Fixes icsharpcode#2605: Add possibility to add submenu items

ILSpy/AboutPage.cs

@@ -38,7 +38,7 @@
 
 namespace ICSharpCode.ILSpy
 {
-	[ExportMainMenuCommand(Menu = nameof(Resources._Help), Header = nameof(Resources._About), MenuOrder = 99999)]
+	[ExportMainMenuCommand(ParentMenuID = nameof(Resources._Help), Header = nameof(Resources._About), MenuOrder = 99999)]
 	sealed class AboutPage : SimpleCommand
 	{
 		public override void Execute(object parameter)

ILSpy/Commands/CheckForUpdatesCommand.cs

@@ -21,7 +21,7 @@
 
 namespace ICSharpCode.ILSpy
 {
-	[ExportMainMenuCommand(Menu = nameof(Resources._Help), Header = nameof(Resources._CheckUpdates), MenuOrder = 5000)]
+	[ExportMainMenuCommand(ParentMenuID = nameof(Resources._Help), Header = nameof(Resources._CheckUpdates), MenuOrder = 5000)]
 	sealed class CheckForUpdatesCommand : SimpleCommand
 	{
 		public override bool CanExecute(object parameter)

ILSpy/Commands/DecompileAllCommand.cs

@@ -30,7 +30,7 @@
 
 namespace ICSharpCode.ILSpy
 {
-	[ExportMainMenuCommand(Menu = nameof(Resources._File), Header = nameof(Resources.DEBUGDecompile), MenuCategory = nameof(Resources.Open), MenuOrder = 2.5)]
+	[ExportMainMenuCommand(ParentMenuID = nameof(Resources._File), Header = nameof(Resources.DEBUGDecompile), MenuCategory = nameof(Resources.Open), MenuOrder = 2.5)]
 	sealed class DecompileAllCommand : SimpleCommand
 	{
 		public override bool CanExecute(object parameter)
@@ -79,7 +79,7 @@ public override void Execute(object parameter)
 		}
 	}
 
-	[ExportMainMenuCommand(Menu = nameof(Resources._File), Header = nameof(Resources.DEBUGDecompile100x), MenuCategory = nameof(Resources.Open), MenuOrder = 2.6)]
+	[ExportMainMenuCommand(ParentMenuID = nameof(Resources._File), Header = nameof(Resources.DEBUGDecompile100x), MenuCategory = nameof(Resources.Open), MenuOrder = 2.6)]
 	sealed class Decompile100TimesCommand : SimpleCommand
 	{
 		public override void Execute(object parameter)

ILSpy/Commands/DisassembleAllCommand.cs

@@ -28,7 +28,7 @@
 
 namespace ICSharpCode.ILSpy
 {
-	[ExportMainMenuCommand(Menu = nameof(Resources._File), Header = nameof(Resources.DEBUGDisassemble), MenuCategory = nameof(Resources.Open), MenuOrder = 2.5)]
+	[ExportMainMenuCommand(ParentMenuID = nameof(Resources._File), Header = nameof(Resources.DEBUGDisassemble), MenuCategory = nameof(Resources.Open), MenuOrder = 2.5)]
 	sealed class DisassembleAllCommand : SimpleCommand
 	{
 		public override bool CanExecute(object parameter)

ILSpy/Commands/ExitCommand.cs

@@ -19,7 +19,7 @@
 
 namespace ICSharpCode.ILSpy
 {
-	[ExportMainMenuCommand(Menu = nameof(Resources._File), Header = nameof(Resources.E_xit), MenuOrder = 99999, MenuCategory = nameof(Resources.Exit))]
+	[ExportMainMenuCommand(ParentMenuID = nameof(Resources._File), Header = nameof(Resources.E_xit), MenuOrder = 99999, MenuCategory = nameof(Resources.Exit))]
 	sealed class ExitCommand : SimpleCommand
 	{
 		public override void Execute(object parameter)

ILSpy/Commands/ExportCommandAttribute.cs

@@ -52,8 +52,11 @@ public ExportToolbarCommandAttribute()
 	#region Main Menu
 	public interface IMainMenuCommandMetadata
 	{
+		string MenuID { get; }
 		string MenuIcon { get; }
 		string Header { get; }
+		string ParentMenuID { get; }
+		[Obsolete("Please use ParentMenuID instead. We decided to rename the property for clarity. It will be removed in ILSpy 8.0.")]
 		string Menu { get; }
 		string MenuCategory { get; }
 		string InputGestureText { get; }
@@ -65,22 +68,36 @@ public interface IMainMenuCommandMetadata
 	[AttributeUsage(AttributeTargets.Class, AllowMultiple = false)]
 	public class ExportMainMenuCommandAttribute : ExportAttribute, IMainMenuCommandMetadata
 	{
-		bool isEnabled = true;
-
 		public ExportMainMenuCommandAttribute()
 			: base("MainMenuCommand", typeof(ICommand))
 		{
 		}
-
+		/// <summary>
+		/// Gets/Sets the ID of this menu item. Menu entries are not required to have an ID,
+		/// however, setting it allows to declare nested menu structures.
+		/// The built-in menus have the IDs "_File", "_View", "_Window" and "_Help".
+		/// Plugin authors are advised to use GUIDs as identifiers to prevent conflicts.
+		/// <para/>
+		/// NOTE: Defining cycles (for example by accidentally setting <see cref="MenuID"/> equal to <see cref="ParentMenuID"/>)
+		/// will lead to a stack-overflow and crash of ILSpy at startup.
+		/// </summary>
+		public string MenuID { get; set; }
 		public string MenuIcon { get; set; }
 		public string Header { get; set; }
-		public string Menu { get; set; }
+		/// <summary>
+		/// Gets/Sets the parent of this menu item. All menu items sharing the same parent will be displayed as sub-menu items.
+		/// If this property is set to <see langword="null"/>, the menu item is displayed in the top-level menu.
+		/// The built-in menus have the IDs "_File", "_View", "_Window" and "_Help".
+		/// <para/>
+		/// NOTE: Defining cycles (for example by accidentally setting <see cref="MenuID"/> equal to <see cref="ParentMenuID"/>)
+		/// will lead to a stack-overflow and crash of ILSpy at startup.
+		/// </summary>
+		public string ParentMenuID { get; set; }
+		[Obsolete("Please use ParentMenuID instead. We decided to rename the property for clarity. It will be removed in ILSpy 8.0.")]
+		public string Menu { get => ParentMenuID; set => ParentMenuID = value; }
 		public string MenuCategory { get; set; }
 		public string InputGestureText { get; set; }
-		public bool IsEnabled {
-			get { return isEnabled; }
-			set { isEnabled = value; }
-		}
+		public bool IsEnabled { get; set; } = true;
 		public double MenuOrder { get; set; }
 	}
 	#endregion

ILSpy/Commands/GeneratePdbContextMenuEntry.cs

@@ -98,7 +98,7 @@ internal static void GeneratePdbForAssembly(LoadedAssembly assembly)
 		}
 	}
 
-	[ExportMainMenuCommand(Menu = nameof(Resources._File), Header = nameof(Resources.GeneratePortable), MenuCategory = nameof(Resources.Save))]
+	[ExportMainMenuCommand(ParentMenuID = nameof(Resources._File), Header = nameof(Resources.GeneratePortable), MenuCategory = nameof(Resources.Save))]
 	class GeneratePdbMainMenuEntry : SimpleCommand
 	{
 		public override bool CanExecute(object parameter)

ILSpy/Commands/ManageAssemblyListsCommand.cs

@@ -21,7 +21,7 @@
 
 namespace ICSharpCode.ILSpy
 {
-	[ExportMainMenuCommand(Menu = nameof(Resources._File), Header = nameof(Resources.ManageAssembly_Lists), MenuIcon = "Images/AssemblyList", MenuCategory = nameof(Resources.Open), MenuOrder = 1.7)]
+	[ExportMainMenuCommand(ParentMenuID = nameof(Resources._File), Header = nameof(Resources.ManageAssembly_Lists), MenuIcon = "Images/AssemblyList", MenuCategory = nameof(Resources.Open), MenuOrder = 1.7)]
 	sealed class ManageAssemblyListsCommand : SimpleCommand
 	{
 		public override void Execute(object parameter)

ILSpy/Commands/OpenCommand.cs

@@ -23,7 +23,7 @@
 namespace ICSharpCode.ILSpy
 {
 	[ExportToolbarCommand(ToolTip = nameof(Resources.Open), ToolbarIcon = "Images/Open", ToolbarCategory = nameof(Resources.Open), ToolbarOrder = 0)]
-	[ExportMainMenuCommand(Menu = nameof(Resources._File), Header = nameof(Resources._Open), MenuIcon = "Images/Open", MenuCategory = nameof(Resources.Open), MenuOrder = 0)]
+	[ExportMainMenuCommand(ParentMenuID = nameof(Resources._File), Header = nameof(Resources._Open), MenuIcon = "Images/Open", MenuCategory = nameof(Resources.Open), MenuOrder = 0)]
 	sealed class OpenCommand : CommandWrapper
 	{
 		public OpenCommand()

ILSpy/Commands/OpenFromGacCommand.cs

@@ -19,7 +19,7 @@
 using ICSharpCode.ILSpy.Properties;
 namespace ICSharpCode.ILSpy
 {
-	[ExportMainMenuCommand(Menu = nameof(Resources._File), Header = nameof(Resources.OpenFrom_GAC), MenuIcon = "Images/AssemblyListGAC", MenuCategory = nameof(Resources.Open), MenuOrder = 1)]
+	[ExportMainMenuCommand(ParentMenuID = nameof(Resources._File), Header = nameof(Resources.OpenFrom_GAC), MenuIcon = "Images/AssemblyListGAC", MenuCategory = nameof(Resources.Open), MenuOrder = 1)]
 	sealed class OpenFromGacCommand : SimpleCommand
 	{
 		public override void Execute(object parameter)

ILSpy/Commands/Pdb2XmlCommand.cs

@@ -33,7 +33,7 @@
 
 namespace ICSharpCode.ILSpy
 {
-	[ExportMainMenuCommand(Menu = nameof(Resources._File), Header = nameof(Resources.DEBUGDumpPDBAsXML), MenuCategory = nameof(Resources.Open), MenuOrder = 2.6)]
+	[ExportMainMenuCommand(ParentMenuID = nameof(Resources._File), Header = nameof(Resources.DEBUGDumpPDBAsXML), MenuCategory = nameof(Resources.Open), MenuOrder = 2.6)]
 	sealed class Pdb2XmlCommand : SimpleCommand
 	{
 		public override bool CanExecute(object parameter)

ILSpy/Commands/RefreshCommand.cs

@@ -23,7 +23,7 @@
 namespace ICSharpCode.ILSpy
 {
 	[ExportToolbarCommand(ToolTip = nameof(Resources.RefreshCommand_ReloadAssemblies), ToolbarIcon = "Images/Refresh", ToolbarCategory = nameof(Resources.Open), ToolbarOrder = 2)]
-	[ExportMainMenuCommand(Menu = nameof(Resources._File), Header = nameof(Resources._Reload), MenuIcon = "Images/Refresh", MenuCategory = nameof(Resources.Open), MenuOrder = 2)]
+	[ExportMainMenuCommand(ParentMenuID = nameof(Resources._File), Header = nameof(Resources._Reload), MenuIcon = "Images/Refresh", MenuCategory = nameof(Resources.Open), MenuOrder = 2)]
 	sealed class RefreshCommand : CommandWrapper
 	{
 		public RefreshCommand()

ILSpy/Commands/RemoveAssembliesWithLoadErrors.cs

@@ -24,7 +24,7 @@
 
 namespace ICSharpCode.ILSpy
 {
-	[ExportMainMenuCommand(Menu = nameof(Resources._File), Header = nameof(Resources._RemoveAssembliesWithLoadErrors), MenuCategory = nameof(Resources.Remove), MenuOrder = 2.6)]
+	[ExportMainMenuCommand(ParentMenuID = nameof(Resources._File), Header = nameof(Resources._RemoveAssembliesWithLoadErrors), MenuCategory = nameof(Resources.Remove), MenuOrder = 2.6)]
 	class RemoveAssembliesWithLoadErrors : SimpleCommand
 	{
 		public override bool CanExecute(object parameter)

ILSpy/Commands/SaveCommand.cs

@@ -22,7 +22,7 @@
 
 namespace ICSharpCode.ILSpy
 {
-	[ExportMainMenuCommand(Menu = nameof(Resources._File), Header = nameof(Resources._SaveCode), MenuIcon = "Images/Save", MenuCategory = nameof(Resources.Save), MenuOrder = 0)]
+	[ExportMainMenuCommand(ParentMenuID = nameof(Resources._File), Header = nameof(Resources._SaveCode), MenuIcon = "Images/Save", MenuCategory = nameof(Resources.Save), MenuOrder = 0)]
 	sealed class SaveCommand : CommandWrapper
 	{
 		public SaveCommand()

ILSpy/Commands/SortAssemblyListCommand.cs

@@ -24,7 +24,7 @@
 
 namespace ICSharpCode.ILSpy
 {
-	[ExportMainMenuCommand(Menu = nameof(Resources._View), Header = nameof(Resources.SortAssembly_listName), MenuIcon = "Images/Sort", MenuCategory = nameof(Resources.View))]
+	[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))]
 	sealed class SortAssemblyListCommand : SimpleCommand, IComparer<LoadedAssembly>
 	{
@@ -40,7 +40,7 @@ int IComparer<LoadedAssembly>.Compare(LoadedAssembly x, LoadedAssembly y)
 		}
 	}
 
-	[ExportMainMenuCommand(Menu = nameof(Resources._View), Header = nameof(Resources._CollapseTreeNodes), MenuIcon = "Images/CollapseAll", MenuCategory = nameof(Resources.View))]
+	[ExportMainMenuCommand(ParentMenuID = nameof(Resources._View), Header = nameof(Resources._CollapseTreeNodes), MenuIcon = "Images/CollapseAll", MenuCategory = nameof(Resources.View))]
 	[ExportToolbarCommand(ToolTip = nameof(Resources.CollapseTreeNodes), ToolbarIcon = "Images/CollapseAll", ToolbarCategory = nameof(Resources.View))]
 	sealed class CollapseAllCommand : SimpleCommand
 	{

ILSpy/ContextMenuEntry.cs

@@ -17,6 +17,7 @@
 // DEALINGS IN THE SOFTWARE.
 
 using System;
+using System.Collections.Generic;
 using System.ComponentModel.Composition;
 using System.Linq;
 using System.Windows;
@@ -117,6 +118,8 @@ public static TextViewContext Create(SharpTreeView treeView = null, DecompilerTe
 
 	public interface IContextMenuEntryMetadata
 	{
+		string MenuID { get; }
+		string ParentMenuID { get; }
 		string Icon { get; }
 		string Header { get; }
 		string Category { get; }
@@ -135,7 +138,23 @@ public ExportContextMenuEntryAttribute()
 			// entries default to end of menu unless given specific order position
 			Order = double.MaxValue;
 		}
-
+		/// <summary>
+		/// Gets/Sets the ID of this menu item. Menu entries are not required to have an ID,
+		/// however, setting it allows to declare nested menu structures.
+		/// Plugin authors are advised to use GUIDs as identifiers to prevent conflicts.
+		/// <para/>
+		/// NOTE: Defining cycles (for example by accidentally setting <see cref="MenuID"/> equal to <see cref="ParentMenuID"/>)
+		/// will lead to a stack-overflow and crash of ILSpy at startup.
+		/// </summary>
+		public string MenuID { get; set; }
+		/// <summary>
+		/// Gets/Sets the parent of this menu item. All menu items sharing the same parent will be displayed as sub-menu items.
+		/// If this property is set to <see langword="null"/>, the menu item is displayed in the top-level menu.
+		/// <para/>
+		/// NOTE: Defining cycles (for example by accidentally setting <see cref="MenuID"/> equal to <see cref="ParentMenuID"/>)
+		/// will lead to a stack-overflow and crash of ILSpy at startup.
+		/// </summary>
+		public string ParentMenuID { get; set; }
 		public string Icon { get; set; }
 		public string Header { get; set; }
 		public string Category { get; set; }
@@ -267,41 +286,64 @@ void dataGrid_ContextMenuOpening(object sender, ContextMenuEventArgs e)
 		bool ShowContextMenu(TextViewContext context, out ContextMenu menu)
 		{
 			menu = new ContextMenu();
-			foreach (var category in entries.OrderBy(c => c.Metadata.Order).GroupBy(c => c.Metadata.Category))
+			var menuGroups = new Dictionary<string, Lazy<IContextMenuEntry, IContextMenuEntryMetadata>[]>();
+			Lazy<IContextMenuEntry, IContextMenuEntryMetadata>[] topLevelGroup = null;
+			foreach (var group in entries.OrderBy(c => c.Metadata.Order).GroupBy(c => c.Metadata.ParentMenuID))
 			{
-				bool needSeparatorForCategory = menu.Items.Count > 0;
-				foreach (var entryPair in category)
+				if (group.Key == null)
 				{
-					IContextMenuEntry entry = entryPair.Value;
-					if (entry.IsVisible(context))
+					topLevelGroup = group.ToArray();
+				}
+				else
+				{
+					menuGroups.Add(group.Key, group.ToArray());
+				}
+			}
+			BuildMenu(topLevelGroup ?? Array.Empty<Lazy<IContextMenuEntry, IContextMenuEntryMetadata>>(), menu.Items);
+			return menu.Items.Count > 0;
+
+			void BuildMenu(Lazy<IContextMenuEntry, IContextMenuEntryMetadata>[] menuGroup, ItemCollection parent)
+			{
+				foreach (var category in menuGroup.GroupBy(c => c.Metadata.Category))
+				{
+					bool needSeparatorForCategory = parent.Count > 0;
+					foreach (var entryPair in category)
 					{
-						if (needSeparatorForCategory)
-						{
-							menu.Items.Add(new Separator());
-							needSeparatorForCategory = false;
-						}
-						MenuItem menuItem = new MenuItem();
-						menuItem.Header = MainWindow.GetResourceString(entryPair.Metadata.Header);
-						menuItem.InputGestureText = entryPair.Metadata.InputGestureText;
-						if (!string.IsNullOrEmpty(entryPair.Metadata.Icon))
+						IContextMenuEntry entry = entryPair.Value;
+						if (entry.IsVisible(context))
 						{
-							menuItem.Icon = new Image {
-								Width = 16,
-								Height = 16,
-								Source = Images.Load(entryPair.Value, entryPair.Metadata.Icon)
-							};
-						}
-						if (entryPair.Value.IsEnabled(context))
-						{
-							menuItem.Click += delegate { entry.Execute(context); };
+							if (needSeparatorForCategory)
+							{
+								parent.Add(new Separator());
+								needSeparatorForCategory = false;
+							}
+							MenuItem menuItem = new MenuItem();
+							menuItem.Header = MainWindow.GetResourceString(entryPair.Metadata.Header);
+							menuItem.InputGestureText = entryPair.Metadata.InputGestureText;
+							if (!string.IsNullOrEmpty(entryPair.Metadata.Icon))
+							{
+								menuItem.Icon = new Image {
+									Width = 16,
+									Height = 16,
+									Source = Images.Load(entryPair.Value, entryPair.Metadata.Icon)
+								};
+							}
+							if (entryPair.Value.IsEnabled(context))
+							{
+								menuItem.Click += delegate { entry.Execute(context); };
+							}
+							else
+								menuItem.IsEnabled = false;
+							parent.Add(menuItem);
+
+							if (entryPair.Metadata.MenuID != null && menuGroups.TryGetValue(entryPair.Metadata.MenuID, out var group))
+							{
+								BuildMenu(group, menuItem.Items);
+							}
 						}
-						else
-							menuItem.IsEnabled = false;
-						menu.Items.Add(menuItem);
 					}
 				}
 			}
-			return menu.Items.Count > 0;
 		}
 	}
 }

ILSpy/Docking/CloseAllDocumentsCommand.cs

@@ -8,7 +8,7 @@
 
 namespace ICSharpCode.ILSpy.Docking
 {
-	[ExportMainMenuCommand(Header = nameof(Resources.Window_CloseAllDocuments), Menu = nameof(Resources._Window))]
+	[ExportMainMenuCommand(Header = nameof(Resources.Window_CloseAllDocuments), ParentMenuID = nameof(Resources._Window))]
 	class CloseAllDocumentsCommand : SimpleCommand
 	{
 		public override void Execute(object parameter)
@@ -17,7 +17,7 @@ public override void Execute(object parameter)
 		}
 	}
 
-	[ExportMainMenuCommand(Header = nameof(Resources.Window_ResetLayout), Menu = nameof(Resources._Window))]
+	[ExportMainMenuCommand(Header = nameof(Resources.Window_ResetLayout), ParentMenuID = nameof(Resources._Window))]
 	class ResetLayoutCommand : SimpleCommand
 	{
 		public override void Execute(object parameter)

ILSpy/ExtensionMethods.cs

@@ -112,20 +112,12 @@ public static void InsertSorted<T>(this IList<T> list, T item, IComparer<T> comp
 			}
 		}
 
-		/*
-		public static bool IsCustomAttribute(this TypeDefinition type)
+		internal static void Deconstruct<TKey, TValue>(this KeyValuePair<TKey, TValue> pair, out TKey key, out TValue value)
 		{
-			while (type.FullName != "System.Object") {
-				var resolvedBaseType = type.BaseType.Resolve();
-				if (resolvedBaseType == null)
-					return false;
-				if (resolvedBaseType.FullName == "System.Attribute")
-					return true;
-				type = resolvedBaseType;
-			}
-			return false;
+			key = pair.Key;
+			value = pair.Value;
 		}
-		*/
+
 		public static string ToSuffixString(this System.Reflection.Metadata.EntityHandle handle)
 		{
 			if (!DisplaySettingsPanel.CurrentDisplaySettings.ShowMetadataTokens)