Add a Control & Extension to Change the Render Transform Origin!

src/AddIns/DisplayBindings/WpfDesign/WpfDesign.Designer/Project/Controls/ControlStyles.xaml

@@ -581,4 +581,16 @@
 			</Setter.Value>
 		</Setter>
 	</Style>
+	<Style TargetType="{x:Type Controls:RenderTransformOriginThumb}">
+		<Setter Property="Template">
+			<Setter.Value>
+				<ControlTemplate TargetType="{x:Type Controls:RenderTransformOriginThumb}">
+					<Grid>
+						<Ellipse Width="2" Height="2" Fill="Black"/>
+						<Ellipse Width="10" Height="10" Fill="Transparent" Stroke="Black" StrokeThickness="2" />
+					</Grid>
+				</ControlTemplate>
+			</Setter.Value>
+		</Setter>
+	</Style>
 </ResourceDictionary>

src/AddIns/DisplayBindings/WpfDesign/WpfDesign.Designer/Project/Controls/RenderTransformOriginThumb.cs

@@ -0,0 +1,28 @@
+// Copyright (c) AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
+// This code is distributed under the GNU LGPL (for details please see \doc\license.txt)
+
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Windows;
+using System.Windows.Input;
+using System.Windows.Controls;
+using System.Windows.Controls.Primitives;
+using ICSharpCode.WpfDesign.Adorners;
+using ICSharpCode.WpfDesign.Extensions;
+
+namespace ICSharpCode.WpfDesign.Designer.Controls
+{
+	/// <summary>
+	/// Description of RenderTransformThumb.
+	/// </summary>
+	public class RenderTransformOriginThumb : Thumb
+	{
+		static RenderTransformOriginThumb()
+		{
+			//This OverrideMetadata call tells the system that this element wants to provide a style that is different than its base class.
+			//This style is defined in themes\generic.xaml
+			DefaultStyleKeyProperty.OverrideMetadata(typeof(RenderTransformOriginThumb), new FrameworkPropertyMetadata(typeof(RenderTransformOriginThumb)));
+		}
+	}
+}

src/AddIns/DisplayBindings/WpfDesign/WpfDesign.Designer/Project/Extensions/RenderTransformOriginExtension.cs

@@ -0,0 +1,88 @@
+// Copyright (c) AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
+// This code is distributed under the GNU LGPL (for details please see \doc\license.txt)
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using ICSharpCode.WpfDesign.Adorners;
+using ICSharpCode.WpfDesign.Extensions;
+using System.Windows.Controls;
+using System.Windows.Controls.Primitives;
+using System.Windows;
+using System.Windows.Input;
+using ICSharpCode.WpfDesign.Designer.Controls;
+using System.Windows.Media;
+
+namespace ICSharpCode.WpfDesign.Designer.Extensions
+{
+	[ExtensionFor(typeof(FrameworkElement))]
+	public class RenderTransformOriginExtension : SelectionAdornerProvider
+	{
+		readonly AdornerPanel adornerPanel;
+		RenderTransformOriginThumb renderTransformOriginThumb;
+		/// <summary>An array containing this.ExtendedItem as only element</summary>
+		readonly DesignItem[] extendedItemArray = new DesignItem[1];
+		IPlacementBehavior resizeBehavior;
+		PlacementOperation operation;
+		ChangeGroup changeGroup;
+		
+		public RenderTransformOriginExtension()
+		{
+			adornerPanel = new AdornerPanel();
+			adornerPanel.Order = AdornerOrder.Foreground;
+			this.Adorners.Add(adornerPanel);
+			
+			CreateRenderTransformOriginThumb();
+		}
+		
+		void CreateRenderTransformOriginThumb()
+		{
+			renderTransformOriginThumb = new RenderTransformOriginThumb();
+			renderTransformOriginThumb.Cursor = Cursors.Hand;
+			
+			AdornerPanel.SetPlacement(renderTransformOriginThumb,
+			                          new RelativePlacement(HorizontalAlignment.Left, VerticalAlignment.Top){XRelativeToContentWidth = renderTransformOrigin.X, YRelativeToContentHeight = renderTransformOrigin.Y});
+			adornerPanel.Children.Add(renderTransformOriginThumb);
+
+			renderTransformOriginThumb.DragDelta += new DragDeltaEventHandler(renderTransformOriginThumb_DragDelta);
+		}
+
+		void renderTransformOriginThumb_DragDelta(object sender, DragDeltaEventArgs e)
+		{
+			var p = AdornerPanel.GetPlacement(renderTransformOriginThumb) as RelativePlacement;
+			var pointAbs = adornerPanel.RelativeToAbsolute(new Vector(p.XRelativeToContentWidth, p.YRelativeToContentHeight));
+			var pointAbsNew = pointAbs + new Vector(e.HorizontalChange, e.VerticalChange);
+			var pRel = adornerPanel.AbsoluteToRelative(pointAbsNew);
+			
+			AdornerPanel.SetPlacement(renderTransformOriginThumb,
+			                          new RelativePlacement(HorizontalAlignment.Left, VerticalAlignment.Top){ XRelativeToContentWidth = pRel.X, YRelativeToContentHeight = pRel.Y });
+			
+			this.ExtendedItem.Properties.GetProperty(FrameworkElement.RenderTransformOriginProperty).SetValue(new Point(pRel.X,pRel.Y));
+		}
+		
+		Point renderTransformOrigin = new Point(0.5, 0.5);
+		
+		protected override void OnInitialized()
+		{
+			base.OnInitialized();
+			extendedItemArray[0] = this.ExtendedItem;
+			this.ExtendedItem.PropertyChanged += OnPropertyChanged;
+			
+			if (this.ExtendedItem.Properties.GetProperty(FrameworkElement.RenderTransformOriginProperty).IsSet) {
+				renderTransformOrigin = (Point)this.ExtendedItem.Properties.GetProperty(FrameworkElement.RenderTransformOriginProperty).ValueOnInstance;
+			}
+			
+			AdornerPanel.SetPlacement(renderTransformOriginThumb,
+			                          new RelativePlacement(HorizontalAlignment.Left, VerticalAlignment.Top){XRelativeToContentWidth = renderTransformOrigin.X, YRelativeToContentHeight = renderTransformOrigin.Y});
+		}
+		
+		void OnPropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
+		{ }
+		
+		protected override void OnRemove()
+		{
+			base.OnRemove();
+		}
+	}
+}

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

@@ -79,6 +79,8 @@
     <Compile Include="..\..\..\..\..\Main\GlobalAssemblyInfo.cs">
       <Link>Configuration\GlobalAssemblyInfo.cs</Link>
     </Compile>
+    <Compile Include="Controls\RenderTransformOriginThumb.cs" />
+    <Compile Include="Extensions\RenderTransformOriginExtension.cs" />
     <Compile Include="Translations.cs" />
     <Compile Include="Configuration\AssemblyInfo.cs" />
     <Compile Include="Controls\AdornerLayer.cs" />

src/AddIns/DisplayBindings/WpfDesign/WpfDesign/Project/Adorners/AdornerPanel.cs

@@ -34,6 +34,16 @@ namespace ICSharpCode.WpfDesign.Adorners
 			return (AdornerPlacement)adorner.GetValue(PlacementProperty);
 		}
 		
+		public Vector AbsoluteToRelative(Vector absolute)
+		{
+			return new Vector(absolute.X / ((FrameworkElement) this._adornedElement).ActualWidth, absolute.Y / ((FrameworkElement) this._adornedElement).ActualHeight);
+		}
+		
+		public Vector RelativeToAbsolute(Vector relative)
+		{
+			return new Vector(relative.X * ((FrameworkElement) this._adornedElement).ActualWidth, relative.Y * ((FrameworkElement) this._adornedElement).ActualHeight);
+		}
+		
 		/// <summary>
 		/// Sets the placement of the specified adorner.
 		/// </summary>