From 5e0dd8fcd38fb85b45aa69d4cc3102edbcd01f06 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Mon, 18 Jan 2016 23:39:36 +0100
Subject: [PATCH] Support Setters with Bindings.

However Styles with activators (e.g. "Foo.class") not yet supported.
---
 src/Perspex.Styling/Styling/Setter.cs         | 46 +++++++++++++++++--
 .../Perspex.Styling.UnitTests.csproj          |  1 +
 .../Perspex.Styling.UnitTests/SetterTests.cs  | 28 +++++++++++
 3 files changed, 71 insertions(+), 4 deletions(-)
 create mode 100644 tests/Perspex.Styling.UnitTests/SetterTests.cs

diff --git a/src/Perspex.Styling/Styling/Setter.cs b/src/Perspex.Styling/Styling/Setter.cs
index 0db359fa40..e93729cf6e 100644
--- a/src/Perspex.Styling/Styling/Setter.cs
+++ b/src/Perspex.Styling/Styling/Setter.cs
@@ -62,15 +62,53 @@ namespace Perspex.Styling
         /// <param name="activator">An optional activator.</param>
         public void Apply(IStyle style, IStyleable control, IObservable<bool> activator)
         {
-            if (activator == null)
+            if (Property == null)
             {
-                control.SetValue(Property, Value, BindingPriority.Style);
+                throw new InvalidOperationException("Setter.Property must be set.");
+            }
+
+            var binding = Value as IBinding;
+
+            if (binding != null)
+            {
+                if (activator == null)
+                {
+                    Bind(control, Property, binding);
+                }
+                else
+                {
+                    throw new NotSupportedException(
+                        "Setter bindings with activators not yet supported.");
+                }
             }
             else
             {
-                var binding = new StyleBinding(activator, Value, style.ToString());
-                control.Bind(Property, binding, BindingPriority.StyleTrigger);
+                if (activator == null)
+                {
+                    control.SetValue(Property, Value, BindingPriority.Style);
+                }
+                else
+                {
+                    var activated = new StyleBinding(activator, Value, style.ToString());
+                    control.Bind(Property, activated, BindingPriority.StyleTrigger);
+                }
             }
         }
+
+        private void Bind(IStyleable control, PerspexProperty property, IBinding binding)
+        {
+            var mode = binding.Mode;
+
+            if (mode == BindingMode.Default)
+            {
+                mode = property.DefaultBindingMode;
+            }
+
+            control.Bind(
+                property,
+                binding.CreateSubject(control, property),
+                mode,
+                binding.Priority);
+        }
     }
 }
diff --git a/tests/Perspex.Styling.UnitTests/Perspex.Styling.UnitTests.csproj b/tests/Perspex.Styling.UnitTests/Perspex.Styling.UnitTests.csproj
index cc22e7f257..b9e82d589d 100644
--- a/tests/Perspex.Styling.UnitTests/Perspex.Styling.UnitTests.csproj
+++ b/tests/Perspex.Styling.UnitTests/Perspex.Styling.UnitTests.csproj
@@ -91,6 +91,7 @@
     <Compile Include="SelectorTests_Template.cs" />
     <Compile Include="StyleActivatorTests.cs" />
     <Compile Include="StyleBindingTests.cs" />
+    <Compile Include="SetterTests.cs" />
     <Compile Include="StyleTests.cs" />
     <Compile Include="TestControlBase.cs" />
     <Compile Include="TestObservable.cs" />
diff --git a/tests/Perspex.Styling.UnitTests/SetterTests.cs b/tests/Perspex.Styling.UnitTests/SetterTests.cs
new file mode 100644
index 0000000000..c42426e97b
--- /dev/null
+++ b/tests/Perspex.Styling.UnitTests/SetterTests.cs
@@ -0,0 +1,28 @@
+// 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.Reactive.Subjects;
+using Moq;
+using Perspex.Controls;
+using Perspex.Data;
+using Xunit;
+
+namespace Perspex.Styling.UnitTests
+{
+    public class SetterTests
+    {
+        [Fact]
+        public void Setter_Should_Apply_Binding_To_Property()
+        {
+            var control = new TextBlock();
+            var subject = new BehaviorSubject<object>("foo");
+            var binding = Mock.Of<IBinding>(x => x.CreateSubject(control, TextBlock.TextProperty) == subject);
+            var style = Mock.Of<IStyle>();
+            var setter = new Setter(TextBlock.TextProperty, binding);
+
+            setter.Apply(style, control, null);
+
+            Assert.Equal("foo", control.Text);
+        }
+    }
+}