From 64d5c967a9c9d1a66f23a09575be981eb3380c22 Mon Sep 17 00:00:00 2001
From: Lubomir Tetak <l.tetak.ext@sportradar.com>
Date: Mon, 25 Oct 2021 10:33:19 +0200
Subject: [PATCH 01/10] DevTools - allow to navigate to children (especially
 DataContext)

(cherry picked from commit 4f89fd5f4d1ec390e5eb20b6c7979e0229151d12)
---
 .../ViewModels/ControlDetailsViewModel.cs     | 132 ++++++++++++++----
 .../Diagnostics/Views/ControlDetailsView.xaml |  17 ++-
 .../Views/ControlDetailsView.xaml.cs          |  11 ++
 3 files changed, 130 insertions(+), 30 deletions(-)

diff --git a/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlDetailsViewModel.cs b/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlDetailsViewModel.cs
index 3790951b0c..d3f07d09e1 100644
--- a/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlDetailsViewModel.cs
+++ b/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlDetailsViewModel.cs
@@ -17,42 +17,26 @@ namespace Avalonia.Diagnostics.ViewModels
     internal class ControlDetailsViewModel : ViewModelBase, IDisposable
     {
         private readonly IVisual _control;
-        private readonly IDictionary<object, List<PropertyViewModel>> _propertyIndex;
+        private IDictionary<object, List<PropertyViewModel>> _propertyIndex;
         private PropertyViewModel? _selectedProperty;
+        private DataGridCollectionView _propertiesView;
         private bool _snapshotStyles;
         private bool _showInactiveStyles;
         private string? _styleStatus;
+        private object _selectedEntity;
+        private readonly Stack<Tuple<string, object>> _selectedEntitiesStack = new();
+        private string _selectedEntityName;
+        private string _selectedEntityType;
 
         public ControlDetailsViewModel(TreePageViewModel treePage, IVisual control)
         {
             _control = control;
 
             TreePage = treePage;
-
-            var properties = GetAvaloniaProperties(control)
-                .Concat(GetClrProperties(control))
-                .OrderBy(x => x, PropertyComparer.Instance)
-                .ThenBy(x => x.Name)
-                .ToList();
-
-            _propertyIndex = properties.GroupBy(x => x.Key).ToDictionary(x => x.Key, x => x.ToList());
-
-            var view = new DataGridCollectionView(properties);
-            view.GroupDescriptions.Add(new DataGridPathGroupDescription(nameof(AvaloniaPropertyViewModel.Group)));
-            view.Filter = FilterProperty;
-            PropertiesView = view;
-
+            
             Layout = new ControlLayoutViewModel(control);
 
-            if (control is INotifyPropertyChanged inpc)
-            {
-                inpc.PropertyChanged += ControlPropertyChanged;
-            }
-
-            if (control is AvaloniaObject ao)
-            {
-                ao.PropertyChanged += ControlPropertyChanged;
-            }
+            NavigateToProperty(control, (control as IControl)?.Name ?? control.ToString()); 
 
             AppliedStyles = new ObservableCollection<StyleViewModel>();
             PseudoClasses = new ObservableCollection<PseudoClassViewModel>();
@@ -133,12 +117,46 @@ namespace Avalonia.Diagnostics.ViewModels
 
         public TreePageViewModel TreePage { get; }
 
-        public DataGridCollectionView PropertiesView { get; }
+        public DataGridCollectionView PropertiesView
+        {
+            get => _propertiesView;
+            private set => RaiseAndSetIfChanged(ref _propertiesView, value);
+        }
 
         public ObservableCollection<StyleViewModel> AppliedStyles { get; }
 
         public ObservableCollection<PseudoClassViewModel> PseudoClasses { get; }
 
+        public object SelectedEntity
+        {
+            get => _selectedEntity;
+            set
+            {
+                RaiseAndSetIfChanged(ref _selectedEntity, value);
+               
+            }
+        }
+
+        public string SelectedEntityName
+        {
+            get => _selectedEntityName;
+            set
+            {
+                RaiseAndSetIfChanged(ref _selectedEntityName, value);
+               
+            }
+        }
+        
+        public string SelectedEntityType
+        {
+            get => _selectedEntityType;
+            set
+            {
+                RaiseAndSetIfChanged(ref _selectedEntityType, value);
+               
+            }
+        }
+        
         public PropertyViewModel? SelectedProperty
         {
             get => _selectedProperty;
@@ -378,5 +396,69 @@ namespace Avalonia.Diagnostics.ViewModels
                 }
             }
         }
+
+        public void ApplySelectedProperty()
+        {
+            if (SelectedProperty == null) return;
+            
+            var property = (_selectedEntity as IControl)?.GetValue(SelectedProperty.Key as AvaloniaProperty);
+            if (property == null)
+            {
+                property = _selectedEntity.GetType().GetProperty(SelectedProperty.Name)?.GetValue(_selectedEntity);
+            }
+
+            if (property == null) return;
+            _selectedEntitiesStack.Push(new Tuple<string, object>(SelectedEntityName, SelectedEntity));
+            NavigateToProperty(property, SelectedProperty.Name);
+        }
+
+        public void ApplyParentProperty()
+        {
+            if (_selectedEntitiesStack.Any())
+            {
+                var property = _selectedEntitiesStack.Pop();
+                NavigateToProperty(property.Item2, property.Item1);
+            }
+        }
+        
+        protected  void NavigateToProperty(object o, string entityName)
+        {
+            if (SelectedEntity is INotifyPropertyChanged inpc1)
+            {
+                inpc1.PropertyChanged -= ControlPropertyChanged;
+            }
+
+            if (SelectedEntity is AvaloniaObject ao1)
+            {
+                ao1.PropertyChanged -= ControlPropertyChanged;
+            }
+            
+            SelectedEntity = o;
+            SelectedEntityName = entityName;
+            SelectedEntityType = o.ToString();
+            var properties = GetAvaloniaProperties(o)
+                .Concat(GetClrProperties(o))
+                .OrderBy(x => x, PropertyComparer.Instance)
+                .ThenBy(x => x.Name)
+                .ToList();
+
+            _propertyIndex = properties.GroupBy(x => x.Key).ToDictionary(x => x.Key, x => x.ToList());
+
+            var view = new DataGridCollectionView(properties);
+            view.GroupDescriptions.Add(new DataGridPathGroupDescription(nameof(AvaloniaPropertyViewModel.Group)));
+            view.Filter = FilterProperty;
+            PropertiesView = view;
+            
+            if (o is INotifyPropertyChanged inpc2)
+            {
+                inpc2.PropertyChanged += ControlPropertyChanged;
+            }
+
+            if (o is AvaloniaObject ao2)
+            {
+                ao2.PropertyChanged += ControlPropertyChanged;
+            }
+
+        }
     }
 }
diff --git a/src/Avalonia.Diagnostics/Diagnostics/Views/ControlDetailsView.xaml b/src/Avalonia.Diagnostics/Diagnostics/Views/ControlDetailsView.xaml
index 4b37438993..0d81127c21 100644
--- a/src/Avalonia.Diagnostics/Diagnostics/Views/ControlDetailsView.xaml
+++ b/src/Avalonia.Diagnostics/Diagnostics/Views/ControlDetailsView.xaml
@@ -13,23 +13,30 @@
 
   <Grid ColumnDefinitions="*,Auto,320">
 
-    <Grid Grid.Column="0" RowDefinitions="Auto,*">
+    <Grid Grid.Column="0" RowDefinitions="Auto,Auto,*">
 
-      <controls:FilterTextBox Grid.Row="0"
+      <Grid ColumnDefinitions="Auto, *" RowDefinitions="Auto, Auto">
+        <Button Grid.Column="0" Grid.RowSpan="2" Content="^" Command="{Binding ApplyParentProperty}" />
+        <TextBlock Grid.Column="1" Grid.Row="0" Text="{Binding SelectedEntityName}" FontWeight="Bold" />
+        <TextBlock Grid.Column="1" Grid.Row="1" Text="{Binding SelectedEntityType}" FontStyle="Italic" />
+      </Grid>
+      
+      <controls:FilterTextBox Grid.Row="1"
                               BorderThickness="0"
                               DataContext="{Binding TreePage.PropertiesFilter}"
                               Text="{Binding FilterString}"
                               Watermark="Filter properties"
                               UseCaseSensitiveFilter="{Binding UseCaseSensitiveFilter}"
                               UseWholeWordFilter="{Binding UseWholeWordFilter}"
-                              UseRegexFilter="{Binding UseRegexFilter}" />
+                              UseRegexFilter="{Binding UseRegexFilter}"/>
       
       <DataGrid Items="{Binding PropertiesView}"
-                Grid.Row="1"
+                Grid.Row="2"
                 BorderThickness="0"
                 RowBackground="Transparent"
                 SelectedItem="{Binding SelectedProperty, Mode=TwoWay}"
-                CanUserResizeColumns="true">
+                CanUserResizeColumns="true"
+                DoubleTapped="PropertiesGrid_OnDoubleTapped">
         <DataGrid.Columns>
           <DataGridTextColumn Header="Property" Binding="{Binding Name}" IsReadOnly="True" />
           <DataGridTextColumn Header="Value" Binding="{Binding Value}" />
diff --git a/src/Avalonia.Diagnostics/Diagnostics/Views/ControlDetailsView.xaml.cs b/src/Avalonia.Diagnostics/Diagnostics/Views/ControlDetailsView.xaml.cs
index c6bd5a18aa..78919a2105 100644
--- a/src/Avalonia.Diagnostics/Diagnostics/Views/ControlDetailsView.xaml.cs
+++ b/src/Avalonia.Diagnostics/Diagnostics/Views/ControlDetailsView.xaml.cs
@@ -1,4 +1,6 @@
 using Avalonia.Controls;
+using Avalonia.Diagnostics.ViewModels;
+using Avalonia.Input;
 using Avalonia.Markup.Xaml;
 
 namespace Avalonia.Diagnostics.Views
@@ -14,5 +16,14 @@ namespace Avalonia.Diagnostics.Views
         {
             AvaloniaXamlLoader.Load(this);
         }
+
+        private void PropertiesGrid_OnDoubleTapped(object sender, TappedEventArgs e)
+        {
+            if (sender is DataGrid grid && grid.DataContext is ControlDetailsViewModel controlDetails)
+            {
+                controlDetails.ApplySelectedProperty();
+            }
+            
+        }
     }
 }

From df16546c2e6ca3ee9547c086ddf9e0b7cbeda143 Mon Sep 17 00:00:00 2001
From: Lubomir Tetak <l.tetak.ext@sportradar.com>
Date: Mon, 25 Oct 2021 15:51:23 +0200
Subject: [PATCH 02/10] fix the build issue not supporting new C# features

---
 .../Diagnostics/ViewModels/ControlDetailsViewModel.cs           | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlDetailsViewModel.cs b/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlDetailsViewModel.cs
index d3f07d09e1..cfc64c8767 100644
--- a/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlDetailsViewModel.cs
+++ b/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlDetailsViewModel.cs
@@ -24,7 +24,7 @@ namespace Avalonia.Diagnostics.ViewModels
         private bool _showInactiveStyles;
         private string? _styleStatus;
         private object _selectedEntity;
-        private readonly Stack<Tuple<string, object>> _selectedEntitiesStack = new();
+        private readonly Stack<Tuple<string, object>> _selectedEntitiesStack = new Stack<Tuple<string, object>>();
         private string _selectedEntityName;
         private string _selectedEntityType;
 

From ca24cae783ea4ade843c5e5e5abe428c839a54c3 Mon Sep 17 00:00:00 2001
From: Giuseppe Lippolis <workgroupengineering@outlook.com>
Date: Thu, 28 Oct 2021 11:10:04 +0200
Subject: [PATCH 03/10] fixes: Warnings CS0219 and CS0168

---
 .../Remote/HtmlTransport/HtmlTransport.cs                       | 2 +-
 src/Avalonia.X11/X11Window.Ime.cs                               | 2 --
 src/Skia/Avalonia.Skia/Gpu/OpenGl/GlSkiaGpu.cs                  | 2 +-
 3 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/src/Avalonia.DesignerSupport/Remote/HtmlTransport/HtmlTransport.cs b/src/Avalonia.DesignerSupport/Remote/HtmlTransport/HtmlTransport.cs
index 804bb09510..6b1934ed06 100644
--- a/src/Avalonia.DesignerSupport/Remote/HtmlTransport/HtmlTransport.cs
+++ b/src/Avalonia.DesignerSupport/Remote/HtmlTransport/HtmlTransport.cs
@@ -25,7 +25,6 @@ namespace Avalonia.DesignerSupport.Remote.HtmlTransport
         private AutoResetEvent _wakeup = new AutoResetEvent(false);
         private FrameMessage _lastFrameMessage = null;
         private FrameMessage _lastSentFrameMessage = null;
-        private RequestViewportResizeMessage _lastViewportRequest;
         private Action<IAvaloniaRemoteTransportConnection, object> _onMessage;
         private Action<IAvaloniaRemoteTransportConnection, Exception> _onException;
         
@@ -177,6 +176,7 @@ namespace Avalonia.DesignerSupport.Remote.HtmlTransport
         
         public void Dispose()
         {
+            _disposed = true;
             _pendingSocket?.Dispose();
             _simpleServer.Dispose();
         }
diff --git a/src/Avalonia.X11/X11Window.Ime.cs b/src/Avalonia.X11/X11Window.Ime.cs
index 0bd1bc8a89..d68feaca78 100644
--- a/src/Avalonia.X11/X11Window.Ime.cs
+++ b/src/Avalonia.X11/X11Window.Ime.cs
@@ -33,8 +33,6 @@ namespace Avalonia.X11
                         && ((int)(style & XIMProperties.XIMStatusNothing) != 0))
                     {
                         XPoint spot = default;
-                        XRectangle area = default;
-
 
                         //using var areaS = new Utf8Buffer("area");
                         using var spotS = new Utf8Buffer("spotLocation");
diff --git a/src/Skia/Avalonia.Skia/Gpu/OpenGl/GlSkiaGpu.cs b/src/Skia/Avalonia.Skia/Gpu/OpenGl/GlSkiaGpu.cs
index a393f0b64d..0ac42277e7 100644
--- a/src/Skia/Avalonia.Skia/Gpu/OpenGl/GlSkiaGpu.cs
+++ b/src/Skia/Avalonia.Skia/Gpu/OpenGl/GlSkiaGpu.cs
@@ -66,7 +66,7 @@ namespace Avalonia.Skia
                 _canCreateSurfaces = true;
                 return surface;
             }
-            catch (Exception e)
+            catch (Exception)
             {
                 Logger.TryGet(LogEventLevel.Error, "OpenGL")
                     ?.Log(this, "Unable to create a Skia-compatible FBO manually");

From 77331a5baf2a792209be9e227c229313893524d6 Mon Sep 17 00:00:00 2001
From: Giuseppe Lippolis <workgroupengineering@outlook.com>
Date: Thu, 28 Oct 2021 16:02:57 +0200
Subject: [PATCH 04/10] fixes: Missing CS0618

---
 src/Avalonia.Headless/HeadlessWindowImpl.cs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/Avalonia.Headless/HeadlessWindowImpl.cs b/src/Avalonia.Headless/HeadlessWindowImpl.cs
index 31315848d1..77976c05fa 100644
--- a/src/Avalonia.Headless/HeadlessWindowImpl.cs
+++ b/src/Avalonia.Headless/HeadlessWindowImpl.cs
@@ -199,7 +199,9 @@ namespace Avalonia.Headless
 
         public ILockedFramebuffer Lock()
         {
+#pragma warning disable CS0618
             var bmp = new WriteableBitmap(PixelSize.FromSize(ClientSize, RenderScaling), new Vector(96, 96) * RenderScaling);
+#pragma warning restore CS0618
             var fb = bmp.Lock();
             return new FramebufferProxy(fb, () =>
             {

From 1468c2a83b486bb6c21518d140a305913a1a55ad Mon Sep 17 00:00:00 2001
From: Yoh Deadfall <yoh.deadfall@hotmail.com>
Date: Fri, 29 Oct 2021 15:06:15 +0300
Subject: [PATCH 05/10] Added lost focus-within to pseudo classes attr

---
 src/Avalonia.Input/InputElement.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Avalonia.Input/InputElement.cs b/src/Avalonia.Input/InputElement.cs
index 63080e74e4..b5ab7b4da1 100644
--- a/src/Avalonia.Input/InputElement.cs
+++ b/src/Avalonia.Input/InputElement.cs
@@ -16,7 +16,7 @@ namespace Avalonia.Input
     /// <summary>
     /// Implements input-related functionality for a control.
     /// </summary>
-    [PseudoClasses(":disabled", ":focus", ":focus-visible", ":pointerover")]
+    [PseudoClasses(":disabled", ":focus", ":focus-visible", ":focus-within", ":pointerover")]
     public class InputElement : Interactive, IInputElement
     {
         /// <summary>

From 0b1e938ff73ac65861adc3403bbb05cffb5dba89 Mon Sep 17 00:00:00 2001
From: Giuseppe Lippolis <workgroupengineering@outlook.com>
Date: Tue, 2 Nov 2021 09:55:18 +0100
Subject: [PATCH 06/10] fixes(DevTools): Double subscribe/unsubscribe
 INotifyPropertyChanged

---
 .../ViewModels/ControlDetailsViewModel.cs     | 24 +++++++++----------
 1 file changed, 11 insertions(+), 13 deletions(-)

diff --git a/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlDetailsViewModel.cs b/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlDetailsViewModel.cs
index cfc64c8767..ba3fafdfaf 100644
--- a/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlDetailsViewModel.cs
+++ b/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlDetailsViewModel.cs
@@ -423,16 +423,16 @@ namespace Avalonia.Diagnostics.ViewModels
         
         protected  void NavigateToProperty(object o, string entityName)
         {
-            if (SelectedEntity is INotifyPropertyChanged inpc1)
+            var oldSelectedEntity = SelectedEntity;
+            if (oldSelectedEntity is IAvaloniaObject ao1)
             {
-                inpc1.PropertyChanged -= ControlPropertyChanged;
+                ao1.PropertyChanged -= ControlPropertyChanged;
             }
-
-            if (SelectedEntity is AvaloniaObject ao1)
+            else if (oldSelectedEntity is INotifyPropertyChanged inpc1)
             {
-                ao1.PropertyChanged -= ControlPropertyChanged;
+                inpc1.PropertyChanged -= ControlPropertyChanged;
             }
-            
+      
             SelectedEntity = o;
             SelectedEntityName = entityName;
             SelectedEntityType = o.ToString();
@@ -448,17 +448,15 @@ namespace Avalonia.Diagnostics.ViewModels
             view.GroupDescriptions.Add(new DataGridPathGroupDescription(nameof(AvaloniaPropertyViewModel.Group)));
             view.Filter = FilterProperty;
             PropertiesView = view;
-            
-            if (o is INotifyPropertyChanged inpc2)
-            {
-                inpc2.PropertyChanged += ControlPropertyChanged;
-            }
 
-            if (o is AvaloniaObject ao2)
+            if (o is IAvaloniaObject ao2)
             {
                 ao2.PropertyChanged += ControlPropertyChanged;
             }
-
+            else if (o is INotifyPropertyChanged inpc2)
+            {
+                inpc2.PropertyChanged += ControlPropertyChanged;
+            }
         }
     }
 }

From 4e19b579c2729a528218df16f82d42bca0cf6ddc Mon Sep 17 00:00:00 2001
From: workgroupengineering <workgroupengineering@users.noreply.github.com>
Date: Wed, 3 Nov 2021 09:20:03 +0100
Subject: [PATCH 07/10] Update src/Avalonia.Headless/HeadlessWindowImpl.cs

Co-authored-by: Max Katz <maxkatz6@outlook.com>
---
 src/Avalonia.Headless/HeadlessWindowImpl.cs | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/src/Avalonia.Headless/HeadlessWindowImpl.cs b/src/Avalonia.Headless/HeadlessWindowImpl.cs
index 77976c05fa..1b582d5775 100644
--- a/src/Avalonia.Headless/HeadlessWindowImpl.cs
+++ b/src/Avalonia.Headless/HeadlessWindowImpl.cs
@@ -199,9 +199,7 @@ namespace Avalonia.Headless
 
         public ILockedFramebuffer Lock()
         {
-#pragma warning disable CS0618
-            var bmp = new WriteableBitmap(PixelSize.FromSize(ClientSize, RenderScaling), new Vector(96, 96) * RenderScaling);
-#pragma warning restore CS0618
+            var bmp = new WriteableBitmap(PixelSize.FromSize(ClientSize, RenderScaling), new Vector(96, 96) * RenderScaling, PixelFormat.Rgba8888, AlphaFormat.Premul);
             var fb = bmp.Lock();
             return new FramebufferProxy(fb, () =>
             {

From 94059f521fe39efdbca23ef94c599671009e3ace Mon Sep 17 00:00:00 2001
From: Yoh Deadfall <yoh.deadfall@hotmail.com>
Date: Wed, 3 Nov 2021 12:52:23 +0300
Subject: [PATCH 08/10] ElementManager follows the behavior of ViewManager

---
 src/Avalonia.Layout/ElementManager.cs | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/src/Avalonia.Layout/ElementManager.cs b/src/Avalonia.Layout/ElementManager.cs
index c2f829d020..681d23a61f 100644
--- a/src/Avalonia.Layout/ElementManager.cs
+++ b/src/Avalonia.Layout/ElementManager.cs
@@ -314,12 +314,11 @@ namespace Avalonia.Layout
                         }
                         break;
 
+                    // Remove clear all realized elements just to align the begavior
+                    // with ViewManager which resets realized item indices to defaults.
+                    // Freeing only removed items causes wrong indices to be stored
+                    // in virtualized info of items under some circumstances.
                     case NotifyCollectionChangedAction.Remove:
-                        {
-                            OnItemsRemoved(args.OldStartingIndex, args.OldItems.Count);
-                        }
-                        break;
-
                     case NotifyCollectionChangedAction.Reset:
                         ClearRealizedRange();
                         break;

From 01582cb552a80238b77a19bd7101d52f32e4c58c Mon Sep 17 00:00:00 2001
From: Giuseppe Lippolis <workgroupengineering@outlook.com>
Date: Wed, 3 Nov 2021 12:55:45 +0100
Subject: [PATCH 09/10] fixes(DevTools): Ambiguous match found Exception

---
 .../ViewModels/AvaloniaPropertyViewModel.cs   |  4 +++-
 .../ViewModels/ClrPropertyViewModel.cs        |  4 +++-
 .../ViewModels/ControlDetailsViewModel.cs     | 24 +++++++++++++------
 .../ViewModels/PropertyViewModel.cs           |  1 +
 4 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/src/Avalonia.Diagnostics/Diagnostics/ViewModels/AvaloniaPropertyViewModel.cs b/src/Avalonia.Diagnostics/Diagnostics/ViewModels/AvaloniaPropertyViewModel.cs
index e4c4ca6115..8ce99d5375 100644
--- a/src/Avalonia.Diagnostics/Diagnostics/ViewModels/AvaloniaPropertyViewModel.cs
+++ b/src/Avalonia.Diagnostics/Diagnostics/ViewModels/AvaloniaPropertyViewModel.cs
@@ -19,7 +19,7 @@ namespace Avalonia.Diagnostics.ViewModels
             Name = property.IsAttached ?
                 $"[{property.OwnerType.Name}.{property.Name}]" :
                 property.Name;
-
+            DeclaringType = property.OwnerType;
             Update();
         }
 
@@ -50,6 +50,8 @@ namespace Avalonia.Diagnostics.ViewModels
 
         public override string Group => _group;
 
+        public override System.Type? DeclaringType { get; }
+
         // [MemberNotNull(nameof(_type), nameof(_group), nameof(_priority))]
         public override void Update()
         {
diff --git a/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ClrPropertyViewModel.cs b/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ClrPropertyViewModel.cs
index 65626aeea5..0a851f4a19 100644
--- a/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ClrPropertyViewModel.cs
+++ b/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ClrPropertyViewModel.cs
@@ -24,7 +24,7 @@ namespace Avalonia.Diagnostics.ViewModels
             {
                 Name = property.DeclaringType.Name + '.' + property.Name;
             }
-
+            DeclaringType = property.DeclaringType;
             Update();
         }
 
@@ -55,6 +55,8 @@ namespace Avalonia.Diagnostics.ViewModels
         public override bool? IsAttached => 
             default;
 
+        public override System.Type? DeclaringType { get; }
+
         // [MemberNotNull(nameof(_type))]
         public override void Update()
         {
diff --git a/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlDetailsViewModel.cs b/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlDetailsViewModel.cs
index ba3fafdfaf..2e95e5dc39 100644
--- a/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlDetailsViewModel.cs
+++ b/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlDetailsViewModel.cs
@@ -24,7 +24,7 @@ namespace Avalonia.Diagnostics.ViewModels
         private bool _showInactiveStyles;
         private string? _styleStatus;
         private object _selectedEntity;
-        private readonly Stack<Tuple<string, object>> _selectedEntitiesStack = new Stack<Tuple<string, object>>();
+        private readonly Stack<(string Name,object Entry)> _selectedEntitiesStack = new();
         private string _selectedEntityName;
         private string _selectedEntityType;
 
@@ -399,17 +399,27 @@ namespace Avalonia.Diagnostics.ViewModels
 
         public void ApplySelectedProperty()
         {
-            if (SelectedProperty == null) return;
+            var selectedProperty = SelectedProperty;
+            var selectedEntity = SelectedEntity;
+            var selectedEntityName = SelectedEntityName;
+            if (selectedProperty == null) return;
             
-            var property = (_selectedEntity as IControl)?.GetValue(SelectedProperty.Key as AvaloniaProperty);
+            var property = (selectedEntity as IControl)?.GetValue(selectedProperty.Key as AvaloniaProperty);
             if (property == null)
             {
-                property = _selectedEntity.GetType().GetProperty(SelectedProperty.Name)?.GetValue(_selectedEntity);
+                property = selectedEntity.GetType().GetProperties()
+                     .FirstOrDefault(pi =>
+                     {
+                         return pi.Name == selectedProperty.Name
+                           && pi.DeclaringType == selectedProperty.DeclaringType
+                           && pi.PropertyType.Name == selectedProperty.Type; 
+                     })
+                     ?.GetValue(selectedEntity);
             }
 
             if (property == null) return;
-            _selectedEntitiesStack.Push(new Tuple<string, object>(SelectedEntityName, SelectedEntity));
-            NavigateToProperty(property, SelectedProperty.Name);
+            _selectedEntitiesStack.Push((Name:selectedEntityName, Entry:selectedEntity));
+            NavigateToProperty(property, selectedProperty.Name);
         }
 
         public void ApplyParentProperty()
@@ -417,7 +427,7 @@ namespace Avalonia.Diagnostics.ViewModels
             if (_selectedEntitiesStack.Any())
             {
                 var property = _selectedEntitiesStack.Pop();
-                NavigateToProperty(property.Item2, property.Item1);
+                NavigateToProperty(property.Entry, property.Name);
             }
         }
         
diff --git a/src/Avalonia.Diagnostics/Diagnostics/ViewModels/PropertyViewModel.cs b/src/Avalonia.Diagnostics/Diagnostics/ViewModels/PropertyViewModel.cs
index fdbd8c1aa3..173dcd165a 100644
--- a/src/Avalonia.Diagnostics/Diagnostics/ViewModels/PropertyViewModel.cs
+++ b/src/Avalonia.Diagnostics/Diagnostics/ViewModels/PropertyViewModel.cs
@@ -15,6 +15,7 @@ namespace Avalonia.Diagnostics.ViewModels
         public abstract string Name { get; }
         public abstract string Group { get; }
         public abstract string Type { get; }
+        public abstract Type? DeclaringType { get; }
         public abstract string Value { get; set; }
         public abstract string Priority { get; }
         public abstract bool? IsAttached { get;  }

From 1b71875276fb9df74cb65a763b9f7cbcd896512f Mon Sep 17 00:00:00 2001
From: Giuseppe Lippolis <workgroupengineering@outlook.com>
Date: Wed, 3 Nov 2021 13:10:19 +0100
Subject: [PATCH 10/10] fixes(DevTools): Null reference exception when
 double-clicking ClrProperties

---
 .../ViewModels/ControlDetailsViewModel.cs     | 26 ++++++++++++-------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlDetailsViewModel.cs b/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlDetailsViewModel.cs
index ba3fafdfaf..65e9c4854c 100644
--- a/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlDetailsViewModel.cs
+++ b/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlDetailsViewModel.cs
@@ -24,7 +24,7 @@ namespace Avalonia.Diagnostics.ViewModels
         private bool _showInactiveStyles;
         private string? _styleStatus;
         private object _selectedEntity;
-        private readonly Stack<Tuple<string, object>> _selectedEntitiesStack = new Stack<Tuple<string, object>>();
+        private readonly Stack<(string Name, object Entry)> _selectedEntitiesStack = new();
         private string _selectedEntityName;
         private string _selectedEntityType;
 
@@ -399,17 +399,25 @@ namespace Avalonia.Diagnostics.ViewModels
 
         public void ApplySelectedProperty()
         {
-            if (SelectedProperty == null) return;
-            
-            var property = (_selectedEntity as IControl)?.GetValue(SelectedProperty.Key as AvaloniaProperty);
-            if (property == null)
+            var selectedProperty = SelectedProperty;
+            var selectedEntity = SelectedEntity;
+            var selectedEntityName = SelectedEntityName;
+            if (selectedProperty == null)
+                return;
+
+            object? property;
+            if (selectedProperty.Key is AvaloniaProperty avaloniaProperty)
+            {
+                property = (_selectedEntity as IControl)?.GetValue(avaloniaProperty);
+            }
+            else
             {
-                property = _selectedEntity.GetType().GetProperty(SelectedProperty.Name)?.GetValue(_selectedEntity);
+                property = _selectedEntity.GetType().GetProperty(selectedProperty.Name)?.GetValue(_selectedEntity);
             }
 
             if (property == null) return;
-            _selectedEntitiesStack.Push(new Tuple<string, object>(SelectedEntityName, SelectedEntity));
-            NavigateToProperty(property, SelectedProperty.Name);
+            _selectedEntitiesStack.Push((Name:selectedEntityName,Entry:selectedEntity));
+            NavigateToProperty(property, selectedProperty.Name);
         }
 
         public void ApplyParentProperty()
@@ -417,7 +425,7 @@ namespace Avalonia.Diagnostics.ViewModels
             if (_selectedEntitiesStack.Any())
             {
                 var property = _selectedEntitiesStack.Pop();
-                NavigateToProperty(property.Item2, property.Item1);
+                NavigateToProperty(property.Entry, property.Name);
             }
         }