fix tool strip border in dark theme (#8899)

GitExtUtils/GitUI/IMenuItemBackgroundFilter.cs

@@ -0,0 +1,9 @@
+using System.Windows.Forms;
+
+namespace GitExtUtils.GitUI
+{
+    public interface IMenuItemBackgroundFilter
+    {
+        bool ShouldRenderMenuItemBackground(ToolStripItemRenderEventArgs e);
+    }
+}

GitExtUtils/GitUI/IToolStripEx.cs

@@ -0,0 +1,10 @@
+namespace GitUI
+{
+    public interface IToolStripEx
+    {
+        /// <summary>
+        /// Gets or sets whether the toolstrip control has a border drawn around it.
+        /// </summary>
+        bool DrawBorder { get; set; }
+    }
+}

GitExtUtils/GitUI/Theming/ThemeFix.cs

@@ -74,14 +74,15 @@ private static void SetupTextBoxBase(TextBoxBase textBox)
 
         private static void SetupToolStrip(ToolStrip strip)
         {
-            strip.Renderer = new ThemeAwareToolStripRenderer();
+            strip.EnableTheming(enable: true);
+
             strip.Items.OfType<ToolStripLabel>()
                 .ForEach(SetupToolStripLabel);
         }
 
         private static void SetupContextMenu(ContextMenuStrip strip)
         {
-            strip.Renderer = new ThemeAwareToolStripRenderer();
+            strip.EnableTheming(enable: true);
         }
 
         private static void SetupToolStripLabel(ToolStripLabel label)

GitExtUtils/GitUI/ToolStripExRenderer.cs

@@ -0,0 +1,24 @@
+using System.Windows.Forms;
+
+namespace GitUI
+{
+    internal sealed class ToolStripExRenderer : ToolStripSystemRenderer
+    {
+        protected override void OnRenderMenuItemBackground(ToolStripItemRenderEventArgs e)
+        {
+            if (e.ToolStrip.GetMenuItemBackgroundFilter()?.ShouldRenderMenuItemBackground(e) != false)
+            {
+                base.OnRenderMenuItemBackground(e);
+            }
+        }
+
+        protected override void OnRenderToolStripBorder(ToolStripRenderEventArgs e)
+        {
+            if (e.ToolStrip is not IToolStripEx { DrawBorder: false })
+            {
+                // render border
+                base.OnRenderToolStripBorder(e);
+            }
+        }
+    }
+}

GitExtUtils/GitUI/ToolStripExThemeAwareRenderer.cs

@@ -0,0 +1,47 @@
+using System.Drawing;
+using System.Runtime.CompilerServices;
+using System.Windows.Forms;
+using GitExtUtils.GitUI.Theming;
+
+namespace GitUI
+{
+    internal sealed class ToolStripExThemeAwareRenderer : ToolStripProfessionalRenderer
+    {
+        private static readonly ConditionalWeakTable<Bitmap, Bitmap> AdaptedImagesCache = new();
+
+        public ToolStripExThemeAwareRenderer()
+        {
+            RoundedEdges = false;
+        }
+
+        protected override void OnRenderItemCheck(ToolStripItemImageRenderEventArgs e)
+        {
+            var image = (Bitmap)e.Image;
+            if (!AdaptedImagesCache.TryGetValue(image, out var adapted))
+            {
+                adapted = image.AdaptLightness();
+                AdaptedImagesCache.Add(image, adapted);
+            }
+
+            base.OnRenderItemCheck(new ToolStripItemImageRenderEventArgs(
+                e.Graphics, e.Item, adapted, e.ImageRectangle));
+        }
+
+        protected override void OnRenderMenuItemBackground(ToolStripItemRenderEventArgs e)
+        {
+            if (e.ToolStrip.GetMenuItemBackgroundFilter()?.ShouldRenderMenuItemBackground(e) != false)
+            {
+                base.OnRenderMenuItemBackground(e);
+            }
+        }
+
+        protected override void OnRenderToolStripBorder(ToolStripRenderEventArgs e)
+        {
+            if (e.ToolStrip is not IToolStripEx { DrawBorder: false })
+            {
+                // render border
+                base.OnRenderToolStripBorder(e);
+            }
+        }
+    }
+}

GitExtUtils/GitUI/ToolStripExtensions.cs

@@ -0,0 +1,61 @@
+using System.Runtime.CompilerServices;
+using System.Windows.Forms;
+using GitExtUtils.GitUI;
+
+namespace GitUI
+{
+    public static class ToolStripExtensions
+    {
+        private static ConditionalWeakTable<ToolStrip, IMenuItemBackgroundFilter> MenuItemBackgroundFilters = new();
+        private static ConditionalWeakTable<ToolStrip, ToolStripExRenderer> Renderers = new();
+        private static ConditionalWeakTable<ToolStrip, ToolStripExThemeAwareRenderer> RenderersThemeAware = new();
+
+        public static void AttachMenuItemBackgroundFilter(this ToolStrip toolStrip, IMenuItemBackgroundFilter? value)
+        {
+            toolStrip.UseCustomRenderer();
+            MenuItemBackgroundFilters.Remove(toolStrip);
+
+            if (value is not null)
+            {
+                MenuItemBackgroundFilters.Add(toolStrip, value);
+            }
+        }
+
+        public static void UseCustomRenderer(this ToolStrip toolStrip)
+        {
+            // use either ToolStripExRenderer or ToolStripExThemeAwareRenderer
+            toolStrip.EnableTheming(enable: toolStrip.IsThemingEnabled());
+        }
+
+        internal static void EnableTheming(this ToolStrip toolStrip, bool enable)
+        {
+            if (enable)
+            {
+                if (toolStrip.Renderer is not ToolStripExThemeAwareRenderer)
+                {
+                    toolStrip.Renderer = RenderersThemeAware.GetOrCreateValue(toolStrip);
+                }
+            }
+            else
+            {
+                if (toolStrip.Renderer is not ToolStripExRenderer)
+                {
+                    toolStrip.Renderer = Renderers.GetOrCreateValue(toolStrip);
+                }
+            }
+        }
+
+        internal static IMenuItemBackgroundFilter? GetMenuItemBackgroundFilter(this ToolStrip toolStrip)
+        {
+            if (MenuItemBackgroundFilters.TryGetValue(toolStrip, out var filter))
+            {
+                return filter;
+            }
+
+            return null;
+        }
+
+        internal static bool IsThemingEnabled(this ToolStrip toolStrip) =>
+            toolStrip.Renderer is ToolStripExThemeAwareRenderer;
+    }
+}

GitUI/UserControls/MenuStripEx.cs

@@ -1,4 +1,5 @@
 using System;
+using System.ComponentModel;
 using System.Windows.Forms;
 
 namespace GitUI
@@ -15,7 +16,9 @@ public class MenuStripEx : MenuStrip
         /// <remarks>
         /// Default value is false, which is the same behavior provided by the base ToolStrip class.
         /// </remarks>
-        public bool ClickThrough { get; set; } = true;
+        [Category("Behavior")]
+        [DefaultValue(false)]
+        public bool ClickThrough { get; set; }
 
         protected override void WndProc(ref Message m)
         {