void UpdateWidth (object sender, LineEventArgs args)
		{
			int currentLineCountLog10 = (int)System.Math.Log10 (editor.Document.LineCount);
			if (oldLineCountLog10 != currentLineCountLog10) {
				CalculateWidth ();
				oldLineCountLog10 = currentLineCountLog10;
				editor.Document.CommitUpdateAll ();
			}
		}

		void HandleLineInserted (object sender, LineEventArgs e)
		{
			if (lineStates == null) 
				return;
			try {
				lineStates.Insert(e.Line.LineNumber, new LineChangeInfo (Mono.TextEditor.TextDocument.LineState.Dirty));
			} catch (Exception ex) {
				Console.WriteLine ("error while DiffTracker.HandleLineInserted:" + ex);
			}
		}

		void HandleLineRemoved (object sender, LineEventArgs e)
		{
			if (lineStates == null) 
				return;
			try {

				lineStates.RemoveAt (e.LineNumber);
			} catch (Exception ex) {
				Console.WriteLine ("error while DiffTracker.HandleLineRemoved:" + ex);
			}
		}

		void HandleDocLineChanged (object sender, LineEventArgs e)
		{
			e.Line.WasChanged = true;
		}

		void SplitterLineSegmentTreeLineChanged (object sender, LineEventArgs e)
		{
			if (LineChanged != null)
				LineChanged (this, e);
		}

		void HandleSplitterLineSegmentTreeLineRemoved (object sender, LineEventArgs e)
		{
			foreach (TextLineMarker marker in e.Line.Markers) {
				if (marker is IExtendingTextLineMarker) {
					lock (extendingTextMarkers) {
						HeightChanged = true;
						extendingTextMarkers.Remove (marker);
					}
					UnRegisterVirtualTextMarker ((IExtendingTextLineMarker)marker);
				}
			}
		}

		void HandleLineRemoved (object sender, LineEventArgs e)
		{
			Rebuild ();
			OnLineUpdateFrom (new HeightChangedEventArgs (e.Line.LineNumber - 1));
			//RemoveLine (e.Line.LineNumber);
		}

		protected virtual void OnHoveredLineChanged (LineEventArgs e)
		{
			EventHandler<LineEventArgs> handler = this.HoveredLineChanged;
			if (handler != null)
				handler (this, e);
		}

		/// <summary>
		/// Marks a line as locally modified
		/// </summary>
		private void EditorDocumentLineChanged (object sender, LineEventArgs e)
		{
			int  startLine = editor.Document.OffsetToLineNumber (e.Line.Offset),
			     endLine = editor.Document.OffsetToLineNumber (e.Line.EndOffset);
			
			if (startLine == endLine) {
				SetAnnotation (startLine, locallyModified);
			}
			for (int i=startLine; i<endLine; ++i) {
				SetAnnotation (i, locallyModified);
			}
		}

		void HandleLineRemoved (object sender, LineEventArgs e)
		{
			RemoveLine (e.Line.LineNumber);
		}

		void HandleLineRemoved (object sender, LineEventArgs e)
		{
			RemoveLine (editor.OffsetToLineNumber (e.Line.Offset));
		}

		void HandleLineInserted (object sender, LineEventArgs e)
		{
			InsertLine (editor.OffsetToLineNumber (e.Line.Offset));
		}

		protected virtual void OnLineInserted (LineEventArgs e)
		{
			EventHandler<LineEventArgs> handler = this.LineInserted;
			if (handler != null)
				handler (this, e);
		}

		void HandleLineChanged (object sender, LineEventArgs e)
		{
			var lineNumber = e.Line.LineNumber;
			try {
				if (lineStates [lineNumber].state == Mono.TextEditor.TextDocument.LineState.Dirty)
					return;
				lineStates [lineNumber] = new LineChangeInfo (Mono.TextEditor.TextDocument.LineState.Dirty);
				if (trackDocument != null)
					trackDocument.CommitLineUpdate (lineNumber); 
			} catch (Exception ex) {
				Console.WriteLine ("error while DiffTracker.HandleLineChanged:" + ex);
			}
		}

		void HandleDocumentsplitterhandleLineInserted (object sender, LineEventArgs e)
		{
			heightTree.InsertLine (OffsetToLineNumber (e.Line.Offset));
		}

		void HandleLineChanged (object sender, LineEventArgs e)
		{
			UpdateBreakpoints ();
			UpdateWidgetPositions ();
			if (messageBubbleCache != null && messageBubbleCache.RemoveLine (e.Line)) {
				MessageBubbleTextMarker marker = currentErrorMarkers.FirstOrDefault (m => m.LineSegment == e.Line);
				if (marker != null) {
					widget.TextEditor.TextViewMargin.RemoveCachedLine (e.Line);
					// ensure that the line cache is renewed
					marker.GetLineHeight (widget.TextEditor);
				}
			}
		}

		void TextEditorDocumentLineChanged (object sender, LineEventArgs e)
		{
			RemoveCachedLine (e.Line);
		}

		void HandleDocLineChanged (object sender, LineEventArgs e)
		{
			if (line == e.Line)
				doc.RemoveMarker (this);
		}

		void HandleLineInserted (object sender, LineEventArgs e)
		{
			InsertLine (e.Line.LineNumber);
		}

		protected virtual void OnLineRemoved (LineEventArgs e)
		{
			EventHandler<LineEventArgs> handler = LineRemoved;
			if (handler != null)
				handler (this, e);
		}