InteropServices;
+using System.Security;
+using System.Windows;
+using System.Windows.Interop;
+using System.Windows.Media;
+
+namespace Tango.Scripting.Editors.Utils
+{
+	/// <summary>
+	/// Wrapper around Win32 functions.
+	/// </summary>
+	static class Win32
+	{
+		/// <summary>
+		/// Gets the caret blink time.
+		/// </summary>
+		public static TimeSpan CaretBlinkTime {
+			get { return TimeSpan.FromMilliseconds(SafeNativeMethods.GetCaretBlinkTime()); }
+		}
+		
+		/// <summary>
+		/// Creates an invisible Win32 caret for the specified Visual with the specified size (coordinates local to the owner visual).
+		/// </summary>
+		public static bool CreateCaret(Visual owner, Size size)
+		{
+			if (owner == null)
+				throw new ArgumentNullException("owner");
+			HwndSource source = PresentationSource.FromVisual(owner) as HwndSource;
+			if (source != null) {
+				Vector r = owner.PointToScreen(new Point(size.Width, size.Height)) - owner.PointToScreen(new Point(0, 0));
+				return SafeNativeMethods.CreateCaret(source.Handle, IntPtr.Zero, (int)Math.Ceiling(r.X), (int)Math.Ceiling(r.Y));
+			} else {
+				return false;
+			}
+		}
+		
+		/// <summary>
+		/// Sets the position of the caret previously created using <see cref="CreateCaret"/>. position is relative to the owner visual.
+		/// </summary>
+		public static bool SetCaretPosition(Visual owner, Point position)
+		{
+			if (owner == null)
+				throw new ArgumentNullException("owner");
+			HwndSource source = PresentationSource.FromVisual(owner) as HwndSource;
+			if (source != null) {
+				Point pointOnRootVisual = owner.TransformToAncestor(source.RootVisual).Transform(position);
+				Point pointOnHwnd = pointOnRootVisual.TransformToDevice(source.RootVisual);
+				return SafeNativeMethods.SetCaretPos((int)pointOnHwnd.X, (int)pointOnHwnd.Y);
+			} else {
+				return false;
+			}
+		}
+		
+		/// <summary>
+		/// Destroys the caret previously created using <see cref="CreateCaret"/>.
+		/// </summary>
+		public static bool DestroyCaret()
+		{
+			return SafeNativeMethods.DestroyCaret();
+		}
+		
+		[SuppressUnmanagedCodeSecurity]
+		static class SafeNativeMethods
+		{
+			[DllImport("user32.dll")]
+			public static extern int GetCaretBlinkTime();
+			
+			[DllImport("user32.dll")]
+			[return: MarshalAs(UnmanagedType.Bool)]
+			public static extern bool CreateCaret(IntPtr hWnd, IntPtr hBitmap, int nWidth, int nHeight);
+			
+			[DllImport("user32.dll")]
+			[return: MarshalAs(UnmanagedType.Bool)]
+			public static extern bool SetCaretPos(int x, int y);
+			
+			[DllImport("user32.dll")]
+			[return: MarshalAs(UnmanagedType.Bool)]
+			public static extern bool DestroyCaret();
+		}
+	}
+}