Fixed layout bug.

Perspex/Controls/TextBoxView.cs

@@ -8,6 +8,7 @@ namespace Perspex.Controls
 {
     using System;
     using System.Globalization;
+    using Perspex.Layout;
     using Perspex.Media;
     using Perspex.Platform;
     using Perspex.Threading;
@@ -98,7 +99,12 @@ namespace Perspex.Controls
 
         protected override Size MeasureOverride(Size constraint)
         {
-            return this.FormattedText.Measure(constraint);
+            if (!string.IsNullOrEmpty(this.parent.Text))
+            {
+                return this.FormattedText.Measure(constraint);
+            }
+
+            return new Size();
         }
 
         private FormattedText CreateFormattedText()

Perspex/Layout/LayoutHelper.cs

@@ -15,6 +15,17 @@ namespace Perspex.Layout
 
     public static class LayoutHelper
     {
+        public static Size ApplyLayoutConstraints(Layoutable control, Size constraints)
+        {
+            double width = (control.Width > 0) ? control.Width : constraints.Width;
+            double height = (control.Height > 0) ? control.Height : constraints.Height;
+            width = Math.Min(width, control.MaxWidth);
+            width = Math.Max(width, control.MinWidth);
+            height = Math.Min(height, control.MaxHeight);
+            height = Math.Max(height, control.MinHeight);
+            return new Size(width, height);
+        }
+        
         public static Size MeasureDecorator(
             Control decorator,
             Control content,
@@ -26,7 +37,7 @@ namespace Perspex.Layout
 
             if (content != null)
             {
-                content.Measure(availableSize);
+                content.Measure(availableSize.Deflate(padding));
                 Size s = content.DesiredSize.Value.Inflate(padding);
                 width = s.Width;
                 height = s.Height;

Perspex/Layout/Layoutable.cs

@@ -217,16 +217,11 @@ namespace Perspex.Layout
         {
             if (this.IsVisible)
             {
-                Size measuredSize = this.MeasureOverride(availableSize.Deflate(this.Margin)).Inflate(this.Margin);
-                double width = (this.Width > 0) ? this.Width : measuredSize.Width;
-                double height = (this.Height > 0) ? this.Height : measuredSize.Height;
+                availableSize = LayoutHelper.ApplyLayoutConstraints(this, availableSize)
+                    .Deflate(this.Margin);
+                var measured = this.MeasureOverride(availableSize);
 
-                width = Math.Min(width, this.MaxWidth);
-                width = Math.Max(width, this.MinWidth);
-                height = Math.Min(height, this.MaxHeight);
-                height = Math.Max(height, this.MinHeight);
-
-                return new Size(width, height);
+                return measured.Inflate(this.Margin);
             }
             else
             {