Added FontSize/VisualParent.

Perspex.Windows/Window.cs

@@ -10,12 +10,20 @@
 
     public class Window : ContentControl, ILayoutRoot
     {
+        public static PerspexProperty<double> FontSizeProperty =
+            TextBlock.FontSizeProperty.AddOwner<Window>();
+
         private UnmanagedMethods.WndProc wndProcDelegate;
 
         private string className;
 
         private Renderer renderer;
 
+        static Window()
+        {
+            FontSizeProperty.OverrideDefaultValue(typeof(Window), 18.0);
+        }
+
         public Window()
         {
             this.CreateWindow();

Perspex/Controls/ContentPresenter.cs

@@ -50,6 +50,11 @@
                             Text = content.ToString(),
                         };
                     }
+
+                    if (this.visualChild != null)
+                    {
+                        this.visualChild.VisualParent = this;
+                    }
                 }
 
                 return Enumerable.Repeat(this.visualChild, this.visualChild != null ? 1 : 0);

Perspex/Controls/Decorator.cs

@@ -9,6 +9,18 @@
         public static readonly PerspexProperty<Control> ContentProperty =
             PerspexProperty.Register<ContentControl, Control>("Content");
 
+        public Decorator()
+        {
+            // TODO: Unset old content's visual parent.
+            this.GetObservable(ContentProperty).Subscribe(x =>
+            {
+                if (x != null)
+                {
+                    x.VisualParent = this;
+                }
+            });
+        }
+
         public Control Content
         {
             get { return this.GetValue(ContentProperty); }

Perspex/Controls/TemplatedControl.cs

@@ -32,6 +32,7 @@
                 if (this.visualChild == null && template != null)
                 {
                     this.visualChild = template(this);
+                    this.visualChild.VisualParent = this;
                 }
 
                 return Enumerable.Repeat(this.visualChild, this.visualChild != null ? 1 : 0);

Perspex/Controls/TextBlock.cs

@@ -7,6 +7,11 @@
         public static readonly PerspexProperty<Brush> BackgroundProperty =
             Border.BackgroundProperty.AddOwner<TextBlock>();
 
+        public static readonly PerspexProperty<double> FontSizeProperty =
+            PerspexProperty.Register<TextBlock, double>(
+                "FontSize",
+                inherits: true);
+
         public static readonly PerspexProperty<Brush> ForegroundProperty =
             PerspexProperty.Register<TextBlock, Brush>(
                 "Foreground",
@@ -22,6 +27,12 @@
             set { this.SetValue(BackgroundProperty, value); }
         }
 
+        public double FontSize
+        {
+            get { return this.GetValue(FontSizeProperty); }
+            set { this.SetValue(FontSizeProperty, value); }
+        }
+
         public Brush Foreground
         {
             get { return this.GetValue(ForegroundProperty); }
@@ -41,7 +52,7 @@
                 return new FormattedText
                 {
                     FontFamilyName = "Segoe UI",
-                    FontSize = 18,
+                    FontSize = this.FontSize,
                     Text = this.Text,
                 };
             }

Perspex/Visual.cs

@@ -14,6 +14,8 @@
         private static readonly PerspexProperty<Rect> BoundsPropertyW =
             PerspexProperty.Register<Visual, Rect>("Bounds", new Rect());
 
+        private Visual visualParent;
+
         public Rect Bounds
         {
             get { return this.GetValue(BoundsPropertyW); }
@@ -25,6 +27,23 @@
             get { return Enumerable.Empty<Visual>(); }
         }
 
+        public Visual VisualParent
+        {
+            get 
+            { 
+                return this.visualParent; 
+            }
+
+            set
+            {
+                if (this.visualParent != value)
+                {
+                    this.visualParent = value;
+                    this.InheritanceParent = value;
+                }
+            }
+        }
+
         public virtual void Render(IDrawingContext context)
         {
             Contract.Requires<ArgumentNullException>(context != null);