From d989085a5881ce85bd36b20e971c429e2b91f142 Mon Sep 17 00:00:00 2001
From: tom-englert <mail@tom-englert.de>
Date: Sat, 5 Oct 2024 19:43:46 +0200
Subject: [PATCH] Fix focus when active tab page is changed via the Window menu

---
 ILSpy/Commands/ShowPane.cs       |  9 +++++++--
 ILSpy/Util/MenuService.cs        |  3 ++-
 ILSpy/ViewModels/TabPageModel.cs | 17 +++++++++++++++++
 3 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/ILSpy/Commands/ShowPane.cs b/ILSpy/Commands/ShowPane.cs
index 372081e0b..1c6694bd9 100644
--- a/ILSpy/Commands/ShowPane.cs
+++ b/ILSpy/Commands/ShowPane.cs
@@ -1,5 +1,4 @@
 using ICSharpCode.ILSpy.Docking;
-using ICSharpCode.ILSpy.Properties;
 using ICSharpCode.ILSpy.ViewModels;
 
 namespace ICSharpCode.ILSpy.Commands
@@ -30,7 +29,13 @@ namespace ICSharpCode.ILSpy.Commands
 
 		public override void Execute(object parameter)
 		{
-			DockWorkspace.Instance.ActiveTabPage = model;
+			var workspace = DockWorkspace.Instance;
+
+			// ensure the tab control is focused before setting the active tab page, else the tab will not be focused
+			workspace.ActiveTabPage?.Focus();
+			// reset first, else clicking on the already active tab will not focus the tab and the menu checkmark will not be updated
+			workspace.ActiveTabPage = null;
+			workspace.ActiveTabPage = model;
 		}
 	}
 }
\ No newline at end of file
diff --git a/ILSpy/Util/MenuService.cs b/ILSpy/Util/MenuService.cs
index a42e8c35a..6b1d2e29d 100644
--- a/ILSpy/Util/MenuService.cs
+++ b/ILSpy/Util/MenuService.cs
@@ -207,7 +207,8 @@ namespace ICSharpCode.ILSpy.Util
 			menuItem.SetBinding(MenuItem.IsCheckedProperty, new Binding(nameof(dock.ActiveTabPage)) {
 				Source = dock,
 				ConverterParameter = pane,
-				Converter = BinaryOperationConverter.Equality
+				Converter = BinaryOperationConverter.Equality,
+				Mode = BindingMode.OneWay
 			});
 
 			return menuItem;
diff --git a/ILSpy/ViewModels/TabPageModel.cs b/ILSpy/ViewModels/TabPageModel.cs
index abcaa4666..691d7d28c 100644
--- a/ILSpy/ViewModels/TabPageModel.cs
+++ b/ILSpy/ViewModels/TabPageModel.cs
@@ -17,10 +17,14 @@
 // DEALINGS IN THE SOFTWARE.
 
 using System;
+using System.Linq;
 using System.Threading.Tasks;
+using System.Windows;
 
 using ICSharpCode.ILSpy.TextView;
 
+using TomsToolbox.Wpf;
+
 namespace ICSharpCode.ILSpy.ViewModels
 {
 	public class TabPageModel : PaneModel
@@ -96,6 +100,19 @@ namespace ICSharpCode.ILSpy.ViewModels
 			tabPage.Title = Properties.Resources.Decompiling;
 			action(textView);
 		}
+
+		public static void Focus(this TabPageModel tabPage)
+		{
+			if (tabPage.Content is not FrameworkElement content)
+				return;
+
+			var focusable = content
+				.VisualDescendantsAndSelf()
+				.OfType<FrameworkElement>()
+				.FirstOrDefault(item => item.Focusable);
+
+			focusable?.Focus();
+		}
 	}
 
 	public interface IHaveState