Merge branch 'master' of https://twinetfs.visualstudio.com/_git/Tango

1 files changed, 85 insertions, 0 deletions

diff --git a/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Document/WeakLineTracker.cs b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Document/WeakLineTracker.cs
new file mode 100644
index 000000000..a70874645
--- /dev/null
+++ b/Software/Visual_Studio/Scripting/Tango.Scripting.Editors/Document/WeakLineTracker.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;
+
+namespace Tango.Scripting.Editors.Document
+{
+	/// <summary>
+	/// Allows registering a line tracker on a TextDocument using a weak reference from the document to the line tracker.
+	/// </summary>
+	public sealed class WeakLineTracker : ILineTracker
+	{
+		TextDocument textDocument;
+		WeakReference targetObject;
+		
+		private WeakLineTracker(TextDocument textDocument, ILineTracker targetTracker)
+		{
+			this.textDocument = textDocument;
+			this.targetObject = new WeakReference(targetTracker);
+		}
+		
+		/// <summary>
+		/// Registers the <paramref name="targetTracker"/> as line tracker for the <paramref name="textDocument"/>.
+		/// A weak reference to the target tracker will be used, and the WeakLineTracker will deregister itself
+		/// when the target tracker is garbage collected.
+		/// </summary>
+		public static WeakLineTracker Register(TextDocument textDocument, ILineTracker targetTracker)
+		{
+			if (textDocument == null)
+				throw new ArgumentNullException("textDocument");
+			if (targetTracker == null)
+				throw new ArgumentNullException("targetTracker");
+			WeakLineTracker wlt = new WeakLineTracker(textDocument, targetTracker);
+			textDocument.LineTrackers.Add(wlt);
+			return wlt;
+		}
+		
+		/// <summary>
+		/// Deregisters the weak line tracker.
+		/// </summary>
+		public void Deregister()
+		{
+			if (textDocument != null) {
+				textDocument.LineTrackers.Remove(this);
+				textDocument = null;
+			}
+		}
+		
+		void ILineTracker.BeforeRemoveLine(DocumentLine line)
+		{
+			ILineTracker targetTracker = targetObject.Target as ILineTracker;
+			if (targetTracker != null)
+				targetTracker.BeforeRemoveLine(line);
+			else
+				Deregister();
+		}
+		
+		void ILineTracker.SetLineLength(DocumentLine line, int newTotalLength)
+		{
+			ILineTracker targetTracker = targetObject.Target as ILineTracker;
+			if (targetTracker != null)
+				targetTracker.SetLineLength(line, newTotalLength);
+			else
+				Deregister();
+		}
+		
+		void ILineTracker.LineInserted(DocumentLine insertionPos, DocumentLine newLine)
+		{
+			ILineTracker targetTracker = targetObject.Target as ILineTracker;
+			if (targetTracker != null)
+				targetTracker.LineInserted(insertionPos, newLine);
+			else
+				Deregister();
+		}
+		
+		void ILineTracker.RebuildDocument()
+		{
+			ILineTracker targetTracker = targetObject.Target as ILineTracker;
+			if (targetTracker != null)
+				targetTracker.RebuildDocument();
+			else
+				Deregister();
+		}
+	}
+}