From 0d32823c598cdd91fb18d90c698b831bf80ce3d8 Mon Sep 17 00:00:00 2001
From: Dariusz Komosinski <darek.komosinski@gmail.com>
Date: Tue, 15 Mar 2022 22:59:29 +0100
Subject: [PATCH 1/2] Fixed compiled self binding not working from setters. Add
 extra tests for both reflection and compiled bindings.

---
 .../AvaloniaXamlIlBindingPathTransformer.cs   | 10 +++++-
 .../AvaloniaXamlIlWellKnownTypes.cs           |  2 ++
 .../CompiledBindingExtensionTests.cs          | 31 ++++++++++++++++++
 .../Xaml/BindingTests.cs                      | 32 +++++++++++++++++++
 4 files changed, 74 insertions(+), 1 deletion(-)

diff --git a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlBindingPathTransformer.cs b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlBindingPathTransformer.cs
index 048a6220c5..3cc3504e16 100644
--- a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlBindingPathTransformer.cs
+++ b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlBindingPathTransformer.cs
@@ -117,7 +117,15 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
                     return parentDataContextNode.DataContextType;
                 };
 
-                XamlIlBindingPathHelper.UpdateCompiledBindingExtension(context, binding, startTypeResolver, context.ParentNodes().OfType<XamlAstConstructableObjectNode>().First().Type.GetClrType());
+                var selfType = context.ParentNodes().OfType<XamlAstConstructableObjectNode>().First().Type.GetClrType();
+                
+                // When using self bindings with setters we need to change target type to resolved selector type.
+                if (context.GetAvaloniaTypes().ISetter.IsAssignableFrom(selfType))
+                {
+                    selfType = context.ParentNodes().OfType<AvaloniaXamlIlTargetTypeMetadataNode>().First().TargetType.GetClrType();
+                }
+
+                XamlIlBindingPathHelper.UpdateCompiledBindingExtension(context, binding, startTypeResolver, selfType);
             }
 
             return node;
diff --git a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlWellKnownTypes.cs b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlWellKnownTypes.cs
index 34a146cf37..99072ace02 100644
--- a/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlWellKnownTypes.cs
+++ b/src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlWellKnownTypes.cs
@@ -91,6 +91,7 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
         public IXamlType TextDecorationCollection { get; }
         public IXamlType TextDecorations { get; }
         public IXamlType TextTrimming { get; }
+        public IXamlType ISetter { get; }
 
         public AvaloniaXamlIlWellKnownTypes(TransformerConfiguration cfg)
         {
@@ -199,6 +200,7 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
             TextDecorationCollection = cfg.TypeSystem.GetType("Avalonia.Media.TextDecorationCollection");
             TextDecorations = cfg.TypeSystem.GetType("Avalonia.Media.TextDecorations");
             TextTrimming = cfg.TypeSystem.GetType("Avalonia.Media.TextTrimming");
+            ISetter = cfg.TypeSystem.GetType("Avalonia.Styling.ISetter");
         }
     }
 
diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/CompiledBindingExtensionTests.cs b/tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/CompiledBindingExtensionTests.cs
index ecfb54a624..c1c2284372 100644
--- a/tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/CompiledBindingExtensionTests.cs
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/CompiledBindingExtensionTests.cs
@@ -1064,6 +1064,37 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
             }
         }
 
+        [Fact]
+        public void Binds_To_Self_In_Style()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var xaml = @"
+<Window xmlns='https://github.com/avaloniaui'
+        xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>
+       
+    <Window.Styles>
+        <Style Selector='Button'>
+            <Setter Property='IsVisible' Value='{CompiledBinding $self.IsEnabled}' />
+        </Style>
+    </Window.Styles>
+
+    <Button Name='button' />
+</Window>";
+                var window = (Window)AvaloniaRuntimeXamlLoader.Load(xaml);
+                var button = window.FindControl<Button>("button");
+
+                window.ApplyTemplate();
+                window.Presenter.ApplyTemplate();
+
+                Assert.True(button.IsVisible);
+
+                button.IsEnabled = false;
+
+                Assert.False(button.IsVisible);
+            }
+        }
+
         [Fact]
         public void SupportsMethodBindingAsDelegate()
         {
diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/BindingTests.cs b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/BindingTests.cs
index 8af638c5d7..7a1c972b9c 100644
--- a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/BindingTests.cs
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/BindingTests.cs
@@ -183,6 +183,38 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
             }
         }
 
+        [Fact]
+        public void Binding_To_Self_In_Style_Works()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var xaml = @"
+<Window xmlns='https://github.com/avaloniaui'
+        xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
+        xmlns:local='clr-namespace:Avalonia.Markup.Xaml.UnitTests.MarkupExtensions;assembly=Avalonia.Markup.Xaml.UnitTests'>
+       
+    <Window.Styles>
+        <Style Selector='Button'>
+            <Setter Property='IsVisible' Value='{Binding $self.IsEnabled}' />
+        </Style>
+    </Window.Styles>
+
+    <Button Name='button' />
+</Window>";
+                var window = (Window)AvaloniaRuntimeXamlLoader.Load(xaml);
+                var button = window.FindControl<Button>("button");
+
+                window.ApplyTemplate();
+                window.Presenter.ApplyTemplate();
+
+                Assert.True(button.IsVisible);
+
+                button.IsEnabled = false;
+
+                Assert.False(button.IsVisible);
+            }
+        }
+
         [Fact]
         public void Stream_Binding_To_Observable_Works()
         {

From d9909ab527abcd1e6421dab0dce7ef721c4507a4 Mon Sep 17 00:00:00 2001
From: Dariusz Komosinski <darek.komosinski@gmail.com>
Date: Tue, 15 Mar 2022 23:06:30 +0100
Subject: [PATCH 2/2] Cleanup test.

---
 tests/Avalonia.Markup.Xaml.UnitTests/Xaml/BindingTests.cs | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/BindingTests.cs b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/BindingTests.cs
index 7a1c972b9c..bcda3f855a 100644
--- a/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/BindingTests.cs
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/Xaml/BindingTests.cs
@@ -190,8 +190,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
             {
                 var xaml = @"
 <Window xmlns='https://github.com/avaloniaui'
-        xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
-        xmlns:local='clr-namespace:Avalonia.Markup.Xaml.UnitTests.MarkupExtensions;assembly=Avalonia.Markup.Xaml.UnitTests'>
+        xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>
        
     <Window.Styles>
         <Style Selector='Button'>