diff --git a/src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/CodeEditor.cs b/src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/CodeEditor.cs
index f83a0b1942..55a3057cb5 100644
--- a/src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/CodeEditor.cs
+++ b/src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/CodeEditor.cs
@@ -35,6 +35,7 @@ namespace ICSharpCode.AvalonEdit.AddIn
 {
 	/// <summary>
 	/// Integrates AvalonEdit with SharpDevelop.
+	/// Also provides support for Split-View (showing two AvalonEdit instances using the same TextDocument)
 	/// </summary>
 	public class CodeEditor : Grid
 	{
@@ -85,8 +86,11 @@ namespace ICSharpCode.AvalonEdit.AddIn
 			get { return primaryTextEditorAdapter.Document; }
 		}
 		
+		public ITextEditor PrimaryTextEditorAdapter {
+			get { return primaryTextEditorAdapter; }
+		}
 		
-		public CodeEditorAdapter ActiveTextEditorAdapter {
+		public ITextEditor ActiveTextEditorAdapter {
 			get { return GetAdapter(this.ActiveTextEditor); }
 		}
 		
@@ -234,8 +238,6 @@ namespace ICSharpCode.AvalonEdit.AddIn
 				
 				secondaryTextEditor.SetBinding(TextEditor.DocumentProperty,
 				                               new Binding(TextEditor.DocumentProperty.Name) { Source = primaryTextEditor });
-				secondaryTextEditor.TextArea.SetBinding(TextArea.IndentationStrategyProperty,
-				                                        new Binding(TextArea.IndentationStrategyProperty.Name) { Source = primaryTextEditor.TextArea });
 				secondaryTextEditor.SyntaxHighlighting = primaryTextEditor.SyntaxHighlighting;
 				
 				SetRow(secondaryTextEditor, 2);
diff --git a/src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/CodeEditorAdapter.cs b/src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/CodeEditorAdapter.cs
index 3088674165..96e02823ca 100644
--- a/src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/CodeEditorAdapter.cs
+++ b/src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/CodeEditorAdapter.cs
@@ -19,7 +19,7 @@ namespace ICSharpCode.AvalonEdit.AddIn
 	/// <summary>
 	/// Wraps the CodeEditor class to provide the ITextEditor interface.
 	/// </summary>
-	public class CodeEditorAdapter : AvalonEditTextEditorAdapter
+	sealed class CodeEditorAdapter : AvalonEditTextEditorAdapter
 	{
 		readonly CodeEditor codeEditor;
 		
@@ -88,5 +88,9 @@ namespace ICSharpCode.AvalonEdit.AddIn
 		public override IInsightWindow ActiveInsightWindow {
 			get { return codeEditor.ActiveInsightWindow; }
 		}
+		
+		public override ITextEditor PrimaryView {
+			get { return codeEditor.PrimaryTextEditorAdapter; }
+		}
 	}
 }
diff --git a/src/Libraries/SharpTreeView/ICSharpCode.TreeView.Demo/ICSharpCode.TreeView.Demo.csproj b/src/Libraries/SharpTreeView/ICSharpCode.TreeView.Demo/ICSharpCode.TreeView.Demo.csproj
index 2032f2470f..128aea42a8 100644
--- a/src/Libraries/SharpTreeView/ICSharpCode.TreeView.Demo/ICSharpCode.TreeView.Demo.csproj
+++ b/src/Libraries/SharpTreeView/ICSharpCode.TreeView.Demo/ICSharpCode.TreeView.Demo.csproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="3.5" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
     <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
@@ -10,7 +10,7 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>ICSharpCode.TreeView.Demo</RootNamespace>
     <AssemblyName>ICSharpCode.TreeView.Demo</AssemblyName>
-    <TargetFrameworkVersion>v3.5</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <ProjectTypeGuids>{60dc8134-eba5-43b8-bcc9-bb4bc16c2548};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
     <WarningLevel>4</WarningLevel>
diff --git a/src/Main/Base/Project/Src/Editor/AvalonEdit/AvalonEditTextEditorAdapter.cs b/src/Main/Base/Project/Src/Editor/AvalonEdit/AvalonEditTextEditorAdapter.cs
index 295ac7a6a2..3f1bf35d67 100644
--- a/src/Main/Base/Project/Src/Editor/AvalonEdit/AvalonEditTextEditorAdapter.cs
+++ b/src/Main/Base/Project/Src/Editor/AvalonEdit/AvalonEditTextEditorAdapter.cs
@@ -223,5 +223,11 @@ namespace ICSharpCode.SharpDevelop.Editor.AvalonEdit
 		{
 			return null;
 		}
+		
+		public virtual ITextEditor PrimaryView {
+			get {
+				return this;
+			}
+		}
 	}
 }
diff --git a/src/Main/Base/Project/Src/Editor/ITextEditor.cs b/src/Main/Base/Project/Src/Editor/ITextEditor.cs
index 09741eea29..44bc3dbe73 100644
--- a/src/Main/Base/Project/Src/Editor/ITextEditor.cs
+++ b/src/Main/Base/Project/Src/Editor/ITextEditor.cs
@@ -26,8 +26,26 @@ namespace ICSharpCode.SharpDevelop.Editor
 	/// </summary>
 	public interface ITextEditor : IServiceProvider
 	{
+		/// <summary>
+		/// Gets the primary view if split-view is active.
+		/// If split-view is disabled, the current ITextEditor instance is returned.
+		/// </summary>
+		/// <example>bool isSecondaryView = (editor != editor.PrimaryView);</example>
+		ITextEditor PrimaryView { get; }
+		
+		/// <summary>
+		/// Gets the document that is being edited.
+		/// </summary>
 		IDocument Document { get; }
+		
+		/// <summary>
+		/// Gets an object that represents the caret inside this text editor.
+		/// </summary>
 		ITextEditorCaret Caret { get; }
+		
+		/// <summary>
+		/// Gets the set of options used in the text editor.
+		/// </summary>
 		ITextEditorOptions Options { get; }
 		
 		ILanguageBinding Language { get; }
diff --git a/src/Main/Base/Project/Src/TextEditor/Gui/TextEditorAdapter.cs b/src/Main/Base/Project/Src/TextEditor/Gui/TextEditorAdapter.cs
index f1e8127027..c4344f536a 100644
--- a/src/Main/Base/Project/Src/TextEditor/Gui/TextEditorAdapter.cs
+++ b/src/Main/Base/Project/Src/TextEditor/Gui/TextEditorAdapter.cs
@@ -250,6 +250,12 @@ namespace ICSharpCode.SharpDevelop
 				throw new NotImplementedException();
 			}
 		}
+		
+		public ITextEditor PrimaryView {
+			get {
+				return this;
+			}
+		}
 	}
 	
 	sealed class CompletionItemListAdapter : ICompletionDataProvider