New Width / Height Calculating.

If you a Control wich has a Width/height set in it's default Style, then this should be used as start size!

src/AddIns/DisplayBindings/WpfDesign/WpfDesign.Designer/Project/ModelTools.cs

@@ -5,6 +5,13 @@ using System;
 using System.Collections.Generic;
 using System.Windows;
 using System.Linq;
+using System.IO;
+using System.Windows.Controls;
+using System.Windows.Documents;
+using System.Windows.Markup;
+using System.Windows.Media;
+using System.Windows.Media.Imaging;
+using System.Windows.Xps.Serialization;
 
 namespace ICSharpCode.WpfDesign.Designer
 {
@@ -96,15 +103,56 @@ namespace ICSharpCode.WpfDesign.Designer
 			}
 		}
 		
+		internal static void CreateVisualTree(this UIElement element)
+		{
+			try {
+				var fixedDoc = new FixedDocument();
+				var pageContent = new PageContent();
+				var fixedPage = new FixedPage();
+				fixedPage.Children.Add(element);
+				(pageContent as IAddChild).AddChild(fixedPage);
+				fixedDoc.Pages.Add(pageContent);
+
+				var f = new XpsSerializerFactory();
+				var w = f.CreateSerializerWriter(new MemoryStream());
+				w.Write(fixedDoc);
+
+				fixedPage.Children.Remove(element);
+			}
+			catch (Exception)
+			{ }
+		}
+		 
 		internal static Size GetDefaultSize(DesignItem createdItem)
 		{
-            var s = Metadata.GetDefaultSize(createdItem.ComponentType);
+			CreateVisualTree(createdItem.View);
+			
+			var s = Metadata.GetDefaultSize(createdItem.ComponentType, false);
+
+			if (double.IsNaN(s.Width) && createdItem.View.DesiredSize.Width > 0)
+			{
+				s.Width = createdItem.View.DesiredSize.Width;
+			}
+			if (double.IsNaN(s.Height) && createdItem.View.DesiredSize.Height > 0)
+			{
+				s.Height = createdItem.View.DesiredSize.Width;
+			}
+
+			var newS = Metadata.GetDefaultSize(createdItem.ComponentType, true);
+
+			if (!(s.Width > 0))
+				s.Width = newS.Width;
+
+			if (!(s.Height > 0))
+				s.Height = newS.Height;
+
 			if (double.IsNaN(s.Width)) {
 				s.Width = GetWidth(createdItem.View);
 			}
 			if (double.IsNaN(s.Height)) {
 				s.Height = GetHeight(createdItem.View);
 			}
+
 			return s;
 		}
 		

src/AddIns/DisplayBindings/WpfDesign/WpfDesign.Designer/Project/WpfDesign.Designer.csproj

@@ -55,6 +55,9 @@
       <SpecificVersion>False</SpecificVersion>
       <RequiredTargetFramework>3.0</RequiredTargetFramework>
     </Reference>
+    <Reference Include="ReachFramework">
+      <RequiredTargetFramework>3.0</RequiredTargetFramework>
+    </Reference>
     <Reference Include="System" />
     <Reference Include="System.Core">
       <RequiredTargetFramework>3.5</RequiredTargetFramework>

src/AddIns/DisplayBindings/WpfDesign/WpfDesign/Project/Metadata.cs

@@ -298,7 +298,7 @@ namespace ICSharpCode.WpfDesign
 		/// Gets the default size for new controls of the specified type,
 		/// or new Size(double.NaN, double.NaN) if no default size was registered.
 		/// </summary>
-		public static Size GetDefaultSize(Type t)
+		public static Size GetDefaultSize(Type t, bool checkBasetype = true)
 		{
 			Size s;
 			lock (defaultSizes) {
@@ -306,7 +306,7 @@ namespace ICSharpCode.WpfDesign
 					if (defaultSizes.TryGetValue(t, out s)) {
 						return s;
 					}
-					t = t.BaseType;
+					 t = checkBasetype ? t.BaseType : null;
 				}
 			}
 			return new Size(double.NaN, double.NaN);