Double-click metadata row opens its entity in the decompiler

DataGrid.DoubleTapped raises a RowActivated event on the metadata
page model. The dock workspace subscribes during AttachCustomContent
and resolves the row's metadataFile + Token to an IEntity via the
type system, then selects the matching tree node — which triggers
ShowSelectedNode → CreateTab → decompiler view, the same path a
click in the assembly tree takes. Falls through silently for rows
whose token doesn't resolve to an IEntity (heap rows, AssemblyRef,
constants).

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

ILSpy.Tests/Metadata/MetadataRowActivationTests.cs

@@ -0,0 +1,85 @@
+// 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.Linq;
+using System.Threading.Tasks;
+
+using Avalonia.Headless.NUnit;
+
+using AwesomeAssertions;
+
+using ILSpy.AppEnv;
+using ILSpy.Metadata;
+using ILSpy.Metadata.CorTables;
+using ILSpy.TreeNodes;
+using ILSpy.ViewModels;
+using ILSpy.Views;
+
+using NUnit.Framework;
+
+namespace ICSharpCode.ILSpy.Tests.Metadata;
+
+[TestFixture]
+public class MetadataRowActivationTests
+{
+	[AvaloniaTest]
+	public async Task Activating_A_TypeDef_Row_Selects_The_Matching_TypeTreeNode()
+	{
+		// Open the TypeDef table for CoreLib, pick the row whose Name == "Object", fire
+		// RowActivated, and confirm the assembly tree's TypeTreeNode for System.Object
+		// is now selected — that's the gateway to the decompiler view.
+
+		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 tab = await vm.DockWorkspace.WaitForMetadataTabAsync();
+
+		var objectRow = tab.Items.Cast<TypeDefTableTreeNode.TypeDefEntry>()
+			.First(e => e.Name == "Object" && e.Namespace == "System");
+
+		tab.RaiseRowActivated(objectRow);
+
+		await Waiters.WaitForAsync(
+			() => vm.AssemblyTreeModel.SelectedItem is TypeTreeNode tn
+				&& tn.Member is global::ICSharpCode.Decompiler.TypeSystem.ITypeDefinition td
+				&& td.FullName == "System.Object");
+		(((TypeTreeNode)vm.AssemblyTreeModel.SelectedItem!).Member
+			as global::ICSharpCode.Decompiler.TypeSystem.ITypeDefinition)!
+			.FullName.Should().Be("System.Object");
+	}
+}
+
+internal static class MetadataRowActivationTestExtensions
+{
+	public static void RaiseRowActivated(this MetadataTablePageModel page, object row) =>
+		typeof(MetadataTablePageModel)
+			.GetMethod("RaiseRowActivated", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance)!
+			.Invoke(page, [row]);
+}

ILSpy/Docking/DockWorkspace.cs

@@ -32,6 +32,8 @@ using Dock.Model.Core;
 using Dock.Model.Core.Events;
 
 using ICSharpCode.Decompiler.Metadata;
+using ICSharpCode.Decompiler.TypeSystem;
+using ICSharpCode.ILSpyX;
 using ICSharpCode.ILSpyX.TreeView;
 
 using ILSpy.AssemblyTree;
@@ -306,11 +308,18 @@ namespace ILSpy.Docking
 		void AttachCustomContent(ContentTabPage main, TabPageModel newContent)
 		{
 			// Detach navigation handlers from the outgoing content; subscribe on the
-			// incoming one so token clicks route through OnMetadataCellClicked.
+			// incoming one so token clicks route through OnMetadataCellClicked and
+			// row activation routes through OnMetadataRowActivated.
 			if (main.Content is MetadataTablePageModel oldMeta)
+			{
 				oldMeta.NavigateToCellRequested -= OnMetadataCellClicked;
+				oldMeta.RowActivated -= OnMetadataRowActivated;
+			}
 			if (newContent is MetadataTablePageModel newMeta)
+			{
 				newMeta.NavigateToCellRequested += OnMetadataCellClicked;
+				newMeta.RowActivated += OnMetadataRowActivated;
+			}
 			main.Content = newContent;
 		}
 
@@ -328,6 +337,50 @@ namespace ILSpy.Docking
 			NavigateToToken(new MetadataTokenReference(metadataFile, MetadataTokens.EntityHandle(token)));
 		}
 
+		internal void OnMetadataRowActivated(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;
+			var tokenProp = row.GetType().GetProperty("Token");
+			if (tokenProp?.GetValue(row) is not int token || token == 0)
+				return;
+			var handle = MetadataTokens.EntityHandle(token);
+			if (handle.IsNil)
+				return;
+
+			var assemblies = assemblyTreeModel.AssemblyList?.GetAssemblies();
+			if (assemblies is null)
+				return;
+			LoadedAssembly? owningAssembly = null;
+			foreach (var a in assemblies)
+			{
+				if (ReferenceEquals(a.GetMetadataFileOrNull(), metadataFile))
+				{
+					owningAssembly = a;
+					break;
+				}
+			}
+			if (owningAssembly is null)
+				return;
+			var ts = owningAssembly.GetTypeSystemOrNull();
+			if (ts?.MainModule is not MetadataModule metadataModule)
+				return;
+			IEntity? entity;
+			try
+			{ entity = metadataModule.ResolveEntity(handle); }
+			catch { return; }
+			if (entity is null)
+				return;
+			var node = assemblyTreeModel.FindTreeNode(entity);
+			if (node is not null)
+				assemblyTreeModel.SelectedItem = node;
+		}
+
 		public void NavigateToToken(MetadataTokenReference reference)
 		{
 			if (reference.Handle.IsNil)

ILSpy/ViewModels/MetadataTablePageModel.cs

@@ -103,6 +103,16 @@ namespace ILSpy.ViewModels
 		internal void RaiseNavigateToCell(object row, string columnName)
 			=> NavigateToCellRequested?.Invoke(new MetadataCellNavigationEventArgs(row, columnName));
 
+		/// <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.
+		/// </summary>
+		public event Action<object>? RowActivated;
+
+		internal void RaiseRowActivated(object row) => RowActivated?.Invoke(row);
+
 		static readonly ConcurrentDictionary<(Type Type, string Column), PropertyInfo?> propertyLookupCache = new();
 
 		static readonly ConcurrentDictionary<string, Regex?> regexCache = new();

ILSpy/Views/MetadataTablePage.axaml.cs

@@ -57,6 +57,21 @@ namespace ILSpy.Views
 			AddHandler(PointerMovedEvent, OnPointerMovedOverGrid);
 			AddHandler(KeyDownEvent, OnKeyDown);
 			AttachContextMenu(TryGetContextMenuEntries());
+			var grid = this.FindControl<DataGrid>("Grid");
+			if (grid is not null)
+				grid.DoubleTapped += OnGridDoubleTapped;
+		}
+
+		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.
+			if (DataContext is not MetadataTablePageModel page)
+				return;
+			var grid = this.FindControl<DataGrid>("Grid");
+			if (grid?.SelectedItem is { } row)
+				page.RaiseRowActivated(row);
 		}
 
 		void OnKeyDown(object? sender, KeyEventArgs e)