Use MEF for the existing File menu items.

ILSpy/AboutPage.cs

@@ -21,7 +21,7 @@ using ICSharpCode.ILSpy.TextView;
 
 namespace ICSharpCode.ILSpy
 {
-	[ExportMainMenuCommand(Menu = "_Help", Header = "_About", Order = 99999)]
+	[ExportMainMenuCommand(Menu = "_Help", Header = "_About", MenuOrder = 99999)]
 	sealed class AboutPage : SimpleCommand
 	{
 		[Import]

ILSpy/AssemblyList.cs

@@ -32,7 +32,7 @@ namespace ICSharpCode.ILSpy
 	/// <summary>
 	/// A list of assemblies.
 	/// </summary>
-	sealed class AssemblyList
+	public sealed class AssemblyList
 	{
 		readonly string listName;
 		
@@ -81,7 +81,7 @@ namespace ICSharpCode.ILSpy
 		/// <summary>
 		/// Saves this assembly list to XML.
 		/// </summary>
-		public XElement SaveAsXml()
+		internal XElement SaveAsXml()
 		{
 			return new XElement(
 				"List",

ILSpy/Commands.cs

@@ -2,11 +2,16 @@
 // This code is distributed under MIT X11 license (for details please see \doc\license.txt)
 
 using System;
+using System.ComponentModel.Composition;
+using System.Linq;
 using System.Windows.Input;
 
+using ICSharpCode.ILSpy.TextView;
+using ICSharpCode.ILSpy.TreeNodes;
+
 namespace ICSharpCode.ILSpy
 {
-	[ExportMainMenuCommand(Menu = "_File", Header = "E_xit", Order = 99999, Category = "Exit")]
+	[ExportMainMenuCommand(Menu = "_File", Header = "E_xit", MenuOrder = 99999, MenuCategory = "Exit")]
 	sealed class ExitCommand : SimpleCommand
 	{
 		public override void Execute(object parameter)
@@ -15,26 +20,57 @@ namespace ICSharpCode.ILSpy
 		}
 	}
 	
-	[ExportToolbarCommand(ToolTip = "Back", Icon = "Images/Back.png", Category = "Navigation")]
+	[ExportToolbarCommand(ToolTip = "Back", ToolbarIcon = "Images/Back.png", ToolbarCategory = "Navigation", ToolbarOrder = 0)]
 	sealed class BrowseBackCommand : CommandWrapper {
 		public BrowseBackCommand() : base(NavigationCommands.BrowseBack) {}
 	}
 	
-	[ExportToolbarCommand(ToolTip = "Forward", Icon = "Images/Forward.png", Category = "Navigation", Order = 1)]
+	[ExportToolbarCommand(ToolTip = "Forward", ToolbarIcon = "Images/Forward.png", ToolbarCategory = "Navigation", ToolbarOrder = 1)]
 	sealed class BrowseForwardCommand : CommandWrapper {
 		public BrowseForwardCommand() : base(NavigationCommands.BrowseForward) {}
 	}
 	
-	[ExportToolbarCommand(ToolTip = "Open", Icon = "Images/Open.png", Category = "Open")]
+	[ExportToolbarCommand(ToolTip = "Open", ToolbarIcon = "Images/Open.png", ToolbarCategory = "Open", ToolbarOrder = 0)]
+	[ExportMainMenuCommand(Menu = "_File", MenuIcon = "Images/Open.png", MenuCategory = "Open", MenuOrder = 0)]
 	sealed class OpenCommand : CommandWrapper {
 		public OpenCommand() : base(ApplicationCommands.Open) {}
 	}
 	
-	[ExportToolbarCommand(ToolTip = "Reload all assemblies", Icon = "Images/Refresh.png", Category = "Open", Order = 1)]
+	[ExportMainMenuCommand(Menu = "_File", Header = "Open from _GAC", MenuCategory = "Open", MenuOrder = 1)]
+	sealed class OpenFromGacCommand : SimpleCommand
+	{
+		public override void Execute(object parameter)
+		{
+			OpenFromGacDialog dlg = new OpenFromGacDialog();
+			dlg.Owner = MainWindow.Instance;
+			if (dlg.ShowDialog() == true) {
+				MainWindow.Instance.OpenFiles(dlg.SelectedFileNames);
+			}
+		}
+	}
+	
+	[ExportToolbarCommand(ToolTip = "Reload all assemblies", ToolbarIcon = "Images/Refresh.png", ToolbarCategory = "Open", ToolbarOrder = 2)]
+	[ExportMainMenuCommand(Menu = "_File", Header = "Reload", MenuIcon = "Images/Refresh.png", MenuCategory = "Open", MenuOrder = 2)]
 	sealed class RefreshCommand : CommandWrapper {
 		public RefreshCommand() : base(NavigationCommands.Refresh) {}
 	}
 	
+	[ExportMainMenuCommand(Menu = "_File", Header = "_Save Code...", MenuIcon = "Images/SaveFile.png", MenuCategory = "Save", MenuOrder = 0)]
+	sealed class SaveCommand : SimpleCommand
+	{
+		public override void Execute(object parameter)
+		{
+			MainWindow mainWindow = MainWindow.Instance;
+			if (mainWindow.SelectedNodes.Count() == 1) {
+				if (mainWindow.SelectedNodes.Single().Save(mainWindow.TextView))
+					return;
+			}
+			mainWindow.TextView.SaveToDisk(mainWindow.CurrentLanguage,
+			                               mainWindow.SelectedNodes,
+			                               new DecompilationOptions() { FullDecompilation = true });
+		}
+	}
+	
 	class CommandWrapper : ICommand
 	{
 		ICommand wrappedCommand;
@@ -44,6 +80,15 @@ namespace ICSharpCode.ILSpy
 			this.wrappedCommand = wrappedCommand;
 		}
 		
+		public static ICommand Unwrap(ICommand command)
+		{
+			CommandWrapper w = command as CommandWrapper;
+			if (w != null)
+				return w.wrappedCommand;
+			else
+				return command;
+		}
+		
 		public event EventHandler CanExecuteChanged {
 			add { wrappedCommand.CanExecuteChanged += value; }
 			remove { wrappedCommand.CanExecuteChanged -= value; }

ILSpy/ExportCommandAttribute.cs

@@ -10,11 +10,11 @@ namespace ICSharpCode.ILSpy
 	#region Toolbar
 	public interface IToolbarCommandMetadata
 	{
-		string Icon { get; }
+		string ToolbarIcon { get; }
 		string ToolTip { get; }
-		string Category { get; }
+		string ToolbarCategory { get; }
 		
-		double Order { get; }
+		double ToolbarOrder { get; }
 	}
 	
 	[MetadataAttribute]
@@ -27,21 +27,21 @@ namespace ICSharpCode.ILSpy
 		}
 		
 		public string ToolTip { get; set; }
-		public string Icon { get; set; }
-		public string Category { get; set; }
-		public double Order { get; set; }
+		public string ToolbarIcon { get; set; }
+		public string ToolbarCategory { get; set; }
+		public double ToolbarOrder { get; set; }
 	}
 	#endregion
 	
 	#region Main Menu
 	public interface IMainMenuCommandMetadata
 	{
-		string Icon { get; }
+		string MenuIcon { get; }
 		string Header { get; }
 		string Menu { get; }
-		string Category { get; }
+		string MenuCategory { get; }
 		
-		double Order { get; }
+		double MenuOrder { get; }
 	}
 	
 	[MetadataAttribute]
@@ -53,11 +53,11 @@ namespace ICSharpCode.ILSpy
 		{
 		}
 		
-		public string Icon { get; set; }
+		public string MenuIcon { get; set; }
 		public string Header { get; set; }
 		public string Menu { get; set; }
-		public string Category { get; set; }
-		public double Order { get; set; }
+		public string MenuCategory { get; set; }
+		public double MenuOrder { get; set; }
 	}
 	#endregion
 }

ILSpy/LoadedAssembly.cs

@@ -14,7 +14,7 @@ namespace ICSharpCode.ILSpy
 	/// <summary>
 	/// Represents an assembly loaded into ILSpy.
 	/// </summary>
-	sealed class LoadedAssembly
+	public sealed class LoadedAssembly
 	{
 		readonly Task<AssemblyDefinition> assemblyTask;
 		readonly AssemblyList assemblyList;

ILSpy/MainWindow.xaml

@@ -34,25 +34,7 @@
 	<DockPanel>
 		<!-- Main menu -->
 		<Menu DockPanel.Dock="Top" Name="mainMenu">
-			<MenuItem Header="_File">
-				<MenuItem Command="Open">
-					<MenuItem.Icon>
-						<Image Width="16" Height="16" Source="Images/Open.png" />
-					</MenuItem.Icon>
-				</MenuItem>
-				<MenuItem Header="Open from _GAC" Click="OpenFromGac_Click" />
-				<MenuItem Command="Refresh" Header="_Reload">
-					<MenuItem.Icon>
-						<Image Width="16" Height="16" Source="Images/Refresh.png" />
-					</MenuItem.Icon>
-				</MenuItem>
-				<Separator />
-				<MenuItem Header="_Save Code" Click="saveCode_Click">
-					<MenuItem.Icon>
-						<Image Width="16" Height="16" Source="Images/SaveFile.png" />
-					</MenuItem.Icon>
-				</MenuItem>
-			</MenuItem>
+			<MenuItem Header="_File" /> <!-- contents of file menu are added using MEF -->
 			<MenuItem Header="_View">
 				<MenuItem Header="Show _internal types and members" IsCheckable="True" IsChecked="{Binding FilterSettings.ShowInternalApi}">
 					<MenuItem.Icon>

ILSpy/MainWindow.xaml.cs

@@ -107,7 +107,7 @@ namespace ICSharpCode.ILSpy
 		{
 			int navigationPos = 0;
 			int openPos = 1;
-			foreach (var commandGroup in toolbarCommands.OrderBy(c => c.Metadata.Order).GroupBy(c => c.Metadata.Category)) {
+			foreach (var commandGroup in toolbarCommands.OrderBy(c => c.Metadata.ToolbarOrder).GroupBy(c => c.Metadata.ToolbarCategory)) {
 				if (commandGroup.Key == "Navigation") {
 					foreach (var command in commandGroup) {
 						toolBar.Items.Insert(navigationPos++, MakeToolbarItem(command));
@@ -130,12 +130,12 @@ namespace ICSharpCode.ILSpy
 		Button MakeToolbarItem(Lazy<ICommand, IToolbarCommandMetadata> command)
 		{
 			return new Button {
-				Command = command.Value,
+				Command = CommandWrapper.Unwrap(command.Value),
 				ToolTip = command.Metadata.ToolTip,
 				Content = new Image {
 					Width = 16,
 					Height = 16,
-					Source = Images.LoadImage(command.Value, command.Metadata.Icon)
+					Source = Images.LoadImage(command.Value, command.Metadata.ToolbarIcon)
 				}
 			};
 		}
@@ -147,25 +147,26 @@ namespace ICSharpCode.ILSpy
 		
 		void InitMainMenu()
 		{
-			foreach (var topLevelMenu in mainMenuCommands.OrderBy(c => c.Metadata.Order).GroupBy(c => c.Metadata.Menu)) {
+			foreach (var topLevelMenu in mainMenuCommands.OrderBy(c => c.Metadata.MenuOrder).GroupBy(c => c.Metadata.Menu)) {
 				var topLevelMenuItem = mainMenu.Items.OfType<MenuItem>().FirstOrDefault(m => (m.Header as string) == topLevelMenu.Key);
-				foreach (var category in topLevelMenu.GroupBy(c => c.Metadata.Category)) {
+				foreach (var category in topLevelMenu.GroupBy(c => c.Metadata.MenuCategory)) {
 					if (topLevelMenuItem == null) {
 						topLevelMenuItem = new MenuItem();
 						topLevelMenuItem.Header = topLevelMenu.Key;
 						mainMenu.Items.Add(topLevelMenuItem);
-					} else {
+					} else if (topLevelMenuItem.Items.Count > 0) {
 						topLevelMenuItem.Items.Add(new Separator());
 					}
 					foreach (var entry in category) {
 						MenuItem menuItem = new MenuItem();
-						menuItem.Header = entry.Metadata.Header;
-						menuItem.Command = entry.Value;
-						if (!string.IsNullOrEmpty(entry.Metadata.Icon)) {
+						menuItem.Command = CommandWrapper.Unwrap(entry.Value);
+						if (!string.IsNullOrEmpty(entry.Metadata.Header))
+							menuItem.Header = entry.Metadata.Header;
+						if (!string.IsNullOrEmpty(entry.Metadata.MenuIcon)) {
 							menuItem.Icon = new Image {
 								Width = 16,
 								Height = 16,
-								Source = Images.LoadImage(entry.Value, entry.Metadata.Icon)
+								Source = Images.LoadImage(entry.Value, entry.Metadata.MenuIcon)
 							};
 						}
 						topLevelMenuItem.Items.Add(menuItem);
@@ -388,8 +389,10 @@ namespace ICSharpCode.ILSpy
 			}
 		}
 		
-		void OpenFiles(string[] fileNames)
+		public void OpenFiles(string[] fileNames)
 		{
+			if (fileNames == null)
+				throw new ArgumentNullException("fileNames");
 			treeView.UnselectAll();
 			SharpTreeNode lastNode = null;
 			foreach (string file in fileNames) {
@@ -413,18 +416,9 @@ namespace ICSharpCode.ILSpy
 			ShowAssemblyList(assemblyListManager.LoadList(ILSpySettings.Load(), assemblyList.ListName));
 			SelectNode(FindNodeByPath(path, true));
 		}
-		
-		void OpenFromGac_Click(object sender, RoutedEventArgs e)
-		{
-			OpenFromGacDialog dlg = new OpenFromGacDialog();
-			dlg.Owner = this;
-			if (dlg.ShowDialog() == true) {
-				OpenFiles(dlg.SelectedFileNames);
-			}
-		}
 		#endregion
 		
-		#region Decompile / Save
+		#region Decompile (TreeView_SelectionChanged)
 		void TreeView_SelectionChanged(object sender, SelectionChangedEventArgs e)
 		{
 			if (treeView.SelectedItems.Count == 1) {
@@ -432,21 +426,23 @@ namespace ICSharpCode.ILSpy
 				if (node != null && node.View(decompilerTextView))
 					return;
 			}
-			decompilerTextView.Decompile(sessionSettings.FilterSettings.Language,
-			                             treeView.GetTopLevelSelection().OfType<ILSpyTreeNode>(),
-			                             new DecompilationOptions());
+			decompilerTextView.Decompile(this.CurrentLanguage, this.SelectedNodes, new DecompilationOptions());
 		}
 		
-		void saveCode_Click(object sender, RoutedEventArgs e)
-		{
-			if (treeView.SelectedItems.Count == 1) {
-				ILSpyTreeNode node = treeView.SelectedItem as ILSpyTreeNode;
-				if (node != null && node.Save(decompilerTextView))
-					return;
+		public DecompilerTextView TextView {
+			get { return decompilerTextView; }
+		}
+		
+		public Language CurrentLanguage {
+			get {
+				return sessionSettings.FilterSettings.Language;
+			}
+		}
+		
+		public IEnumerable<ILSpyTreeNode> SelectedNodes {
+			get {
+				return treeView.GetTopLevelSelection().OfType<ILSpyTreeNode>();
 			}
-			decompilerTextView.SaveToDisk(sessionSettings.FilterSettings.Language,
-			                              treeView.GetTopLevelSelection().OfType<ILSpyTreeNode>(),
-			                              new DecompilationOptions() { FullDecompilation = true });
 		}
 		#endregion
 		

ILSpy/TreeNodes/AssemblyTreeNode.cs

@@ -38,7 +38,7 @@ namespace ICSharpCode.ILSpy.TreeNodes
 	/// Tree node representing an assembly.
 	/// This class is responsible for loading both namespace and type nodes.
 	/// </summary>
-	sealed class AssemblyTreeNode : ILSpyTreeNode
+	public sealed class AssemblyTreeNode : ILSpyTreeNode
 	{
 		readonly LoadedAssembly assembly;
 		readonly List<TypeTreeNode> classes = new List<TypeTreeNode>();

ILSpy/TreeNodes/EventTreeNode.cs

@@ -25,7 +25,7 @@ namespace ICSharpCode.ILSpy.TreeNodes
 	/// <summary>
 	/// Represents an event in the TreeView.
 	/// </summary>
-	sealed class EventTreeNode : ILSpyTreeNode
+	public sealed class EventTreeNode : ILSpyTreeNode
 	{
 		readonly EventDefinition ev;
 		

ILSpy/TreeNodes/FieldTreeNode.cs

@@ -27,7 +27,7 @@ namespace ICSharpCode.ILSpy.TreeNodes
 	/// <summary>
 	/// Represents a field in the TreeView.
 	/// </summary>
-	sealed class FieldTreeNode : ILSpyTreeNode
+	public sealed class FieldTreeNode : ILSpyTreeNode
 	{
 		readonly FieldDefinition field;
 		

ILSpy/TreeNodes/MethodTreeNode.cs

@@ -29,7 +29,7 @@ namespace ICSharpCode.ILSpy.TreeNodes
 	/// <summary>
 	/// Tree Node representing a field, method, property, or event.
 	/// </summary>
-	sealed class MethodTreeNode : ILSpyTreeNode
+	public sealed class MethodTreeNode : ILSpyTreeNode
 	{
 		MethodDefinition method;
 		

ILSpy/TreeNodes/NamespaceTreeNode.cs

@@ -25,7 +25,7 @@ namespace ICSharpCode.ILSpy.TreeNodes
 	/// <summary>
 	/// Namespace node. The loading of the type nodes is handled by the parent AssemblyTreeNode.
 	/// </summary>
-	sealed class NamespaceTreeNode : ILSpyTreeNode
+	public sealed class NamespaceTreeNode : ILSpyTreeNode
 	{
 		string name;
 		

ILSpy/TreeNodes/PropertyTreeNode.cs

@@ -25,7 +25,7 @@ namespace ICSharpCode.ILSpy.TreeNodes
 	/// <summary>
 	/// Represents a property in the TreeView.
 	/// </summary>
-	sealed class PropertyTreeNode : ILSpyTreeNode
+	public sealed class PropertyTreeNode : ILSpyTreeNode
 	{
 		readonly PropertyDefinition property;
 		readonly bool isIndexer;

ILSpy/TreeNodes/TypeTreeNode.cs

@@ -26,7 +26,7 @@ using Mono.Cecil;
 
 namespace ICSharpCode.ILSpy.TreeNodes
 {
-	sealed class TypeTreeNode : ILSpyTreeNode
+	public sealed class TypeTreeNode : ILSpyTreeNode
 	{
 		readonly TypeDefinition type;
 		readonly AssemblyTreeNode parentAssemblyNode;