From 11f18e0c10c5e6be8f16de908a744880013aa02c Mon Sep 17 00:00:00 2001
From: Dan Walmsley <dan@walms.co.uk>
Date: Wed, 19 May 2021 16:14:48 +0100
Subject: [PATCH] Merge pull request #5949 from
 MarchingCube/ux-treepage-highlight

Fix devtools selection highlight requiring direct hover over the control
---
 .../Diagnostics/Views/TreePageView.xaml       |  1 +
 .../Diagnostics/Views/TreePageView.xaml.cs    | 19 ++++++++++++++-----
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/src/Avalonia.Diagnostics/Diagnostics/Views/TreePageView.xaml b/src/Avalonia.Diagnostics/Diagnostics/Views/TreePageView.xaml
index 86137dfc57a..fd631f0dffb 100644
--- a/src/Avalonia.Diagnostics/Diagnostics/Views/TreePageView.xaml
+++ b/src/Avalonia.Diagnostics/Diagnostics/Views/TreePageView.xaml
@@ -20,6 +20,7 @@
       <TreeView.Styles>
         <Style Selector="TreeViewItem">
           <Setter Property="IsExpanded" Value="{Binding IsExpanded, Mode=TwoWay}"/>
+          <Setter Property="Background" Value="Transparent" />
         </Style>
       </TreeView.Styles>
     </TreeView>
diff --git a/src/Avalonia.Diagnostics/Diagnostics/Views/TreePageView.xaml.cs b/src/Avalonia.Diagnostics/Diagnostics/Views/TreePageView.xaml.cs
index 1b61986ce60..3e1a238b362 100644
--- a/src/Avalonia.Diagnostics/Diagnostics/Views/TreePageView.xaml.cs
+++ b/src/Avalonia.Diagnostics/Diagnostics/Views/TreePageView.xaml.cs
@@ -1,3 +1,4 @@
+using System.Diagnostics;
 using System.Linq;
 using Avalonia.Controls;
 using Avalonia.Controls.Generators;
@@ -6,6 +7,7 @@
 using Avalonia.Input;
 using Avalonia.Markup.Xaml;
 using Avalonia.Media;
+using Avalonia.VisualTree;
 
 namespace Avalonia.Diagnostics.Views
 {
@@ -100,12 +102,19 @@ private void TreeViewItemMaterialized(object sender, ItemContainerEventArgs e)
         private void TreeViewItemTemplateApplied(object sender, TemplateAppliedEventArgs e)
         {
             var item = (TreeViewItem)sender;
-            var headerPresenter = item.HeaderPresenter;
-            headerPresenter.ApplyTemplate();
 
-            var header = headerPresenter.Child;
-            header.PointerEnter += AddAdorner;
-            header.PointerLeave += RemoveAdorner;
+            // This depends on the default tree item template.
+            // We want to handle events in the item header but exclude events coming from children.
+            var header = item.FindDescendantOfType<Border>();
+
+            Debug.Assert(header != null);
+
+            if (header != null)
+            {
+                header.PointerEnter += AddAdorner;
+                header.PointerLeave += RemoveAdorner;
+            }
+
             item.TemplateApplied -= TreeViewItemTemplateApplied;
         }
     }