Open metadata row in new tab via Shift+dbl-click or menu

Extends the double-click-to-decompile path with a new-tab variant. RaiseRowActivated
now carries an OpenInNewTab flag; DockWorkspace branches on it to either reuse the
active tab (existing tree-selection path) or spawn a fresh DecompilerTabPageModel.
The view's OnGridDoubleTapped reads KeyModifiers.Shift; a new
DecompileMetadataRowInNewTabCommand exports the same gesture as a context-menu entry.

Assisted-by: Claude:claude-opus-4-7:Claude Code

ILSpy.Tests/ContextMenus/DecompileInNewViewTests.cs

@@ -28,6 +28,7 @@ using ICSharpCode.ILSpyX.TreeView;
 
 using ILSpy;
 using ILSpy.AppEnv;
+using ILSpy.Commands;
 using ILSpy.Docking;
 using ILSpy.TextView;
 using ILSpy.TreeNodes;
@@ -70,7 +71,8 @@ public class DecompileInNewViewTests
 		await vm.AssemblyTreeModel.WaitForAssembliesAsync(minimumCount: 1);
 		var registry = AppComposition.Current.GetExport<ContextMenuEntryRegistry>();
 		var entry = registry.Entries
-			.Single(e => e.Metadata.Header == nameof(Resources.DecompileToNewPanel))
+			.Single(e => e.Metadata.Header == nameof(Resources.DecompileToNewPanel)
+				&& e.Value is DecompileInNewViewCommand)
 			.Value;
 
 		var asm = vm.AssemblyTreeModel.FindNode<AssemblyTreeNode>("System.Linq");
@@ -108,7 +110,8 @@ public class DecompileInNewViewTests
 
 		var registry = AppComposition.Current.GetExport<ContextMenuEntryRegistry>();
 		var entry = registry.Entries
-			.Single(e => e.Metadata.Header == nameof(Resources.DecompileToNewPanel))
+			.Single(e => e.Metadata.Header == nameof(Resources.DecompileToNewPanel)
+				&& e.Value is DecompileInNewViewCommand)
 			.Value;
 
 		var documents = ((ILSpyDockFactory)vm.DockWorkspace.Factory).Documents!;

ILSpy.Tests/Metadata/MetadataRowActivationTests.cs

@@ -23,7 +23,10 @@ using Avalonia.Headless.NUnit;
 
 using AwesomeAssertions;
 
+using ILSpy;
 using ILSpy.AppEnv;
+using ILSpy.Commands;
+using ILSpy.Docking;
 using ILSpy.Metadata;
 using ILSpy.Metadata.CorTables;
 using ILSpy.TreeNodes;
@@ -74,12 +77,61 @@ public class MetadataRowActivationTests
 			as global::ICSharpCode.Decompiler.TypeSystem.ITypeDefinition)!
 			.FullName.Should().Be("System.Object");
 	}
+
+	[AvaloniaTest]
+	public async Task Activating_A_Row_With_OpenInNewTab_Spawns_A_Fresh_Decompiler_Tab()
+	{
+		// Shift+double-click on a metadata row should NOT replace the active tab — it should
+		// open a brand-new decompiler tab containing the row's entity. The single-tab-reuse
+		// path stays put.
+		var window = AppComposition.Current.GetExport<MainWindow>();
+		window.Show();
+		var vm = (MainWindowViewModel)window.DataContext!;
+		await vm.AssemblyTreeModel.WaitForAssembliesAsync(minimumCount: 1);
+
+		var coreLibName = typeof(object).Assembly.GetName().Name!;
+		var assemblyNode = vm.AssemblyTreeModel.FindNode<AssemblyTreeNode>(coreLibName);
+		assemblyNode.EnsureLazyChildren();
+		var metadataNode = assemblyNode.Children.OfType<MetadataTreeNode>().Single();
+		metadataNode.EnsureLazyChildren();
+		var tablesNode = metadataNode.Children.OfType<MetadataTablesTreeNode>().Single();
+		tablesNode.EnsureLazyChildren();
+		var typeDefNode = tablesNode.Children.OfType<TypeDefTableTreeNode>().Single();
+
+		vm.AssemblyTreeModel.SelectNode(typeDefNode);
+		var metadataTab = await vm.DockWorkspace.WaitForMetadataTabAsync();
+		var objectRow = metadataTab.Items.Cast<TypeDefTableTreeNode.TypeDefEntry>()
+			.First(e => e.Name == "Object" && e.Namespace == "System");
+
+		var documents = ((ILSpyDockFactory)vm.DockWorkspace.Factory).Documents!;
+		var initialCount = documents.VisibleDockables?.Count ?? 0;
+
+		metadataTab.RaiseRowActivated(objectRow, openInNewTab: true);
+
+		await Waiters.WaitForAsync(
+			() => (documents.VisibleDockables?.Count ?? 0) > initialCount);
+		var decompiledTab = await vm.DockWorkspace.WaitForDecompiledTextAsync();
+		decompiledTab.Text.Should().Contain("System.Object");
+	}
+
+	[AvaloniaTest]
+	public async Task DecompileMetadataRowInNewTab_Entry_Is_Registered()
+	{
+		// Right-click on a metadata-grid row shows a "Decompile to new tab" entry alongside
+		// Go-to-token / Show-in-metadata. Verifies the [ExportContextMenuEntry] is discovered.
+		var window = AppComposition.Current.GetExport<MainWindow>();
+		window.Show();
+		var registry = AppComposition.Current.GetExport<ContextMenuEntryRegistry>();
+
+		registry.Entries.Should().Contain(
+			e => e.Value is DecompileMetadataRowInNewTabCommand);
+	}
 }
 
 internal static class MetadataRowActivationTestExtensions
 {
-	public static void RaiseRowActivated(this MetadataTablePageModel page, object row) =>
+	public static void RaiseRowActivated(this MetadataTablePageModel page, object row, bool openInNewTab = false) =>
 		typeof(MetadataTablePageModel)
 			.GetMethod("RaiseRowActivated", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance)!
-			.Invoke(page, [row]);
+			.Invoke(page, [row, openInNewTab]);
 }

ILSpy/Commands/DecompileMetadataRowInNewTabCommand.cs

@@ -0,0 +1,81 @@
+// Copyright (c) 2026 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.Composition;
+
+using Avalonia.Controls;
+
+using ICSharpCode.ILSpy.Properties;
+
+using ILSpy.Docking;
+using ILSpy.Languages;
+using ILSpy.TextView;
+
+namespace ILSpy.Commands
+{
+	/// <summary>
+	/// Right-click on a metadata-grid row whose token resolves to an
+	/// <see cref="ICSharpCode.Decompiler.TypeSystem.IEntity"/> → "Decompile to new tab".
+	/// Opens the entity in a fresh decompiler tab via <see cref="DockWorkspace.OpenNewTab"/>,
+	/// matching the gesture <see cref="DecompileInNewViewCommand"/> exposes for the
+	/// assembly-tree right-click. Visible only when the click landed in a metadata grid
+	/// (<see cref="TextViewContext.DataGrid"/> set) and the focused row resolves.
+	/// </summary>
+	[ExportContextMenuEntry(
+		Header = nameof(Resources.DecompileToNewPanel),
+		Category = "Metadata",
+		Order = 110)]
+	[Shared]
+	internal sealed class DecompileMetadataRowInNewTabCommand : IContextMenuEntry
+	{
+		readonly DockWorkspace dockWorkspace;
+		readonly LanguageService languageService;
+
+		[ImportingConstructor]
+		public DecompileMetadataRowInNewTabCommand(DockWorkspace dockWorkspace, LanguageService languageService)
+		{
+			this.dockWorkspace = dockWorkspace;
+			this.languageService = languageService;
+		}
+
+		public bool IsVisible(TextViewContext context) => ResolveRow(context) is not null;
+
+		public bool IsEnabled(TextViewContext context) => true;
+
+		public void Execute(TextViewContext context)
+		{
+			if (ResolveRow(context) is not { } row)
+				return;
+			var node = dockWorkspace.TryResolveRowToTreeNode(row);
+			if (node is null)
+				return;
+			var content = new DecompilerTabPageModel { Language = languageService.CurrentLanguage };
+			dockWorkspace.OpenNewTab(content);
+			content.CurrentNodes = new[] { node };
+		}
+
+		static object? ResolveRow(TextViewContext context)
+		{
+			if (context.DataGrid is null)
+				return null;
+			if (context.OriginalSource is not DataGridCell cell)
+				return null;
+			return cell.DataContext;
+		}
+	}
+}

ILSpy/Docking/DockWorkspace.cs

@@ -337,25 +337,48 @@ namespace ILSpy.Docking
 			NavigateToToken(new MetadataTokenReference(metadataFile, MetadataTokens.EntityHandle(token)));
 		}
 
-		internal void OnMetadataRowActivated(object row)
+		internal void OnMetadataRowActivated(MetadataRowActivationEventArgs e)
+		{
+			// Row double-click: resolve the row's Token + metadataFile to an IEntity, then
+			// either select the matching tree node (single-tab reuse) or open it in a fresh
+			// decompiler tab (new-tab gesture — Shift+double-click or context menu).
+			var node = TryResolveRowToTreeNode(e.Row);
+			if (node is null)
+				return;
+			if (e.OpenInNewTab)
+			{
+				var content = new DecompilerTabPageModel { Language = languageService.CurrentLanguage };
+				OpenNewTab(content);
+				content.CurrentNodes = new[] { node };
+			}
+			else
+			{
+				assemblyTreeModel.SelectedItem = node;
+			}
+		}
+
+		/// <summary>
+		/// Reflection-based resolution of a metadata-grid row to the matching assembly-tree
+		/// node, sharing the path between row double-click and the "Decompile to new tab"
+		/// context-menu entry. Returns <see langword="null"/> when the row's token doesn't
+		/// resolve to an <see cref="IEntity"/> the tree knows how to model (heap rows,
+		/// AssemblyRef rows pointing at unloaded assemblies, etc.).
+		/// </summary>
+		internal ILSpyTreeNode? TryResolveRowToTreeNode(object row)
 		{
-			// Row double-click: try to resolve the row's Token + metadataFile to a real
-			// IEntity via the type system, then select the matching tree node. That
-			// triggers ShowSelectedNode → CreateTab → decompiler view, the same path a
-			// click in the assembly tree takes.
 			var fileField = row.GetType().GetField("metadataFile", BindingFlags.Instance | BindingFlags.NonPublic);
 			if (fileField?.GetValue(row) is not MetadataFile metadataFile)
-				return;
+				return null;
 			var tokenProp = row.GetType().GetProperty("Token");
 			if (tokenProp?.GetValue(row) is not int token || token == 0)
-				return;
+				return null;
 			var handle = MetadataTokens.EntityHandle(token);
 			if (handle.IsNil)
-				return;
+				return null;
 
 			var assemblies = assemblyTreeModel.AssemblyList?.GetAssemblies();
 			if (assemblies is null)
-				return;
+				return null;
 			LoadedAssembly? owningAssembly = null;
 			foreach (var a in assemblies)
 			{
@@ -366,19 +389,17 @@ namespace ILSpy.Docking
 				}
 			}
 			if (owningAssembly is null)
-				return;
+				return null;
 			var ts = owningAssembly.GetTypeSystemOrNull();
 			if (ts?.MainModule is not MetadataModule metadataModule)
-				return;
+				return null;
 			IEntity? entity;
 			try
 			{ entity = metadataModule.ResolveEntity(handle); }
-			catch { return; }
+			catch { return null; }
 			if (entity is null)
-				return;
-			var node = assemblyTreeModel.FindTreeNode(entity);
-			if (node is not null)
-				assemblyTreeModel.SelectedItem = node;
+				return null;
+			return assemblyTreeModel.FindTreeNode(entity);
 		}
 
 		public void NavigateToToken(MetadataTokenReference reference)

ILSpy/ViewModels/MetadataTablePageModel.cs

@@ -106,12 +106,15 @@ namespace ILSpy.ViewModels
 		/// <summary>
 		/// Raised when the user double-clicks (or otherwise activates) a metadata grid
 		/// row. The dock workspace resolves the row's <c>metadataFile</c> + <c>Token</c>
-		/// to an <see cref="ICSharpCode.Decompiler.TypeSystem.IEntity"/> and selects the
-		/// matching tree node, which opens the entity in the decompiler view.
+		/// to an <see cref="ICSharpCode.Decompiler.TypeSystem.IEntity"/>; when
+		/// <see cref="MetadataRowActivationEventArgs.OpenInNewTab"/> is true the entity
+		/// is decompiled into a fresh tab, otherwise it replaces the active tab via the
+		/// regular tree-selection path.
 		/// </summary>
-		public event Action<object>? RowActivated;
+		public event Action<MetadataRowActivationEventArgs>? RowActivated;
 
-		internal void RaiseRowActivated(object row) => RowActivated?.Invoke(row);
+		internal void RaiseRowActivated(object row, bool openInNewTab = false)
+			=> RowActivated?.Invoke(new MetadataRowActivationEventArgs(row, openInNewTab));
 
 		static readonly ConcurrentDictionary<(Type Type, string Column), PropertyInfo?> propertyLookupCache = new();
 
@@ -318,4 +321,8 @@ namespace ILSpy.ViewModels
 
 	/// <summary>The (row, column) pair clicked in a token cell.</summary>
 	public sealed record MetadataCellNavigationEventArgs(object Row, string ColumnName);
+
+	/// <summary>The activated row plus whether the activation was a new-tab gesture
+	/// (Shift+double-click or "Decompile to new tab" context-menu entry).</summary>
+	public sealed record MetadataRowActivationEventArgs(object Row, bool OpenInNewTab);
 }

ILSpy/Views/MetadataTablePage.axaml.cs

@@ -64,14 +64,17 @@ namespace ILSpy.Views
 
 		void OnGridDoubleTapped(object? sender, global::Avalonia.Input.TappedEventArgs e)
 		{
-			// Dispatch row-activation through the page model. The dock workspace's
-			// subscriber resolves the row's metadataFile + Token to an IEntity and selects
-			// the matching tree node; that opens the entity in the decompiler view.
+			// Dispatch row-activation through the page model. Shift+double-click opens
+			// the entity in a new tab; a plain double-click reuses the active tab via
+			// the regular tree-selection path.
 			if (DataContext is not MetadataTablePageModel page)
 				return;
 			var grid = this.FindControl<DataGrid>("Grid");
 			if (grid?.SelectedItem is { } row)
-				page.RaiseRowActivated(row);
+			{
+				bool openInNewTab = (e.KeyModifiers & global::Avalonia.Input.KeyModifiers.Shift) != 0;
+				page.RaiseRowActivated(row, openInNewTab);
+			}
 		}
 
 		void OnKeyDown(object? sender, KeyEventArgs e)