Fix setting window title.

Closes #82.

Tests/Perspex.Controls.UnitTests/WindowTests.cs

@@ -0,0 +1,43 @@
+// -----------------------------------------------------------------------
+// <copyright file="WindowTests.cs" company="Steven Kirk">
+// Copyright 2015 MIT Licence. See licence.md for more information.
+// </copyright>
+// -----------------------------------------------------------------------
+
+namespace Perspex.Controls.UnitTests
+{
+    using System.Reactive;
+    using System.Reactive.Subjects;
+    using Moq;
+    using Perspex.Controls.Presenters;
+    using Perspex.Controls.Templates;
+    using Perspex.Input;
+    using Perspex.Input.Raw;
+    using Perspex.Layout;
+    using Perspex.Platform;
+    using Perspex.Rendering;
+    using Perspex.Styling;
+    using Ploeh.AutoFixture;
+    using Ploeh.AutoFixture.AutoMoq;
+    using Splat;
+    using Xunit;
+
+    public class WindowTests
+    {
+        [Fact]
+        public void Setting_Title_Should_Set_Impl_Title()
+        {
+            using (Locator.CurrentMutable.WithResolver())
+            {
+                var windowImpl = new Mock<IWindowImpl>();
+                Locator.CurrentMutable.RegisterConstant(windowImpl.Object, typeof(IWindowImpl));
+
+                var target = new Window();
+
+                target.Title = "Hello World";
+
+                windowImpl.Verify(x => x.SetTitle("Hello World"));
+            }
+        }
+    }
+}

src/Perspex.Controls/Window.cs

@@ -66,6 +66,7 @@ namespace Perspex.Controls
         static Window()
         {
             BackgroundProperty.OverrideDefaultValue(typeof(Window), Brushes.White);
+            TitleProperty.Changed.AddClassHandler<Window>(x => x.TitleChanged);
         }
 
         /// <summary>
@@ -234,5 +235,10 @@ namespace Perspex.Controls
 
             base.HandleResized(clientSize);
         }
+
+        private void TitleChanged(PerspexPropertyChangedEventArgs e)
+        {
+            this.PlatformImpl.SetTitle((string)e.NewValue);
+        }
     }
 }