Added IControl interface.

Perspex.Controls/Control.cs

@@ -29,7 +29,7 @@ namespace Perspex.Controls
     /// - Implements <see cref="IStyleable"/> to allow styling to work on the control.
     /// - Implements <see cref="ILogical"/> to form part of a logical tree.
     /// </remarks>
-    public class Control : InputElement, INamed, ILogical, IStyleable, IStyleHost
+    public class Control : InputElement, IControl
     {
         /// <summary>
         /// Defines the <see cref="DataContext"/> property.
@@ -46,8 +46,8 @@ namespace Perspex.Controls
         /// <summary>
         /// Defines the <see cref="Parent"/> property.
         /// </summary>
-        public static readonly PerspexProperty<Control> ParentProperty =
-            PerspexProperty.Register<Control, Control>(nameof(Parent));
+        public static readonly PerspexProperty<IControl> ParentProperty =
+            PerspexProperty.Register<Control, IControl>(nameof(Parent));
 
         /// <summary>
         /// Defines the <see cref="Tag"/> property.
@@ -228,7 +228,7 @@ namespace Perspex.Controls
         /// <summary>
         /// Gets the control's logical parent.
         /// </summary>
-        public Control Parent
+        public IControl Parent
         {
             get { return this.GetValue(ParentProperty); }
             internal set { this.SetValue(ParentProperty, value); }

Perspex.Controls/IControl.cs

@@ -0,0 +1,33 @@
+// -----------------------------------------------------------------------
+// <copyright file="IControl.cs" company="Steven Kirk">
+// Copyright 2015 MIT Licence. See licence.md for more information.
+// </copyright>
+// -----------------------------------------------------------------------
+
+namespace Perspex.Controls
+{
+    using Perspex.Input;
+    using Perspex.Layout;
+    using Perspex.Styling;
+
+    /// <summary>
+    /// Interface for Perspex controls.
+    /// </summary>
+    public interface IControl : IVisual, ILogical, ILayoutable, IInputElement, INamed, IStyleable, IStyleHost
+    {
+        /// <summary>
+        /// Gets or sets the control's data context.
+        /// </summary>
+        object DataContext { get; set; }
+
+        /// <summary>
+        /// Gets the data templates for the control.
+        /// </summary>
+        DataTemplates DataTemplates { get; }
+
+        /// <summary>
+        /// Gets the control's logical parent.
+        /// </summary>
+        IControl Parent { get; }
+    }
+}

Perspex.Controls/Perspex.Controls.csproj

@@ -36,6 +36,7 @@
     <WarningLevel>4</WarningLevel>
   </PropertyGroup>
   <ItemGroup>
+    <Compile Include="IControl.cs" />
     <Compile Include="MenuItemAccessKeyHandler.cs" />
     <Compile Include="Parsers\GridLengthsParser.cs" />
     <Compile Include="Primitives\AccessText.cs" />

Perspex.Controls/PopupRoot.cs

@@ -43,7 +43,7 @@ namespace Perspex.Controls
         public PopupRoot(IDependencyResolver dependencyResolver)
             : base(Locator.Current.GetService<IPopupImpl>(), dependencyResolver)
         {
-            this.GetObservable(ParentProperty).Subscribe(x => this.InheritanceParent = x);
+            this.GetObservable(ParentProperty).Subscribe(x => this.InheritanceParent = (PerspexObject)x);
         }
 
         /// <summary>