Merge pull request #3274 from tom-englert/dev/WpfRefactoring

WPF Refactoring

ICSharpCode.ILSpyX/AssemblyList.cs

@@ -186,7 +186,7 @@ namespace ICSharpCode.ILSpyX
 			get { return listName; }
 		}
 
-		internal void Move(LoadedAssembly[] assembliesToMove, int index)
+		public void Move(LoadedAssembly[] assembliesToMove, int index)
 		{
 			VerifyAccess();
 			lock (lockObj)
@@ -230,7 +230,7 @@ namespace ICSharpCode.ILSpyX
 			}
 		}
 
-		internal void RefreshSave()
+		public void RefreshSave()
 		{
 			// Whenever the assembly list is modified, mark it as dirty
 			// and enqueue a task that saves it once the UI has finished modifying the assembly list.
@@ -281,8 +281,9 @@ namespace ICSharpCode.ILSpyX
 		{
 			file = Path.GetFullPath(file);
 			return OpenAssembly(file, () => {
-				var newAsm = new LoadedAssembly(this, file, fileLoaders: manager?.LoaderRegistry, applyWinRTProjections: ApplyWinRTProjections, useDebugSymbols: UseDebugSymbols);
+				var newAsm = new LoadedAssembly(this, file, fileLoaders: manager?.LoaderRegistry, applyWinRTProjections: ApplyWinRTProjections, useDebugSymbols: UseDebugSymbols) {
-				newAsm.IsAutoLoaded = isAutoLoaded;
+					IsAutoLoaded = isAutoLoaded
+				};
 				return newAsm;
 			});
 		}

ICSharpCode.ILSpyX/AssemblyListManager.cs

@@ -39,7 +39,7 @@ namespace ICSharpCode.ILSpyX
 		public const string DotNet35List = ".NET 3.5";
 		public const string ASPDotNetMVC3List = "ASP.NET (MVC3)";
 
-		private ISettingsProvider settingsProvider;
+		private readonly ISettingsProvider settingsProvider;
 
 		public AssemblyListManager(ISettingsProvider settingsProvider)
 		{
@@ -59,9 +59,9 @@ namespace ICSharpCode.ILSpyX
 
 		public bool UseDebugSymbols { get; set; }
 
-		public ObservableCollection<string> AssemblyLists { get; } = new ObservableCollection<string>();
+		public ObservableCollection<string> AssemblyLists { get; } = [];
 
-		public FileLoaderRegistry LoaderRegistry { get; } = new FileLoaderRegistry();
+		public FileLoaderRegistry LoaderRegistry { get; } = new();
 
 		/// <summary>
 		/// Loads an assembly list from the ILSpySettings.
@@ -69,14 +69,13 @@ namespace ICSharpCode.ILSpyX
 		/// </summary>
 		public AssemblyList LoadList(string listName)
 		{
-			this.settingsProvider = this.settingsProvider.Load();
 			AssemblyList list = DoLoadList(listName);
 			if (!AssemblyLists.Contains(list.ListName))
 				AssemblyLists.Add(list.ListName);
 			return list;
 		}
 
-		AssemblyList DoLoadList(string listName)
+		AssemblyList DoLoadList(string? listName)
 		{
 			XElement doc = this.settingsProvider["AssemblyLists"];
 			if (listName != null)

ICSharpCode.ILSpyX/Extensions/CollectionExtensions.cs

@@ -27,7 +27,7 @@ namespace ICSharpCode.ILSpyX.Extensions
 {
 	public static class CollectionExtensions
 	{
-		public static void AddRange<T>(this ICollection<T> list, IEnumerable<T> items)
+		internal static void AddRange<T>(this ICollection<T> list, IEnumerable<T> items)
 		{
 			foreach (T item in items)
 				if (!list.Contains(item))

ICSharpCode.ILSpyX/ICSharpCode.ILSpyX.csproj

@@ -41,7 +41,6 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <InternalsVisibleTo Include="ILSpy" Key="00240000048000009400000006020000002400005253413100040000010001004dcf3979c4e902efa4dd2163a039701ed5822e6f1134d77737296abbb97bf0803083cfb2117b4f5446a217782f5c7c634f9fe1fc60b4c11d62c5b3d33545036706296d31903ddcf750875db38a8ac379512f51620bb948c94d0831125fbc5fe63707cbb93f48c1459c4d1749eb7ac5e681a2f0d6d7c60fa527a3c0b8f92b02bf" />
     <InternalsVisibleTo Include="ILSpy.Tests" Key="00240000048000009400000006020000002400005253413100040000010001004dcf3979c4e902efa4dd2163a039701ed5822e6f1134d77737296abbb97bf0803083cfb2117b4f5446a217782f5c7c634f9fe1fc60b4c11d62c5b3d33545036706296d31903ddcf750875db38a8ac379512f51620bb948c94d0831125fbc5fe63707cbb93f48c1459c4d1749eb7ac5e681a2f0d6d7c60fa527a3c0b8f92b02bf" />
   </ItemGroup>
 

ICSharpCode.ILSpyX/LoadedPackage.cs

@@ -51,14 +51,14 @@ namespace ICSharpCode.ILSpyX
 
 		public PackageKind Kind { get; }
 
-		internal SingleFileBundle.Header BundleHeader { get; set; }
+		public SingleFileBundle.Header BundleHeader { get; set; }
 
 		/// <summary>
 		/// List of all entries, including those in sub-directories within the package.
 		/// </summary>
 		public IReadOnlyList<PackageEntry> Entries { get; }
 
-		internal PackageFolder RootFolder { get; }
+		public PackageFolder RootFolder { get; }
 
 		public LoadedPackage(PackageKind kind, IEnumerable<PackageEntry> entries)
 		{
@@ -256,7 +256,7 @@ namespace ICSharpCode.ILSpyX
 		public abstract string FullName { get; }
 	}
 
-	sealed class PackageFolder : IAssemblyResolver
+	public sealed class PackageFolder : IAssemblyResolver
 	{
 		/// <summary>
 		/// Gets the short name of the folder.
@@ -326,7 +326,7 @@ namespace ICSharpCode.ILSpyX
 
 		readonly Dictionary<string, LoadedAssembly?> assemblies = new Dictionary<string, LoadedAssembly?>(StringComparer.OrdinalIgnoreCase);
 
-		internal LoadedAssembly? ResolveFileName(string name)
+		public LoadedAssembly? ResolveFileName(string name)
 		{
 			if (package.LoadedAssembly == null)
 				return null;

ICSharpCode.ILSpyX/PdbProvider/PortableDebugInfoProvider.cs

@@ -32,7 +32,7 @@ using static ICSharpCode.Decompiler.Metadata.MetadataFile;
 
 namespace ICSharpCode.ILSpyX.PdbProvider
 {
-	class PortableDebugInfoProvider : IDebugInfoProvider
+	public class PortableDebugInfoProvider : IDebugInfoProvider
 	{
 		string? pdbFileName;
 		string moduleFileName;
@@ -40,7 +40,7 @@ namespace ICSharpCode.ILSpyX.PdbProvider
 		MetadataReaderOptions options;
 		bool hasError;
 
-		internal bool IsEmbedded => pdbFileName == null;
+		public bool IsEmbedded => pdbFileName == null;
 
 		public PortableDebugInfoProvider(string moduleFileName, MetadataReaderProvider provider,
 			MetadataReaderOptions options = MetadataReaderOptions.Default,
@@ -69,7 +69,7 @@ namespace ICSharpCode.ILSpyX.PdbProvider
 			}
 		}
 
-		internal MetadataReader? GetMetadataReader()
+		public MetadataReader? GetMetadataReader()
 		{
 			try
 			{

ICSharpCode.ILSpyX/Settings/ILSpySettings.cs

@@ -34,16 +34,11 @@ namespace ICSharpCode.ILSpyX.Settings
 		/// </summary>
 		public static ISettingsFilePathProvider? SettingsFilePathProvider { get; set; }
 
-		readonly XElement root;
+		XElement root;
 
-		ILSpySettings()
+		ILSpySettings(XElement? root = null)
 		{
-			this.root = new XElement("ILSpy");
+			this.root = root ?? new XElement("ILSpy");
-		}
-
-		ILSpySettings(XElement root)
-		{
-			this.root = root;
 		}
 
 		public XElement this[XName section] {
@@ -64,13 +59,7 @@ namespace ICSharpCode.ILSpyX.Settings
 			{
 				try
 				{
-					XDocument doc = LoadWithoutCheckingCharacters(GetConfigFile());
+					return new ILSpySettings(LoadFile(GetConfigFile()).Root);
-					if (null == doc.Root)
-					{
-						return new ILSpySettings();
-					}
-
-					return new ILSpySettings(doc.Root);
 				}
 				catch (IOException)
 				{
@@ -83,7 +72,7 @@ namespace ICSharpCode.ILSpyX.Settings
 			}
 		}
 
-		static XDocument LoadWithoutCheckingCharacters(string fileName)
+		static XDocument LoadFile(string fileName)
 		{
 			return XDocument.Load(fileName, LoadOptions.None);
 		}
@@ -91,15 +80,14 @@ namespace ICSharpCode.ILSpyX.Settings
 		/// <summary>
 		/// Saves a setting section.
 		/// </summary>
-		public static void SaveSettings(XElement section)
+		public void SaveSettings(XElement section)
 		{
-			Update(
+			Update(rootElement => {
-				delegate (XElement root) {
+				XElement? existingElement = rootElement.Element(section.Name);
-					XElement? existingElement = root.Element(section.Name);
 				if (existingElement != null)
 					existingElement.ReplaceWith(section);
 				else
-						root.Add(section);
+					rootElement.Add(section);
 			});
 		}
 
@@ -108,7 +96,7 @@ namespace ICSharpCode.ILSpyX.Settings
 		/// We always reload the file on updates to ensure we aren't overwriting unrelated changes performed
 		/// by another ILSpy instance.
 		/// </summary>
-		public static void Update(Action<XElement> action)
+		public void Update(Action<XElement> action)
 		{
 			using (new MutexProtector(ConfigFileMutex))
 			{
@@ -116,7 +104,7 @@ namespace ICSharpCode.ILSpyX.Settings
 				XDocument doc;
 				try
 				{
-					doc = LoadWithoutCheckingCharacters(config);
+					doc = LoadFile(config);
 				}
 				catch (IOException)
 				{
@@ -131,14 +119,10 @@ namespace ICSharpCode.ILSpyX.Settings
 				doc.Root!.SetAttributeValue("version", DecompilerVersionInfo.Major + "." + DecompilerVersionInfo.Minor + "." + DecompilerVersionInfo.Build + "." + DecompilerVersionInfo.Revision);
 				action(doc.Root);
 				doc.Save(config, SaveOptions.None);
+				this.root = doc.Root;
 			}
 		}
 
-		void ISettingsProvider.Update(Action<XElement> action)
-		{
-			Update(action);
-		}
-
 		static string GetConfigFile()
 		{
 			if (null != SettingsFilePathProvider)
@@ -148,11 +132,6 @@ namespace ICSharpCode.ILSpyX.Settings
 			// return "ILSpy.xml";
 		}
 
-		ISettingsProvider ISettingsProvider.Load()
-		{
-			return Load();
-		}
-
 		const string ConfigFileMutex = "01A91708-49D1-410D-B8EB-4DE2662B3971";
 
 		/// <summary>
@@ -164,10 +143,10 @@ namespace ICSharpCode.ILSpyX.Settings
 
 			public MutexProtector(string name)
 			{
-				bool createdNew;
+				this.mutex = new Mutex(true, name, out bool createdNew);
-				this.mutex = new Mutex(true, name, out createdNew);
+				if (createdNew)
-				if (!createdNew)
+					return;
-				{
+
 				try
 				{
 					mutex.WaitOne();
@@ -176,7 +155,6 @@ namespace ICSharpCode.ILSpyX.Settings
 				{
 				}
 			}
-			}
 
 			public void Dispose()
 			{

ICSharpCode.ILSpyX/Settings/IMiscSettings.cs

@@ -1,42 +0,0 @@
-// Copyright (c) 2022 AlphaSierraPapa for the SharpDevelop Team
-// 
-// Permission is hereby granted, free of charge, to any person obtaining a copy of this
-// software and associated documentation files (the "Software"), to deal in the Software
-// without restriction, including without limitation the rights to use, copy, modify, merge,
-// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
-// to whom the Software is furnished to do so, subject to the following conditions:
-// 
-// The above copyright notice and this permission notice shall be included in all copies or
-// substantial portions of the Software.
-// 
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
-// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
-// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
-// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
-// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
-// DEALINGS IN THE SOFTWARE.
-
-using System;
-using System.Xml.Linq;
-
-namespace ICSharpCode.ILSpyX.Settings
-{
-	public interface IMiscSettings
-	{
-		public bool AllowMultipleInstances { get; set; }
-		public bool LoadPreviousAssemblies { get; set; }
-
-		public static void Save(XElement root, IMiscSettings miscSettings)
-		{
-			var section = new XElement("MiscSettings");
-			section.SetAttributeValue(nameof(miscSettings.AllowMultipleInstances), miscSettings.AllowMultipleInstances);
-			section.SetAttributeValue(nameof(miscSettings.LoadPreviousAssemblies), miscSettings.LoadPreviousAssemblies);
-
-			XElement? existingElement = root.Element("MiscSettings");
-			if (existingElement != null)
-				existingElement.ReplaceWith(section);
-			else
-				root.Add(section);
-		}
-	}
-}

ICSharpCode.ILSpyX/Settings/ISettingsFilePathProvider.cs

@@ -16,8 +16,6 @@
 // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 // DEALINGS IN THE SOFTWARE.
 
-using System;
-
 namespace ICSharpCode.ILSpyX.Settings
 {
 	public interface ISettingsFilePathProvider

ICSharpCode.ILSpyX/Settings/ISettingsProvider.cs

@@ -17,13 +17,8 @@
 // DEALINGS IN THE SOFTWARE.
 
 using System;
-using System.ComponentModel;
-using System.Linq;
-using System.Reflection;
 using System.Xml.Linq;
 
-using static System.Collections.Specialized.BitVector32;
-
 namespace ICSharpCode.ILSpyX.Settings
 {
 	public interface ISettingsProvider
@@ -31,39 +26,7 @@ namespace ICSharpCode.ILSpyX.Settings
 		XElement this[XName section] { get; }
 
 		void Update(Action<XElement> action);
-		ISettingsProvider Load();
-
-		public static ICSharpCode.Decompiler.DecompilerSettings LoadDecompilerSettings(ISettingsProvider settingsProvider)
-		{
-			XElement e = settingsProvider["DecompilerSettings"];
-			var newSettings = new Decompiler.DecompilerSettings();
-			var properties = typeof(Decompiler.DecompilerSettings).GetProperties()
-				.Where(p => p.GetCustomAttribute<BrowsableAttribute>()?.Browsable != false);
-			foreach (var p in properties)
-			{
-				var value = (bool?)e.Attribute(p.Name);
-				if (value.HasValue)
-					p.SetValue(newSettings, value.Value);
-			}
-			return newSettings;
-		}
 
-		public static void SaveDecompilerSettings(XElement root, ICSharpCode.Decompiler.DecompilerSettings newSettings)
+		void SaveSettings(XElement section);
-		{
-			var properties = typeof(Decompiler.DecompilerSettings).GetProperties()
-				.Where(p => p.GetCustomAttribute<BrowsableAttribute>()?.Browsable != false);
-
-			XElement section = new XElement("DecompilerSettings");
-			foreach (var p in properties)
-			{
-				section.SetAttributeValue(p.Name, p.GetValue(newSettings));
-			}
-
-			XElement? existingElement = root.Element("DecompilerSettings");
-			if (existingElement != null)
-				existingElement.ReplaceWith(section);
-			else
-				root.Add(section);
-		}
 	}
 }

ICSharpCode.ILSpyX/Settings/ISettingsSection.cs

@@ -1,32 +0,0 @@
-// Copyright (c) 2022 AlphaSierraPapa for the SharpDevelop Team
-// 
-// Permission is hereby granted, free of charge, to any person obtaining a copy of this
-// software and associated documentation files (the "Software"), to deal in the Software
-// without restriction, including without limitation the rights to use, copy, modify, merge,
-// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
-// to whom the Software is furnished to do so, subject to the following conditions:
-// 
-// The above copyright notice and this permission notice shall be included in all copies or
-// substantial portions of the Software.
-// 
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
-// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
-// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
-// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
-// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
-// DEALINGS IN THE SOFTWARE.
-
-using System;
-
-namespace ICSharpCode.ILSpyX.Settings
-{
-	public interface ISettingsSection<TSelf>
-	{
-		// This should be abstract, but that needs C# 11.0 (see IParseable<TSelf>)
-		// Keep it to be enabled in the future
-		public static TSelf Load(ISettingsProvider settingsProvider)
-		{
-			throw new NotImplementedException();
-		}
-	}
-}

ICSharpCode.ILSpyX/TreeView/SharpTreeNode.cs

@@ -182,7 +182,7 @@ namespace ICSharpCode.ILSpyX.TreeView
 		#endregion
 
 		#region OnChildrenChanged
-		protected internal virtual void OnChildrenChanged(NotifyCollectionChangedEventArgs e)
+		public virtual void OnChildrenChanged(NotifyCollectionChangedEventArgs e)
 		{
 			if (e.OldItems != null)
 			{
@@ -359,7 +359,7 @@ namespace ICSharpCode.ILSpyX.TreeView
 			return TreeTraversal.PreOrder(this.Children.Where(c => c.isVisible), n => n.Children.Where(c => c.isVisible));
 		}
 
-		internal IEnumerable<SharpTreeNode> VisibleDescendantsAndSelf()
+		public IEnumerable<SharpTreeNode> VisibleDescendantsAndSelf()
 		{
 			return TreeTraversal.PreOrder(this, n => n.Children.Where(c => c.isVisible));
 		}
@@ -637,7 +637,7 @@ namespace ICSharpCode.ILSpyX.TreeView
 			return false;
 		}
 
-		internal void InternalDrop(IPlatformDragEventArgs e, int index)
+		public void InternalDrop(IPlatformDragEventArgs e, int index)
 		{
 			if (LazyLoading)
 			{

ICSharpCode.ILSpyX/TreeView/TreeFlattener.cs

@@ -26,7 +26,7 @@ using System.Diagnostics;
 
 namespace ICSharpCode.ILSpyX.TreeView
 {
-	sealed class TreeFlattener : IList, INotifyCollectionChanged
+	public sealed class TreeFlattener : IList, INotifyCollectionChanged
 	{
 		/// <summary>
 		/// The root node of the flat list tree.

ILSpy.ReadyToRun/ReadyToRunDisassembler.cs

@@ -26,6 +26,7 @@ using Iced.Intel;
 using ICSharpCode.Decompiler;
 using ICSharpCode.Decompiler.IL;
 using ICSharpCode.Decompiler.Metadata;
+using ICSharpCode.ILSpy.Util;
 
 using ILCompiler.Reflection.ReadyToRun;
 using ILCompiler.Reflection.ReadyToRun.Amd64;
@@ -50,11 +51,13 @@ namespace ICSharpCode.ILSpy.ReadyToRun
 			ReadyToRunMethod readyToRunMethod = runtimeFunction.Method;
 			WriteCommentLine(readyToRunMethod.SignatureString);
 
-			if (ReadyToRunOptions.GetIsShowGCInfo(null))
+			var options = SettingsService.Instance.GetSettings<ReadyToRunOptions>();
+
+			if (options.IsShowGCInfo)
 			{
 				if (readyToRunMethod.GcInfo != null)
 				{
-					string[] lines = readyToRunMethod.GcInfo.ToString().Split(Environment.NewLine);
+					string[] lines = readyToRunMethod.GcInfo.ToString()?.Split(Environment.NewLine) ?? [];
 					WriteCommentLine("GC info:");
 					foreach (string line in lines)
 					{
@@ -68,12 +71,12 @@ namespace ICSharpCode.ILSpy.ReadyToRun
 			}
 
 			Dictionary<ulong, UnwindCode> unwindInfo = null;
-			if (ReadyToRunOptions.GetIsShowUnwindInfo(null) && bitness == 64)
+			if (options.IsShowUnwindInfo && bitness == 64)
 			{
 				unwindInfo = WriteUnwindInfo();
 			}
 
-			bool isShowDebugInfo = ReadyToRunOptions.GetIsShowDebugInfo(null);
+			bool isShowDebugInfo = options.IsShowDebugInfo;
 			DebugInfoHelper debugInfo = null;
 			if (isShowDebugInfo)
 			{
@@ -97,7 +100,7 @@ namespace ICSharpCode.ILSpy.ReadyToRun
 				decoder.Decode(out instructions.AllocUninitializedElement());
 			}
 
-			string disassemblyFormat = ReadyToRunOptions.GetDisassemblyFormat(null);
+			string disassemblyFormat = options.DisassemblyFormat;
 			Formatter formatter = null;
 			if (disassemblyFormat.Equals(ReadyToRunOptions.intel))
 			{
@@ -144,7 +147,7 @@ namespace ICSharpCode.ILSpy.ReadyToRun
 						}
 					}
 				}
-				if (ReadyToRunOptions.GetIsShowGCInfo(null))
+				if (options.IsShowGCInfo)
 				{
 					DecorateGCInfo(instr, baseInstrIP, readyToRunMethod.GcInfo);
 				}

ILSpy.ReadyToRun/ReadyToRunOptionPage.xaml

@@ -1,7 +1,11 @@
 <UserControl x:Class="ICSharpCode.ILSpy.ReadyToRun.ReadyToRunOptionPage"
 	xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
 	xmlns:properties="clr-namespace:ILSpy.ReadyToRun.Properties"
-	xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+	xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+	xmlns:d="http://schemas.microsoft.com/expression/blend/2008" d:DesignHeight="500" d:DesignWidth="500" mc:Ignorable="d"
+	xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+	xmlns:readyToRun="clr-namespace:ICSharpCode.ILSpy.ReadyToRun"
+	d:DataContext="{d:DesignInstance readyToRun:ReadyToRunOptionsViewModel}">
 	<Grid>
 		<Grid.ColumnDefinitions>
 			<ColumnDefinition />
@@ -14,12 +18,12 @@
 			<RowDefinition Height="Auto" />
 		</Grid.RowDefinitions>
 		<TextBlock Margin="3" Text="{x:Static properties:Resources.DisassemblyFormat}" />
-		<ComboBox Grid.Column="1" Margin="3" ItemsSource="{Binding DisassemblyFormats}" SelectedItem="{Binding DisassemblyFormat}" />
+		<ComboBox Grid.Row="0" Grid.Column="1" Margin="3" ItemsSource="{Binding Options.DisassemblyFormats}" SelectedItem="{Binding Options.DisassemblyFormat}" />
-		<TextBlock Grid.Row="1" Margin="3" Text="{x:Static properties:Resources.ShowStackUnwindInfo}"/>
+		<TextBlock Grid.Row="1" Grid.Column="0"  Margin="3" Text="{x:Static properties:Resources.ShowStackUnwindInfo}"/>
-		<CheckBox Grid.Row="1" Grid.Column="1" Margin="3" IsChecked="{Binding IsShowUnwindInfo}" />
+		<CheckBox Grid.Row="1" Grid.Column="1" Margin="3" IsChecked="{Binding Options.IsShowUnwindInfo}" />
 		<TextBlock Grid.Row="2" Margin="3" Text="{x:Static properties:Resources.ShowDebugInfo}"/>
-		<CheckBox Grid.Row="2" Grid.Column="1" Margin="3" IsChecked="{Binding IsShowDebugInfo}" />
+		<CheckBox Grid.Row="2" Grid.Column="1" Margin="3" IsChecked="{Binding Options.IsShowDebugInfo}" />
 		<TextBlock Grid.Row="3" Margin="3" Text="{x:Static properties:Resources.ShowGCInfo}"/>
-		<CheckBox Grid.Row="3" Grid.Column="1" Margin="3" IsChecked="{Binding IsShowGCInfo}" />
+		<CheckBox Grid.Row="3" Grid.Column="1" Margin="3" IsChecked="{Binding Options.IsShowGCInfo}" />
 	</Grid>
 </UserControl>

ILSpy.ReadyToRun/ReadyToRunOptionPage.xaml.cs

@@ -16,112 +16,47 @@
 // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 // DEALINGS IN THE SOFTWARE.
 
-using System.ComponentModel;
 using System.ComponentModel.Composition;
-using System.Windows.Controls;
-using System.Xml.Linq;
 
 using ICSharpCode.ILSpy.Options;
-using ICSharpCode.ILSpyX.Settings;
+using ICSharpCode.ILSpy.Util;
+
+using TomsToolbox.Wpf;
+using TomsToolbox.Wpf.Composition.Mef;
 
 namespace ICSharpCode.ILSpy.ReadyToRun
 {
-	[ExportOptionPage(Title = nameof(global::ILSpy.ReadyToRun.Properties.Resources.ReadyToRun), Order = 40)]
+	[DataTemplate(typeof(ReadyToRunOptionsViewModel))]
 	[PartCreationPolicy(CreationPolicy.NonShared)]
-	partial class ReadyToRunOptionPage : UserControl, IOptionPage
+	partial class ReadyToRunOptionPage
 	{
 		public ReadyToRunOptionPage()
 		{
 			InitializeComponent();
 		}
-
-		public void Load(ILSpySettings settings)
-		{
-			Options s = new Options();
-			s.DisassemblyFormat = ReadyToRunOptions.GetDisassemblyFormat(settings);
-			s.IsShowUnwindInfo = ReadyToRunOptions.GetIsShowUnwindInfo(settings);
-			s.IsShowDebugInfo = ReadyToRunOptions.GetIsShowDebugInfo(settings);
-			s.IsShowGCInfo = ReadyToRunOptions.GetIsShowGCInfo(settings);
-
-			this.DataContext = s;
 	}
 
-		public void LoadDefaults()
+	[ExportOptionPage(Order = 40)]
-		{
+	[PartCreationPolicy(CreationPolicy.NonShared)]
-			this.DataContext = new Options();
+	class ReadyToRunOptionsViewModel : ObservableObject, IOptionPage
-		}
-
-		public void Save(XElement root)
-		{
-			Options s = (Options)this.DataContext;
-			ReadyToRunOptions.SetDisassemblyOptions(root, s.DisassemblyFormat, s.IsShowUnwindInfo, s.IsShowDebugInfo, s.IsShowGCInfo);
-		}
-	}
-
-	internal class Options : INotifyPropertyChanged
 	{
-		public string[] DisassemblyFormats {
+		private ReadyToRunOptions options;
-			get {
-				return ReadyToRunOptions.disassemblyFormats;
-			}
-		}
 
-		private bool isShowUnwindInfo;
+		public ReadyToRunOptions Options {
-		public bool IsShowUnwindInfo {
+			get => options;
-			get {
+			set => SetProperty(ref options, value);
-				return isShowUnwindInfo;
-			}
-			set {
-				isShowUnwindInfo = value;
-				OnPropertyChanged(nameof(IsShowUnwindInfo));
-			}
 		}
 
-		private bool isShowDebugInfo;
+		public string Title => global::ILSpy.ReadyToRun.Properties.Resources.ReadyToRun;
 
-		public bool IsShowDebugInfo {
+		public void Load(SettingsSnapshot snapshot)
-			get {
-				return isShowDebugInfo;
-			}
-			set {
-				isShowDebugInfo = value;
-				OnPropertyChanged(nameof(IsShowDebugInfo));
-			}
-		}
-
-		private bool isShowGCInfo;
-
-		public bool IsShowGCInfo {
-			get {
-				return isShowGCInfo;
-			}
-			set {
-				isShowGCInfo = value;
-				OnPropertyChanged(nameof(IsShowGCInfo));
-			}
-		}
-
-		private string disassemblyFormat;
-
-		public string DisassemblyFormat {
-			get { return disassemblyFormat; }
-			set {
-				if (disassemblyFormat != value)
 		{
-					disassemblyFormat = value;
+			Options = snapshot.GetSettings<ReadyToRunOptions>();
-					OnPropertyChanged(nameof(DisassemblyFormat));
-				}
-			}
 		}
 
-		public event PropertyChangedEventHandler PropertyChanged;
+		public void LoadDefaults()
-
-		protected virtual void OnPropertyChanged(string propertyName)
-		{
-			if (PropertyChanged != null)
 		{
-				PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
+			Options.LoadFromXml(new("empty"));
-			}
 		}
 	}
 }

ILSpy.ReadyToRun/ReadyToRunOptions.cs

@@ -18,110 +18,77 @@
 
 using System.Xml.Linq;
 
-using ICSharpCode.ILSpyX;
+using ICSharpCode.ILSpy.Util;
-using ICSharpCode.ILSpyX.Settings;
+
+using TomsToolbox.Wpf;
 
 namespace ICSharpCode.ILSpy.ReadyToRun
 {
-	internal class ReadyToRunOptions
+	internal partial class ReadyToRunOptions : ObservableObject, ISettingsSection
 	{
 		private static readonly XNamespace ns = "http://www.ilspy.net/ready-to-run";
 
 		internal static string intel = "Intel";
 		internal static string gas = "AT & T";
-		internal static string[] disassemblyFormats = new string[] { intel, gas };
+		internal static string[] disassemblyFormats = [intel, gas];
 
-		public static string GetDisassemblyFormat(ILSpySettings settings)
+		public string[] DisassemblyFormats {
-		{
+			get {
-			if (settings == null)
+				return disassemblyFormats;
-			{
-				settings = ILSpySettings.Load();
-			}
-			XElement e = settings[ns + "ReadyToRunOptions"];
-			XAttribute a = e.Attribute("DisassemblyFormat");
-			if (a == null)
-			{
-				return ReadyToRunOptions.intel;
-			}
-			else
-			{
-				return (string)a;
 			}
 		}
 
-		public static bool GetIsShowUnwindInfo(ILSpySettings settings)
+		private bool isShowUnwindInfo;
-		{
+		public bool IsShowUnwindInfo {
-			if (settings == null)
+			get => isShowUnwindInfo;
-			{
+			set => SetProperty(ref isShowUnwindInfo, value);
-				settings = ILSpySettings.Load();
 		}
-			XElement e = settings[ns + "ReadyToRunOptions"];
-			XAttribute a = e.Attribute("IsShowUnwindInfo");
 
-			if (a == null)
+		private bool isShowDebugInfo;
-			{
+		public bool IsShowDebugInfo {
-				return false;
+			get => isShowDebugInfo;
-			}
+			set => SetProperty(ref isShowDebugInfo, value);
-			else
-			{
-				return (bool)a;
-			}
 		}
 
-		public static bool GetIsShowDebugInfo(ILSpySettings settings)
+		private bool isShowGCInfo;
-		{
+		public bool IsShowGCInfo {
-			if (settings == null)
+			get => isShowGCInfo;
-			{
+			set => SetProperty(ref isShowGCInfo, value);
-				settings = ILSpySettings.Load();
 		}
-			XElement e = settings[ns + "ReadyToRunOptions"];
-			XAttribute a = e.Attribute("IsShowDebugInfo");
 
-			if (a == null)
+		private string disassemblyFormat;
-			{
+		public string DisassemblyFormat {
-				return true;
+			get => disassemblyFormat;
-			}
+			set => SetProperty(ref disassemblyFormat, value);
-			else
-			{
-				return (bool)a;
-			}
 		}
 
-		public static bool GetIsShowGCInfo(ILSpySettings settings)
+		public XName SectionName { get; } = ns + "ReadyToRunOptions";
-		{
-			if (settings == null)
-			{
-				settings = ILSpySettings.Load();
-			}
-			XElement e = settings[ns + "ReadyToRunOptions"];
-			XAttribute a = e.Attribute("IsShowGCInfo");
 
-			if (a == null)
+		public void LoadFromXml(XElement e)
 		{
-				return false;
+			XAttribute format = e.Attribute("DisassemblyFormat");
-			}
+			DisassemblyFormat = format == null ? intel : (string)format;
-			else
+
-			{
+			XAttribute unwind = e.Attribute("IsShowUnwindInfo");
-				return (bool)a;
+			IsShowUnwindInfo = unwind != null && (bool)unwind;
-			}
+
+			XAttribute debug = e.Attribute("IsShowDebugInfo");
+			IsShowDebugInfo = debug == null || (bool)debug;
+
+			XAttribute showGc = e.Attribute("IsShowGCInfo");
+			IsShowGCInfo = showGc != null && (bool)showGc;
 		}
 
-		public static void SetDisassemblyOptions(XElement root, string disassemblyFormat, bool isShowUnwindInfo, bool isShowDebugInfo, bool isShowGCInfo)
+		public XElement SaveToXml()
 		{
-			XElement section = new XElement(ns + "ReadyToRunOptions");
+			var section = new XElement(SectionName);
+
 			section.SetAttributeValue("DisassemblyFormat", disassemblyFormat);
 			section.SetAttributeValue("IsShowUnwindInfo", isShowUnwindInfo);
 			section.SetAttributeValue("IsShowDebugInfo", isShowDebugInfo);
 			section.SetAttributeValue("IsShowGCInfo", isShowGCInfo);
-			XElement existingElement = root.Element(ns + "ReadyToRunOptions");
+
-			if (existingElement != null)
+			return section;
-			{
-				existingElement.ReplaceWith(section);
-			}
-			else
-			{
-				root.Add(section);
-			}
 		}
 	}
 }

ILSpy/AboutPage.cs

@@ -42,7 +42,7 @@ namespace ICSharpCode.ILSpy
 	{
 		public override void Execute(object parameter)
 		{
-			MainWindow.Instance.NavigateTo(
+			MainWindow.Instance.AssemblyTreeModel.NavigateTo(
 				new RequestNavigateEventArgs(new Uri("resource://aboutpage"), null),
 				inNewTabPage: true
 			);
@@ -76,7 +76,7 @@ namespace ICSharpCode.ILSpy
 				CheckBox checkBox = new CheckBox();
 				checkBox.Margin = new Thickness(4);
 				checkBox.Content = Resources.AutomaticallyCheckUpdatesEveryWeek;
-				UpdateSettings settings = new UpdateSettings(ILSpySettings.Load());
+				UpdateSettings settings = new UpdateSettings(SettingsService.Instance.SpySettings);
 				checkBox.SetBinding(CheckBox.IsCheckedProperty, new Binding("AutomaticUpdateCheckEnabled") { Source = settings });
 				return new StackPanel {
 					Margin = new Thickness(0, 4, 0, 0),

ILSpy/Analyzers/AnalyzeCommand.cs

@@ -78,12 +78,12 @@ namespace ICSharpCode.ILSpy.Analyzers
 
 		public override bool CanExecute(object parameter)
 		{
-			return MainWindow.Instance.SelectedNodes.All(n => n is IMemberTreeNode);
+			return MainWindow.Instance.AssemblyTreeModel.SelectedNodes.All(n => n is IMemberTreeNode);
 		}
 
 		public override void Execute(object parameter)
 		{
-			foreach (var node in MainWindow.Instance.SelectedNodes.OfType<IMemberTreeNode>())
+			foreach (var node in MainWindow.Instance.AssemblyTreeModel.SelectedNodes.OfType<IMemberTreeNode>())
 			{
 				AnalyzerTreeView.Analyze(node.Member);
 			}

ILSpy/Analyzers/AnalyzerEntityTreeNode.cs

@@ -42,7 +42,8 @@ namespace ICSharpCode.ILSpy.Analyzers
 				MessageBox.Show(Properties.Resources.CannotAnalyzeMissingRef, "ILSpy");
 				return;
 			}
-			MainWindow.Instance.JumpToReference(new EntityReference(this.Member.ParentModule.MetadataFile, this.Member.MetadataToken));
+
+			MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(this.Member.ParentModule?.MetadataFile, this.Member.MetadataToken)));
 		}
 
 		public override bool HandleAssemblyListChanged(ICollection<LoadedAssembly> removedAssemblies, ICollection<LoadedAssembly> addedAssemblies)

ILSpy/Analyzers/AnalyzerRootNode.cs

@@ -2,7 +2,6 @@
 using System.Collections.Specialized;
 using System.Linq;
 
-using ICSharpCode.ILSpy.Util;
 using ICSharpCode.ILSpyX;
 using ICSharpCode.ILSpyX.TreeView;
 

ILSpy/Analyzers/AnalyzerSearchTreeNode.cs

@@ -61,7 +61,7 @@ namespace ICSharpCode.ILSpy.Analyzers
 				var context = new AnalyzerContext() {
 					CancellationToken = ct,
 					Language = Language,
-					AssemblyList = MainWindow.Instance.CurrentAssemblyList
+					AssemblyList = MainWindow.Instance.AssemblyTreeModel.AssemblyList
 				};
 				var results = analyzer.Analyze(symbol, context).Select(SymbolTreeNodeFactory);
 				if (context.SortResults)

ILSpy/Analyzers/AnalyzerTreeNode.cs

@@ -18,7 +18,6 @@
 
 using System.Collections.Generic;
 
-using ICSharpCode.ILSpy.Util;
 using ICSharpCode.ILSpyX;
 using ICSharpCode.ILSpyX.TreeView;
 

ILSpy/Analyzers/TreeNodes/AnalyzedModuleTreeNode.cs

@@ -61,7 +61,7 @@ namespace ICSharpCode.ILSpy.Analyzers.TreeNodes
 				MessageBox.Show(Properties.Resources.CannotAnalyzeMissingRef, "ILSpy");
 				return;
 			}
-			MainWindow.Instance.JumpToReference(analyzedModule.MetadataFile);
+			MessageBus.Send(this, new NavigateToReferenceEventArgs(analyzedModule.MetadataFile));
 		}
 
 		public override IEntity Member => null;

ILSpy/App.xaml

@@ -3,13 +3,12 @@
 			 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
 			 xmlns:styles="urn:TomsToolbox.Wpf.Styles"
 			 xmlns:toms="urn:TomsToolbox"
-             xmlns:themes="clr-namespace:ICSharpCode.ILSpy.Themes"
+			 xmlns:themes="clr-namespace:ICSharpCode.ILSpy.Themes">
-             StartupUri="MainWindow.xaml">
 	<Application.Resources>
 		<Style x:Key="DialogWindow" TargetType="{x:Type Window}">
-			<Setter Property="ShowInTaskbar" Value="False"/>
+			<Setter Property="ShowInTaskbar" Value="False" />
-			<Setter Property="UseLayoutRounding" Value="True"/>
+			<Setter Property="UseLayoutRounding" Value="True" />
-			<Setter Property="TextOptions.TextFormattingMode" Value="Display"/>
+			<Setter Property="TextOptions.TextFormattingMode" Value="Display" />
 			<Setter Property="toms:StyleBindings.Behaviors">
 				<Setter.Value>
 					<toms:BehaviorCollection>

ILSpy/App.xaml.cs

@@ -31,9 +31,8 @@ using System.Windows.Navigation;
 using System.Windows.Threading;
 
 using ICSharpCode.ILSpy.AppEnv;
-using ICSharpCode.ILSpy.Options;
+using ICSharpCode.ILSpy.AssemblyTree;
 using ICSharpCode.ILSpyX.Analyzers;
-using ICSharpCode.ILSpyX.Settings;
 
 using Medo.Application;
 
@@ -44,7 +43,9 @@ using ICSharpCode.ILSpyX.TreeView;
 
 using TomsToolbox.Composition;
 using TomsToolbox.Wpf.Composition;
-using System.ComponentModel.Composition.Hosting;
+using ICSharpCode.ILSpy.Themes;
+using System.Globalization;
+using System.Threading;
 
 namespace ICSharpCode.ILSpy
 {
@@ -66,31 +67,31 @@ namespace ICSharpCode.ILSpy
 
 		public App()
 		{
-			ILSpySettings.SettingsFilePathProvider = new ILSpySettingsFilePathProvider();
-
 			var cmdArgs = Environment.GetCommandLineArgs().Skip(1);
-			App.CommandLineArguments = CommandLineArguments.Create(cmdArgs);
+			CommandLineArguments = CommandLineArguments.Create(cmdArgs);
 
-			bool forceSingleInstance = (App.CommandLineArguments.SingleInstance ?? true)
+			bool forceSingleInstance = (CommandLineArguments.SingleInstance ?? true)
-				&& !MiscSettingsPanel.CurrentMiscSettings.AllowMultipleInstances;
+									   && !SettingsService.Instance.MiscSettings.AllowMultipleInstances;
 			if (forceSingleInstance)
 			{
 				SingleInstance.Attach();  // will auto-exit for second instance
 				SingleInstance.NewInstanceDetected += SingleInstance_NewInstanceDetected;
 			}
 
-			SharpTreeNode.SetImagesProvider(new WpfWindowsTreeNodeImagesProvider());
-
 			InitializeComponent();
 
-			Resources.RegisterDefaultStyles();
+			if (!Debugger.IsAttached)
-
-			if (!System.Diagnostics.Debugger.IsAttached)
 			{
 				AppDomain.CurrentDomain.UnhandledException += ShowErrorBox;
 				Dispatcher.CurrentDispatcher.UnhandledException += Dispatcher_UnhandledException;
 			}
+
 			TaskScheduler.UnobservedTaskException += DotNet40_UnobservedTaskException;
+
+			SharpTreeNode.SetImagesProvider(new WpfWindowsTreeNodeImagesProvider());
+
+			Resources.RegisterDefaultStyles();
+
 			InitializeMef().GetAwaiter().GetResult();
 
 			// Register the export provider so that it can be accessed from WPF/XAML components.
@@ -98,30 +99,34 @@ namespace ICSharpCode.ILSpy
 			// Add data templates registered via MEF.
 			Resources.MergedDictionaries.Add(DataTemplateManager.CreateDynamicDataTemplates(ExportProvider));
 
+			var sessionSettings = SettingsService.Instance.SessionSettings;
+			ThemeManager.Current.Theme = sessionSettings.Theme;
+			if (!string.IsNullOrEmpty(sessionSettings.CurrentCulture))
+			{
+				Thread.CurrentThread.CurrentUICulture = CultureInfo.DefaultThreadCurrentUICulture = new CultureInfo(sessionSettings.CurrentCulture);
+			}
+
 			EventManager.RegisterClassHandler(typeof(Window),
 											  Hyperlink.RequestNavigateEvent,
 											  new RequestNavigateEventHandler(Window_RequestNavigate));
 			ILSpyTraceListener.Install();
 
-			if (App.CommandLineArguments.ArgumentsParser.IsShowingInformation)
+			if (CommandLineArguments.ArgumentsParser.IsShowingInformation)
 			{
-				MessageBox.Show(App.CommandLineArguments.ArgumentsParser.GetHelpText(), "ILSpy Command Line Arguments");
+				MessageBox.Show(CommandLineArguments.ArgumentsParser.GetHelpText(), "ILSpy Command Line Arguments");
 			}
 
-			if (App.CommandLineArguments.ArgumentsParser.RemainingArguments.Any())
+			if (CommandLineArguments.ArgumentsParser.RemainingArguments.Any())
 			{
-				string unknownArguments = string.Join(", ", App.CommandLineArguments.ArgumentsParser.RemainingArguments);
+				string unknownArguments = string.Join(", ", CommandLineArguments.ArgumentsParser.RemainingArguments);
 				MessageBox.Show(unknownArguments, "ILSpy Unknown Command Line Arguments Passed");
 			}
-		}
 
-		private static void SingleInstance_NewInstanceDetected(object sender, NewInstanceEventArgs e)
+			SettingsService.Instance.AssemblyListManager.CreateDefaultAssemblyLists();
-		{
-#pragma warning disable CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
-			ICSharpCode.ILSpy.MainWindow.Instance.HandleSingleInstanceCommandLineArguments(e.Args);
-#pragma warning restore CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
 		}
 
+		private static void SingleInstance_NewInstanceDetected(object sender, NewInstanceEventArgs e) => ExportProvider.GetExportedValue<AssemblyTreeModel>().HandleSingleInstanceCommandLineArguments(e.Args).HandleExceptions();
+
 		static Assembly ResolvePluginDependencies(AssemblyLoadContext context, AssemblyName assemblyName)
 		{
 			var rootPath = Path.GetDirectoryName(typeof(App).Assembly.Location);
@@ -200,6 +205,8 @@ namespace ICSharpCode.ILSpy
 
 		protected override void OnStartup(StartupEventArgs e)
 		{
+			base.OnStartup(e);
+
 			var output = new StringBuilder();
 
 			if (StartupExceptions.FormatExceptions(output))
@@ -207,7 +214,12 @@ namespace ICSharpCode.ILSpy
 				MessageBox.Show(output.ToString(), "Sorry we crashed!");
 				Environment.Exit(1);
 			}
-			base.OnStartup(e);
+
+			MainWindow = new MainWindow();
+			MainWindow.Loaded += (sender, args) => {
+				ExportProvider.GetExportedValue<AssemblyTreeModel>().Initialize();
+			};
+			MainWindow.Show();
 		}
 
 		void DotNet40_UnobservedTaskException(object sender, UnobservedTaskExceptionEventArgs e)
@@ -268,7 +280,7 @@ namespace ICSharpCode.ILSpy
 
 		void Window_RequestNavigate(object sender, RequestNavigateEventArgs e)
 		{
-			ILSpy.MainWindow.Instance.NavigateTo(e);
+			ExportProvider.GetExportedValue<AssemblyTreeModel>().NavigateTo(e);
 		}
 	}
 }

ILSpy/AssemblyTree/AssemblyListPane.xaml

@@ -0,0 +1,54 @@
+<treeView:SharpTreeView x:Class="ICSharpCode.ILSpy.AssemblyTree.AssemblyListPane"
+						xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+						xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+						xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+						xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+						xmlns:treeView="clr-namespace:ICSharpCode.ILSpy.Controls.TreeView"
+						xmlns:treeNodes="clr-namespace:ICSharpCode.ILSpy.TreeNodes"
+						xmlns:assemblyTree="clr-namespace:ICSharpCode.ILSpy.AssemblyTree"
+						xmlns:toms="urn:TomsToolbox"
+						mc:Ignorable="d" d:DesignHeight="450" d:DesignWidth="800"
+						d:DataContext="{d:DesignInstance assemblyTree:AssemblyTreeModel}"
+						AutomationProperties.Name="Assemblies and Classes"
+						ShowRoot="False"
+						AllowDropOrder="True"
+						AllowDrop="True"
+						BorderThickness="0" Visibility="Visible"
+						Root="{Binding Root}"
+						SelectedItem="{Binding SelectedItem, Mode=TwoWay}"
+						toms:MultiSelectorExtensions.SelectionBinding="{Binding SelectedItems}">
+	<treeView:SharpTreeView.ItemContainerStyle>
+		<Style TargetType="treeView:SharpTreeViewItem">
+			<Setter Property="Template">
+				<Setter.Value>
+					<ControlTemplate TargetType="{x:Type treeView:SharpTreeViewItem}"
+									 d:DataContext="{d:DesignInstance treeNodes:ILSpyTreeNode}">
+						<Border Background="Transparent">
+							<Border Background="{TemplateBinding Background}">
+								<treeView:SharpTreeNodeView x:Name="nodeView" HorizontalAlignment="Left" />
+							</Border>
+						</Border>
+						<ControlTemplate.Triggers>
+							<DataTrigger Binding="{Binding IsAutoLoaded}" Value="True">
+								<Setter Property="Foreground" Value="SteelBlue" />
+							</DataTrigger>
+							<DataTrigger Binding="{Binding IsPublicAPI}" Value="False">
+								<Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}" />
+							</DataTrigger>
+							<Trigger Property="IsSelected" Value="True">
+								<Setter TargetName="nodeView" Property="TextBackground"
+										Value="{DynamicResource {x:Static SystemColors.HighlightBrushKey}}" />
+								<Setter TargetName="nodeView" Property="Foreground"
+										Value="{DynamicResource {x:Static SystemColors.HighlightTextBrushKey}}" />
+							</Trigger>
+							<Trigger Property="IsEnabled" Value="False">
+								<Setter TargetName="nodeView" Property="Foreground"
+										Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}" />
+							</Trigger>
+						</ControlTemplate.Triggers>
+					</ControlTemplate>
+				</Setter.Value>
+			</Setter>
+		</Style>
+	</treeView:SharpTreeView.ItemContainerStyle>
+</treeView:SharpTreeView>

ILSpy/AssemblyTree/AssemblyListPane.xaml.cs

@@ -0,0 +1,44 @@
+using System.ComponentModel.Composition;
+using System.Windows;
+
+using ICSharpCode.ILSpyX.TreeView;
+
+using TomsToolbox.Wpf.Composition.Mef;
+
+namespace ICSharpCode.ILSpy.AssemblyTree
+{
+	/// <summary>
+	/// Interaction logic for AssemblyListPane.xaml
+	/// </summary>
+	[DataTemplate(typeof(AssemblyTreeModel))]
+	[PartCreationPolicy(CreationPolicy.NonShared)]
+	public partial class AssemblyListPane
+	{
+		public AssemblyListPane()
+		{
+			InitializeComponent();
+
+			ContextMenuProvider.Add(this);
+		}
+
+		protected override void OnPropertyChanged(DependencyPropertyChangedEventArgs e)
+		{
+			base.OnPropertyChanged(e);
+
+			if (e.Property == DataContextProperty)
+			{
+				if (e.NewValue is not AssemblyTreeModel model)
+					return;
+
+				model.SetActiveView(this);
+			}
+			else if (e.Property == SelectedItemProperty)
+			{
+				if (e.NewValue is not SharpTreeNode treeNode)
+					return;
+
+				FocusNode(treeNode);
+			}
+		}
+	}
+}

ILSpy/AssemblyTree/AssemblyTreeModel.cs

@@ -0,0 +1,932 @@
+// Copyright (c) 2019 AlphaSierraPapa for the SharpDevelop Team
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy of this
+// software and associated documentation files (the "Software"), to deal in the Software
+// without restriction, including without limitation the rights to use, copy, modify, merge,
+// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
+// to whom the Software is furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in all copies or
+// substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
+// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+
+using System.Collections.Generic;
+using System;
+using System.Collections.ObjectModel;
+using System.ComponentModel.Composition;
+using System.IO;
+using System.Threading.Tasks;
+using System.Windows.Input;
+using System.Windows.Threading;
+
+using ICSharpCode.Decompiler.TypeSystem;
+using ICSharpCode.ILSpy.Docking;
+using ICSharpCode.ILSpy.Properties;
+using ICSharpCode.ILSpy.TextView;
+using ICSharpCode.ILSpy.TreeNodes;
+using ICSharpCode.ILSpy.ViewModels;
+using ICSharpCode.ILSpyX;
+using ICSharpCode.ILSpyX.Settings;
+using ICSharpCode.ILSpyX.TreeView;
+using System.Collections.Specialized;
+using System.ComponentModel;
+using System.Linq;
+using ICSharpCode.Decompiler.Metadata;
+
+using System.Reflection.Metadata.Ecma335;
+using System.Windows;
+using ICSharpCode.Decompiler.Documentation;
+using ICSharpCode.Decompiler.TypeSystem.Implementation;
+using System.Reflection.Metadata;
+
+using ICSharpCode.ILSpy.AppEnv;
+using ICSharpCode.ILSpy.Search;
+using ICSharpCode.Decompiler;
+using System.Text;
+
+using TomsToolbox.Essentials;
+using TomsToolbox.Wpf;
+using System.Windows.Navigation;
+
+namespace ICSharpCode.ILSpy.AssemblyTree
+{
+	[ExportToolPane]
+	[PartCreationPolicy(CreationPolicy.Shared)]
+	[Export]
+	public class AssemblyTreeModel : ToolPaneModel
+	{
+		public const string PaneContentId = "assemblyListPane";
+
+		AssemblyListPane activeView;
+		AssemblyListTreeNode assemblyListTreeNode;
+
+		readonly NavigationHistory<NavigationState> history = new();
+
+		public AssemblyTreeModel()
+		{
+			Title = Resources.Assemblies;
+			ContentId = PaneContentId;
+			IsCloseable = false;
+			ShortcutKey = new KeyGesture(Key.F6);
+
+			MessageBus<NavigateToReferenceEventArgs>.Subscribers += JumpToReference;
+			MessageBus<SettingsChangedEventArgs>.Subscribers += (sender, e) => Settings_PropertyChanged(sender, e);
+
+			var selectionChangeThrottle = new DispatcherThrottle(DispatcherPriority.Background, TreeView_SelectionChanged);
+			SelectedItems.CollectionChanged += (_, _) => selectionChangeThrottle.Tick();
+		}
+
+		private void Settings_PropertyChanged(object sender, PropertyChangedEventArgs e)
+		{
+			if (sender is SessionSettings sessionSettings)
+			{
+				switch (e.PropertyName)
+				{
+					case nameof(SessionSettings.ActiveAssemblyList):
+						ShowAssemblyList(sessionSettings.ActiveAssemblyList);
+						break;
+					case nameof(SessionSettings.Theme):
+						// update syntax highlighting and force reload (AvalonEdit does not automatically refresh on highlighting change)
+						DecompilerTextView.RegisterHighlighting();
+						DecompileSelectedNodes(
+							DockWorkspace.Instance.ActiveTabPage.GetState() as DecompilerTextViewState);
+						break;
+					case nameof(SessionSettings.CurrentCulture):
+						MessageBox.Show(Properties.Resources.SettingsChangeRestartRequired, "ILSpy");
+						break;
+				}
+			}
+			else if (sender is LanguageSettings)
+			{
+				switch (e.PropertyName)
+				{
+					case nameof(LanguageSettings.Language) or nameof(LanguageSettings.LanguageVersion):
+						DecompileSelectedNodes(recordHistory: false);
+						break;
+				}
+			}
+		}
+
+		public AssemblyList AssemblyList { get; private set; }
+
+		private SharpTreeNode root;
+		public SharpTreeNode Root {
+			get => root;
+			set => SetProperty(ref root, value);
+		}
+
+		private SharpTreeNode selectedItem;
+		public SharpTreeNode SelectedItem {
+			get => selectedItem;
+			set => SetProperty(ref selectedItem, value);
+		}
+
+		public ObservableCollection<SharpTreeNode> SelectedItems { get; } = [];
+
+		public string[] SelectedPath => GetPathForNode(SelectedItem);
+
+		readonly List<LoadedAssembly> commandLineLoadedAssemblies = [];
+
+		public bool HandleCommandLineArguments(CommandLineArguments args)
+		{
+			LoadAssemblies(args.AssembliesToLoad, commandLineLoadedAssemblies, focusNode: false);
+			if (args.Language != null)
+				SettingsService.Instance.SessionSettings.LanguageSettings.Language = Languages.GetLanguage(args.Language);
+			return true;
+		}
+
+		/// <summary>
+		/// Called on startup or when passed arguments via WndProc from a second instance.
+		/// In the format case, spySettings is non-null; in the latter it is null.
+		/// </summary>
+		public void HandleCommandLineArgumentsAfterShowList(CommandLineArguments args, ISettingsProvider spySettings = null)
+		{
+			var sessionSettings = SettingsService.Instance.SessionSettings;
+
+			var relevantAssemblies = commandLineLoadedAssemblies.ToList();
+			commandLineLoadedAssemblies.Clear(); // clear references once we don't need them anymore
+			NavigateOnLaunch(args.NavigateTo, sessionSettings.ActiveTreeViewPath, spySettings, relevantAssemblies);
+			if (args.Search != null)
+			{
+				var searchPane = App.ExportProvider.GetExportedValue<SearchPaneModel>();
+
+				searchPane.SearchTerm = args.Search;
+				searchPane.Show();
+			}
+		}
+
+		public async Task HandleSingleInstanceCommandLineArguments(string[] args)
+		{
+			var cmdArgs = CommandLineArguments.Create(args);
+
+			await Dispatcher.InvokeAsync(() => {
+
+				if (!HandleCommandLineArguments(cmdArgs))
+					return;
+
+				var window = Application.Current.MainWindow;
+
+				if (!cmdArgs.NoActivate && window is { WindowState: WindowState.Minimized })
+				{
+					window.WindowState = WindowState.Normal;
+				}
+
+				HandleCommandLineArgumentsAfterShowList(cmdArgs);
+			});
+		}
+
+		public async void NavigateOnLaunch(string navigateTo, string[] activeTreeViewPath, ISettingsProvider spySettings, List<LoadedAssembly> relevantAssemblies)
+		{
+			var initialSelection = SelectedItem;
+			if (navigateTo != null)
+			{
+				bool found = false;
+				if (navigateTo.StartsWith("N:", StringComparison.Ordinal))
+				{
+					string namespaceName = navigateTo.Substring(2);
+					foreach (LoadedAssembly asm in relevantAssemblies)
+					{
+						AssemblyTreeNode asmNode = assemblyListTreeNode.FindAssemblyNode(asm);
+						if (asmNode != null)
+						{
+							// FindNamespaceNode() blocks the UI if the assembly is not yet loaded,
+							// so use an async wait instead.
+							await asm.GetMetadataFileAsync().Catch<Exception>(ex => { });
+							NamespaceTreeNode nsNode = asmNode.FindNamespaceNode(namespaceName);
+							if (nsNode != null)
+							{
+								found = true;
+								if (SelectedItem == initialSelection)
+								{
+									SelectNode(nsNode);
+								}
+								break;
+							}
+						}
+					}
+				}
+				else if (navigateTo == "none")
+				{
+					// Don't navigate anywhere; start empty.
+					// Used by ILSpy VS addin, it'll send us the real location to navigate to via IPC.
+					found = true;
+				}
+				else
+				{
+					IEntity mr = await Task.Run(() => FindEntityInRelevantAssemblies(navigateTo, relevantAssemblies));
+					// Make sure we wait for assemblies being loaded...
+					// BeginInvoke in LoadedAssembly.LookupReferencedAssemblyInternal
+					await Dispatcher.InvokeAsync(delegate { }, DispatcherPriority.Normal);
+					if (mr != null && mr.ParentModule?.MetadataFile != null)
+					{
+						found = true;
+						if (SelectedItem == initialSelection)
+						{
+							await JumpToReferenceAsync(mr);
+						}
+					}
+				}
+				if (!found && SelectedItem == initialSelection)
+				{
+					AvalonEditTextOutput output = new AvalonEditTextOutput();
+					output.Write($"Cannot find '{navigateTo}' in command line specified assemblies.");
+					DockWorkspace.Instance.ShowText(output);
+				}
+			}
+			else if (relevantAssemblies.Count == 1)
+			{
+				// NavigateTo == null and an assembly was given on the command-line:
+				// Select the newly loaded assembly
+				AssemblyTreeNode asmNode = assemblyListTreeNode.FindAssemblyNode(relevantAssemblies[0]);
+				if (asmNode != null && SelectedItem == initialSelection)
+				{
+					SelectNode(asmNode);
+				}
+			}
+			else if (spySettings != null)
+			{
+				SharpTreeNode node = null;
+				if (activeTreeViewPath?.Length > 0)
+				{
+					foreach (var asm in AssemblyList.GetAssemblies())
+					{
+						if (asm.FileName == activeTreeViewPath[0])
+						{
+							// FindNodeByPath() blocks the UI if the assembly is not yet loaded,
+							// so use an async wait instead.
+							await asm.GetMetadataFileAsync().Catch<Exception>(ex => { });
+						}
+					}
+					node = FindNodeByPath(activeTreeViewPath, true);
+				}
+				if (SelectedItem == initialSelection)
+				{
+					if (node != null)
+					{
+						SelectNode(node);
+
+						// only if not showing the about page, perform the update check:
+						await MainWindow.Instance.ShowMessageIfUpdatesAvailableAsync(spySettings);
+					}
+					else
+					{
+						DockWorkspace.Instance.ActiveTabPage.ShowTextView(AboutPage.Display);
+					}
+				}
+			}
+		}
+
+		public static IEntity FindEntityInRelevantAssemblies(string navigateTo, IEnumerable<LoadedAssembly> relevantAssemblies)
+		{
+			ITypeReference typeRef;
+			IMemberReference memberRef = null;
+			if (navigateTo.StartsWith("T:", StringComparison.Ordinal))
+			{
+				typeRef = IdStringProvider.ParseTypeName(navigateTo);
+			}
+			else
+			{
+				memberRef = IdStringProvider.ParseMemberIdString(navigateTo);
+				typeRef = memberRef.DeclaringTypeReference;
+			}
+			foreach (LoadedAssembly asm in relevantAssemblies.ToList())
+			{
+				var module = asm.GetMetadataFileOrNull();
+				if (CanResolveTypeInPEFile(module, typeRef, out var typeHandle))
+				{
+					ICompilation compilation = typeHandle.Kind == HandleKind.ExportedType
+						? new DecompilerTypeSystem(module, module.GetAssemblyResolver())
+						: new SimpleCompilation((PEFile)module, MinimalCorlib.Instance);
+					return memberRef == null
+						? typeRef.Resolve(new SimpleTypeResolveContext(compilation)) as ITypeDefinition
+						: memberRef.Resolve(new SimpleTypeResolveContext(compilation));
+				}
+			}
+			return null;
+		}
+
+		static bool CanResolveTypeInPEFile(MetadataFile module, ITypeReference typeRef, out EntityHandle typeHandle)
+		{
+			// We intentionally ignore reference assemblies, so that the loop continues looking for another assembly that might have a usable definition.
+			if (module.IsReferenceAssembly())
+			{
+				typeHandle = default;
+				return false;
+			}
+
+			switch (typeRef)
+			{
+				case GetPotentiallyNestedClassTypeReference topLevelType:
+					typeHandle = topLevelType.ResolveInPEFile(module);
+					return !typeHandle.IsNil;
+				case NestedTypeReference nestedType:
+					if (!CanResolveTypeInPEFile(module, nestedType.DeclaringTypeReference, out typeHandle))
+						return false;
+					if (typeHandle.Kind == HandleKind.ExportedType)
+						return true;
+					var typeDef = module.Metadata.GetTypeDefinition((TypeDefinitionHandle)typeHandle);
+					typeHandle = typeDef.GetNestedTypes().FirstOrDefault(t => {
+						var td = module.Metadata.GetTypeDefinition(t);
+						var typeName = ReflectionHelper.SplitTypeParameterCountFromReflectionName(module.Metadata.GetString(td.Name), out int typeParameterCount);
+						return nestedType.AdditionalTypeParameterCount == typeParameterCount && nestedType.Name == typeName;
+					});
+					return !typeHandle.IsNil;
+				default:
+					typeHandle = default;
+					return false;
+			}
+		}
+
+		public void Initialize()
+		{
+			this.AssemblyList = SettingsService.Instance.LoadInitialAssemblyList();
+
+			HandleCommandLineArguments(App.CommandLineArguments);
+
+			var loadPreviousAssemblies = SettingsService.Instance.MiscSettings.LoadPreviousAssemblies;
+			if (AssemblyList.GetAssemblies().Length == 0
+				&& AssemblyList.ListName == AssemblyListManager.DefaultListName
+				&& loadPreviousAssemblies)
+			{
+				LoadInitialAssemblies();
+			}
+
+			ShowAssemblyList(this.AssemblyList);
+
+			var sessionSettings = SettingsService.Instance.SessionSettings;
+			if (sessionSettings.ActiveAutoLoadedAssembly != null
+				&& File.Exists(sessionSettings.ActiveAutoLoadedAssembly))
+			{
+				this.AssemblyList.Open(sessionSettings.ActiveAutoLoadedAssembly, true);
+			}
+
+			Dispatcher.BeginInvoke(DispatcherPriority.Loaded, OpenAssemblies);
+		}
+
+		void OpenAssemblies()
+		{
+			HandleCommandLineArgumentsAfterShowList(App.CommandLineArguments, SettingsService.Instance.SpySettings);
+
+			AvalonEditTextOutput output = new();
+			if (FormatExceptions(App.StartupExceptions.ToArray(), output))
+				DockWorkspace.Instance.ShowText(output);
+		}
+
+		static bool FormatExceptions(App.ExceptionData[] exceptions, ITextOutput output)
+		{
+			var stringBuilder = new StringBuilder();
+			var result = exceptions.FormatExceptions(stringBuilder);
+			if (result)
+			{
+				output.Write(stringBuilder.ToString());
+			}
+			return result;
+		}
+
+		public void ShowAssemblyList(string name)
+		{
+			AssemblyList list = SettingsService.Instance.AssemblyListManager.LoadList(name);
+			//Only load a new list when it is a different one
+			if (list.ListName != AssemblyList.ListName)
+			{
+				ShowAssemblyList(list);
+				SelectNode(Root);
+			}
+		}
+
+		void ShowAssemblyList(AssemblyList assemblyList)
+		{
+			history.Clear();
+			if (this.AssemblyList != null)
+			{
+				this.AssemblyList.CollectionChanged -= assemblyList_CollectionChanged;
+			}
+
+			this.AssemblyList = assemblyList;
+
+			assemblyList.CollectionChanged += assemblyList_CollectionChanged;
+
+			assemblyListTreeNode = new(assemblyList) {
+				Select = x => SelectNode(x)
+			};
+
+			Root = assemblyListTreeNode;
+
+			if (assemblyList.ListName == AssemblyListManager.DefaultListName)
+#if DEBUG
+				this.Title = $"ILSpy {DecompilerVersionInfo.FullVersion}";
+#else
+				this.Title = "ILSpy";
+#endif
+			else
+#if DEBUG
+				this.Title = $"ILSpy {DecompilerVersionInfo.FullVersion} - " + assemblyList.ListName;
+#else
+				this.Title = "ILSpy - " + assemblyList.ListName;
+#endif
+		}
+
+		void assemblyList_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
+		{
+			if (e.Action == NotifyCollectionChangedAction.Reset)
+			{
+				history.RemoveAll(_ => true);
+			}
+			if (e.OldItems != null)
+			{
+				var oldAssemblies = new HashSet<LoadedAssembly>(e.OldItems.Cast<LoadedAssembly>());
+				history.RemoveAll(n => n.TreeNodes.Any(
+					nd => nd.AncestorsAndSelf().OfType<AssemblyTreeNode>().Any(
+						a => oldAssemblies.Contains(a.LoadedAssembly))));
+			}
+
+			MessageBus.Send(this, new CurrentAssemblyListChangedEventArgs(e));
+		}
+
+		void LoadInitialAssemblies()
+		{
+			// Called when loading an empty assembly list; so that
+			// the user can see something initially.
+			System.Reflection.Assembly[] initialAssemblies = {
+				typeof(object).Assembly,
+				typeof(Uri).Assembly,
+				typeof(System.Linq.Enumerable).Assembly,
+				typeof(System.Xml.XmlDocument).Assembly,
+				typeof(System.Windows.Markup.MarkupExtension).Assembly,
+				typeof(System.Windows.Rect).Assembly,
+				typeof(System.Windows.UIElement).Assembly,
+				typeof(System.Windows.FrameworkElement).Assembly
+			};
+			foreach (System.Reflection.Assembly asm in initialAssemblies)
+				AssemblyList.OpenAssembly(asm.Location);
+		}
+
+		public AssemblyTreeNode FindAssemblyNode(LoadedAssembly asm)
+		{
+			return assemblyListTreeNode.FindAssemblyNode(asm);
+		}
+
+		#region Node Selection
+
+		public void SelectNode(SharpTreeNode node, bool inNewTabPage = false)
+		{
+			if (node == null)
+				return;
+
+			if (node.AncestorsAndSelf().Any(item => item.IsHidden))
+			{
+				MessageBox.Show(Properties.Resources.NavigationFailed, "ILSpy", MessageBoxButton.OK, MessageBoxImage.Exclamation);
+				return;
+			}
+
+			if (inNewTabPage)
+			{
+				DockWorkspace.Instance.AddTabPage();
+				SelectedItem = null;
+			}
+
+			if (SelectedItem == node)
+			{
+				Dispatcher.BeginInvoke(RefreshDecompiledView);
+			}
+			else
+			{
+				activeView?.ScrollIntoView(node);
+				SelectedItem = node;
+			}
+		}
+
+		internal void SelectNodes(IEnumerable<SharpTreeNode> nodes, bool ignoreCompilationRequests = false)
+		{
+			this.ignoreDecompilationRequests = ignoreCompilationRequests;
+
+			try
+			{
+				// Ensure nodes exist
+				var nodesList = nodes.Select(n => FindNodeByPath(GetPathForNode(n), true))
+					.Where(n => n != null)
+					.ToArray();
+
+				if (!nodesList.Any() || nodesList.Any(n => n.AncestorsAndSelf().Any(a => a.IsHidden)))
+				{
+					return;
+				}
+
+				if (SelectedItems.SequenceEqual(nodesList))
+				{
+					Dispatcher.BeginInvoke(RefreshDecompiledView);
+					return;
+				}
+
+				SelectedItems.Clear();
+				SelectedItems.AddRange(nodesList);
+			}
+			finally
+			{
+				this.ignoreDecompilationRequests = false;
+			}
+
+		}
+
+		/// <summary>
+		/// Retrieves a node using the .ToString() representations of its ancestors.
+		/// </summary>
+		public SharpTreeNode FindNodeByPath(string[] path, bool returnBestMatch)
+		{
+			if (path == null)
+				return null;
+			SharpTreeNode node = Root;
+			SharpTreeNode bestMatch = node;
+			foreach (var element in path)
+			{
+				if (node == null)
+					break;
+				bestMatch = node;
+				node.EnsureLazyChildren();
+				if (node is ILSpyTreeNode ilSpyTreeNode)
+					ilSpyTreeNode.EnsureChildrenFiltered();
+				node = node.Children.FirstOrDefault(c => c.ToString() == element);
+			}
+			if (returnBestMatch)
+				return node ?? bestMatch;
+			else
+				return node;
+		}
+
+		/// <summary>
+		/// Gets the .ToString() representation of the node's ancestors.
+		/// </summary>
+		public static string[] GetPathForNode(SharpTreeNode node)
+		{
+			if (node == null)
+				return null;
+			List<string> path = new List<string>();
+			while (node.Parent != null)
+			{
+				path.Add(node.ToString());
+				node = node.Parent;
+			}
+			path.Reverse();
+			return path.ToArray();
+		}
+
+		public ILSpyTreeNode FindTreeNode(object reference)
+		{
+			switch (reference)
+			{
+				case LoadedAssembly lasm:
+					return assemblyListTreeNode.FindAssemblyNode(lasm);
+				case MetadataFile asm:
+					return assemblyListTreeNode.FindAssemblyNode(asm);
+				case Resource res:
+					return assemblyListTreeNode.FindResourceNode(res);
+				case ValueTuple<Resource, string> resName:
+					return assemblyListTreeNode.FindResourceNode(resName.Item1, resName.Item2);
+				case ITypeDefinition type:
+					return assemblyListTreeNode.FindTypeNode(type);
+				case IField fd:
+					return assemblyListTreeNode.FindFieldNode(fd);
+				case IMethod md:
+					return assemblyListTreeNode.FindMethodNode(md);
+				case IProperty pd:
+					return assemblyListTreeNode.FindPropertyNode(pd);
+				case IEvent ed:
+					return assemblyListTreeNode.FindEventNode(ed);
+				case INamespace nd:
+					return assemblyListTreeNode.FindNamespaceNode(nd);
+				default:
+					return null;
+			}
+		}
+
+		private void JumpToReference(object sender, NavigateToReferenceEventArgs e)
+		{
+			JumpToReferenceAsync(e.Reference, e.InNewTabPage).HandleExceptions();
+		}
+
+		/// <summary>
+		/// Jumps to the specified reference.
+		/// </summary>
+		/// <returns>
+		/// Returns a task that will signal completion when the decompilation of the jump target has finished.
+		/// The task will be marked as canceled if the decompilation is canceled.
+		/// </returns>
+		private Task JumpToReferenceAsync(object reference, bool inNewTabPage = false)
+		{
+			var decompilationTask = Task.CompletedTask;
+
+			switch (reference)
+			{
+				case Decompiler.Disassembler.OpCodeInfo opCode:
+					MainWindow.OpenLink(opCode.Link);
+					break;
+				case EntityReference unresolvedEntity:
+					string protocol = unresolvedEntity.Protocol;
+					var file = unresolvedEntity.ResolveAssembly(AssemblyList);
+					if (file == null)
+					{
+						break;
+					}
+					if (protocol != "decompile")
+					{
+						var protocolHandlers = App.ExportProvider.GetExportedValues<IProtocolHandler>();
+						foreach (var handler in protocolHandlers)
+						{
+							var node = handler.Resolve(protocol, file, unresolvedEntity.Handle, out bool newTabPage);
+							if (node != null)
+							{
+								SelectNode(node, newTabPage || inNewTabPage);
+								return decompilationTask;
+							}
+						}
+					}
+					var possibleToken = MetadataTokenHelpers.TryAsEntityHandle(MetadataTokens.GetToken(unresolvedEntity.Handle));
+					if (possibleToken != null)
+					{
+						var typeSystem = new DecompilerTypeSystem(file, file.GetAssemblyResolver(), TypeSystemOptions.Default | TypeSystemOptions.Uncached);
+						reference = typeSystem.MainModule.ResolveEntity(possibleToken.Value);
+						goto default;
+					}
+					break;
+				default:
+					ILSpyTreeNode treeNode = FindTreeNode(reference);
+					if (treeNode != null)
+						SelectNode(treeNode, inNewTabPage);
+					break;
+			}
+			return decompilationTask;
+		}
+
+		#endregion
+
+		public void LoadAssemblies(IEnumerable<string> fileNames, List<LoadedAssembly> loadedAssemblies = null, bool focusNode = true)
+		{
+			using (Keyboard.FocusedElement.PreserveFocus(!focusNode))
+			{
+				AssemblyTreeNode lastNode = null;
+
+				foreach (string file in fileNames)
+				{
+					var assembly = AssemblyList.OpenAssembly(file);
+
+					if (loadedAssemblies != null)
+					{
+						loadedAssemblies.Add(assembly);
+					}
+					else
+					{
+						var node = assemblyListTreeNode.FindAssemblyNode(assembly);
+						if (node != null && focusNode)
+						{
+							lastNode = node;
+							SelectedItems.Add(node);
+						}
+					}
+				}
+				if (focusNode && lastNode != null)
+				{
+					activeView?.FocusNode(lastNode);
+				}
+			}
+		}
+
+		#region Decompile (TreeView_SelectionChanged)
+
+		void TreeView_SelectionChanged()
+		{
+			var delayDecompilationRequestDueToContextMenu = Mouse.RightButton == MouseButtonState.Pressed;
+
+			if (!delayDecompilationRequestDueToContextMenu)
+			{
+				DecompileSelectedNodes();
+			}
+			else
+			{
+				ContextMenuProvider.ContextMenuClosed += ContextMenuClosed;
+			}
+
+			MessageBus.Send(this, new AssemblyTreeSelectionChangedEventArgs());
+
+			return;
+
+			void ContextMenuClosed(object sender, EventArgs e)
+			{
+				ContextMenuProvider.ContextMenuClosed -= ContextMenuClosed;
+
+				Dispatcher.BeginInvoke(DispatcherPriority.Background, () => {
+					if (Mouse.RightButton != MouseButtonState.Pressed)
+					{
+						DecompileSelectedNodes(DockWorkspace.Instance.ActiveTabPage.GetState() as DecompilerTextViewState);
+					}
+				});
+			}
+		}
+
+		private bool ignoreDecompilationRequests;
+
+		public void DecompileSelectedNodes(DecompilerTextViewState newState = null, bool recordHistory = true)
+		{
+			if (ignoreDecompilationRequests)
+				return;
+
+			var activeTabPage = DockWorkspace.Instance.ActiveTabPage;
+
+			if (recordHistory)
+			{
+				var currentState = activeTabPage.GetState();
+				if (currentState != null)
+					history.UpdateCurrent(new NavigationState(activeTabPage, currentState));
+				history.Record(new NavigationState(activeTabPage, SelectedItems));
+			}
+
+			activeTabPage.SupportsLanguageSwitching = true;
+
+			if (SelectedItems.Count == 1)
+			{
+				if (SelectedItem is ILSpyTreeNode node && node.View(activeTabPage))
+					return;
+			}
+			if (newState?.ViewedUri != null)
+			{
+				MainWindow.Instance.AssemblyTreeModel.NavigateTo(new(newState.ViewedUri, null), recordHistory: false);
+				return;
+			}
+
+			var options = SettingsService.Instance.CreateDecompilationOptions(activeTabPage);
+			options.TextViewState = newState;
+			activeTabPage.ShowTextViewAsync(textView => textView.DecompileAsync(this.CurrentLanguage, this.SelectedNodes, options));
+		}
+
+		public void RefreshDecompiledView()
+		{
+			DecompileSelectedNodes();
+		}
+
+		public Language CurrentLanguage => SettingsService.Instance.SessionSettings.LanguageSettings.Language;
+
+		public LanguageVersion CurrentLanguageVersion => SettingsService.Instance.SessionSettings.LanguageSettings.LanguageVersion;
+
+		public IEnumerable<ILSpyTreeNode> SelectedNodes {
+			get {
+				return GetTopLevelSelection().OfType<ILSpyTreeNode>();
+			}
+		}
+
+		#endregion
+
+		public void NavigateHistory(bool forward)
+		{
+			TabPageModel tabPage = DockWorkspace.Instance.ActiveTabPage;
+			var state = tabPage.GetState();
+			if (state != null)
+				history.UpdateCurrent(new NavigationState(tabPage, state));
+			var newState = forward ? history.GoForward() : history.GoBack();
+
+			DockWorkspace.Instance.ActiveTabPage = newState.TabPage;
+
+			SelectNodes(newState.TreeNodes, ignoreCompilationRequests: true);
+			DecompileSelectedNodes(newState.ViewState as DecompilerTextViewState, false);
+		}
+
+		public bool CanNavigateBack => history.CanNavigateBack;
+
+		public bool CanNavigateForward => history.CanNavigateForward;
+
+		internal void NavigateTo(RequestNavigateEventArgs e, bool recordHistory = true, bool inNewTabPage = false)
+		{
+			if (e.Uri.Scheme == "resource")
+			{
+				if (inNewTabPage)
+				{
+					DockWorkspace.Instance.AddTabPage();
+				}
+
+				if (e.Uri.Host == "aboutpage")
+				{
+					RecordHistory();
+					DockWorkspace.Instance.ActiveTabPage.ShowTextView(AboutPage.Display);
+					e.Handled = true;
+					return;
+				}
+				AvalonEditTextOutput output = new AvalonEditTextOutput {
+					Address = e.Uri,
+					Title = e.Uri.AbsolutePath,
+					EnableHyperlinks = true
+				};
+				using (Stream s = typeof(App).Assembly.GetManifestResourceStream(typeof(App), e.Uri.AbsolutePath))
+				{
+					using (StreamReader r = new StreamReader(s))
+					{
+						string line;
+						while ((line = r.ReadLine()) != null)
+						{
+							output.Write(line);
+							output.WriteLine();
+						}
+					}
+				}
+				RecordHistory();
+				DockWorkspace.Instance.ShowText(output);
+				e.Handled = true;
+			}
+
+			void RecordHistory()
+			{
+				if (!recordHistory)
+					return;
+				TabPageModel tabPage = DockWorkspace.Instance.ActiveTabPage;
+				var currentState = tabPage.GetState();
+				if (currentState != null)
+					history.UpdateCurrent(new NavigationState(tabPage, currentState));
+
+				UnselectAll(ignoreCompilationRequests: true);
+
+				history.Record(new NavigationState(tabPage, new ViewState { ViewedUri = e.Uri }));
+			}
+		}
+
+		public void Refresh()
+		{
+			using (Keyboard.FocusedElement.PreserveFocus())
+			{
+				var path = GetPathForNode(SelectedItem);
+				ShowAssemblyList(SettingsService.Instance.AssemblyListManager.LoadList(AssemblyList.ListName));
+				SelectNode(FindNodeByPath(path, true), inNewTabPage: false);
+			}
+		}
+
+		public void UnselectAll(bool ignoreCompilationRequests = false)
+		{
+			this.ignoreDecompilationRequests = ignoreCompilationRequests;
+			SelectedItems.Clear();
+			this.ignoreDecompilationRequests = false;
+		}
+
+		public IEnumerable<SharpTreeNode> GetTopLevelSelection()
+		{
+			var selection = this.SelectedItems;
+			var selectionHash = new HashSet<SharpTreeNode>(selection);
+
+			return selection.Where(item => item.Ancestors().All(a => !selectionHash.Contains(a)));
+		}
+
+		public void SetActiveView(AssemblyListPane activeView)
+		{
+			this.activeView = activeView;
+		}
+
+		public void SortAssemblyList()
+		{
+			using (activeView?.LockUpdates())
+			{
+				AssemblyList.Sort(AssemblyComparer.Instance);
+			}
+		}
+
+		private class AssemblyComparer : IComparer<LoadedAssembly>
+		{
+			public static readonly AssemblyComparer Instance = new();
+			int IComparer<LoadedAssembly>.Compare(LoadedAssembly x, LoadedAssembly y)
+			{
+				return string.Compare(x?.ShortName, y?.ShortName, StringComparison.CurrentCulture);
+			}
+		}
+
+		public void CollapseAll()
+		{
+			using (activeView.LockUpdates())
+			{
+				CollapseChildren(Root);
+			}
+		}
+
+		static void CollapseChildren(SharpTreeNode node)
+		{
+			foreach (var child in node.Children)
+			{
+				if (!child.IsExpanded)
+					continue;
+
+				CollapseChildren(child);
+				child.IsExpanded = false;
+			}
+		}
+
+		public void OpenFiles(string[] fileNames, bool focusNode = true)
+		{
+			if (fileNames == null)
+				throw new ArgumentNullException(nameof(fileNames));
+
+			if (focusNode)
+				UnselectAll();
+
+			LoadAssemblies(fileNames, focusNode: focusNode);
+		}
+	}
+}

ILSpy/Commands/BrowseBackCommand.cs

@@ -19,6 +19,7 @@
 using System.ComponentModel.Composition;
 using System.Windows.Input;
 
+using ICSharpCode.ILSpy.AssemblyTree;
 using ICSharpCode.ILSpy.Properties;
 
 namespace ICSharpCode.ILSpy
@@ -27,9 +28,30 @@ namespace ICSharpCode.ILSpy
 	[PartCreationPolicy(CreationPolicy.Shared)]
 	sealed class BrowseBackCommand : CommandWrapper
 	{
-		public BrowseBackCommand()
+		readonly AssemblyTreeModel assemblyTreeModel;
+
+		[ImportingConstructor]
+		public BrowseBackCommand(AssemblyTreeModel assemblyTreeModel)
 			: base(NavigationCommands.BrowseBack)
 		{
+			this.assemblyTreeModel = assemblyTreeModel;
+		}
+
+		protected override void OnCanExecute(object sender, CanExecuteRoutedEventArgs e)
+		{
+			base.OnCanExecute(sender, e);
+
+			e.Handled = true;
+			e.CanExecute = assemblyTreeModel.CanNavigateBack;
+		}
+
+		protected override void OnExecute(object sender, ExecutedRoutedEventArgs e)
+		{
+			if (assemblyTreeModel.CanNavigateBack)
+			{
+				e.Handled = true;
+				assemblyTreeModel.NavigateHistory(false);
+			}
 		}
 	}
 }

ILSpy/Commands/BrowseForwardCommand.cs

@@ -19,6 +19,7 @@
 using System.ComponentModel.Composition;
 using System.Windows.Input;
 
+using ICSharpCode.ILSpy.AssemblyTree;
 using ICSharpCode.ILSpy.Properties;
 
 namespace ICSharpCode.ILSpy
@@ -27,9 +28,31 @@ namespace ICSharpCode.ILSpy
 	[PartCreationPolicy(CreationPolicy.Shared)]
 	sealed class BrowseForwardCommand : CommandWrapper
 	{
-		public BrowseForwardCommand()
+		private readonly AssemblyTreeModel assemblyTreeModel;
+
+		[ImportingConstructor]
+		public BrowseForwardCommand(AssemblyTreeModel assemblyTreeModel)
 			: base(NavigationCommands.BrowseForward)
 		{
+			this.assemblyTreeModel = assemblyTreeModel;
+		}
+
+		protected override void OnCanExecute(object sender, CanExecuteRoutedEventArgs e)
+		{
+			base.OnCanExecute(sender, e);
+
+			e.Handled = true;
+			e.CanExecute = assemblyTreeModel.CanNavigateForward;
 		}
+
+		protected override void OnExecute(object sender, ExecutedRoutedEventArgs e)
+		{
+			if (assemblyTreeModel.CanNavigateForward)
+			{
+				e.Handled = true;
+				assemblyTreeModel.NavigateHistory(true);
+			}
+		}
+
 	}
 }

ILSpy/Commands/CheckForUpdatesCommand.cs

@@ -20,7 +20,6 @@
 using System.ComponentModel.Composition;
 
 using ICSharpCode.ILSpy.Properties;
-using ICSharpCode.ILSpyX.Settings;
 
 namespace ICSharpCode.ILSpy
 {
@@ -35,7 +34,7 @@ namespace ICSharpCode.ILSpy
 
 		public override async void Execute(object parameter)
 		{
-			await MainWindow.Instance.ShowMessageIfUpdatesAvailableAsync(ILSpySettings.Load(), forceCheck: true);
+			await MainWindow.Instance.ShowMessageIfUpdatesAvailableAsync(SettingsService.Instance.SpySettings, forceCheck: true);
 		}
 	}
 }

ILSpy/Commands/CommandWrapper.cs

@@ -17,25 +17,27 @@
 // DEALINGS IN THE SOFTWARE.
 
 using System;
+using System.Windows;
 using System.Windows.Input;
 
 namespace ICSharpCode.ILSpy
 {
-	class CommandWrapper : ICommand
+	abstract class CommandWrapper : ICommand
 	{
 		private readonly ICommand wrappedCommand;
 
-		public CommandWrapper(ICommand wrappedCommand)
+		protected CommandWrapper(ICommand wrappedCommand)
 		{
 			this.wrappedCommand = wrappedCommand;
+
+			Application.Current.MainWindow?.CommandBindings.Add(new CommandBinding(wrappedCommand, OnExecute, OnCanExecute));
 		}
 
 		public static ICommand Unwrap(ICommand command)
 		{
-			CommandWrapper w = command as CommandWrapper;
+			if (command is CommandWrapper w)
-			if (w != null)
 				return w.wrappedCommand;
-			else
+
 			return command;
 		}
 
@@ -53,5 +55,12 @@ namespace ICSharpCode.ILSpy
 		{
 			return wrappedCommand.CanExecute(parameter);
 		}
+
+		protected abstract void OnExecute(object sender, ExecutedRoutedEventArgs e);
+
+		protected virtual void OnCanExecute(object sender, CanExecuteRoutedEventArgs e)
+		{
+			e.CanExecute = true;
+		}
 	}
 }

ILSpy/Commands/DecompileAllCommand.cs

@@ -26,9 +26,9 @@ using System.Linq;
 using System.Threading.Tasks;
 
 using ICSharpCode.Decompiler;
+using ICSharpCode.ILSpy.Docking;
 using ICSharpCode.ILSpy.Properties;
 using ICSharpCode.ILSpy.TextView;
-using ICSharpCode.ILSpy.Util;
 using ICSharpCode.ILSpyX;
 
 using TomsToolbox.Essentials;
@@ -49,7 +49,7 @@ namespace ICSharpCode.ILSpy
 			Docking.DockWorkspace.Instance.RunWithCancellation(ct => Task<AvalonEditTextOutput>.Factory.StartNew(() => {
 				AvalonEditTextOutput output = new AvalonEditTextOutput();
 				Parallel.ForEach(
-					Partitioner.Create(MainWindow.Instance.CurrentAssemblyList.GetAssemblies(), loadBalance: true),
+					Partitioner.Create(MainWindow.Instance.AssemblyTreeModel.AssemblyList.GetAssemblies(), loadBalance: true),
 					new ParallelOptions { MaxDegreeOfParallelism = Environment.ProcessorCount, CancellationToken = ct },
 					delegate (LoadedAssembly asm) {
 						if (!asm.HasLoadError)
@@ -60,7 +60,7 @@ namespace ICSharpCode.ILSpy
 							{
 								try
 								{
-									var options = MainWindow.Instance.CreateDecompilationOptions();
+									var options = SettingsService.Instance.CreateDecompilationOptions(DockWorkspace.Instance.ActiveTabPage);
 									options.CancellationToken = ct;
 									options.FullDecompilation = true;
 									new CSharpLanguage().DecompileAssembly(asm, new PlainTextOutput(writer), options);
@@ -96,9 +96,10 @@ namespace ICSharpCode.ILSpy
 		{
 			const int numRuns = 100;
 			var language = SettingsService.Instance.SessionSettings.LanguageSettings.Language;
-			var nodes = MainWindow.Instance.SelectedNodes.ToArray();
+			var nodes = MainWindow.Instance.AssemblyTreeModel.SelectedNodes.ToArray();
-			var options = MainWindow.Instance.CreateDecompilationOptions();
+			DockWorkspace dockWorkspace = DockWorkspace.Instance;
-			Docking.DockWorkspace.Instance.RunWithCancellation(ct => Task<AvalonEditTextOutput>.Factory.StartNew(() => {
+			var options = SettingsService.Instance.CreateDecompilationOptions(dockWorkspace.ActiveTabPage);
+			dockWorkspace.RunWithCancellation(ct => Task<AvalonEditTextOutput>.Factory.StartNew(() => {
 				options.CancellationToken = ct;
 				Stopwatch w = Stopwatch.StartNew();
 				for (int i = 0; i < numRuns; ++i)
@@ -113,7 +114,7 @@ namespace ICSharpCode.ILSpy
 				double msPerRun = w.Elapsed.TotalMilliseconds / numRuns;
 				output.Write($"Average time: {msPerRun.ToString("f1")}ms\n");
 				return output;
-			}, ct)).Then(output => Docking.DockWorkspace.Instance.ShowText(output)).HandleExceptions();
+			}, ct)).Then(output => dockWorkspace.ShowText(output)).HandleExceptions();
 		}
 	}
 }

ILSpy/Commands/DecompileCommand.cs

@@ -66,7 +66,7 @@ namespace ICSharpCode.ILSpy.Commands
 				selection = entity;
 			}
 			if (selection != null)
-				MainWindow.Instance.JumpToReference(selection);
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(selection));
 		}
 	}
 }

ILSpy/Commands/DecompileInNewViewCommand.cs

@@ -25,9 +25,10 @@ using System.Windows.Threading;
 using ICSharpCode.Decompiler.TypeSystem;
 using ICSharpCode.ILSpy.Docking;
 using ICSharpCode.ILSpy.Properties;
-using ICSharpCode.ILSpy.TextView;
 using ICSharpCode.ILSpy.TreeNodes;
 
+using TomsToolbox.Essentials;
+
 namespace ICSharpCode.ILSpy.Commands
 {
 	[ExportContextMenuEntry(Header = nameof(Resources.DecompileToNewPanel), InputGestureText = "MMB", Icon = "images/Search", Category = nameof(Resources.Analyze), Order = 90)]
@@ -53,18 +54,18 @@ namespace ICSharpCode.ILSpy.Commands
 		{
 			if (context.SelectedTreeNodes != null)
 			{
-				if (context.TreeView != MainWindow.Instance.AssemblyTreeView)
+				if (context.TreeView.DataContext != MainWindow.Instance.AssemblyTreeModel)
 				{
-					return context.SelectedTreeNodes.OfType<IMemberTreeNode>().Select(FindTreeNode).Where(n => n != null);
+					return context.SelectedTreeNodes.OfType<IMemberTreeNode>().Select(FindTreeNode).ExceptNullItems();
 				}
 				else
 				{
-					return context.SelectedTreeNodes.OfType<ILSpyTreeNode>().Where(n => n != null);
+					return context.SelectedTreeNodes.OfType<ILSpyTreeNode>();
 				}
 			}
 			else if (context.Reference?.Reference is IEntity entity)
 			{
-				if (MainWindow.Instance.FindTreeNode(entity) is ILSpyTreeNode node)
+				if (MainWindow.Instance.AssemblyTreeModel.FindTreeNode(entity) is { } node)
 				{
 					return new[] { node };
 				}
@@ -75,7 +76,7 @@ namespace ICSharpCode.ILSpy.Commands
 			{
 				if (node is ILSpyTreeNode ilspyNode)
 					return ilspyNode;
-				return MainWindow.Instance.FindTreeNode(node.Member);
+				return MainWindow.Instance.AssemblyTreeModel.FindTreeNode(node.Member);
 			}
 		}
 
@@ -84,8 +85,9 @@ namespace ICSharpCode.ILSpy.Commands
 			if (nodes.Length == 0)
 				return;
 
-			MainWindow.Instance.SelectNodes(nodes, inNewTabPage: true);
+			DockWorkspace.Instance.AddTabPage();
-			MainWindow.Instance.Dispatcher.BeginInvoke(DispatcherPriority.Background, (Action)MainWindow.Instance.RefreshDecompiledView);
+
+			MainWindow.Instance.AssemblyTreeModel.SelectNodes(nodes);
 		}
 	}
 }

ILSpy/Commands/DisassembleAllCommand.cs

@@ -26,7 +26,6 @@ using System.Threading.Tasks;
 
 using ICSharpCode.ILSpy.Properties;
 using ICSharpCode.ILSpy.TextView;
-using ICSharpCode.ILSpyX;
 
 namespace ICSharpCode.ILSpy
 {
@@ -41,12 +40,14 @@ namespace ICSharpCode.ILSpy
 
 		public override void Execute(object parameter)
 		{
-			Docking.DockWorkspace.Instance.RunWithCancellation(ct => Task<AvalonEditTextOutput>.Factory.StartNew(() => {
+			var dockWorkspace = Docking.DockWorkspace.Instance;
-				AvalonEditTextOutput output = new AvalonEditTextOutput();
+
+			dockWorkspace.RunWithCancellation(ct => Task<AvalonEditTextOutput>.Factory.StartNew(() => {
+				AvalonEditTextOutput output = new();
 				Parallel.ForEach(
-					Partitioner.Create(MainWindow.Instance.CurrentAssemblyList.GetAssemblies(), loadBalance: true),
+					Partitioner.Create(MainWindow.Instance.AssemblyTreeModel.AssemblyList.GetAssemblies(), loadBalance: true),
-					new ParallelOptions { MaxDegreeOfParallelism = Environment.ProcessorCount, CancellationToken = ct },
+					new() { MaxDegreeOfParallelism = Environment.ProcessorCount, CancellationToken = ct },
-					delegate (LoadedAssembly asm) {
+					asm => {
 						if (!asm.HasLoadError)
 						{
 							Stopwatch w = Stopwatch.StartNew();
@@ -55,7 +56,7 @@ namespace ICSharpCode.ILSpy
 							{
 								try
 								{
-									var options = MainWindow.Instance.CreateDecompilationOptions();
+									var options = SettingsService.Instance.CreateDecompilationOptions(dockWorkspace.ActiveTabPage);
 									options.FullDecompilation = true;
 									options.CancellationToken = ct;
 									new ILLanguage().DecompileAssembly(asm, new Decompiler.PlainTextOutput(writer), options);
@@ -79,7 +80,7 @@ namespace ICSharpCode.ILSpy
 						}
 					});
 				return output;
-			}, ct)).Then(output => Docking.DockWorkspace.Instance.ShowText(output)).HandleExceptions();
+			}, ct)).Then(dockWorkspace.ShowText).HandleExceptions();
 		}
 	}
 }

ILSpy/Commands/GeneratePdbContextMenuEntry.cs

@@ -29,6 +29,7 @@ using ICSharpCode.Decompiler.CSharp;
 using ICSharpCode.Decompiler.CSharp.ProjectDecompiler;
 using ICSharpCode.Decompiler.DebugInfo;
 using ICSharpCode.Decompiler.Metadata;
+using ICSharpCode.ILSpy.Docking;
 using ICSharpCode.ILSpy.Properties;
 using ICSharpCode.ILSpy.TextView;
 using ICSharpCode.ILSpy.TreeNodes;
@@ -73,9 +74,10 @@ namespace ICSharpCode.ILSpy
 			dlg.InitialDirectory = Path.GetDirectoryName(assembly.FileName);
 			if (dlg.ShowDialog() != true)
 				return;
-			DecompilationOptions options = MainWindow.Instance.CreateDecompilationOptions();
+			DockWorkspace dockWorkspace = DockWorkspace.Instance;
+			DecompilationOptions options = SettingsService.Instance.CreateDecompilationOptions(dockWorkspace.ActiveTabPage);
 			string fileName = dlg.FileName;
-			Docking.DockWorkspace.Instance.RunWithCancellation(ct => Task<AvalonEditTextOutput>.Factory.StartNew(() => {
+			dockWorkspace.RunWithCancellation(ct => Task<AvalonEditTextOutput>.Factory.StartNew(() => {
 				AvalonEditTextOutput output = new AvalonEditTextOutput();
 				Stopwatch stopwatch = Stopwatch.StartNew();
 				options.CancellationToken = ct;
@@ -110,14 +112,14 @@ namespace ICSharpCode.ILSpy
 	{
 		public override bool CanExecute(object parameter)
 		{
-			return MainWindow.Instance.SelectedNodes?.Count() == 1
+			return MainWindow.Instance.AssemblyTreeModel.SelectedNodes?.Count() == 1
-				&& MainWindow.Instance.SelectedNodes?.FirstOrDefault() is AssemblyTreeNode tn
+				&& MainWindow.Instance.AssemblyTreeModel.SelectedNodes?.FirstOrDefault() is AssemblyTreeNode tn
 				&& !tn.LoadedAssembly.HasLoadError;
 		}
 
 		public override void Execute(object parameter)
 		{
-			var assembly = (MainWindow.Instance.SelectedNodes?.FirstOrDefault() as AssemblyTreeNode)?.LoadedAssembly;
+			var assembly = (MainWindow.Instance.AssemblyTreeModel.SelectedNodes?.FirstOrDefault() as AssemblyTreeNode)?.LoadedAssembly;
 			if (assembly == null)
 				return;
 			GeneratePdbContextMenuEntry.GeneratePdbForAssembly(assembly);

ILSpy/Commands/OpenCommand.cs

@@ -19,8 +19,11 @@
 using System.ComponentModel.Composition;
 using System.Windows.Input;
 
+using ICSharpCode.ILSpy.AssemblyTree;
 using ICSharpCode.ILSpy.Properties;
 
+using Microsoft.Win32;
+
 namespace ICSharpCode.ILSpy
 {
 	[ExportToolbarCommand(ToolTip = nameof(Resources.Open), ToolbarIcon = "Images/Open", ToolbarCategory = nameof(Resources.Open), ToolbarOrder = 0)]
@@ -28,9 +31,28 @@ namespace ICSharpCode.ILSpy
 	[PartCreationPolicy(CreationPolicy.Shared)]
 	sealed class OpenCommand : CommandWrapper
 	{
-		public OpenCommand()
+		private readonly AssemblyTreeModel assemblyTreeModel;
+
+		[ImportingConstructor]
+		public OpenCommand(AssemblyTreeModel assemblyTreeModel)
 			: base(ApplicationCommands.Open)
 		{
+			this.assemblyTreeModel = assemblyTreeModel;
+		}
+
+		protected override void OnExecute(object sender, ExecutedRoutedEventArgs e)
+		{
+			e.Handled = true;
+			OpenFileDialog dlg = new OpenFileDialog {
+				Filter = ".NET assemblies|*.dll;*.exe;*.winmd;*.wasm|Nuget Packages (*.nupkg)|*.nupkg|Portable Program Database (*.pdb)|*.pdb|All files|*.*",
+				Multiselect = true,
+				RestoreDirectory = true
+			};
+
+			if (dlg.ShowDialog() == true)
+			{
+				assemblyTreeModel.OpenFiles(dlg.FileNames);
+			}
 		}
 	}
 }

ILSpy/Commands/OpenFromGacCommand.cs

@@ -19,6 +19,7 @@
 using System.ComponentModel.Composition;
 
 using ICSharpCode.ILSpy.AppEnv;
+using ICSharpCode.ILSpy.AssemblyTree;
 using ICSharpCode.ILSpy.Properties;
 
 namespace ICSharpCode.ILSpy
@@ -27,6 +28,14 @@ namespace ICSharpCode.ILSpy
 	[PartCreationPolicy(CreationPolicy.Shared)]
 	sealed class OpenFromGacCommand : SimpleCommand
 	{
+		private readonly AssemblyTreeModel assemblyTreeModel;
+
+		[ImportingConstructor]
+		public OpenFromGacCommand(AssemblyTreeModel assemblyTreeModel)
+		{
+			this.assemblyTreeModel = assemblyTreeModel;
+		}
+
 		public override bool CanExecute(object parameter)
 		{
 			return AppEnvironment.IsWindows;
@@ -34,10 +43,14 @@ namespace ICSharpCode.ILSpy
 
 		public override void Execute(object parameter)
 		{
-			OpenFromGacDialog dlg = new OpenFromGacDialog();
+			OpenFromGacDialog dlg = new OpenFromGacDialog {
-			dlg.Owner = MainWindow.Instance;
+				Owner = MainWindow.Instance
+			};
+
 			if (dlg.ShowDialog() == true)
-				MainWindow.Instance.OpenFiles(dlg.SelectedFileNames);
+			{
+				assemblyTreeModel.OpenFiles(dlg.SelectedFileNames);
+			}
 		}
 	}
 }

ILSpy/Commands/Pdb2XmlCommand.cs

@@ -40,14 +40,14 @@ namespace ICSharpCode.ILSpy
 	{
 		public override bool CanExecute(object parameter)
 		{
-			var selectedNodes = MainWindow.Instance.SelectedNodes;
+			var selectedNodes = MainWindow.Instance.AssemblyTreeModel.SelectedNodes;
 			return selectedNodes?.Any() == true
 				&& selectedNodes.All(n => n is AssemblyTreeNode asm && !asm.LoadedAssembly.HasLoadError);
 		}
 
 		public override void Execute(object parameter)
 		{
-			Execute(MainWindow.Instance.SelectedNodes.OfType<AssemblyTreeNode>());
+			Execute(MainWindow.Instance.AssemblyTreeModel.SelectedNodes.OfType<AssemblyTreeNode>());
 		}
 
 		internal static void Execute(IEnumerable<AssemblyTreeNode> nodes)

ILSpy/Commands/RefreshCommand.cs

@@ -19,6 +19,7 @@
 using System.ComponentModel.Composition;
 using System.Windows.Input;
 
+using ICSharpCode.ILSpy.AssemblyTree;
 using ICSharpCode.ILSpy.Properties;
 
 namespace ICSharpCode.ILSpy
@@ -28,9 +29,18 @@ namespace ICSharpCode.ILSpy
 	[PartCreationPolicy(CreationPolicy.Shared)]
 	sealed class RefreshCommand : CommandWrapper
 	{
-		public RefreshCommand()
+		private readonly AssemblyTreeModel assemblyTreeModel;
+
+		[ImportingConstructor]
+		public RefreshCommand(AssemblyTreeModel assemblyTreeModel)
 			: base(NavigationCommands.Refresh)
 		{
+			this.assemblyTreeModel = assemblyTreeModel;
+		}
+
+		protected override void OnExecute(object sender, ExecutedRoutedEventArgs e)
+		{
+			assemblyTreeModel.Refresh();
 		}
 	}
 }

ILSpy/Commands/RemoveAssembliesWithLoadErrors.cs

@@ -29,16 +29,16 @@ namespace ICSharpCode.ILSpy
 	{
 		public override bool CanExecute(object parameter)
 		{
-			return MainWindow.Instance.CurrentAssemblyList?.GetAssemblies().Any(l => l.HasLoadError) == true;
+			return MainWindow.Instance.AssemblyTreeModel.AssemblyList?.GetAssemblies().Any(l => l.HasLoadError) == true;
 		}
 
 		public override void Execute(object parameter)
 		{
-			foreach (var asm in MainWindow.Instance.CurrentAssemblyList.GetAssemblies())
+			foreach (var asm in MainWindow.Instance.AssemblyTreeModel.AssemblyList.GetAssemblies())
 			{
 				if (!asm.HasLoadError)
 					continue;
-				var node = MainWindow.Instance.AssemblyListTreeNode.FindAssemblyNode(asm);
+				var node = MainWindow.Instance.AssemblyTreeModel.FindAssemblyNode(asm);
 				if (node != null && node.CanDelete())
 					node.Delete();
 			}
@@ -51,12 +51,12 @@ namespace ICSharpCode.ILSpy
 	{
 		public override bool CanExecute(object parameter)
 		{
-			return MainWindow.Instance.CurrentAssemblyList?.Count > 0;
+			return MainWindow.Instance.AssemblyTreeModel.AssemblyList?.Count > 0;
 		}
 
 		public override void Execute(object parameter)
 		{
-			MainWindow.Instance.CurrentAssemblyList?.Clear();
+			MainWindow.Instance.AssemblyTreeModel.AssemblyList?.Clear();
 		}
 	}
 }

ILSpy/Commands/SaveCodeContextMenuEntry.cs

@@ -32,7 +32,8 @@ using Microsoft.Win32;
 using ICSharpCode.ILSpyX.TreeView;
 using System.ComponentModel.Composition;
 
-using ICSharpCode.ILSpy.Util;
+using ICSharpCode.ILSpy.Docking;
+
 
 namespace ICSharpCode.ILSpy.TextView
 {
@@ -62,8 +63,11 @@ namespace ICSharpCode.ILSpy.TextView
 
 		public static void Execute(IReadOnlyList<SharpTreeNode> selectedNodes)
 		{
-			var currentLanguage = SettingsService.Instance.SessionSettings.LanguageSettings.Language;
+			var settingsService = SettingsService.Instance;
-			var tabPage = Docking.DockWorkspace.Instance.ActiveTabPage;
+			var dockWorkspace = Docking.DockWorkspace.Instance;
+
+			var currentLanguage = settingsService.SessionSettings.LanguageSettings.Language;
+			var tabPage = dockWorkspace.ActiveTabPage;
 			tabPage.ShowTextView(textView => {
 				if (selectedNodes.Count == 1 && selectedNodes[0] is ILSpyTreeNode singleSelection)
 				{
@@ -88,7 +92,7 @@ namespace ICSharpCode.ILSpy.TextView
 
 				// Fallback: if nobody was able to handle the request, use default behavior.
 				// try to save all nodes to disk.
-				var options = MainWindow.Instance.CreateDecompilationOptions();
+				var options = settingsService.CreateDecompilationOptions(dockWorkspace.ActiveTabPage);
 				options.FullDecompilation = true;
 				textView.SaveToDisk(currentLanguage, selectedNodes.OfType<ILSpyTreeNode>(), options);
 			});

ILSpy/Commands/SaveCommand.cs

@@ -17,9 +17,12 @@
 // DEALINGS IN THE SOFTWARE.
 
 using System.ComponentModel.Composition;
+using System.Linq;
 using System.Windows.Input;
 
+using ICSharpCode.ILSpy.AssemblyTree;
 using ICSharpCode.ILSpy.Properties;
+using ICSharpCode.ILSpy.TextView;
 
 namespace ICSharpCode.ILSpy
 {
@@ -27,9 +30,24 @@ namespace ICSharpCode.ILSpy
 	[PartCreationPolicy(CreationPolicy.Shared)]
 	sealed class SaveCommand : CommandWrapper
 	{
-		public SaveCommand()
+		private AssemblyTreeModel assemblyTreeModel;
+
+		[ImportingConstructor]
+		public SaveCommand(AssemblyTreeModel assemblyTreeModel)
 			: base(ApplicationCommands.Save)
 		{
+			this.assemblyTreeModel = assemblyTreeModel;
+		}
+
+		protected override void OnCanExecute(object sender, CanExecuteRoutedEventArgs e)
+		{
+			e.Handled = true;
+			e.CanExecute = SaveCodeContextMenuEntry.CanExecute(assemblyTreeModel.SelectedNodes.ToList());
+		}
+
+		protected override void OnExecute(object sender, ExecutedRoutedEventArgs e)
+		{
+			SaveCodeContextMenuEntry.Execute(assemblyTreeModel.SelectedNodes.ToList());
 		}
 	}
 }

ILSpy/Commands/SelectPdbContextMenuEntry.cs

@@ -48,10 +48,10 @@ namespace ICSharpCode.ILSpy
 				await assembly.LoadDebugInfo(dlg.FileName);
 			}
 
-			var node = (AssemblyTreeNode)MainWindow.Instance.FindNodeByPath(new[] { assembly.FileName }, true);
+			var node = (AssemblyTreeNode)MainWindow.Instance.AssemblyTreeModel.FindNodeByPath(new[] { assembly.FileName }, true);
 			node.UpdateToolTip();
-			MainWindow.Instance.SelectNode(node);
+			MainWindow.Instance.AssemblyTreeModel.SelectNode(node);
-			MainWindow.Instance.RefreshDecompiledView();
+			MainWindow.Instance.AssemblyTreeModel.RefreshDecompiledView();
 		}
 
 		public bool IsEnabled(TextViewContext context) => true;

ILSpy/Commands/SetThemeCommand.cs

@@ -1,5 +1,4 @@
-using ICSharpCode.ILSpy.Util;
+
-
 namespace ICSharpCode.ILSpy.Commands
 {
 	public class SetThemeCommand : SimpleCommand
@@ -7,7 +6,9 @@ namespace ICSharpCode.ILSpy.Commands
 		public override void Execute(object parameter)
 		{
 			if (parameter is string theme)
+			{
 				SettingsService.Instance.SessionSettings.Theme = theme;
 			}
 		}
+	}
 }

ILSpy/Commands/ShowCFGContextMenuEntry.cs

@@ -6,7 +6,6 @@ using System.Windows;
 using ICSharpCode.Decompiler.FlowAnalysis;
 using ICSharpCode.Decompiler.IL;
 using ICSharpCode.Decompiler.IL.ControlFlow;
-using ICSharpCode.ILSpy.Util;
 
 namespace ICSharpCode.ILSpy.Commands
 {

ILSpy/Commands/SortAssemblyListCommand.cs

@@ -29,17 +29,11 @@ namespace ICSharpCode.ILSpy
 	[ExportMainMenuCommand(ParentMenuID = nameof(Resources._View), Header = nameof(Resources.SortAssembly_listName), MenuIcon = "Images/Sort", MenuCategory = nameof(Resources.View))]
 	[ExportToolbarCommand(ToolTip = nameof(Resources.SortAssemblyListName), ToolbarIcon = "Images/Sort", ToolbarCategory = nameof(Resources.View))]
 	[PartCreationPolicy(CreationPolicy.Shared)]
-	sealed class SortAssemblyListCommand : SimpleCommand, IComparer<LoadedAssembly>
+	sealed class SortAssemblyListCommand : SimpleCommand
 	{
 		public override void Execute(object parameter)
 		{
-			using (MainWindow.Instance.AssemblyTreeView.LockUpdates())
+			MainWindow.Instance.AssemblyTreeModel.SortAssemblyList();
-				MainWindow.Instance.CurrentAssemblyList.Sort(this);
-		}
-
-		int IComparer<LoadedAssembly>.Compare(LoadedAssembly x, LoadedAssembly y)
-		{
-			return string.Compare(x.ShortName, y.ShortName, StringComparison.CurrentCulture);
 		}
 	}
 
@@ -50,19 +44,8 @@ namespace ICSharpCode.ILSpy
 	{
 		public override void Execute(object parameter)
 		{
-			using (MainWindow.Instance.AssemblyTreeView.LockUpdates())
+			MainWindow.Instance.AssemblyTreeModel.CollapseAll();
-				CollapseChildren(MainWindow.Instance.AssemblyTreeView.Root);
 
-			void CollapseChildren(SharpTreeNode node)
-			{
-				foreach (var child in node.Children)
-				{
-					if (!child.IsExpanded)
-						continue;
-					CollapseChildren(child);
-					child.IsExpanded = false;
-				}
-			}
 		}
 	}
 }

ILSpy/ContextMenuEntry.cs

@@ -22,8 +22,6 @@ using System.ComponentModel.Composition;
 using System.Linq;
 using System.Windows;
 using System.Windows.Controls;
-using System.Windows.Input;
-using System.Windows.Media;
 
 using ICSharpCode.AvalonEdit;
 using ICSharpCode.ILSpy.TextView;
@@ -32,6 +30,7 @@ using ICSharpCode.ILSpy.Controls.TreeView;
 using ICSharpCode.ILSpyX.TreeView;
 
 using TomsToolbox.Composition;
+using TomsToolbox.Essentials;
 
 namespace ICSharpCode.ILSpy
 {
@@ -86,36 +85,40 @@ namespace ICSharpCode.ILSpy
 		/// </summary>
 		public TextViewPosition? Position { get; private set; }
 
-		public Point MousePosition { get; private set; }
+		/// <summary>
+		/// Returns the original source of the context menu event.
+		/// </summary>
+		public DependencyObject OriginalSource { get; private set; }
 
-		public static TextViewContext Create(SharpTreeView treeView = null, DecompilerTextView textView = null, ListBox listBox = null, DataGrid dataGrid = null)
+		public static TextViewContext Create(ContextMenuEventArgs eventArgs, SharpTreeView treeView = null, DecompilerTextView textView = null, ListBox listBox = null, DataGrid dataGrid = null)
 		{
 			ReferenceSegment reference;
-			if (textView != null)
+
+			if (textView is not null)
+			{
 				reference = textView.GetReferenceSegmentAtMousePosition();
-			else if (listBox?.SelectedItem is SearchResult result)
+			}
-				reference = new ReferenceSegment { Reference = result.Reference };
-			else if (listBox?.SelectedItem is TreeNodes.IMemberTreeNode provider)
-				reference = new ReferenceSegment { Reference = provider.Member };
-			else if (listBox?.SelectedItem != null)
-				reference = new ReferenceSegment { Reference = listBox.SelectedItem };
-			else if (dataGrid?.SelectedItem is TreeNodes.IMemberTreeNode provider2)
-				reference = new ReferenceSegment { Reference = provider2.Member };
-			else if (dataGrid?.SelectedItem != null)
-				reference = new ReferenceSegment { Reference = dataGrid.SelectedItem };
 			else
-				reference = null;
+			{
-			var position = textView != null ? textView.GetPositionFromMousePosition() : null;
+				reference = (listBox?.SelectedItem ?? dataGrid?.SelectedItem) switch {
-			var selectedTreeNodes = treeView != null ? treeView.GetTopLevelSelection().ToArray() : null;
+					SearchResult searchResult => new() { Reference = searchResult.Reference },
-			return new TextViewContext {
+					TreeNodes.IMemberTreeNode treeNode => new() { Reference = treeNode.Member }, { } value => new() { Reference = value },
+					_ => null
+				};
+			}
+
+			var position = textView?.GetPositionFromMousePosition();
+			var selectedTreeNodes = treeView?.GetTopLevelSelection().ToArray();
+
+			return new() {
 				ListBox = listBox,
 				DataGrid = dataGrid,
 				TreeView = treeView,
-				SelectedTreeNodes = selectedTreeNodes,
 				TextView = textView,
+				SelectedTreeNodes = selectedTreeNodes,
 				Reference = reference,
 				Position = position,
-				MousePosition = ((Visual)textView ?? treeView ?? (Visual)listBox ?? dataGrid).PointToScreen(Mouse.GetPosition((IInputElement)textView ?? treeView ?? (IInputElement)listBox ?? dataGrid))
+				OriginalSource = eventArgs.OriginalSource as DependencyObject
 			};
 		}
 	}
@@ -168,6 +171,13 @@ namespace ICSharpCode.ILSpy
 
 	internal class ContextMenuProvider
 	{
+		private static readonly WeakEventSource<EventArgs> ContextMenuClosedEventSource = new();
+
+		public static event EventHandler<EventArgs> ContextMenuClosed {
+			add => ContextMenuClosedEventSource.Subscribe(value);
+			remove => ContextMenuClosedEventSource.Unsubscribe(value);
+		}
+
 		/// <summary>
 		/// Enables extensible context menu support for the specified tree view.
 		/// </summary>
@@ -203,51 +213,54 @@ namespace ICSharpCode.ILSpy
 			dataGrid.ContextMenu = new ContextMenu();
 		}
 
+		readonly Control control;
 		readonly SharpTreeView treeView;
 		readonly DecompilerTextView textView;
 		readonly ListBox listBox;
 		readonly DataGrid dataGrid;
 		readonly IExport<IContextMenuEntry, IContextMenuEntryMetadata>[] entries;
 
-		private ContextMenuProvider()
+		private ContextMenuProvider(Control control)
 		{
 			entries = App.ExportProvider.GetExports<IContextMenuEntry, IContextMenuEntryMetadata>().ToArray();
+
+			this.control = control;
 		}
 
 		ContextMenuProvider(DecompilerTextView textView)
-			: this()
+			: this((Control)textView)
 		{
 			this.textView = textView ?? throw new ArgumentNullException(nameof(textView));
 		}
 
 		ContextMenuProvider(SharpTreeView treeView)
-			: this()
+			: this((Control)treeView)
 		{
 			this.treeView = treeView ?? throw new ArgumentNullException(nameof(treeView));
 		}
 
 		ContextMenuProvider(ListBox listBox)
-			: this()
+			: this((Control)listBox)
 		{
 			this.listBox = listBox ?? throw new ArgumentNullException(nameof(listBox));
 		}
 
 		ContextMenuProvider(DataGrid dataGrid)
-			: this()
+			: this((Control)dataGrid)
 		{
 			this.dataGrid = dataGrid ?? throw new ArgumentNullException(nameof(dataGrid));
 		}
 
 		void treeView_ContextMenuOpening(object sender, ContextMenuEventArgs e)
 		{
-			TextViewContext context = TextViewContext.Create(treeView);
+			var context = TextViewContext.Create(e, treeView: treeView);
 			if (context.SelectedTreeNodes.Length == 0)
 			{
 				e.Handled = true; // don't show the menu
 				return;
 			}
-			ContextMenu menu;
+
-			if (ShowContextMenu(context, out menu))
+			if (ShowContextMenu(context, out var menu))
 				treeView.ContextMenu = menu;
 			else
 				// hide the context menu.
@@ -256,9 +269,8 @@ namespace ICSharpCode.ILSpy
 
 		void textView_ContextMenuOpening(object sender, ContextMenuEventArgs e)
 		{
-			TextViewContext context = TextViewContext.Create(textView: textView);
+			var context = TextViewContext.Create(e, textView: textView);
-			ContextMenu menu;
+			if (ShowContextMenu(context, out var menu))
-			if (ShowContextMenu(context, out menu))
 				textView.ContextMenu = menu;
 			else
 				// hide the context menu.
@@ -267,9 +279,8 @@ namespace ICSharpCode.ILSpy
 
 		void listBox_ContextMenuOpening(object sender, ContextMenuEventArgs e)
 		{
-			TextViewContext context = TextViewContext.Create(listBox: listBox);
+			var context = TextViewContext.Create(e, listBox: listBox);
-			ContextMenu menu;
+			if (ShowContextMenu(context, out var menu))
-			if (ShowContextMenu(context, out menu))
 				listBox.ContextMenu = menu;
 			else
 				// hide the context menu.
@@ -278,9 +289,8 @@ namespace ICSharpCode.ILSpy
 
 		void dataGrid_ContextMenuOpening(object sender, ContextMenuEventArgs e)
 		{
-			TextViewContext context = TextViewContext.Create(dataGrid: dataGrid);
+			var context = TextViewContext.Create(e, dataGrid: dataGrid);
-			ContextMenu menu;
+			if (ShowContextMenu(context, out var menu))
-			if (ShowContextMenu(context, out menu))
 				dataGrid.ContextMenu = menu;
 			else
 				// hide the context menu.
@@ -289,7 +299,18 @@ namespace ICSharpCode.ILSpy
 
 		bool ShowContextMenu(TextViewContext context, out ContextMenu menu)
 		{
+			// Closing event is raised on the control where mouse is clicked, not on the control that opened the menu, so we hook on the global window event.
+			var window = Window.GetWindow(control)!;
+			window.ContextMenuClosing += ContextMenu_Closing;
+
+			void ContextMenu_Closing(object sender, EventArgs e)
+			{
+				window.ContextMenuClosing -= ContextMenu_Closing;
+				ContextMenuClosedEventSource.Raise(this, EventArgs.Empty);
+			}
+
 			menu = new ContextMenu();
+
 			var menuGroups = new Dictionary<string, IExport<IContextMenuEntry, IContextMenuEntryMetadata>[]>();
 			IExport<IContextMenuEntry, IContextMenuEntryMetadata>[] topLevelGroup = null;
 			foreach (var group in entries.OrderBy(c => c.Metadata.Order).GroupBy(c => c.Metadata.ParentMenuID))
@@ -310,10 +331,10 @@ namespace ICSharpCode.ILSpy
 			{
 				foreach (var category in menuGroup.GroupBy(c => c.Metadata.Category))
 				{
-					bool needSeparatorForCategory = parent.Count > 0;
+					var needSeparatorForCategory = parent.Count > 0;
 					foreach (var entryPair in category)
 					{
-						IContextMenuEntry entry = entryPair.Value;
+						var entry = entryPair.Value;
 						if (entry.IsVisible(context))
 						{
 							if (needSeparatorForCategory)
@@ -321,8 +342,8 @@ namespace ICSharpCode.ILSpy
 								parent.Add(new Separator());
 								needSeparatorForCategory = false;
 							}
-							MenuItem menuItem = new MenuItem();
+							var menuItem = new MenuItem();
-							menuItem.Header = MainWindow.GetResourceString(entryPair.Metadata.Header);
+							menuItem.Header = ResourceHelper.GetString(entryPair.Metadata.Header);
 							menuItem.InputGestureText = entryPair.Metadata.InputGestureText;
 							if (!string.IsNullOrEmpty(entryPair.Metadata.Icon))
 							{

ILSpy/Controls/TreeView/SharpTreeView.cs

@@ -158,6 +158,7 @@ namespace ICSharpCode.ILSpy.Controls.TreeView
 			if (flattener != null)
 			{
 				flattener.Stop();
+				flattener.CollectionChanged -= flattener_CollectionChanged;
 			}
 			if (Root != null)
 			{
@@ -818,9 +819,9 @@ namespace ICSharpCode.ILSpy.Controls.TreeView
 		/// </summary>
 		public IEnumerable<SharpTreeNode> GetTopLevelSelection()
 		{
-			var selection = this.SelectedItems.OfType<SharpTreeNode>();
+			var selection = this.SelectedItems.OfType<SharpTreeNode>().ToHashSet();
-			var selectionHash = new HashSet<SharpTreeNode>(selection);
+
-			return selection.Where(item => item.Ancestors().All(a => !selectionHash.Contains(a)));
+			return selection.Where(item => item.Ancestors().All(a => !selection.Contains(a)));
 		}
 
 		#endregion

ILSpy/DecompilationOptions.cs

@@ -23,6 +23,8 @@ using ICSharpCode.Decompiler;
 using ICSharpCode.ILSpy.Options;
 using ICSharpCode.ILSpyX;
 
+using DecompilerSettings = ICSharpCode.ILSpy.Options.DecompilerSettings;
+
 namespace ICSharpCode.ILSpy
 {
 	/// <summary>
@@ -87,7 +89,9 @@ namespace ICSharpCode.ILSpy
 		{
 			if (!Enum.TryParse(version?.Version, out Decompiler.CSharp.LanguageVersion languageVersion))
 				languageVersion = Decompiler.CSharp.LanguageVersion.Latest;
+
 			var newSettings = this.DecompilerSettings = settings.Clone();
+
 			newSettings.SetLanguageVersion(languageVersion);
 			newSettings.ExpandMemberDefinitions = displaySettings.ExpandMemberDefinitions;
 			newSettings.ExpandUsingDeclarations = displaySettings.ExpandUsingDeclarations;

ILSpy/Docking/DockLayoutSettings.cs

@@ -19,7 +19,6 @@
 using System;
 using System.IO;
 using System.Linq;
-using System.Xml;
 using System.Xml.Linq;
 
 using AvalonDock.Layout.Serialization;

ILSpy/Docking/DockWorkspace.cs

@@ -33,9 +33,11 @@ using ICSharpCode.AvalonEdit.Highlighting;
 using ICSharpCode.ILSpy.Analyzers;
 using ICSharpCode.ILSpy.Search;
 using ICSharpCode.ILSpy.TextView;
-using ICSharpCode.ILSpy.Util;
 using ICSharpCode.ILSpy.ViewModels;
+using ICSharpCode.ILSpyX.Extensions;
 
+using TomsToolbox.Composition;
+using TomsToolbox.Essentials;
 using TomsToolbox.Wpf;
 
 namespace ICSharpCode.ILSpy.Docking
@@ -44,11 +46,22 @@ namespace ICSharpCode.ILSpy.Docking
 	{
 		private static SessionSettings SessionSettings => SettingsService.Instance.SessionSettings;
 
+		private readonly IExportProvider exportProvider = App.ExportProvider;
+
 		public static readonly DockWorkspace Instance = new();
 
+		private readonly ObservableCollection<TabPageModel> tabPages = [];
+		private readonly ObservableCollection<ToolPaneModel> toolPanes = [];
+
 		private DockWorkspace()
 		{
-			this.TabPages.CollectionChanged += Documents_CollectionChanged;
+			this.tabPages.CollectionChanged += TabPages_CollectionChanged;
+			TabPages = new(tabPages);
+			ToolPanes = new(toolPanes);
+
+			// Make sure there is at least one tab open
+			AddTabPage();
+
 			MessageBus<CurrentAssemblyListChangedEventArgs>.Subscribers += (sender, e) => CurrentAssemblyList_Changed(sender, e);
 		}
 
@@ -58,52 +71,57 @@ namespace ICSharpCode.ILSpy.Docking
 			{
 				return;
 			}
-			foreach (var tab in TabPages.ToArray())
+			foreach (var tab in tabPages.ToArray())
 			{
 				var state = tab.GetState();
-				if (state == null || state.DecompiledNodes == null)
+				var decompiledNodes = state?.DecompiledNodes;
-				{
+				if (decompiledNodes == null)
 					continue;
-				}
+
-				bool found = false;
+				bool found = decompiledNodes
-				foreach (var node in state.DecompiledNodes)
+					.Select(node => node.Ancestors().OfType<TreeNodes.AssemblyTreeNode>().LastOrDefault())
-				{
+					.ExceptNullItems()
-					var assemblyNode = node.Ancestors().OfType<TreeNodes.AssemblyTreeNode>().LastOrDefault();
+					.Any(assemblyNode => !e.OldItems.Contains(assemblyNode.LoadedAssembly));
-					if (assemblyNode != null && !e.OldItems.Contains(assemblyNode.LoadedAssembly))
+
-					{
+				if (!found && tabPages.Count > 1)
-						found = true;
-						break;
-					}
-				}
-				if (!found && TabPages.Count > 1)
 				{
-					TabPages.Remove(tab);
+					tabPages.Remove(tab);
 				}
 			}
 		}
 
-		private void Documents_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
+		private void TabPages_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
 		{
-			var collection = (PaneCollection<TabPageModel>)sender;
 			if (e.Action == NotifyCollectionChangedAction.Add)
 			{
-				ActiveTabPage = e.NewItems?[0] as TabPageModel;
+				if (e.NewItems?[0] is TabPageModel model)
+				{
+					ActiveTabPage = model;
+					model.IsActive = true;
+					model.IsVisible = true;
 				}
+			}
+
+			bool canClose = tabPages.Count > 1;
 
-			bool canClose = collection.Count > 1;
+			foreach (var item in tabPages)
-			foreach (var item in collection)
 			{
 				item.IsCloseable = canClose;
 			}
 		}
 
-		public PaneCollection<TabPageModel> TabPages { get; } = new PaneCollection<TabPageModel>();
+		public void AddTabPage(TabPageModel tabPage = null)
+		{
+			tabPages.Add(tabPage ?? new TabPageModel());
+		}
+
+		public ReadOnlyObservableCollection<TabPageModel> TabPages { get; }
 
-		public ObservableCollection<ToolPaneModel> ToolPanes { get; } = new ObservableCollection<ToolPaneModel>();
+		public ReadOnlyObservableCollection<ToolPaneModel> ToolPanes { get; }
 
 		public bool ShowToolPane(string contentId)
 		{
-			var pane = ToolPanes.FirstOrDefault(p => p.ContentId == contentId);
+			var pane = toolPanes.FirstOrDefault(p => p.ContentId == contentId);
 			if (pane != null)
 			{
 				pane.Show();
@@ -115,7 +133,7 @@ namespace ICSharpCode.ILSpy.Docking
 		public void Remove(PaneModel model)
 		{
 			if (model is TabPageModel document)
-				TabPages.Remove(document);
+				tabPages.Remove(document);
 			if (model is ToolPaneModel tool)
 				tool.IsVisible = false;
 		}
@@ -131,25 +149,27 @@ namespace ICSharpCode.ILSpy.Docking
 					return;
 				}
 
-				var state = value.GetState();
+				var state = value?.GetState();
 				if (state != null)
 				{
 					if (state.DecompiledNodes != null)
 					{
-						MainWindow.Instance.SelectNodes(state.DecompiledNodes,
+						MainWindow.Instance.AssemblyTreeModel.SelectNodes(state.DecompiledNodes);
-							inNewTabPage: false, setFocus: true, changingActiveTab: true);
 					}
 					else
 					{
-						MainWindow.Instance.NavigateTo(new(state.ViewedUri, null));
+						MainWindow.Instance.AssemblyTreeModel.NavigateTo(new(state.ViewedUri, null));
 					}
 				}
-				MessageBus.Send(this, new DockWorkspaceActiveTabPageChangedEventArgs());
 			}
 		}
 
 		public void InitializeLayout(DockingManager manager)
 		{
+			var panes = exportProvider.GetExportedValues<ToolPaneModel>("ToolPane").OrderBy(item => item.Title);
+
+			this.toolPanes.AddRange(panes);
+
 			manager.LayoutUpdateStrategy = this;
 			XmlLayoutSerializer serializer = new XmlLayoutSerializer(manager);
 			serializer.LayoutSerializationCallback += LayoutSerializationCallback;
@@ -168,7 +188,7 @@ namespace ICSharpCode.ILSpy.Docking
 			switch (e.Model)
 			{
 				case LayoutAnchorable la:
-					e.Content = ToolPanes.FirstOrDefault(p => p.ContentId == la.ContentId);
+					e.Content = this.toolPanes.FirstOrDefault(p => p.ContentId == la.ContentId);
 					e.Cancel = e.Content == null;
 					la.CanDockAsTabbedDocument = false;
 					if (!e.Cancel)
@@ -200,23 +220,23 @@ namespace ICSharpCode.ILSpy.Docking
 
 		internal void CloseAllTabs()
 		{
-			foreach (var doc in TabPages.ToArray())
+			foreach (var doc in tabPages.ToArray())
 			{
 				if (doc.IsCloseable)
-					TabPages.Remove(doc);
+					tabPages.Remove(doc);
 			}
 		}
 
 		internal void ResetLayout()
 		{
-			foreach (var pane in ToolPanes)
+			foreach (var pane in toolPanes)
 			{
 				pane.IsVisible = false;
 			}
 			CloseAllTabs();
 			SessionSettings.DockLayout.Reset();
 			InitializeLayout(MainWindow.Instance.dockManager);
-			MainWindow.Instance.Dispatcher.BeginInvoke(DispatcherPriority.Background, (Action)MainWindow.Instance.RefreshDecompiledView);
+			MainWindow.Instance.Dispatcher.BeginInvoke(DispatcherPriority.Background, (Action)MainWindow.Instance.AssemblyTreeModel.RefreshDecompiledView);
 		}
 
 		static readonly PropertyInfo previousContainerProperty = typeof(LayoutContent).GetProperty("PreviousContainer", BindingFlags.NonPublic | BindingFlags.Instance);

ILSpy/Docking/PaneCollection.cs

@@ -1,59 +0,0 @@
-// Copyright (c) 2019 AlphaSierraPapa for the SharpDevelop Team
-// 
-// Permission is hereby granted, free of charge, to any person obtaining a copy of this
-// software and associated documentation files (the "Software"), to deal in the Software
-// without restriction, including without limitation the rights to use, copy, modify, merge,
-// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
-// to whom the Software is furnished to do so, subject to the following conditions:
-// 
-// The above copyright notice and this permission notice shall be included in all copies or
-// substantial portions of the Software.
-// 
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
-// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
-// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
-// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
-// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
-// DEALINGS IN THE SOFTWARE.
-
-using System.Collections;
-using System.Collections.Generic;
-using System.Collections.ObjectModel;
-using System.Collections.Specialized;
-
-using ICSharpCode.ILSpy.ViewModels;
-
-namespace ICSharpCode.ILSpy.Docking
-{
-	public class PaneCollection<T> : INotifyCollectionChanged, ICollection<T>
-		where T : PaneModel, new()
-	{
-		private ObservableCollection<T> observableCollection = new ObservableCollection<T>();
-
-		public event NotifyCollectionChangedEventHandler CollectionChanged;
-
-		public PaneCollection()
-		{
-			observableCollection.CollectionChanged += (sender, e) => CollectionChanged?.Invoke(this, e);
-		}
-
-		public void Add(T item = null)
-		{
-			item ??= new T();
-
-			observableCollection.Add(item);
-
-			item.IsVisible = true;
-			item.IsActive = true;
-		}
-
-		public int Count => observableCollection.Count;
-		public bool IsReadOnly => false;
-		public void Clear() => observableCollection.Clear();
-		public bool Contains(T item) => observableCollection.Contains(item);
-		public void CopyTo(T[] array, int arrayIndex) => observableCollection.CopyTo(array, arrayIndex);
-		public bool Remove(T item) => observableCollection.Remove(item);
-		public IEnumerator<T> GetEnumerator() => observableCollection.GetEnumerator();
-		IEnumerator IEnumerable.GetEnumerator() => observableCollection.GetEnumerator();
-	}
-}

ILSpy/ExtensionMethods.cs

@@ -27,9 +27,10 @@ using System.Windows.Media;
 
 using ICSharpCode.Decompiler.Metadata;
 using ICSharpCode.Decompiler.TypeSystem;
-using ICSharpCode.ILSpy.Util;
 using ICSharpCode.ILSpyX;
 
+using TomsToolbox.Essentials;
+
 namespace ICSharpCode.ILSpy
 {
 	/// <summary>
@@ -125,9 +126,9 @@ namespace ICSharpCode.ILSpy
 				for (int i = 0; i < VisualTreeHelper.GetChildrenCount(depObj); i++)
 				{
 					DependencyObject child = VisualTreeHelper.GetChild(depObj, i);
-					if (child != null && child is T)
+					if (child is T dependencyObject)
 					{
-						return (T)child;
+						return dependencyObject;
 					}
 
 					T? childItem = FindVisualChild<T>(child);
@@ -178,20 +179,37 @@ namespace ICSharpCode.ILSpy
 				else
 					output.AppendLine("-------------------------------------------------");
 				output.AppendLine("Error(s) loading plugin: " + item.PluginName);
-				if (item.Exception is System.Reflection.ReflectionTypeLoadException)
+				if (item.Exception is System.Reflection.ReflectionTypeLoadException exception)
 				{
-					var e = (System.Reflection.ReflectionTypeLoadException)item.Exception;
+					foreach (var ex in exception.LoaderExceptions.ExceptNullItems())
-					foreach (var ex in e.LoaderExceptions)
 					{
 						output.AppendLine(ex.ToString());
 						output.AppendLine();
 					}
 				}
 				else
+				{
 					output.AppendLine(item.Exception.ToString());
 				}
+			}
 
 			return true;
 		}
+
+		public static IDisposable PreserveFocus(this IInputElement? inputElement, bool preserve = true)
+		{
+			return new RestoreFocusHelper(inputElement, preserve);
+		}
+
+		private sealed class RestoreFocusHelper(IInputElement? inputElement, bool preserve) : IDisposable
+		{
+			public void Dispose()
+			{
+				if (preserve)
+				{
+					inputElement?.Focus();
+				}
+			}
+		}
 	}
 }

ILSpy/GlobalUsings.cs

@@ -0,0 +1 @@
+global using ICSharpCode.ILSpy.Util;

ILSpy/ILSpy.csproj

@@ -1,5 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
-<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <OutputType>WinExe</OutputType>

ILSpy/LanguageSettings.cs

@@ -16,22 +16,20 @@
 // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 // DEALINGS IN THE SOFTWARE.
 
-using System;
 using System.Collections.Generic;
-using System.ComponentModel;
 using System.Linq;
-using System.Runtime.CompilerServices;
 using System.Xml.Linq;
 
-using ICSharpCode.ILSpy.Util;
 using ICSharpCode.ILSpyX;
 
+using TomsToolbox.Wpf;
+
 namespace ICSharpCode.ILSpy
 {
 	/// <summary>
 	/// Represents the filters applied to the tree view.
 	/// </summary>
-	public class LanguageSettings : INotifyPropertyChanged
+	public class LanguageSettings : ObservableObject, IChildSettings
 	{
 		/// <summary>
 		/// This dictionary is necessary to remember language versions across language changes. For example, 
@@ -40,14 +38,17 @@ namespace ICSharpCode.ILSpy
 		/// </summary>
 		private readonly Dictionary<Language, LanguageVersion> languageVersionHistory = new Dictionary<Language, LanguageVersion>();
 
-		public LanguageSettings(XElement element)
+		public LanguageSettings(XElement element, ISettingsSection parent)
 		{
+			Parent = parent;
 			this.ShowApiLevel = (ApiVisibility?)(int?)element.Element("ShowAPILevel") ?? ApiVisibility.PublicAndInternal;
 			this.Language = Languages.GetLanguage((string)element.Element("Language")) ?? Languages.AllLanguages.First();
 			this.LanguageVersion = Language.LanguageVersions.FirstOrDefault(v => v.Version == (string)element.Element("LanguageVersion"))
 								   ?? Language.LanguageVersions.LastOrDefault();
 		}
 
+		public ISettingsSection Parent { get; }
+
 		public XElement SaveAsXml()
 		{
 			return new XElement(
@@ -173,20 +174,6 @@ namespace ICSharpCode.ILSpy
 			}
 		}
 
-		public event PropertyChangedEventHandler PropertyChanged;
-
-		protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
-		{
-			if (PropertyChanged != null)
-			{
-				var args = new PropertyChangedEventArgs(propertyName);
-
-				PropertyChanged(this, args);
-				MessageBus.Send(this, new LanguageSettingsChangedEventArgs(args));
-			}
-		}
-
-
 		// This class has been initially called FilterSettings, but then has been Hijacked to store language settings as well.
 		// While the filter settings were some sort of local, the language settings are global. This is a bit of a mess.
 		// There has been a lot of workarounds cloning the FilterSettings to pass them down to the tree nodes, without messing up the global language settings.

ILSpy/Languages/CSharpILMixedLanguage.cs

@@ -34,7 +34,6 @@ using ICSharpCode.Decompiler.Disassembler;
 using ICSharpCode.Decompiler.Metadata;
 using ICSharpCode.Decompiler.TypeSystem;
 using ICSharpCode.Decompiler.Util;
-using ICSharpCode.ILSpy.Util;
 using ICSharpCode.ILSpyX;
 using ICSharpCode.ILSpyX.Extensions;
 

ILSpy/Languages/CSharpLanguage.cs

@@ -41,7 +41,6 @@ using ICSharpCode.Decompiler.TypeSystem;
 using ICSharpCode.Decompiler.Util;
 using ICSharpCode.ILSpy.TextView;
 using ICSharpCode.ILSpy.TreeNodes;
-using ICSharpCode.ILSpy.Util;
 using ICSharpCode.ILSpyX;
 
 using LanguageVersion = ICSharpCode.ILSpyX.LanguageVersion;
@@ -359,15 +358,15 @@ namespace ICSharpCode.ILSpy
 
 		void AddReferenceWarningMessage(MetadataFile module, ITextOutput output)
 		{
-			var loadedAssembly = MainWindow.Instance.CurrentAssemblyList.GetAssemblies().FirstOrDefault(la => la.GetMetadataFileOrNull() == module);
+			var loadedAssembly = MainWindow.Instance.AssemblyTreeModel.AssemblyList.GetAssemblies().FirstOrDefault(la => la.GetMetadataFileOrNull() == module);
 			if (loadedAssembly == null || !loadedAssembly.LoadedAssemblyReferencesInfo.HasErrors)
 				return;
 			string line1 = Properties.Resources.WarningSomeAssemblyReference;
 			string line2 = Properties.Resources.PropertyManuallyMissingReferencesListLoadedAssemblies;
 			AddWarningMessage(module, output, line1, line2, Properties.Resources.ShowAssemblyLoad, Images.ViewCode, delegate {
-				ILSpyTreeNode assemblyNode = MainWindow.Instance.FindTreeNode(module);
+				ILSpyTreeNode assemblyNode = MainWindow.Instance.AssemblyTreeModel.FindTreeNode(module);
 				assemblyNode.EnsureLazyChildren();
-				MainWindow.Instance.SelectNode(assemblyNode.Children.OfType<ReferenceFolderTreeNode>().Single());
+				MainWindow.Instance.AssemblyTreeModel.SelectNode(assemblyNode.Children.OfType<ReferenceFolderTreeNode>().Single());
 			});
 		}
 

ILSpy/Languages/ILLanguage.cs

@@ -29,8 +29,8 @@ using ICSharpCode.Decompiler.Metadata;
 using ICSharpCode.Decompiler.Solution;
 using ICSharpCode.Decompiler.TypeSystem;
 using ICSharpCode.Decompiler.Util;
+using ICSharpCode.ILSpy.Docking;
 using ICSharpCode.ILSpy.TextView;
-using ICSharpCode.ILSpy.Util;
 using ICSharpCode.ILSpyX;
 
 namespace ICSharpCode.ILSpy
@@ -198,7 +198,10 @@ namespace ICSharpCode.ILSpy
 		public override RichText GetRichTextTooltip(IEntity entity)
 		{
 			var output = new AvalonEditTextOutput() { IgnoreNewLineAndIndent = true };
-			var disasm = CreateDisassembler(output, MainWindow.Instance.CreateDecompilationOptions());
+			var settingsService = SettingsService.Instance;
+			var dockWorkspace = DockWorkspace.Instance;
+
+			var disasm = CreateDisassembler(output, settingsService.CreateDecompilationOptions(dockWorkspace.ActiveTabPage));
 			MetadataFile module = entity.ParentModule?.MetadataFile;
 			if (module == null)
 			{

ILSpy/Languages/Languages.cs

@@ -16,6 +16,8 @@
 // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 // DEALINGS IN THE SOFTWARE.
 
+#nullable enable
+
 using System;
 using System.Collections.ObjectModel;
 using System.Linq;
@@ -31,9 +33,9 @@ namespace ICSharpCode.ILSpy
 		/// </summary>
 		public static ReadOnlyCollection<Language> AllLanguages { get; } = Initialize(App.ExportProvider);
 
-		static ReadOnlyCollection<Language> Initialize(IExportProvider ep)
+		static ReadOnlyCollection<Language> Initialize(IExportProvider exportProvider)
 		{
-			var languages = ep.GetExportedValues<Language>().ToList();
+			var languages = exportProvider.GetExportedValues<Language>().ToList();
 
 			languages.Sort((a, b) => string.Compare(a.Name, b.Name, StringComparison.Ordinal));
 #if DEBUG
@@ -52,7 +54,8 @@ namespace ICSharpCode.ILSpy
 			return AllLanguages.FirstOrDefault(l => l.Name == name) ?? AllLanguages.First();
 		}
 
-		static ILLanguage ilLanguage;
+		static ILLanguage? ilLanguage;
+
 		public static ILLanguage ILLanguage {
 			get {
 				if (ilLanguage == null)

ILSpy/MainWindow.xaml

@@ -1,10 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
-
+<Window x:Class="ICSharpCode.ILSpy.MainWindow"
-<Window
-	x:Class="ICSharpCode.ILSpy.MainWindow"
 		xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
 		xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-	xmlns:tv="clr-namespace:ICSharpCode.ILSpy.Controls.TreeView"
 		xmlns:local="clr-namespace:ICSharpCode.ILSpy"
 		xmlns:avalondock="https://github.com/Dirkster99/AvalonDock"
 		xmlns:controls="clr-namespace:ICSharpCode.ILSpy.Controls"
@@ -21,52 +18,8 @@
 		xmlns:themes="clr-namespace:ICSharpCode.ILSpy.Themes"
 		xmlns:toms="urn:TomsToolbox"
 		xmlns:viewModels="clr-namespace:ICSharpCode.ILSpy.ViewModels"
-	xmlns:treeNodes="clr-namespace:ICSharpCode.ILSpy.TreeNodes"
-	xmlns:util="clr-namespace:ICSharpCode.ILSpy.Util"
 		d:DataContext="{d:DesignInstance local:MainWindowViewModel}">
 	<Window.Resources>
-		<tv:SharpTreeView x:Key="AssemblyTreeView"
-		                  AutomationProperties.Name="Assemblies and Classes"
-		                  SelectionChanged="TreeView_SelectionChanged"
-		                  ShowRoot="False"
-		                  AllowDropOrder="True"
-		                  AllowDrop="True"
-		                  BorderThickness="0" Visibility="Visible">
-			<tv:SharpTreeView.ItemContainerStyle>
-				<Style TargetType="tv:SharpTreeViewItem">
-					<Setter Property="Template">
-						<Setter.Value>
-							<ControlTemplate TargetType="{x:Type tv:SharpTreeViewItem}" d:DataContext="{d:DesignInstance treeNodes:ILSpyTreeNode}">
-								<Border Background="Transparent">
-									<Border Background="{TemplateBinding Background}">
-										<tv:SharpTreeNodeView x:Name="nodeView" HorizontalAlignment="Left" />
-									</Border>
-								</Border>
-								<ControlTemplate.Triggers>
-									<DataTrigger Binding="{Binding IsAutoLoaded}" Value="True">
-										<Setter Property="Foreground" Value="SteelBlue" />
-									</DataTrigger>
-									<DataTrigger Binding="{Binding IsPublicAPI}" Value="False">
-										<Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}" />
-									</DataTrigger>
-									<Trigger Property="IsSelected" Value="True">
-										<Setter TargetName="nodeView" Property="TextBackground" Value="{DynamicResource {x:Static SystemColors.HighlightBrushKey}}" />
-										<Setter TargetName="nodeView" Property="Foreground" Value="{DynamicResource {x:Static SystemColors.HighlightTextBrushKey}}" />
-									</Trigger>
-									<Trigger Property="IsEnabled" Value="False">
-										<Setter TargetName="nodeView" Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}" />
-									</Trigger>
-								</ControlTemplate.Triggers>
-							</ControlTemplate>
-						</Setter.Value>
-					</Setter>
-				</Style>
-			</tv:SharpTreeView.ItemContainerStyle>
-		</tv:SharpTreeView>
-
-		<DataTemplate DataType="{x:Type viewModels:AssemblyListPaneModel}">
-			<ContentControl Content="{StaticResource AssemblyTreeView}" />
-		</DataTemplate>
 
 		<DataTemplate DataType="{x:Type viewModels:TabPageModel}">
 			<ContentPresenter Content="{Binding Content}" />
@@ -76,38 +29,12 @@
 			<ContentPresenter Content="{Binding Content}" />
 		</DataTemplate>
 
-		<toms:BindingRelay x:Key="WindowBinding" DataContext="{Binding}" />
-
 	</Window.Resources>
 
 	<b:Interaction.Behaviors>
 		<themes:WindowStyleManagerBehavior />
 	</b:Interaction.Behaviors>
 
-	<Window.CommandBindings>
-		<CommandBinding
-			Command="Open"
-			Executed="OpenCommandExecuted" />
-		<CommandBinding
-			Command="Refresh"
-			Executed="RefreshCommandExecuted" />
-		<CommandBinding
-			Command="Save"
-			CanExecute="SaveCommandCanExecute"
-			Executed="SaveCommandExecuted" />
-		<CommandBinding
-			Command="BrowseBack"
-			CanExecute="BackCommandCanExecute"
-			Executed="BackCommandExecuted" />
-		<CommandBinding
-			Command="BrowseForward"
-			CanExecute="ForwardCommandCanExecute"
-			Executed="ForwardCommandExecuted" />
-		<CommandBinding
-			Command="Search"
-			Executed="SearchCommandExecuted" />
-	</Window.CommandBindings>
-
 	<Window.InputBindings>
 		<KeyBinding Key="R" Modifiers="Control" Command="{x:Static local:ILSpyCommands.Analyze}" />
 	</Window.InputBindings>
@@ -122,9 +49,12 @@
 			<MenuItem Header="{x:Static properties:Resources._File}" Tag="_File" />
 			<!-- contents of file menu are added using MEF -->
 			<MenuItem Header="{x:Static properties:Resources._View}" Tag="_View">
-				<MenuItem Header="{x:Static properties:Resources.Show_publiconlyTypesMembers}" IsCheckable="True" IsChecked="{Binding SessionSettings.LanguageSettings.ApiVisPublicOnly}" />
+				<MenuItem Header="{x:Static properties:Resources.Show_publiconlyTypesMembers}" IsCheckable="True"
-				<MenuItem Header="{x:Static properties:Resources.Show_internalTypesMembers}" IsCheckable="True" IsChecked="{Binding SessionSettings.LanguageSettings.ApiVisPublicAndInternal}" />
+						  IsChecked="{Binding SessionSettings.LanguageSettings.ApiVisPublicOnly}" />
-				<MenuItem Header="{x:Static properties:Resources.Show_allTypesAndMembers}" IsCheckable="True" IsChecked="{Binding SessionSettings.LanguageSettings.ApiVisAll}" />
+				<MenuItem Header="{x:Static properties:Resources.Show_internalTypesMembers}" IsCheckable="True"
+						  IsChecked="{Binding SessionSettings.LanguageSettings.ApiVisPublicAndInternal}" />
+				<MenuItem Header="{x:Static properties:Resources.Show_allTypesAndMembers}" IsCheckable="True"
+						  IsChecked="{Binding SessionSettings.LanguageSettings.ApiVisAll}" />
 				<Separator />
 				<MenuItem Header="{x:Static properties:Resources.Theme}" ItemsSource="{x:Static themes:ThemeManager.AllThemes}">
 					<MenuItem.ItemContainerStyle>
@@ -137,7 +67,7 @@
 								<Setter.Value>
 									<MultiBinding Converter="{x:Static toms:BinaryOperationConverter.Equality}" Mode="OneWay">
 										<Binding />
-										<Binding Source="{StaticResource WindowBinding}" Path="DataContext.SessionSettings.Theme" />
+										<Binding Path="DataContext.SessionSettings.Theme" RelativeSource="{RelativeSource FindAncestor, AncestorType=Window}"/>
 									</MultiBinding>
 								</Setter.Value>
 							</Setter>
@@ -145,9 +75,12 @@
 					</MenuItem.ItemContainerStyle>
 				</MenuItem>
 				<MenuItem Header="{x:Static properties:Resources.UILanguage}">
-					<MenuItem Header="{x:Static properties:Resources.UILanguage_System}" IsCheckable="True" IsChecked="{Binding SessionSettings.CurrentCulture, Converter={controls:CultureSelectionConverter}, ConverterParameter={x:Null}}" />
+					<MenuItem Header="{x:Static properties:Resources.UILanguage_System}" IsCheckable="True"
-					<MenuItem Header="English" IsCheckable="True" IsChecked="{Binding SessionSettings.CurrentCulture, Converter={controls:CultureSelectionConverter}, ConverterParameter=en-US}" />
+							  IsChecked="{Binding SessionSettings.CurrentCulture, Converter={controls:CultureSelectionConverter}, ConverterParameter={x:Null}}" />
-					<MenuItem Header="中文" IsCheckable="True" IsChecked="{Binding SessionSettings.CurrentCulture, Converter={controls:CultureSelectionConverter}, ConverterParameter=zh-Hans}" />
+					<MenuItem Header="English" IsCheckable="True"
+							  IsChecked="{Binding SessionSettings.CurrentCulture, Converter={controls:CultureSelectionConverter}, ConverterParameter=en-US}" />
+					<MenuItem Header="中文" IsCheckable="True"
+							  IsChecked="{Binding SessionSettings.CurrentCulture, Converter={controls:CultureSelectionConverter}, ConverterParameter=zh-Hans}" />
 				</MenuItem>
 			</MenuItem>
 			<MenuItem Header="{x:Static properties:Resources._Window}" Tag="_Window" />
@@ -223,11 +156,11 @@
 		<!-- Update panel -->
 		<Border DockPanel.Dock="Top" BorderBrush="Black" BorderThickness="1" Name="updatePanel" Visibility="Collapsed">
 			<DockPanel KeyboardNavigation.TabNavigation="Contained">
-				<Button DockPanel.Dock="Right" Click="updatePanelCloseButtonClick" MinWidth="0">X</Button>
+				<Button DockPanel.Dock="Right" Click="UpdatePanelCloseButtonClick" MinWidth="0">X</Button>
 				<StackPanel Orientation="Horizontal">
 					<TextBlock Name="updatePanelMessage" Margin="4,0" VerticalAlignment="Center"
 							   Text="{x:Static properties:Resources.ILSpyVersionAvailable}" />
-					<Button Name="downloadOrCheckUpdateButton" Click="downloadOrCheckUpdateButtonClick"
+					<Button Name="downloadOrCheckUpdateButton" Click="DownloadOrCheckUpdateButtonClick"
 							Content="{x:Static properties:Resources.Download}" />
 				</StackPanel>
 			</DockPanel>

ILSpy/MainWindowViewModel.cs

@@ -19,12 +19,14 @@
 using ICSharpCode.ILSpy.Docking;
 using ICSharpCode.ILSpyX;
 
+using TomsToolbox.Wpf;
+
 namespace ICSharpCode.ILSpy
 {
-	class MainWindowViewModel
+	class MainWindowViewModel : ObservableObject
 	{
-		public DockWorkspace Workspace { get; set; }
+		public DockWorkspace Workspace => DockWorkspace.Instance;
-		public SessionSettings SessionSettings { get; set; }
+		public SessionSettings SessionSettings => SettingsService.Instance.SessionSettings;
-		public AssemblyListManager AssemblyListManager { get; set; }
+		public AssemblyListManager AssemblyListManager => SettingsService.Instance.AssemblyListManager;
 	}
 }

ILSpy/Metadata/CoffHeaderTreeNode.cs

@@ -28,6 +28,8 @@ using ICSharpCode.ILSpy.TreeNodes;
 using ICSharpCode.ILSpy.ViewModels;
 using ICSharpCode.ILSpyX.Extensions;
 
+using TomsToolbox.Essentials;
+
 namespace ICSharpCode.ILSpy.Metadata
 {
 	class CoffHeaderTreeNode : ILSpyTreeNode

ILSpy/Metadata/CorTables/ClassLayoutTableTreeNode.cs

@@ -97,7 +97,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnParentClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference("metadata", classLayout.Parent));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference("metadata", classLayout.Parent)));
 			}
 
 			string parentTooltip;

ILSpy/Metadata/CorTables/ConstantTableTreeNode.cs

@@ -88,7 +88,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnParentClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, constant.Parent, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, constant.Parent, protocol: "metadata")));
 			}
 
 			string parentTooltip;

ILSpy/Metadata/CorTables/CustomAttributeTableTreeNode.cs

@@ -83,7 +83,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnParentClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, customAttr.Parent, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, customAttr.Parent, protocol: "metadata")));
 			}
 
 			string parentTooltip;
@@ -94,7 +94,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnConstructorClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, customAttr.Constructor, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, customAttr.Constructor, protocol: "metadata")));
 			}
 
 			string constructorTooltip;

ILSpy/Metadata/CorTables/DeclSecurityTableTreeNode.cs

@@ -84,7 +84,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnParentClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, declSecAttr.Parent, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, declSecAttr.Parent, protocol: "metadata")));
 			}
 
 			string parentTooltip;

ILSpy/Metadata/CorTables/EventMapTableTreeNode.cs

@@ -95,7 +95,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnParentClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, eventMap.Parent, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, eventMap.Parent, protocol: "metadata")));
 			}
 
 			string parentTooltip;
@@ -106,7 +106,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnEventListClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, eventMap.EventList, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, eventMap.EventList, protocol: "metadata")));
 			}
 
 			string eventListTooltip;

ILSpy/Metadata/CorTables/EventTableTreeNode.cs

@@ -103,7 +103,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnTypeClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, eventDef.Type, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, eventDef.Type, protocol: "metadata")));
 			}
 
 			string typeTooltip;

ILSpy/Metadata/CorTables/ExportedTypeTableTreeNode.cs

@@ -107,7 +107,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnImplementationClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, type.Implementation, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, type.Implementation, protocol: "metadata")));
 			}
 
 			string implementationTooltip;

ILSpy/Metadata/CorTables/FieldLayoutTableTreeNode.cs

@@ -96,7 +96,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnFieldClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, fieldLayout.Field, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, fieldLayout.Field, protocol: "metadata")));
 			}
 
 			string fieldTooltip;

ILSpy/Metadata/CorTables/FieldMarshalTableTreeNode.cs

@@ -95,7 +95,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnParentClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, fieldMarshal.Parent, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, fieldMarshal.Parent, protocol: "metadata")));
 			}
 
 			string parentTooltip;

ILSpy/Metadata/CorTables/FieldRVATableTreeNode.cs

@@ -99,7 +99,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnFieldClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, fieldRVA.Field, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, fieldRVA.Field, protocol: "metadata")));
 			}
 
 			string fieldTooltip;

ILSpy/Metadata/CorTables/GenericParamConstraintTableTreeNode.cs

@@ -84,7 +84,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnOwnerClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, genericParamConstraint.Parameter, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, genericParamConstraint.Parameter, protocol: "metadata")));
 			}
 
 			string ownerTooltip;
@@ -108,7 +108,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnTypeClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, genericParamConstraint.Type, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, genericParamConstraint.Type, protocol: "metadata")));
 			}
 
 			string typeTooltip;

ILSpy/Metadata/CorTables/GenericParamTableTreeNode.cs

@@ -92,7 +92,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnOwnerClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, genericParam.Parent, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, genericParam.Parent, protocol: "metadata")));
 			}
 
 			string ownerTooltip;

ILSpy/Metadata/CorTables/ImplMapTableTreeNode.cs

@@ -113,7 +113,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnMemberForwardedClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, implMap.MemberForwarded, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, implMap.MemberForwarded, protocol: "metadata")));
 			}
 
 			string memberForwardedTooltip;
@@ -124,7 +124,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnImportScopeClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, implMap.ImportScope, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, implMap.ImportScope, protocol: "metadata")));
 			}
 
 			string importScopeTooltip;

ILSpy/Metadata/CorTables/InterfaceImplTableTreeNode.cs

@@ -96,7 +96,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnClassClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, interfaceImpl.Class, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, interfaceImpl.Class, protocol: "metadata")));
 			}
 
 			string classTooltip;
@@ -107,7 +107,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnInterfaceClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, interfaceImpl.Interface, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, interfaceImpl.Interface, protocol: "metadata")));
 			}
 
 			string interfaceTooltip;

ILSpy/Metadata/CorTables/ManifestResourceTableTreeNode.cs

@@ -93,7 +93,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnImplementationClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, manifestResource.Implementation, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, manifestResource.Implementation, protocol: "metadata")));
 			}
 
 			string implementationTooltip;

ILSpy/Metadata/CorTables/MemberRefTableTreeNode.cs

@@ -83,7 +83,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnParentClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, memberRef.Parent, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, memberRef.Parent, protocol: "metadata")));
 			}
 
 			string parentTooltip;

ILSpy/Metadata/CorTables/MethodImplTableTreeNode.cs

@@ -82,7 +82,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnMethodDeclarationClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, methodImpl.MethodDeclaration, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, methodImpl.MethodDeclaration, protocol: "metadata")));
 			}
 
 			string methodDeclarationTooltip;
@@ -93,7 +93,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnMethodBodyClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, methodImpl.MethodBody, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, methodImpl.MethodBody, protocol: "metadata")));
 			}
 
 			string methodBodyTooltip;
@@ -104,7 +104,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnTypeClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, methodImpl.Type, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, methodImpl.Type, protocol: "metadata")));
 			}
 
 			string typeTooltip;

ILSpy/Metadata/CorTables/MethodSemanticsTableTreeNode.cs

@@ -90,7 +90,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnMethodClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, method, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, method, protocol: "metadata")));
 			}
 
 			string methodTooltip;
@@ -101,7 +101,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnAssociationClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, association, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, association, protocol: "metadata")));
 			}
 
 			string associationTooltip;

ILSpy/Metadata/CorTables/MethodSpecTableTreeNode.cs

@@ -85,7 +85,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnMethodClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, methodSpec.Method, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, methodSpec.Method, protocol: "metadata")));
 			}
 
 			string methodTooltip;

ILSpy/Metadata/CorTables/MethodTableTreeNode.cs

@@ -118,7 +118,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnParamListClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, methodDef.GetParameters().FirstOrDefault(), protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, methodDef.GetParameters().FirstOrDefault(), protocol: "metadata")));
 			}
 
 			string paramListTooltip;

ILSpy/Metadata/CorTables/NestedClassTableTreeNode.cs

@@ -95,7 +95,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnNestedClassClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, nestedClass.Nested, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, nestedClass.Nested, protocol: "metadata")));
 			}
 
 			string nestedClassTooltip;
@@ -106,7 +106,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnEnclosingClassClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, nestedClass.Enclosing, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, nestedClass.Enclosing, protocol: "metadata")));
 			}
 
 			string enclosingClassTooltip;

ILSpy/Metadata/CorTables/PropertyMapTableTreeNode.cs

@@ -95,7 +95,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnParentClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, propertyMap.Parent, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, propertyMap.Parent, protocol: "metadata")));
 			}
 
 			string parentTooltip;
@@ -106,7 +106,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnPropertyListClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, propertyMap.PropertyList, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, propertyMap.PropertyList, protocol: "metadata")));
 			}
 
 			string propertyListTooltip;

ILSpy/Metadata/CorTables/PtrTableTreeNode.cs

@@ -112,7 +112,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnHandleClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, handlePtr.Handle, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, handlePtr.Handle, protocol: "metadata")));
 			}
 
 			string handleTooltip;

ILSpy/Metadata/CorTables/TypeDefTableTreeNode.cs

@@ -111,7 +111,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnBaseTypeClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, typeDef.BaseType, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, typeDef.BaseType, protocol: "metadata")));
 			}
 
 			public string BaseTypeTooltip {
@@ -142,7 +142,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnFieldListClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, typeDef.GetFields().FirstOrDefault(), protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, typeDef.GetFields().FirstOrDefault(), protocol: "metadata")));
 			}
 
 			string fieldListTooltip;
@@ -160,7 +160,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnMethodListClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, typeDef.GetMethods().FirstOrDefault(), protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, typeDef.GetMethods().FirstOrDefault(), protocol: "metadata")));
 			}
 
 			string methodListTooltip;

ILSpy/Metadata/CorTables/TypeRefTableTreeNode.cs

@@ -83,7 +83,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnResolutionScopeClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, typeRef.ResolutionScope, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, typeRef.ResolutionScope, protocol: "metadata")));
 			}
 
 			string resolutionScopeTooltip;

ILSpy/Metadata/DebugMetadataTablesTreeNode.cs

@@ -21,7 +21,6 @@ using System.Reflection.Metadata.Ecma335;
 using ICSharpCode.Decompiler;
 using ICSharpCode.Decompiler.Metadata;
 using ICSharpCode.ILSpy.TreeNodes;
-using ICSharpCode.ILSpy.Util;
 using ICSharpCode.ILSpy.ViewModels;
 
 namespace ICSharpCode.ILSpy.Metadata

ILSpy/Metadata/DebugTables/CustomDebugInformationTableTreeNode.cs

@@ -188,7 +188,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnParentClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, debugInfo.Parent, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, debugInfo.Parent, protocol: "metadata")));
 			}
 
 			string parentTooltip;

ILSpy/Metadata/DebugTables/ImportScopeTableTreeNode.cs

@@ -80,7 +80,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnParentClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, localScope.Parent, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, localScope.Parent, protocol: "metadata")));
 			}
 
 			[ColumnInfo("X8", Kind = ColumnKind.HeapOffset)]

ILSpy/Metadata/DebugTables/LocalScopeTableTreeNode.cs

@@ -81,7 +81,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnMethodClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, localScope.Method, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, localScope.Method, protocol: "metadata")));
 			}
 
 			string methodTooltip;
@@ -92,7 +92,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnImportScopeClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, localScope.ImportScope, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, localScope.ImportScope, protocol: "metadata")));
 			}
 
 			[ColumnInfo("X8", Kind = ColumnKind.Token)]
@@ -100,7 +100,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnVariableListClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, localScope.GetLocalVariables().FirstOrDefault(), protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, localScope.GetLocalVariables().FirstOrDefault(), protocol: "metadata")));
 			}
 
 			[ColumnInfo("X8", Kind = ColumnKind.Token)]
@@ -108,7 +108,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnConstantListClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, localScope.GetLocalConstants().FirstOrDefault(), protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, localScope.GetLocalConstants().FirstOrDefault(), protocol: "metadata")));
 			}
 
 			public int StartOffset => localScope.StartOffset;

ILSpy/Metadata/DebugTables/MethodDebugInformationTableTreeNode.cs

@@ -83,7 +83,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnDocumentClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, debugInfo.Document, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, debugInfo.Document, protocol: "metadata")));
 			}
 
 			public string DocumentTooltip {
@@ -116,7 +116,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnLocalSignatureClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, debugInfo.LocalSignature, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, debugInfo.LocalSignature, protocol: "metadata")));
 			}
 
 			public string LocalSignatureTooltip {

ILSpy/Metadata/DebugTables/StateMachineMethodTableTreeNode.cs

@@ -83,7 +83,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnMoveNextMethodClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, moveNextMethod, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, moveNextMethod, protocol: "metadata")));
 			}
 
 			string moveNextMethodTooltip;
@@ -94,7 +94,7 @@ namespace ICSharpCode.ILSpy.Metadata
 
 			public void OnKickofMethodClick()
 			{
-				MainWindow.Instance.JumpToReference(new EntityReference(metadataFile, kickoffMethod, protocol: "metadata"));
+				MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(metadataFile, kickoffMethod, protocol: "metadata")));
 			}
 
 			string kickoffMethodTooltip;

ILSpy/Metadata/GoToTokenCommand.cs

@@ -23,12 +23,13 @@ using System.Reflection;
 using System.Reflection.Metadata.Ecma335;
 using System.Windows;
 using System.Windows.Controls;
-using System.Windows.Media;
 
 using ICSharpCode.Decompiler.Metadata;
 using ICSharpCode.ILSpy.Metadata;
 using ICSharpCode.ILSpy.Properties;
 
+using TomsToolbox.Wpf;
+
 namespace ICSharpCode.ILSpy.Commands
 {
 	[ExportContextMenuEntry(Header = nameof(Resources.GoToToken), Order = 10)]
@@ -38,7 +39,7 @@ namespace ICSharpCode.ILSpy.Commands
 		public void Execute(TextViewContext context)
 		{
 			int token = GetSelectedToken(context.DataGrid, out MetadataFile module).Value;
-			MainWindow.Instance.JumpToReference(new EntityReference(module, MetadataTokens.Handle(token), protocol: "metadata"));
+			MessageBus.Send(this, new NavigateToReferenceEventArgs(new EntityReference(module, MetadataTokens.Handle(token), protocol: "metadata")));
 		}
 
 		public bool IsEnabled(TextViewContext context)
@@ -75,7 +76,7 @@ namespace ICSharpCode.ILSpy.Commands
 	{
 		public void Execute(TextViewContext context)
 		{
-			string content = GetSelectedCellContent(context.DataGrid, context.MousePosition);
+			string content = GetSelectedCellContent(context.OriginalSource);
 			Clipboard.SetText(content);
 		}
 
@@ -87,21 +88,14 @@ namespace ICSharpCode.ILSpy.Commands
 		public bool IsVisible(TextViewContext context)
 		{
 			return context.DataGrid?.Name == "MetadataView"
-				&& GetSelectedCellContent(context.DataGrid, context.MousePosition) != null;
+				&& GetSelectedCellContent(context.OriginalSource) != null;
 		}
 
-		private string GetSelectedCellContent(DataGrid grid, Point position)
+		private static string GetSelectedCellContent(DependencyObject originalSource)
 		{
-			position = grid.PointFromScreen(position);
+			var cell = originalSource.AncestorsAndSelf().OfType<DataGridCell>().FirstOrDefault();
-			var hit = VisualTreeHelper.HitTest(grid, position);
+
-			if (hit == null)
+			return cell?.Column.OnCopyingCellClipboardContent(cell.DataContext).ToString();
-				return null;
-			var cell = hit.VisualHit.GetParent<DataGridCell>();
-			if (cell == null)
-				return null;
-			return cell.DataContext.GetType()
-				.GetProperty(cell.Column.Header.ToString(), BindingFlags.Instance | BindingFlags.Public)
-				.GetValue(cell.DataContext).ToString();
 		}
 	}
 }

ILSpy/Metadata/MetadataProtocolHandler.cs

@@ -34,7 +34,7 @@ namespace ICSharpCode.ILSpy.Metadata
 			newTabPage = true;
 			if (protocol != "metadata")
 				return null;
-			var assemblyTreeNode = MainWindow.Instance.FindTreeNode(module) as AssemblyTreeNode;
+			var assemblyTreeNode = MainWindow.Instance.AssemblyTreeModel.FindTreeNode(module) as AssemblyTreeNode;
 			if (assemblyTreeNode == null)
 				return null;
 			var mxNode = assemblyTreeNode.Children.OfType<MetadataTreeNode>().FirstOrDefault();