Added mutable SolidColorBrush.

As a hack for lack of immutability support in XAML.

src/Perspex.SceneGraph/Media/Mutable/SolidColorBrush.cs

@@ -0,0 +1,35 @@
+// 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.
+
+namespace Perspex.Media.Mutable
+{
+    /// <summary>
+    /// Fills an area with a solid color.
+    /// </summary>
+    /// <remarks>
+    /// This is a mutable version of the normal immutable <see cref="Perspex.Media.SolidColorBrush"/>
+    /// for use in XAML. XAML really needs support for immutable data...
+    /// </remarks>
+    public class SolidColorBrush : Brush
+    {
+        public static readonly DirectProperty<SolidColorBrush, Color> ColorProperty =
+            PerspexProperty.RegisterDirect<SolidColorBrush, Color>(
+                "Color",
+                o => o.Color,
+                (o, v) => o.Color = v);
+
+        /// <summary>
+        /// Gets the color of the brush.
+        /// </summary>
+        public Color Color { get; set; }
+
+        /// <summary>
+        /// Returns a string representation of the brush.
+        /// </summary>
+        /// <returns>A string representation of the brush.</returns>
+        public override string ToString()
+        {
+            return Color.ToString();
+        }
+    }
+}

src/Perspex.SceneGraph/Perspex.SceneGraph.csproj

@@ -73,6 +73,7 @@
     <Compile Include="Media\GradientSpreadMethod.cs" />
     <Compile Include="Media\GradientStop.cs" />
     <Compile Include="Media\LineGeometry.cs" />
+    <Compile Include="Media\Mutable\SolidColorBrush.cs" />
     <Compile Include="Media\PenLineJoin.cs" />
     <Compile Include="Media\PolylineGeometry.cs" />
     <Compile Include="Media\RadialGradientBrush.cs" />

src/Perspex.SceneGraph/Properties/AssemblyInfo.cs

@@ -5,4 +5,5 @@ using System.Reflection;
 using Perspex.Metadata;
 
 [assembly: AssemblyTitle("Perspex.SceneGraph")]
-[assembly: XmlnsDefinition("https://github.com/perspex", "Perspex.Media")]
+[assembly: XmlnsDefinition("https://github.com/perspex", "Perspex.Media")]
+[assembly: XmlnsDefinition("https://github.com/perspex/mutable", "Perspex.Media.Mutable")]

src/Windows/Perspex.Direct2D1/Media/DrawingContext.cs

@@ -294,6 +294,7 @@ namespace Perspex.Direct2D1.Media
         public BrushImpl CreateBrush(Perspex.Media.Brush brush, Size destinationSize)
         {
             var solidColorBrush = brush as Perspex.Media.SolidColorBrush;
+            var mutableSolidColorBrush = brush as Perspex.Media.Mutable.SolidColorBrush;
             var linearGradientBrush = brush as Perspex.Media.LinearGradientBrush;
             var radialGradientBrush = brush as Perspex.Media.RadialGradientBrush;
             var imageBrush = brush as Perspex.Media.ImageBrush;
@@ -303,6 +304,10 @@ namespace Perspex.Direct2D1.Media
             {
                 return new SolidColorBrushImpl(solidColorBrush, _renderTarget);
             }
+            if (mutableSolidColorBrush != null)
+            {
+                return new SolidColorBrushImpl(mutableSolidColorBrush, _renderTarget);
+            }
             else if (linearGradientBrush != null)
             {
                 return new LinearGradientBrushImpl(linearGradientBrush, _renderTarget, destinationSize);
@@ -321,7 +326,7 @@ namespace Perspex.Direct2D1.Media
             }
             else
             {
-                return new SolidColorBrushImpl(null, _renderTarget);
+                return new SolidColorBrushImpl((Perspex.Media.SolidColorBrush)null, _renderTarget);
             }
         }
     }

src/Windows/Perspex.Direct2D1/Media/SolidColorBrushImpl.cs

@@ -17,5 +17,18 @@ namespace Perspex.Direct2D1.Media
                 }
             );
         }
+
+        public SolidColorBrushImpl(Perspex.Media.Mutable.SolidColorBrush brush, SharpDX.Direct2D1.RenderTarget target)
+        {
+            PlatformBrush = new SharpDX.Direct2D1.SolidColorBrush(
+                target,
+                brush?.Color.ToDirect2D() ?? new SharpDX.Mathematics.Interop.RawColor4(),
+                new SharpDX.Direct2D1.BrushProperties
+                {
+                    Opacity = brush != null ? (float)brush.Opacity : 1.0f,
+                    Transform = target.Transform
+                }
+            );
+        }
     }
 }