Make ColumnRulerRenderer internal; expose pen instead of brush.

src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/CustomizableHighlightingColorizer.cs

@@ -30,6 +30,7 @@ namespace ICSharpCode.AvalonEdit.AddIn
 		public const string LinkText = "Link text";
 		public const string BreakpointMarker = "Breakpoint";
 		public const string InstructionPointerMarker = "Current statement";
+		public const string ColumnRuler = "Column ruler";
 		
 		public static void ApplyCustomizationsToDefaultElements(TextEditor textEditor, IEnumerable<CustomizedHighlightingColor> customizations)
 		{
@@ -42,7 +43,7 @@ namespace ICSharpCode.AvalonEdit.AddIn
 			textEditor.TextArea.TextView.ClearValue(TextView.NonPrintableCharacterBrushProperty);
 			textEditor.TextArea.TextView.ClearValue(TextView.LinkTextForegroundBrushProperty);
 			textEditor.TextArea.TextView.ClearValue(TextView.LinkTextBackgroundBrushProperty);
-			textEditor.TextArea.TextView.ClearValue(TextView.ColumnRulerBrushProperty);
+			textEditor.TextArea.TextView.ClearValue(TextView.ColumnRulerPenProperty);
 			
 			// 'assigned' flags are used so that the first matching customization wins.
 			// This is necessary because more specific customizations come first in the list
@@ -109,12 +110,12 @@ namespace ICSharpCode.AvalonEdit.AddIn
 						if (color.Background != null)
 							textEditor.TextArea.TextView.LinkTextBackgroundBrush = CreateFrozenBrush(color.Background.Value);
 						break;
-					case ColumnRulerRenderer.Name:
+					case ColumnRuler:
 						if (assignedColumnRulerColor)
 							continue;
 						assignedColumnRulerColor = true;
 						if (color.Foreground != null)
-							textEditor.TextArea.TextView.ColumnRulerBrush = CreateFrozenBrush(color.Foreground.Value); 
+							textEditor.TextArea.TextView.ColumnRulerPen = CreateFrozenPen(color.Foreground.Value); 
 						break;
 				}
 			}
@@ -224,5 +225,12 @@ namespace ICSharpCode.AvalonEdit.AddIn
 			brush.Freeze();
 			return brush;
 		}
+		
+		static Pen CreateFrozenPen(Color color)
+		{
+			Pen pen = new Pen(CreateFrozenBrush(color), 1);
+			pen.Freeze();
+			return pen;
+		}
 	}
 }

src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/Options/HighlightingOptions.xaml.cs

@@ -431,14 +431,14 @@ namespace ICSharpCode.AvalonEdit.AddIn.Options
 			items.Add(currentStatementMarker);
 			
 			IHighlightingItem columnRuler = new SimpleHighlightingItem(
-				ColumnRulerRenderer.Name,
+				CustomizableHighlightingColorizer.ColumnRuler,
 				ta => {
 					ta.Document.Text = "some line with a lot of text";
 					ta.TextView.Options.ColumnRulerPosition = 15;
 					ta.TextView.Options.ShowColumnRuler = true;
 				})
 			{
-				Foreground = ColumnRulerRenderer.DefaultForeground
+				Foreground = Colors.LightGray
 			};
 			columnRuler = new CustomizedHighlightingItem(customizationList, columnRuler, language, canSetFont: false, canSetBackground: false);
 			columnRuler.PropertyChanged += item_PropertyChanged;

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Rendering/ColumnRulerRenderer.cs

@@ -8,18 +8,17 @@ using System.Windows.Media;
 using ICSharpCode.AvalonEdit.Rendering;
 using ICSharpCode.AvalonEdit.Utils;
 
-namespace ICSharpCode.AvalonEdit
+namespace ICSharpCode.AvalonEdit.Rendering
 {
 	/// <summary>
 	/// Renders a ruler at a certain column.
 	/// </summary>
-	public class ColumnRulerRenderer : IBackgroundRenderer
+	sealed class ColumnRulerRenderer : IBackgroundRenderer
 	{
 		Pen pen;
 		int column;
 		TextView textView;
 		
-		public const string Name = "Column ruler";
 		public static readonly Color DefaultForeground = Colors.LightGray;
 		
 		public ColumnRulerRenderer(TextView textView)
@@ -37,15 +36,14 @@ namespace ICSharpCode.AvalonEdit
 			get { return KnownLayer.Background; }
 		}
 		
-		public void SetRuler(int column, Brush brush)
+		public void SetRuler(int column, Pen pen)
 		{
 			if (this.column != column) {
 				this.column = column;
 				textView.InvalidateLayer(this.Layer);
 			}
-			if (pen.Brush != brush) {
-				this.pen = new Pen(brush, 1);
-				this.pen.Freeze();
+			if (this.pen != pen) {
+				this.pen = pen;
 				textView.InvalidateLayer(this.Layer);
 			}
 		}

src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Rendering/TextView.cs

@@ -54,7 +54,7 @@ namespace ICSharpCode.AvalonEdit.Rendering
 			backgroundRenderers = new ObserveAddRemoveCollection<IBackgroundRenderer>(BackgroundRenderer_Added, BackgroundRenderer_Removed);
 			columnRulerRenderer = new ColumnRulerRenderer(this);
 			this.Options = new TextEditorOptions();
-			this.columnRulerRenderer.SetRuler(Options.ColumnRulerPosition, ColumnRulerBrush);
+			this.columnRulerRenderer.SetRuler(Options.ColumnRulerPosition, ColumnRulerPen);
 			
 			Debug.Assert(singleCharacterElementGenerator != null); // assert that the option change created the builtin element generators
 			
@@ -204,13 +204,10 @@ namespace ICSharpCode.AvalonEdit.Rendering
 				OptionChanged(this, e);
 			}
 			
-			// PropertyName == null means all properties are changed
-			if (e.PropertyName == null || e.PropertyName == "ColumnRulerPosition" || e.PropertyName == "ShowColumnRuler") {
-				if (Options.ShowColumnRuler)
-					columnRulerRenderer.SetRuler(Options.ColumnRulerPosition, ColumnRulerBrush);
-				else
-					columnRulerRenderer.SetRuler(-1, ColumnRulerBrush);
-			}
+			if (Options.ShowColumnRuler)
+				columnRulerRenderer.SetRuler(Options.ColumnRulerPosition, ColumnRulerPen);
+			else
+				columnRulerRenderer.SetRuler(-1, ColumnRulerPen);
 			
 			UpdateBuiltinElementGeneratorsFromOptions();
 			Redraw();
@@ -1942,24 +1939,33 @@ namespace ICSharpCode.AvalonEdit.Rendering
 				InvalidateDefaultTextMetrics();
 				Redraw();
 			}
+			if (e.Property == ColumnRulerPenProperty) {
+				columnRulerRenderer.SetRuler(this.Options.ColumnRulerPosition, this.ColumnRulerPen);
+			}
 		}
 		
-		public static readonly DependencyProperty ColumnRulerBrushProperty =
-			DependencyProperty.Register("ColumnRulerBrush", typeof(Brush), typeof(TextView),
-			                            new FrameworkPropertyMetadata(Brushes.LightGray, OnUpdateBrushes));
-		
-		public Brush ColumnRulerBrush {
-			get { return (Brush)GetValue(ColumnRulerBrushProperty); }
-			set { SetValue(ColumnRulerBrushProperty, value); }
-		}
+		/// <summary>
+		/// The pen used to draw the column ruler.
+		/// <seealso cref="TextEditorOptions.ShowColumnRuler"/>
+		/// </summary>
+		public static readonly DependencyProperty ColumnRulerPenProperty =
+			DependencyProperty.Register("ColumnRulerBrush", typeof(Pen), typeof(TextView),
+			                            new FrameworkPropertyMetadata(CreateFrozenPen(Brushes.LightGray)));
 		
-		public static void OnUpdateBrushes(DependencyObject d, DependencyPropertyChangedEventArgs e)
+		static Pen CreateFrozenPen(SolidColorBrush brush)
 		{
-			TextView view = d as TextView;
-			if (view == null) return;
-			if (e.Property == ColumnRulerBrushProperty)
-				view.columnRulerRenderer.SetRuler(view.Options.ColumnRulerPosition, (Brush)e.NewValue);
+			Pen pen = new Pen(brush, 1);
+			pen.Freeze();
+			return pen;
 		}
 		
+		/// <summary>
+		/// Gets/Sets the pen used to draw the column ruler.
+		/// <seealso cref="TextEditorOptions.ShowColumnRuler"/>
+		/// </summary>
+		public Pen ColumnRulerPen {
+			get { return (Pen)GetValue(ColumnRulerPenProperty); }
+			set { SetValue(ColumnRulerPenProperty, value); }
+		}
 	}
 }