From f62f32c83c8b620cb9940b2438352ca198faba2e Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Fri, 19 Feb 2016 17:53:05 +0100
Subject: [PATCH] Allow {StyleResource} in setter.

---
 .../Data/StyleResourceBinding.cs              | 87 +++++++++++++++++++
 .../StyleResourceExtension.cs                 | 30 +------
 src/Markup/Perspex.Markup.Xaml/OmniXAML       |  2 +-
 .../Perspex.Markup.Xaml.csproj                |  1 +
 .../StyleTests.cs                             | 32 ++++---
 5 files changed, 111 insertions(+), 41 deletions(-)
 create mode 100644 src/Markup/Perspex.Markup.Xaml/Data/StyleResourceBinding.cs

diff --git a/src/Markup/Perspex.Markup.Xaml/Data/StyleResourceBinding.cs b/src/Markup/Perspex.Markup.Xaml/Data/StyleResourceBinding.cs
new file mode 100644
index 0000000000..f1c897dfd9
--- /dev/null
+++ b/src/Markup/Perspex.Markup.Xaml/Data/StyleResourceBinding.cs
@@ -0,0 +1,87 @@
+// Copyright (c) The Perspex Project. All rights reserved.
+// Licensed under the MIT license. See licence.md file in the project root for full license information.
+
+using System;
+using System.Reactive.Disposables;
+using System.Reactive.Linq;
+using System.Reactive.Subjects;
+using Perspex.Data;
+using Perspex.Styling;
+
+namespace Perspex.Markup.Xaml.Data
+{
+    public class StyleResourceBinding : IBinding
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="StyleResourceBinding"/> class.
+        /// </summary>
+        /// <param name="name">The resource name.</param>
+        public StyleResourceBinding(string name)
+        {
+            Name = name;
+        }
+
+        /// <inheritdoc/>
+        public BindingMode Mode => BindingMode.OneTime;
+
+        /// <summary>
+        /// Gets the resource name.
+        /// </summary>
+        public string Name { get; }
+
+        /// <inheritdoc/>
+        public BindingPriority Priority => BindingPriority.LocalValue;
+
+        /// <inheritdoc/>
+        public ISubject<object> CreateSubject(IPerspexObject target, PerspexProperty targetProperty)
+        {
+            return new Subject(target, Name);
+        }
+
+        private class Subject : ISubject<object>
+        {
+            private IPerspexObject _target;
+            private string _name;
+
+            public Subject(IPerspexObject target, string name)
+            {
+                _target = target;
+                _name = name;
+            }
+
+            public void OnCompleted()
+            {
+            }
+
+            public void OnError(Exception error)
+            {
+            }
+
+            public void OnNext(object value)
+            {
+            }
+
+            public IDisposable Subscribe(IObserver<object> observer)
+            {
+                // HACK around OmniXAML issue #84.
+                var po = (PerspexObject)_target;
+                var parent = PerspexPropertyRegistry.Instance.FindRegistered(po, "Parent");
+
+                return po.GetObservable(parent)
+                    .Where(x => x != PerspexProperty.UnsetValue && x != null)
+                    .Take(1)
+                    .Subscribe(_ =>
+                    {
+                        var resource = ((IStyleHost)_target).FindStyleResource(_name);
+
+                        if (resource != PerspexProperty.UnsetValue)
+                        {
+                            observer.OnNext(resource);
+                        }
+
+                        observer.OnCompleted();
+                    });
+            }
+        }
+    }
+}
diff --git a/src/Markup/Perspex.Markup.Xaml/MarkupExtensions/StyleResourceExtension.cs b/src/Markup/Perspex.Markup.Xaml/MarkupExtensions/StyleResourceExtension.cs
index 1a1e5f12eb..48bec12be2 100644
--- a/src/Markup/Perspex.Markup.Xaml/MarkupExtensions/StyleResourceExtension.cs
+++ b/src/Markup/Perspex.Markup.Xaml/MarkupExtensions/StyleResourceExtension.cs
@@ -5,6 +5,7 @@ using System;
 using System.Reactive.Linq;
 using OmniXaml;
 using Perspex.LogicalTree;
+using Perspex.Markup.Xaml.Data;
 using Perspex.Styling;
 
 namespace Perspex.Markup.Xaml.MarkupExtensions
@@ -18,34 +19,7 @@ namespace Perspex.Markup.Xaml.MarkupExtensions
 
         public override object ProvideValue(MarkupExtensionContext extensionContext)
         {
-            var styleHost = extensionContext.TargetObject as IStyleHost;
-
-            if (styleHost == null)
-            {
-                throw new ParseException(
-                    $"StyleResource cannot be assigned to an object of type '{extensionContext.TargetObject.GetType()}'.");
-            }
-
-            // HACK: This should be as simple as:
-            //     return styleHost.FindStyleResource(Name);
-            // Waiting on OmniXAML issue #84 to be fixed before it can be that simple though.
-            var po = (PerspexObject)styleHost;
-            var parent = PerspexPropertyRegistry.Instance.FindRegistered(po, "Parent");
-
-            po.GetObservable(parent)
-                .Where(x => x != PerspexProperty.UnsetValue && x != null)
-                .Take(1)
-                .Subscribe(_ =>
-                {
-                    var resource = styleHost.FindStyleResource(Name);
-
-                    if (resource != PerspexProperty.UnsetValue)
-                    {
-                        extensionContext.TargetProperty.SetValue(extensionContext.TargetObject, resource);
-                    }
-                });
-
-            return PerspexProperty.UnsetValue;
+            return new StyleResourceBinding(this.Name);
         }
 
         public string Name { get; set; }
diff --git a/src/Markup/Perspex.Markup.Xaml/OmniXAML b/src/Markup/Perspex.Markup.Xaml/OmniXAML
index e1a5fb60b0..2b41f290bd 160000
--- a/src/Markup/Perspex.Markup.Xaml/OmniXAML
+++ b/src/Markup/Perspex.Markup.Xaml/OmniXAML
@@ -1 +1 @@
-Subproject commit e1a5fb60b09862183ba5c48c36a52bea7a66bd42
+Subproject commit 2b41f290bdf4dce07730a8f55622a637f966945b
diff --git a/src/Markup/Perspex.Markup.Xaml/Perspex.Markup.Xaml.csproj b/src/Markup/Perspex.Markup.Xaml/Perspex.Markup.Xaml.csproj
index 35aff8a3a2..830eb87498 100644
--- a/src/Markup/Perspex.Markup.Xaml/Perspex.Markup.Xaml.csproj
+++ b/src/Markup/Perspex.Markup.Xaml/Perspex.Markup.Xaml.csproj
@@ -78,6 +78,7 @@
     <Compile Include="Data\MultiBinding.cs" />
     <Compile Include="Data\RelativeSource.cs" />
     <Compile Include="Data\SourceBindingEndpoint.cs" />
+    <Compile Include="Data\StyleResourceBinding.cs" />
     <Compile Include="Data\TargetBindingEndpoint.cs" />
     <Compile Include="MarkupExtensions\StyleResourceExtension.cs" />
     <Compile Include="MarkupExtensions\BindingExtension.cs" />
diff --git a/tests/Perspex.Markup.Xaml.UnitTests/StyleTests.cs b/tests/Perspex.Markup.Xaml.UnitTests/StyleTests.cs
index 321ac355fc..8fa212c17a 100644
--- a/tests/Perspex.Markup.Xaml.UnitTests/StyleTests.cs
+++ b/tests/Perspex.Markup.Xaml.UnitTests/StyleTests.cs
@@ -5,6 +5,7 @@ using System.Linq;
 using System.Reactive.Linq;
 using Perspex.Controls;
 using Perspex.Data;
+using Perspex.Input;
 using Perspex.Markup.Xaml.Data;
 using Perspex.Media;
 using Perspex.Styling;
@@ -91,27 +92,34 @@ namespace Perspex.Markup.Xaml.UnitTests
         [Fact]
         public void StyleResource_Can_Be_Assigned_To_Setter()
         {
-            var xaml = @"
-<UserControl xmlns='https://github.com/perspex'
-             xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>
-    <UserControl.Styles>
+            // For some reason this type can't always be found if we don't do this.
+            var hack = typeof(KeyboardNavigation);
+
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var xaml = @"
+<Window xmlns='https://github.com/perspex'
+        xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>
+    <Window.Styles>
         <Style>
             <Style.Resources>
                 <SolidColorBrush x:Key='brush'>#ff506070</SolidColorBrush>
             </Style.Resources>
         </Style>
         <Style Selector='Button'>
-            <Setter Property='Background' Value='#ff808080'/>
+            <Setter Property='Background' Value='{StyleResource brush}'/>
         </Style>
-    </UserControl.Styles>
-</UserControl>";
+    </Window.Styles>
+    <Button Name='button'/>
+</Window>";
 
-            var loader = new PerspexXamlLoader();
-            var userControl = (UserControl)loader.Load(xaml);
-            var style = (Style)userControl.Styles[1];
-            var setter = (Setter)style.Setters.Single();
+                var loader = new PerspexXamlLoader();
+                var window = (Window)loader.Load(xaml);
+                var button = window.FindControl<Button>("button");
+                var brush = (SolidColorBrush)button.Background;
 
-            Assert.NotNull(setter.Value);
+                Assert.Equal(0xff506070, brush.Color.ToUint32());
+            }
         }
 
         [Fact]