1 files changed, 242 insertions, 0 deletions
diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Document/DocumentLine.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Document/DocumentLine.cs
new file mode 100644
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+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Document/DocumentLine.cs
@@ -0,0 +1,242 @@
+// 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.Globalization;
+
+namespace Tango.Scripting.Editors.Document
+{
+	/// <summary>
+	/// Represents a line inside a <see cref="TextDocument"/>.
+	/// </summary>
+	/// <remarks>
+	/// <para>
+	/// The <see cref="TextDocument.Lines"/> collection contains one DocumentLine instance
+	/// for every line in the document. This collection is read-only to user code and is automatically
+	/// updated to reflect the current document content.
+	/// </para>
+	/// <para>
+	/// Internally, the DocumentLine instances are arranged in a binary tree that allows for both efficient updates and lookup.
+	/// Converting between offset and line number is possible in O(lg N) time,
+	/// and the data structure also updates all offsets in O(lg N) whenever a line is inserted or removed.
+	/// </para>
+	/// </remarks>
+	public sealed partial class DocumentLine : ISegment
+	{
+		#region Constructor
+		#if DEBUG
+		// Required for thread safety check which is done only in debug builds.
+		// To save space, we don't store the document reference in release builds as we don't need it there.
+		readonly TextDocument document;
+		#endif
+		
+		internal bool isDeleted;
+		
+		internal DocumentLine(TextDocument document)
+		{
+			#if DEBUG
+			Debug.Assert(document != null);
+			this.document = document;
+			#endif
+		}
+		
+		[Conditional("DEBUG")]
+		void DebugVerifyAccess()
+		{
+			#if DEBUG
+			document.DebugVerifyAccess();
+			#endif
+		}
+		#endregion
+		
+		#region Events
+//		/// <summary>
+//		/// Is raised when the line is deleted.
+//		/// </summary>
+//		public event EventHandler Deleted;
+//
+//		/// <summary>
+//		/// Is raised when the line's text changes.
+//		/// </summary>
+//		public event EventHandler TextChanged;
+//
+//		/// <summary>
+//		/// Raises the Deleted or TextChanged event.
+//		/// </summary>
+//		internal void RaiseChanged()
+//		{
+//			if (IsDeleted) {
+//				if (Deleted != null)
+//					Deleted(this, EventArgs.Empty);
+//			} else {
+//				if (TextChanged != null)
+//					TextChanged(this, EventArgs.Empty);
+//			}
+//		}
+		#endregion
+		
+		#region Properties stored in tree
+		/// <summary>
+		/// Gets if this line was deleted from the document.
+		/// </summary>
+		public bool IsDeleted {
+			get {
+				DebugVerifyAccess();
+				return isDeleted;
+			}
+		}
+		
+		/// <summary>
+		/// Gets the number of this line.
+		/// Runtime: O(log n)
+		/// </summary>
+		/// <exception cref="InvalidOperationException">The line was deleted.</exception>
+		public int LineNumber {
+			get {
+				if (IsDeleted)
+					throw new InvalidOperationException();
+				return DocumentLineTree.GetIndexFromNode(this) + 1;
+			}
+		}
+		
+		/// <summary>
+		/// Gets the starting offset of the line in the document's text.
+		/// Runtime: O(log n)
+		/// </summary>
+		/// <exception cref="InvalidOperationException">The line was deleted.</exception>
+		public int Offset {
+			get {
+				if (IsDeleted)
+					throw new InvalidOperationException();
+				return DocumentLineTree.GetOffsetFromNode(this);
+			}
+		}
+		
+		/// <summary>
+		/// Gets the end offset of the line in the document's text (the offset before the line delimiter).
+		/// Runtime: O(log n)
+		/// </summary>
+		/// <exception cref="InvalidOperationException">The line was deleted.</exception>
+		/// <remarks>EndOffset = <see cref="Offset"/> + <see cref="Length"/>.</remarks>
+		public int EndOffset {
+			get { return this.Offset + this.Length; }
+		}
+		#endregion
+		
+		#region Length
+		int totalLength;
+		byte delimiterLength;
+		
+		/// <summary>
+		/// Gets the length of this line. The length does not include the line delimiter. O(1)
+		/// </summary>
+		/// <remarks>This property is still available even if the line was deleted;
+		/// in that case, it contains the line's length before the deletion.</remarks>
+		public int Length {
+			get {
+				DebugVerifyAccess();
+				return totalLength - delimiterLength;
+			}
+		}
+		
+		/// <summary>
+		/// Gets the length of this line, including the line delimiter. O(1)
+		/// </summary>
+		/// <remarks>This property is still available even if the line was deleted;
+		/// in that case, it contains the line's length before the deletion.</remarks>
+		public int TotalLength {
+			get {
+				DebugVerifyAccess();
+				return totalLength;
+			}
+			internal set {
+				// this is set by DocumentLineTree
+				totalLength = value;
+			}
+		}
+		
+		/// <summary>
+		/// <para>Gets the length of the line delimiter.</para>
+		/// <para>The value is 1 for single <c>"\r"</c> or <c>"\n"</c>, 2 for the <c>"\r\n"</c> sequence;
+		/// and 0 for the last line in the document.</para>
+		/// </summary>
+		/// <remarks>This property is still available even if the line was deleted;
+		/// in that case, it contains the line delimiter's length before the deletion.</remarks>
+		public int DelimiterLength {
+			get {
+				DebugVerifyAccess();
+				return delimiterLength;
+			}
+			internal set {
+				Debug.Assert(value >= 0 && value <= 2);
+				delimiterLength = (byte)value;
+			}
+		}
+		#endregion
+		
+		#region Previous / Next Line
+		/// <summary>
+		/// Gets the next line in the document.
+		/// </summary>
+		/// <returns>The line following this line, or null if this is the last line.</returns>
+		public DocumentLine NextLine {
+			get {
+				DebugVerifyAccess();
+				
+				if (right != null) {
+					return right.LeftMost;
+				} else {
+					DocumentLine node = this;
+					DocumentLine oldNode;
+					do {
+						oldNode = node;
+						node = node.parent;
+						// we are on the way up from the right part, don't output node again
+					} while (node != null && node.right == oldNode);
+					return node;
+				}
+			}
+		}
+		
+		/// <summary>
+		/// Gets the previous line in the document.
+		/// </summary>
+		/// <returns>The line before this line, or null if this is the first line.</returns>
+		public DocumentLine PreviousLine {
+			get {
+				DebugVerifyAccess();
+				
+				if (left != null) {
+					return left.RightMost;
+				} else {
+					DocumentLine node = this;
+					DocumentLine oldNode;
+					do {
+						oldNode = node;
+						node = node.parent;
+						// we are on the way up from the left part, don't output node again
+					} while (node != null && node.left == oldNode);
+					return node;
+				}
+			}
+		}
+		#endregion
+		
+		#region ToString
+		/// <summary>
+		/// Gets a string with debug output showing the line number and offset.
+		/// Does not include the line's text.
+		/// </summary>
+		public override string ToString()
+		{
+			if (IsDeleted)
+				return "[DocumentLine deleted]";
+			else
+				return string.Format(
+					CultureInfo.InvariantCulture,
+					"[DocumentLine Number={0} Offset={1} Length={2}]", LineNumber, Offset, Length);
+		}
+		#endregion
+	}
+}