Added a new binding syntax.

Allows binding to be done in initializer lists when using the new syntax
available in the Roslyn preview.

Perspex/PerspexObject.cs

@@ -123,6 +123,27 @@ namespace Perspex
             }
         }
 
+
+        /// <summary>
+        /// Gets or sets the value of a <see cref="PerspexProperty"/>.
+        /// </summary>
+        /// <param name="property">The property.</param>
+        public object this[PerspexProperty property]
+        {
+            get { return this.GetValue(property); }
+            set { this.SetValue(property, value); }
+        }
+
+        /// <summary>
+        /// Gets or sets the binding for a <see cref="PerspexProperty"/>.
+        /// </summary>
+        /// <param name="property">The property.</param>
+        public object this[PerspexProperty.BindingAccessor property]
+        {
+            get { return this.GetObservable(property.Property); }
+            set { this.Bind(property.Property, (IObservable<object>)value, property.Priority); }
+        }
+
         /// <summary>
         /// Gets all <see cref="PerspexProperty"/>s registered on a type.
         /// </summary>

Perspex/PerspexProperty.cs

@@ -105,6 +105,28 @@ namespace Perspex
             return result;
         }
 
+        /// <summary>
+        /// Provides access to a property's binding via the <see cref="PerspexObject"/> 
+        /// indexer.
+        /// </summary>
+        /// <param name="property">The property.</param>
+        /// <returns>A <see cref="BindingAccessor"/> describing the binding.</returns>
+        public static BindingAccessor operator!(PerspexProperty property)
+        {
+            return new BindingAccessor(property, BindingPriority.LocalValue);
+        }
+
+        /// <summary>
+        /// Provides access to a property's template binding via the <see cref="PerspexObject"/>
+        /// indexer.
+        /// </summary>
+        /// <param name="property">The property.</param>
+        /// <returns>A <see cref="BindingAccessor"/> describing the binding.</returns>
+        public static BindingAccessor operator ~(PerspexProperty property)
+        {
+            return new BindingAccessor(property, BindingPriority.TemplatedParent);
+        }
+
         /// <summary>
         /// Gets the default value for the property on the specified type.
         /// </summary>
@@ -167,6 +189,27 @@ namespace Perspex
         {
             return this.Name;
         }
+
+        public class BindingAccessor
+        {
+            public BindingAccessor(PerspexProperty property, BindingPriority priority)
+            {
+                this.Property = property;
+                this.Priority = priority;
+            }
+
+            public PerspexProperty Property
+            {
+                get;
+                private set;
+            }
+
+            public BindingPriority Priority
+            {
+                get;
+                private set;
+            }
+        }
     }
 
     /// <summary>

Perspex/Themes/Default/ButtonStyle.cs

@@ -65,11 +65,13 @@ namespace Perspex.Themes.Default
             {
                 Id = "border",
                 Padding = new Thickness(3),
-                Content = new ContentPresenter(),
+                Content = new ContentPresenter
+                {
+                    [~ContentPresenter.ContentProperty] = control[~Button.ContentProperty],
+                },
+                [~Border.BackgroundProperty] = control[~Button.BackgroundProperty],
             };
 
-            border.TemplateBinding(control, Border.BackgroundProperty);
-            border.Content.TemplateBinding(control, ContentPresenter.ContentProperty);
             return border;
         }
     }

Perspex/Themes/Default/CheckBoxStyle.cs

@@ -47,6 +47,7 @@ namespace Perspex.Themes.Default
         {
             Border result = new Border
             {
+                [~Border.BackgroundProperty] = control[~CheckBox.BackgroundProperty],
                 Content = new StackPanel
                 {
                     Orientation = Orientation.Horizontal,
@@ -69,15 +70,12 @@ namespace Perspex.Themes.Default
                         },
                         new ContentPresenter
                         {
+                            [~ContentPresenter.ContentProperty] = control[~CheckBox.ContentProperty],
                         },
                     },
                 },
             };
 
-            result.TemplateBinding(control, Border.BackgroundProperty);
-            StackPanel stack = (StackPanel)result.Content;
-            ContentPresenter cp = (ContentPresenter)stack.Children[1];
-            cp.TemplateBinding(control, ContentPresenter.ContentProperty);
             return result;
         }
     }

TestApplication/Program.cs

@@ -52,19 +52,6 @@ namespace TestApplication
                     Gap = 6,
                     Children = new PerspexList<Control>
                     {
-                        new Border
-                        {
-                            BorderBrush = Brushes.Black,
-                            BorderThickness = 1,
-                            Width = 10,
-                            Height = 10,
-                        },
-                        new Path
-                        {
-                            Data = StreamGeometry.Parse("M0,0 L10,0"),
-                            Stroke = Brushes.Black,
-                            StrokeThickness = 1,
-                        },
                         new Button
                         {
                             Content = "Button",