diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/Caret.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/Caret.cs
index 2149bdfe03..e1da701371 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/Caret.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/Caret.cs
@@ -102,7 +102,7 @@ namespace ICSharpCode.AvalonEdit.Editing
 		/// </summary>
 		public TextLocation Location {
 			get {
-				return position;
+				return position.Location;
 			}
 			set {
 				this.Position = new TextViewPosition(value);
@@ -174,7 +174,7 @@ namespace ICSharpCode.AvalonEdit.Editing
 				if (document == null) {
 					return 0;
 				} else {
-					return document.GetOffset(position);
+					return document.GetOffset(position.Location);
 				}
 			}
 			set {
@@ -279,7 +279,7 @@ namespace ICSharpCode.AvalonEdit.Editing
 			// mark column as validated
 			visualColumnValid = true;
 			
-			int caretOffset = textView.Document.GetOffset(position);
+			int caretOffset = textView.Document.GetOffset(position.Location);
 			int firstDocumentLineOffset = visualLine.FirstDocumentLine.Offset;
 			position.VisualColumn = visualLine.ValidateVisualColumn(position, textArea.Selection.EnableVirtualSpace);
 			
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/RectangleSelection.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/RectangleSelection.cs
index c201780ead..387ae39560 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/RectangleSelection.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/RectangleSelection.cs
@@ -45,8 +45,8 @@ namespace ICSharpCode.AvalonEdit.Editing
 			this.endLine = end.Line;
 			this.startXPos = GetXPos(textArea, start);
 			this.endXPos = GetXPos(textArea, end);
-			this.startOffset = document.GetOffset(start);
-			this.endOffset = document.GetOffset(end);
+			this.startOffset = document.GetOffset(start.Location);
+			this.endOffset = document.GetOffset(end.Location);
 			CalculateSegments();
 		}
 		
@@ -59,7 +59,7 @@ namespace ICSharpCode.AvalonEdit.Editing
 			this.startXPos = startXPos;
 			this.endXPos = GetXPos(textArea, end);
 			this.startOffset = startOffset;
-			this.endOffset = document.GetOffset(end);
+			this.endOffset = document.GetOffset(end.Location);
 			CalculateSegments();
 		}
 		
@@ -71,7 +71,7 @@ namespace ICSharpCode.AvalonEdit.Editing
 			this.endLine = endLine;
 			this.startXPos = GetXPos(textArea, start);
 			this.endXPos = endXPos;
-			this.startOffset = document.GetOffset(start);
+			this.startOffset = document.GetOffset(start.Location);
 			this.endOffset = endOffset;
 			CalculateSegments();
 		}
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/Selection.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/Selection.cs
index 0a119379d7..4826775f25 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/Selection.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Editing/Selection.cs
@@ -35,7 +35,7 @@ namespace ICSharpCode.AvalonEdit.Editing
 		{
 			if (textArea == null)
 				throw new ArgumentNullException("textArea");
-			if (textArea.Document.GetOffset(start) == textArea.Document.GetOffset(end) && start.VisualColumn == end.VisualColumn)
+			if (textArea.Document.GetOffset(start.Location) == textArea.Document.GetOffset(end.Location) && start.VisualColumn == end.VisualColumn)
 				return textArea.emptySelection;
 			else
 				return new SimpleSelection(textArea, start, end);
@@ -112,6 +112,9 @@ namespace ICSharpCode.AvalonEdit.Editing
 			get { return Length == 0; }
 		}
 		
+		/// <summary>
+		/// Gets whether virtual space is enabled for this selection.
+		/// </summary>
 		public virtual bool EnableVirtualSpace {
 			get { return textArea.Options.EnableVirtualSpace; }
 		}
@@ -128,8 +131,8 @@ namespace ICSharpCode.AvalonEdit.Editing
 		public abstract Selection SetEndpoint(TextViewPosition endPosition);
 		
 		/// <summary>
-		/// If this selection is empty, starts a new selection from <paramref name="startOffset"/> to
-		/// <paramref name="newEndOffset"/>, otherwise, changes the endpoint of this selection.
+		/// If this selection is empty, starts a new selection from <paramref name="startPosition"/> to
+		/// <paramref name="endPosition"/>, otherwise, changes the endpoint of this selection.
 		/// </summary>
 		public abstract Selection StartSelectionOrSetEndpoint(TextViewPosition startPosition, TextViewPosition endPosition);
 		
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Rendering/VisualLine.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Rendering/VisualLine.cs
index f6ac5e1737..c49607f61f 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Rendering/VisualLine.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Rendering/VisualLine.cs
@@ -65,6 +65,9 @@ namespace ICSharpCode.AvalonEdit.Rendering
 		/// </summary>
 		public int VisualLength { get; private set; }
 		
+		/// <summary>
+		/// Length in visual line coordinates including the end of line marker, if TextEditorOptions.ShowEndOfLine is enabled.
+		/// </summary>
 		public int VisualLengthWithEndOfLineMarker {
 			get {
 				int length = VisualLength;
@@ -346,11 +349,19 @@ namespace ICSharpCode.AvalonEdit.Rendering
 			return GetVisualColumn(point, textView.Options.EnableVirtualSpace);
 		}
 		
+		/// <summary>
+		/// Gets the visual column from a document position (relative to top left of the document).
+		/// If the user clicks between two visual columns, rounds to the nearest column.
+		/// </summary>
 		public int GetVisualColumn(Point point, bool allowVirtualSpace)
 		{
 			return GetVisualColumn(GetTextLineByVisualYPosition(point.Y), point.X, allowVirtualSpace);
 		}
 		
+		/// <summary>
+		/// Gets the visual column from a document position (relative to top left of the document).
+		/// If the user clicks between two visual columns, rounds to the nearest column.
+		/// </summary>
 		public int GetVisualColumn(TextLine textLine, double xPos, bool allowVirtualSpace)
 		{
 			if (xPos > textLine.WidthIncludingTrailingWhitespace) {
@@ -363,11 +374,17 @@ namespace ICSharpCode.AvalonEdit.Rendering
 			return ch.FirstCharacterIndex + ch.TrailingLength;
 		}
 		
+		/// <summary>
+		/// Validates the visual column and returns the correct one.
+		/// </summary>
 		public int ValidateVisualColumn(TextViewPosition position, bool allowVirtualSpace)
 		{
-			return ValidateVisualColumn(Document.GetOffset(position), position.VisualColumn, allowVirtualSpace);
+			return ValidateVisualColumn(Document.GetOffset(position.Location), position.VisualColumn, allowVirtualSpace);
 		}
 		
+		/// <summary>
+		/// Validates the visual column and returns the correct one.
+		/// </summary>
 		public int ValidateVisualColumn(int offset, int visualColumn, bool allowVirtualSpace)
 		{
 			int firstDocumentLineOffset = this.FirstDocumentLine.Offset;
@@ -396,6 +413,10 @@ namespace ICSharpCode.AvalonEdit.Rendering
 			return GetVisualColumnFloor(point, textView.Options.EnableVirtualSpace);
 		}
 		
+		/// <summary>
+		/// Gets the visual column from a document position (relative to top left of the document).
+		/// If the user clicks between two visual columns, returns the first of those columns.
+		/// </summary>
 		public int GetVisualColumnFloor(Point point, bool allowVirtualSpace)
 		{
 			TextLine textLine = GetTextLineByVisualYPosition(point.Y);