Move command handling from main window to command implementations.

ILSpy/App.xaml.cs

@@ -43,6 +43,9 @@ using ICSharpCode.ILSpyX.TreeView;
 
 using TomsToolbox.Composition;
 using TomsToolbox.Wpf.Composition;
+using ICSharpCode.ILSpy.Themes;
+using System.Globalization;
+using System.Threading;
 
 namespace ICSharpCode.ILSpy
 {
@@ -75,18 +78,20 @@ namespace ICSharpCode.ILSpy
 				SingleInstance.NewInstanceDetected += SingleInstance_NewInstanceDetected;
 			}
 
-			SharpTreeNode.SetImagesProvider(new WpfWindowsTreeNodeImagesProvider());
-
 			InitializeComponent();
 
-			Resources.RegisterDefaultStyles();
-
 			if (!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.
@@ -94,6 +99,13 @@ 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));
@@ -109,9 +121,11 @@ namespace ICSharpCode.ILSpy
 				string unknownArguments = string.Join(", ", CommandLineArguments.ArgumentsParser.RemainingArguments);
 				MessageBox.Show(unknownArguments, "ILSpy Unknown Command Line Arguments Passed");
 			}
+
+			SettingsService.Instance.AssemblyListManager.CreateDefaultAssemblyLists();
 		}
 
-		private static void SingleInstance_NewInstanceDetected(object sender, NewInstanceEventArgs e) => ExportProvider.GetExportedValue<AssemblyListPaneModel>().HandleSingleInstanceCommandLineArguments(e.Args).HandleExceptions();
+		private static void SingleInstance_NewInstanceDetected(object sender, NewInstanceEventArgs e) => ExportProvider.GetExportedValue<AssemblyTreeModel>().HandleSingleInstanceCommandLineArguments(e.Args).HandleExceptions();
 
 		static Assembly ResolvePluginDependencies(AssemblyLoadContext context, AssemblyName assemblyName)
 		{
@@ -203,7 +217,7 @@ namespace ICSharpCode.ILSpy
 
 			MainWindow = new MainWindow();
 			MainWindow.Loaded += (sender, args) => {
-				ExportProvider.GetExportedValue<AssemblyListPaneModel>().Initialize();
+				ExportProvider.GetExportedValue<AssemblyTreeModel>().Initialize();
 			};
 			MainWindow.Show();
 		}
@@ -266,7 +280,7 @@ namespace ICSharpCode.ILSpy
 
 		void Window_RequestNavigate(object sender, RequestNavigateEventArgs e)
 		{
-			ExportProvider.GetExportedValue<AssemblyListPaneModel>().NavigateTo(e);
+			ExportProvider.GetExportedValue<AssemblyTreeModel>().NavigateTo(e);
 		}
 	}
 }

ILSpy/AssemblyTree/AssemblyListPane.xaml

@@ -8,7 +8,7 @@
 						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:AssemblyListPaneModel}"
+						d:DataContext="{d:DesignInstance assemblyTree:AssemblyTreeModel}"
 						AutomationProperties.Name="Assemblies and Classes"
 						ShowRoot="False"
 						AllowDropOrder="True"

ILSpy/AssemblyTree/AssemblyListPane.xaml.cs

@@ -10,7 +10,7 @@ namespace ICSharpCode.ILSpy.AssemblyTree
 	/// <summary>
 	/// Interaction logic for AssemblyListPane.xaml
 	/// </summary>
-	[DataTemplate(typeof(AssemblyListPaneModel))]
+	[DataTemplate(typeof(AssemblyTreeModel))]
 	[PartCreationPolicy(CreationPolicy.NonShared)]
 	public partial class AssemblyListPane
 	{
@@ -27,7 +27,7 @@ namespace ICSharpCode.ILSpy.AssemblyTree
 
 			if (e.Property == DataContextProperty)
 			{
-				if (e.NewValue is not AssemblyListPaneModel model)
+				if (e.NewValue is not AssemblyTreeModel model)
 					return;
 
 				model.SetActiveView(this);

ILSpy/AssemblyTree/AssemblyTreeModel.cs

@@ -45,7 +45,6 @@ using ICSharpCode.Decompiler.Documentation;
 using ICSharpCode.Decompiler.TypeSystem.Implementation;
 using System.Reflection.Metadata;
 
-using ICSharpCode.ILSpyX.Extensions;
 using ICSharpCode.ILSpy.AppEnv;
 using ICSharpCode.ILSpy.Search;
 using ICSharpCode.Decompiler;
@@ -60,16 +59,16 @@ namespace ICSharpCode.ILSpy.AssemblyTree
 	[ExportToolPane]
 	[PartCreationPolicy(CreationPolicy.Shared)]
 	[Export]
-	public class AssemblyListPaneModel : ToolPaneModel
+	public class AssemblyTreeModel : ToolPaneModel
 	{
 		public const string PaneContentId = "assemblyListPane";
 
 		AssemblyListPane activeView;
 		AssemblyListTreeNode assemblyListTreeNode;
 
-		readonly NavigationHistoryService history = NavigationHistoryService.Instance;
+		readonly NavigationHistory<NavigationState> history = new();
 
-		public AssemblyListPaneModel()
+		public AssemblyTreeModel()
 		{
 			Title = Resources.Assemblies;
 			ContentId = PaneContentId;
@@ -795,6 +794,10 @@ namespace ICSharpCode.ILSpy.AssemblyTree
 			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")
@@ -914,5 +917,16 @@ namespace ICSharpCode.ILSpy.AssemblyTree
 				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 +28,32 @@ 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)
+		{
+			base.OnExecute(sender, 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 +28,33 @@ 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)
+		{
+			base.OnExecute(sender, e);
+
+			if (assemblyTreeModel.CanNavigateForward)
+			{
+				e.Handled = true;
+				assemblyTreeModel.NavigateHistory(true);
+			}
 		}
+
 	}
 }

ILSpy/Commands/CommandWrapper.cs

@@ -17,6 +17,7 @@
 // DEALINGS IN THE SOFTWARE.
 
 using System;
+using System.Windows;
 using System.Windows.Input;
 
 namespace ICSharpCode.ILSpy
@@ -28,15 +29,16 @@ namespace ICSharpCode.ILSpy
 		public 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 (w != null)
+			if (command is CommandWrapper w)
 				return w.wrappedCommand;
-			else
-				return command;
+
+			return command;
 		}
 
 		public event EventHandler CanExecuteChanged {
@@ -53,5 +55,14 @@ namespace ICSharpCode.ILSpy
 		{
 			return wrappedCommand.CanExecute(parameter);
 		}
+
+		protected virtual void OnExecute(object sender, ExecutedRoutedEventArgs e)
+		{
+		}
+
+		protected virtual void OnCanExecute(object sender, CanExecuteRoutedEventArgs e)
+		{
+			e.CanExecute = true;
+		}
 	}
 }

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 +31,30 @@ 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)
+		{
+			base.OnExecute(sender, 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();
-			dlg.Owner = MainWindow.Instance;
+			OpenFromGacDialog dlg = new OpenFromGacDialog {
+				Owner = MainWindow.Instance
+			};
+
 			if (dlg.ShowDialog() == true)
-				MainWindow.Instance.OpenFiles(dlg.SelectedFileNames);
+			{
+				assemblyTreeModel.OpenFiles(dlg.SelectedFileNames);
+			}
 		}
 	}
 }

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 +29,20 @@ 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)
+		{
+			base.OnExecute(sender, e);
+
+			assemblyTreeModel.Refresh();
 		}
 	}
 }

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 +30,26 @@ 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)
+		{
+			base.OnExecute(sender, e);
+
+			SaveCodeContextMenuEntry.Execute(assemblyTreeModel.SelectedNodes.ToList());
 		}
 	}
 }

ILSpy/Commands/SetThemeCommand.cs

@@ -7,12 +7,7 @@ namespace ICSharpCode.ILSpy.Commands
 		{
 			if (parameter is string theme)
 			{
-				var snapshot = SettingsService.Instance.CreateSnapshot();
-				var sessionSettings = snapshot.GetSettings<SessionSettings>();
-
-				sessionSettings.Theme = theme;
-
-				snapshot.Save();
+				SettingsService.Instance.SessionSettings.Theme = theme;
 			}
 		}
 	}

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/LanguageSettings.cs

@@ -16,11 +16,8 @@
 // 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.ILSpyX;
@@ -32,7 +29,7 @@ namespace ICSharpCode.ILSpy
 	/// <summary>
 	/// Represents the filters applied to the tree view.
 	/// </summary>
-	public class LanguageSettings : ObservableObject
+	public class LanguageSettings : ObservableObject, IChildSettings
 	{
 		/// <summary>
 		/// This dictionary is necessary to remember language versions across language changes. For example, 
@@ -41,14 +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(

ILSpy/Languages/Languages.cs

@@ -33,9 +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

ILSpy/MainWindow.xaml

@@ -35,30 +35,6 @@
 		<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>
@@ -184,7 +160,7 @@
 				<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/MainWindow.xaml.cs

@@ -20,9 +20,7 @@ using System;
 using System.ComponentModel;
 using System.Diagnostics;
 using System.Drawing;
-using System.Globalization;
 using System.Linq;
-using System.Threading;
 using System.Threading.Tasks;
 using System.Windows;
 using System.Windows.Input;
@@ -32,17 +30,12 @@ using AvalonDock.Layout.Serialization;
 
 using ICSharpCode.ILSpy.AssemblyTree;
 using ICSharpCode.ILSpy.Docking;
-using ICSharpCode.ILSpy.Search;
-using ICSharpCode.ILSpy.TextView;
-using ICSharpCode.ILSpy.Themes;
 using ICSharpCode.ILSpy.TreeNodes;
 using ICSharpCode.ILSpy.Updates;
 using ICSharpCode.ILSpyX.FileLoaders;
 using ICSharpCode.ILSpyX.Settings;
 using ICSharpCode.ILSpyX.TreeView;
 
-using Microsoft.Win32;
-
 using Screen = System.Windows.Forms.Screen;
 
 namespace ICSharpCode.ILSpy
@@ -52,17 +45,17 @@ namespace ICSharpCode.ILSpy
 	/// </summary>
 	partial class MainWindow : Window
 	{
-		readonly NavigationHistoryService history = NavigationHistoryService.Instance;
-
 		static MainWindow instance;
 
+		private readonly MainWindowViewModel mainWindowViewModel = new();
+
 		public static MainWindow Instance {
 			get { return instance; }
 		}
 
-		public AssemblyListPaneModel AssemblyTreeModel {
+		public AssemblyTreeModel AssemblyTreeModel {
 			get {
-				return App.ExportProvider.GetExportedValue<AssemblyListPaneModel>();
+				return App.ExportProvider.GetExportedValue<AssemblyTreeModel>();
 			}
 		}
 
@@ -70,27 +63,14 @@ namespace ICSharpCode.ILSpy
 		{
 			instance = this;
 
-			var sessionSettings = SettingsService.Instance.SessionSettings;
-			ThemeManager.Current.Theme = sessionSettings.Theme;
-
 			// Make sure Images are initialized on the UI thread.
 			this.Icon = Images.ILSpyIcon;
 
-			this.DataContext = new MainWindowViewModel {
-				Workspace = DockWorkspace.Instance,
-				SessionSettings = sessionSettings,
-				AssemblyListManager = SettingsService.Instance.AssemblyListManager
-			};
-
-			SettingsService.Instance.AssemblyListManager.CreateDefaultAssemblyLists();
-			if (!string.IsNullOrEmpty(sessionSettings.CurrentCulture))
-			{
-				Thread.CurrentThread.CurrentUICulture = new CultureInfo(sessionSettings.CurrentCulture);
-			}
+			this.DataContext = mainWindowViewModel;
 
 			InitializeComponent();
 
-			DockWorkspace.Instance.InitializeLayout(dockManager);
+			mainWindowViewModel.Workspace.InitializeLayout(dockManager);
 
 			MenuService.Instance.Init(mainMenu, toolBar, InputBindings);
 
@@ -165,6 +145,7 @@ namespace ICSharpCode.ILSpy
 		}
 
 		#region Update Check
+
 		string updateAvailableDownloadUrl;
 
 		public async Task ShowMessageIfUpdatesAvailableAsync(ISettingsProvider spySettings, bool forceCheck = false)
@@ -188,7 +169,7 @@ namespace ICSharpCode.ILSpy
 			updatePanel.Visibility = Visibility.Collapsed;
 		}
 
-		async void downloadOrCheckUpdateButtonClick(object sender, RoutedEventArgs e)
+		async void DownloadOrCheckUpdateButtonClick(object sender, RoutedEventArgs e)
 		{
 			if (updateAvailableDownloadUrl != null)
 			{
@@ -217,6 +198,7 @@ namespace ICSharpCode.ILSpy
 				downloadOrCheckUpdateButton.Content = Properties.Resources.CheckAgain;
 			}
 		}
+
 		#endregion
 
 		public static void OpenLink(string link)
@@ -249,85 +231,6 @@ namespace ICSharpCode.ILSpy
 			}
 		}
 
-		#region Open/Refresh
-		void OpenCommandExecuted(object sender, ExecutedRoutedEventArgs e)
-		{
-			e.Handled = true;
-			OpenFileDialog dlg = new OpenFileDialog();
-			dlg.Filter = ".NET assemblies|*.dll;*.exe;*.winmd;*.wasm|Nuget Packages (*.nupkg)|*.nupkg|Portable Program Database (*.pdb)|*.pdb|All files|*.*";
-			dlg.Multiselect = true;
-			dlg.RestoreDirectory = true;
-			if (dlg.ShowDialog() == true)
-			{
-				OpenFiles(dlg.FileNames);
-			}
-		}
-
-		public void OpenFiles(string[] fileNames, bool focusNode = true)
-		{
-			if (fileNames == null)
-				throw new ArgumentNullException(nameof(fileNames));
-
-			if (focusNode)
-				AssemblyTreeModel.UnselectAll();
-
-			AssemblyTreeModel.LoadAssemblies(fileNames, focusNode: focusNode);
-		}
-
-		void RefreshCommandExecuted(object sender, ExecutedRoutedEventArgs e)
-		{
-			AssemblyTreeModel.Refresh();
-		}
-
-		void SearchCommandExecuted(object sender, ExecutedRoutedEventArgs e)
-		{
-			DockWorkspace.Instance.ShowToolPane(SearchPaneModel.PaneContentId);
-		}
-		#endregion
-
-		void SaveCommandCanExecute(object sender, CanExecuteRoutedEventArgs e)
-		{
-			e.Handled = true;
-			e.CanExecute = SaveCodeContextMenuEntry.CanExecute(AssemblyTreeModel.SelectedNodes.ToList());
-		}
-
-		void SaveCommandExecuted(object sender, ExecutedRoutedEventArgs e)
-		{
-			SaveCodeContextMenuEntry.Execute(AssemblyTreeModel.SelectedNodes.ToList());
-		}
-
-		#region Back/Forward navigation
-		void BackCommandCanExecute(object sender, CanExecuteRoutedEventArgs e)
-		{
-			e.Handled = true;
-			e.CanExecute = history.CanNavigateBack;
-		}
-
-		void BackCommandExecuted(object sender, ExecutedRoutedEventArgs e)
-		{
-			if (history.CanNavigateBack)
-			{
-				e.Handled = true;
-				AssemblyTreeModel.NavigateHistory(false);
-			}
-		}
-
-		void ForwardCommandCanExecute(object sender, CanExecuteRoutedEventArgs e)
-		{
-			e.Handled = true;
-			e.CanExecute = history.CanNavigateForward;
-		}
-
-		void ForwardCommandExecuted(object sender, ExecutedRoutedEventArgs e)
-		{
-			if (history.CanNavigateForward)
-			{
-				e.Handled = true;
-				AssemblyTreeModel.NavigateHistory(true);
-			}
-		}
-		#endregion
-
 		protected override void OnStateChanged(EventArgs e)
 		{
 			base.OnStateChanged(e);

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 SessionSettings SessionSettings { get; set; }
-		public AssemblyListManager AssemblyListManager { get; set; }
+		public DockWorkspace Workspace => DockWorkspace.Instance;
+		public SessionSettings SessionSettings => SettingsService.Instance.SessionSettings;
+		public AssemblyListManager AssemblyListManager => SettingsService.Instance.AssemblyListManager;
 	}
 }

ILSpy/Options/OptionsDialog.xaml.cs

@@ -18,10 +18,9 @@
 
 using System;
 using System.ComponentModel.Composition;
-using System.Xml.Linq;
 
+using ICSharpCode.ILSpy.AssemblyTree;
 using ICSharpCode.ILSpy.Properties;
-using ICSharpCode.ILSpyX.Settings;
 
 namespace ICSharpCode.ILSpy.Options
 {
@@ -62,6 +61,14 @@ namespace ICSharpCode.ILSpy.Options
 	[PartCreationPolicy(CreationPolicy.Shared)]
 	sealed class ShowOptionsCommand : SimpleCommand
 	{
+		private readonly AssemblyTreeModel assemblyTreeModel;
+
+		[ImportingConstructor]
+		public ShowOptionsCommand(AssemblyTreeModel assemblyTreeModel)
+		{
+			this.assemblyTreeModel = assemblyTreeModel;
+		}
+
 		public override void Execute(object parameter)
 		{
 			OptionsDialog dlg = new() {
@@ -69,7 +76,7 @@ namespace ICSharpCode.ILSpy.Options
 			};
 			if (dlg.ShowDialog() == true)
 			{
-				new RefreshCommand().Execute(parameter);
+				assemblyTreeModel.Refresh();
 			}
 		}
 	}

ILSpy/Search/SearchPane.xaml.cs

@@ -33,6 +33,7 @@ using System.Windows.Media;
 using System.Windows.Threading;
 
 using ICSharpCode.ILSpy.AppEnv;
+using ICSharpCode.ILSpy.Docking;
 using ICSharpCode.ILSpy.ViewModels;
 using ICSharpCode.ILSpyX;
 using ICSharpCode.ILSpyX.Extensions;
@@ -546,5 +547,12 @@ namespace ICSharpCode.ILSpy.Search
 			gestures.Add(new KeyGesture(Key.F, ModifierKeys.Control | ModifierKeys.Shift));
 			gestures.Add(new KeyGesture(Key.E, ModifierKeys.Control));
 		}
+
+		protected override void OnExecute(object sender, ExecutedRoutedEventArgs e)
+		{
+			base.OnExecute(sender, e);
+
+			DockWorkspace.Instance.ShowToolPane(SearchPaneModel.PaneContentId);
+		}
 	}
 }

ILSpy/SessionSettings.cs

@@ -45,7 +45,7 @@ namespace ICSharpCode.ILSpy
 		{
 			XElement filterSettings = section.Element("FilterSettings") ?? new XElement("FilterSettings");
 
-			LanguageSettings = new(filterSettings);
+			LanguageSettings = new(filterSettings, this);
 			LanguageSettings.PropertyChanged += (sender, e) => PropertyChanged?.Invoke(sender, e);
 
 			ActiveAssemblyList = (string)section.Element("ActiveAssemblyList");

ILSpy/TextView/DecompilerTextView.cs

@@ -474,7 +474,7 @@ namespace ICSharpCode.ILSpy.TextView
 
 			IEntity? ResolveReference(string idString)
 			{
-				return AssemblyListPaneModel.FindEntityInRelevantAssemblies(idString, MainWindow.Instance.AssemblyTreeModel.AssemblyList.GetAssemblies());
+				return AssemblyTreeModel.FindEntityInRelevantAssemblies(idString, MainWindow.Instance.AssemblyTreeModel.AssemblyList.GetAssemblies());
 			}
 		}
 

ILSpy/TreeNodes/AssemblyTreeNode.cs

@@ -631,7 +631,7 @@ namespace ICSharpCode.ILSpy.TreeNodes
 			{
 				foreach (var node in context.SelectedTreeNodes)
 				{
-					paths.Add(AssemblyListPaneModel.GetPathForNode(node));
+					paths.Add(AssemblyTreeModel.GetPathForNode(node));
 					var la = ((AssemblyTreeNode)node).LoadedAssembly;
 					la.AssemblyList.ReloadAssembly(la.FileName);
 				}

ILSpy/Util/NavigationHistoryService.cs

@@ -1,48 +0,0 @@
-using System;
-
-namespace ICSharpCode.ILSpy.Util
-{
-	public class NavigationHistoryService
-	{
-		readonly NavigationHistory<NavigationState> history = new();
-
-		public static NavigationHistoryService Instance { get; } = new();
-
-		public bool CanNavigateBack => history.CanNavigateBack;
-		public bool CanNavigateForward => history.CanNavigateForward;
-
-		private NavigationHistoryService()
-		{
-		}
-
-		public void UpdateCurrent(NavigationState navigationState)
-		{
-			history.UpdateCurrent(navigationState);
-		}
-
-		public void Record(NavigationState navigationState)
-		{
-			history.Record(navigationState);
-		}
-
-		public NavigationState GoForward()
-		{
-			return history.GoForward();
-		}
-
-		public NavigationState GoBack()
-		{
-			return history.GoBack();
-		}
-
-		public void Clear()
-		{
-			history.Clear();
-		}
-
-		public void RemoveAll(Predicate<NavigationState> predicate)
-		{
-			history.RemoveAll(predicate);
-		}
-	}
-}

ILSpy/Util/SettingsService.cs

@@ -15,6 +15,11 @@ using DecompilerSettings = ICSharpCode.ILSpy.Options.DecompilerSettings;
 
 namespace ICSharpCode.ILSpy.Util
 {
+	public interface IChildSettings
+	{
+		ISettingsSection Parent { get; }
+	}
+
 	public interface ISettingsSection : INotifyPropertyChanged
 	{
 		XName SectionName { get; }
@@ -49,6 +54,19 @@ namespace ICSharpCode.ILSpy.Util
 			});
 		}
 
+		protected void SaveSection(ISettingsSection section, XElement root)
+		{
+			var element = SpySettings[section.SectionName];
+
+			section.SaveToSection(element);
+
+			var existingElement = root.Element(section.SectionName);
+			if (existingElement != null)
+				existingElement.ReplaceWith(element);
+			else
+				root.Add(element);
+		}
+
 		protected virtual void Section_PropertyChanged(object? sender, PropertyChangedEventArgs e)
 		{
 		}
@@ -68,15 +86,7 @@ namespace ICSharpCode.ILSpy.Util
 			SpySettings.Update(root => {
 				foreach (var section in sections.Values)
 				{
-					var element = SpySettings[section.SectionName];
-
-					section.SaveToSection(element);
-
-					var existingElement = root.Element(section.SectionName);
-					if (existingElement != null)
-						existingElement.ReplaceWith(element);
-					else
-						root.Add(element);
+					SaveSection(section, root);
 				}
 			});
 
@@ -160,7 +170,14 @@ namespace ICSharpCode.ILSpy.Util
 
 			if (!reloading)
 			{
-				throw new InvalidOperationException("Settings are read only, use a snapshot to modify.");
+				var section = (sender as IChildSettings)?.Parent ?? sender as ISettingsSection;
+
+				if (section != null)
+				{
+					SpySettings.Update(root => {
+						SaveSection(section, root);
+					});
+				};
 			}
 
 			if (sender is DecompilerSettings decompilerSettings && assemblyListManager != null)