Started adding StyleResource markup extension.

OmniXAML issue #84 is now blocking us.

src/Markup/Perspex.Markup.Xaml/MarkupExtensions/StyleResourceExtension.cs

@@ -0,0 +1,33 @@
+// 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 OmniXaml;
+using Perspex.LogicalTree;
+using Perspex.Styling;
+
+namespace Perspex.Markup.Xaml.MarkupExtensions
+{
+    public class StyleResourceExtension : MarkupExtension
+    {
+        public StyleResourceExtension(string name)
+        {
+            Name = name;
+        }
+
+        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 '{styleHost.GetType()}'.");
+            }
+
+            return styleHost.FindStyleResource(Name);
+        }
+
+        public string Name { get; set; }
+    }
+}

src/Markup/Perspex.Markup.Xaml/Perspex.Markup.Xaml.csproj

@@ -55,6 +55,7 @@
     <Compile Include="Converters\BitmapTypeConverter.cs" />
     <Compile Include="Converters\BrushTypeConverter.cs" />
     <Compile Include="Converters\ClassesTypeConverter.cs" />
+    <Compile Include="Converters\SolidColorBrushTypeConverter.cs" />
     <Compile Include="Converters\ColorTypeConverter.cs" />
     <Compile Include="Converters\ColumnDefinitionsTypeConverter.cs" />
     <Compile Include="Converters\CursorTypeConverter.cs" />
@@ -78,6 +79,7 @@
     <Compile Include="Data\RelativeSource.cs" />
     <Compile Include="Data\SourceBindingEndpoint.cs" />
     <Compile Include="Data\TargetBindingEndpoint.cs" />
+    <Compile Include="MarkupExtensions\StyleResourceExtension.cs" />
     <Compile Include="MarkupExtensions\BindingExtension.cs" />
     <Compile Include="MarkupExtensions\RelativeSourceExtension.cs" />
     <Compile Include="MarkupExtensions\StaticExtension.cs" />

src/Markup/Perspex.Markup.Xaml/Styling/StyleInclude.cs

@@ -35,5 +35,17 @@ namespace Perspex.Markup.Xaml.Styling
                 Loaded.Attach(control, container);
             }
         }
+
+        /// <summary>
+        /// Tries to find a named resource within the style.
+        /// </summary>
+        /// <param name="name">The resource name.</param>
+        /// <returns>
+        /// The resource if found, otherwise <see cref="PerspexProperty.UnsetValue"/>.
+        /// </returns>
+        public object FindResource(string name)
+        {
+            return Loaded.FindResource(name);
+        }
     }
 }

src/Perspex.Styling/Perspex.Styling.csproj

@@ -63,6 +63,7 @@
     <Compile Include="Styling\Style.cs" />
     <Compile Include="Styling\StyleActivator.cs" />
     <Compile Include="Styling\ActivatedObservable.cs" />
+    <Compile Include="Styling\StyleExtensions.cs" />
     <Compile Include="Styling\Styler.cs" />
     <Compile Include="Styling\Styles.cs" />
   </ItemGroup>

src/Perspex.Styling/Styling/IStyle.cs

@@ -16,5 +16,14 @@ namespace Perspex.Styling
         /// The control that contains this style. May be null.
         /// </param>
         void Attach(IStyleable control, IStyleHost container);
+
+        /// <summary>
+        /// Tries to find a named resource within the style.
+        /// </summary>
+        /// <param name="name">The resource name.</param>
+        /// <returns>
+        /// The resource if found, otherwise <see cref="PerspexProperty.UnsetValue"/>.
+        /// </returns>
+        object FindResource(string name);
     }
 }

src/Perspex.Styling/Styling/Style.cs

@@ -14,14 +14,13 @@ namespace Perspex.Styling
     public class Style : IStyle
     {
         private static readonly IObservable<bool> True = Observable.Never<bool>().StartWith(true);
-        private Lazy<Dictionary<string, object>> _resources;
+        private Dictionary<string, object> _resources;
 
         /// <summary>
         /// Initializes a new instance of the <see cref="Style"/> class.
         /// </summary>
         public Style()
         {
-            _resources = new Lazy<Dictionary<string, object>>(() => new Dictionary<string, object>());
         }
 
         /// <summary>
@@ -34,9 +33,30 @@ namespace Perspex.Styling
         }
 
         /// <summary>
-        /// Gets a dictionary of style resources.
+        /// Gets or sets a dictionary of style resources.
         /// </summary>
-        public IDictionary<string, object> Resources => _resources.Value;
+        public IDictionary<string, object> Resources
+        {
+            get
+            {
+                if (_resources == null)
+                {
+                    _resources = new Dictionary<string, object>();
+                }
+
+                return _resources;
+            }
+
+            set
+            {
+                var resources = Resources;
+
+                foreach (var i in value)
+                {
+                    resources.Add(i);
+                }
+            }
+        }
 
         /// <summary>
         /// Gets or sets style's selector.
@@ -83,6 +103,27 @@ namespace Perspex.Styling
             }
         }
 
+        /// <summary>
+        /// Tries to find a named resource within the style.
+        /// </summary>
+        /// <param name="name">The resource name.</param>
+        /// <returns>
+        /// The resource if found, otherwise <see cref="PerspexProperty.UnsetValue"/>.
+        /// </returns>
+        public object FindResource(string name)
+        {
+            object result = null;
+
+            if (_resources?.TryGetValue(name, out result) == true)
+            {
+                return result;
+            }
+            else
+            {
+                return PerspexProperty.UnsetValue;
+            }
+        }
+
         /// <summary>
         /// Returns a string representation of the style.
         /// </summary>

src/Perspex.Styling/Styling/StyleExtensions.cs

@@ -0,0 +1,39 @@
+// 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;
+
+namespace Perspex.Styling
+{
+    public static class StyleExtensions
+    {
+        /// <summary>
+        /// Tries to find a named style resource.
+        /// </summary>
+        /// <param name="control">The control from which to find the resource.</param>
+        /// <param name="name">The resource name.</param>
+        /// <returns>
+        /// The resource if found, otherwise <see cref="PerspexProperty.UnsetValue"/>.
+        /// </returns>
+        public static object FindStyleResource(this IStyleHost control, string name)
+        {
+            Contract.Requires<ArgumentNullException>(control != null);
+            Contract.Requires<ArgumentNullException>(name != null);
+            Contract.Requires<ArgumentException>(!string.IsNullOrWhiteSpace(name));
+
+            while (control != null)
+            {
+                var result = control.Styles.FindResource(name);
+
+                if (result != PerspexProperty.UnsetValue)
+                {
+                    return result;
+                }
+
+                control = control.StylingParent;
+            }
+
+            return PerspexProperty.UnsetValue;
+        }
+    }
+}

src/Perspex.Styling/Styling/Styles.cs

@@ -1,6 +1,7 @@
 // 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.Linq;
 using Perspex.Collections;
 
 namespace Perspex.Styling
@@ -24,5 +25,27 @@ namespace Perspex.Styling
                 style.Attach(control, container);
             }
         }
+
+        /// <summary>
+        /// Tries to find a named resource within the style.
+        /// </summary>
+        /// <param name="name">The resource name.</param>
+        /// <returns>
+        /// The resource if found, otherwise <see cref="PerspexProperty.UnsetValue"/>.
+        /// </returns>
+        public object FindResource(string name)
+        {
+            foreach (var style in this.Reverse())
+            {
+                var result = style.FindResource(name);
+
+                if (result != PerspexProperty.UnsetValue)
+                {
+                    return result;
+                }
+            }
+
+            return PerspexProperty.UnsetValue;
+        }
     }
 }

tests/Perspex.Markup.Xaml.UnitTests/StyleTests.cs

@@ -19,7 +19,7 @@ namespace Perspex.Markup.Xaml.UnitTests
         public void Color_Can_Be_Added_To_Style_Resources()
         {
             using (UnitTestApplication.Start(TestServices.MockPlatformWrapper))
-            {                
+            {
                 var xaml = @"
 <UserControl xmlns='https://github.com/perspex'
              xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>
@@ -63,6 +63,31 @@ namespace Perspex.Markup.Xaml.UnitTests
             }
         }
 
+        [Fact]
+        public void StyleResource_Can_Be_Assigned_To_Property()
+        {
+            var xaml = @"
+<UserControl xmlns='https://github.com/perspex'
+             xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>
+    <UserControl.Styles>
+        <Style>
+            <Style.Resources>
+                <SolidColorBrush x:Key='brush'>#ff506070</SolidColorBrush>
+            </Style.Resources>
+        </Style>
+    </UserControl.Styles>
+
+    <Border Name='border' Background='{StyleResource brush}'/>
+</UserControl>";
+
+            var loader = new PerspexXamlLoader();
+            var userControl = (UserControl)loader.Load(xaml);
+            var border = userControl.FindControl<Border>("border");
+            var brush = (SolidColorBrush)border.Background;
+
+            Assert.Equal(0xff506070, brush.Color.ToUint32());
+        }
+
         [Fact]
         public void Binding_Should_Be_Assigned_To_Setter_Value_Instead_Of_Bound()
         {

tests/Perspex.Styling.UnitTests/Perspex.Styling.UnitTests.csproj

@@ -97,6 +97,7 @@
     <Compile Include="SelectorTests_PropertyEquals.cs" />
     <Compile Include="SelectorTests_OfType.cs" />
     <Compile Include="SelectorTests_Template.cs" />
+    <Compile Include="ResourceTests.cs" />
     <Compile Include="StyleActivatorTests.cs" />
     <Compile Include="ActivatedObservableTests.cs" />
     <Compile Include="SetterTests.cs" />

tests/Perspex.Styling.UnitTests/ResourceTests.cs

@@ -0,0 +1,78 @@
+// 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.Collections.Generic;
+using Perspex.Controls;
+using Xunit;
+
+namespace Perspex.Styling.UnitTests
+{
+    public class ResourceTests
+    {
+        [Fact]
+        public void FindStyleResource_Should_Find_Correct_Resource()
+        {
+            Border target;
+
+            var tree = new Decorator
+            {
+                Styles = new Styles
+                {
+                    new Style
+                    {
+                        Resources = new Dictionary<string, object>
+                        {
+                            { "Foo", "foo resource" },
+                            { "Bar", "overridden" },
+                        }
+                    }
+                },
+                Child = target = new Border
+                {
+                    Styles = new Styles
+                    {
+                        new Style
+                        {
+                            Resources = new Dictionary<string, object>
+                            {
+                                { "Bar", "again overridden" },
+                            }
+                        },
+                        new Style
+                        {
+                            Resources = new Dictionary<string, object>
+                            {
+                                { "Bar", "bar resource" },
+                            }
+                        }
+                    }
+                }
+            };
+
+            Assert.Equal("foo resource", target.FindStyleResource("Foo"));
+            Assert.Equal("bar resource", target.FindStyleResource("Bar"));
+        }
+
+        [Fact]
+        public void FindStyleResource_Should_Return_UnsetValue_For_Not_Found()
+        {
+            Border target;
+
+            var tree = target = new Border
+            {
+                Styles = new Styles
+                    {
+                        new Style
+                        {
+                            Resources = new Dictionary<string, object>
+                            {
+                                { "Foo", "foo" },
+                            }
+                        },
+                    }
+            };
+
+            Assert.Equal(PerspexProperty.UnsetValue, target.FindStyleResource("Baz"));
+        }
+    }
+}