WPF Diagram Designer: Part 1

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:s="clr-namespace:DiagramDesigner">

  <ResourceDictionary.MergedDictionaries>
    <ResourceDictionary Source="SizeChrome.xaml"/>
    <ResourceDictionary Source="ResizeRotateChrome.xaml"/>
  </ResourceDictionary.MergedDictionaries>

  <ControlTemplate x:Key="MoveThumbTemplate"  TargetType="{x:Type s:MoveThumb}">
    <Rectangle Fill="Transparent"/>
  </ControlTemplate>

  <Style x:Key="DesignerItemStyle" TargetType="ContentControl">
    <Setter Property="MinHeight" Value="50"/>
    <Setter Property="MinWidth" Value="50"/>
    <Setter Property="RenderTransformOrigin" Value="0.5,0.5"/>
    <Setter Property="SnapsToDevicePixels" Value="true"/>
    <Setter Property="Template">
      <Setter.Value>
        <ControlTemplate TargetType="ContentControl">
          <Grid DataContext="{Binding RelativeSource={RelativeSource TemplatedParent}}">
            <s:MoveThumb Cursor="SizeAll" Template="{StaticResource MoveThumbTemplate}" />
            <ContentPresenter Content="{TemplateBinding ContentControl.Content}"
                              Margin="{TemplateBinding Padding}"/>
            <s:DesignerItemDecorator x:Name="ItemDecorator"/>
          </Grid>
          <ControlTemplate.Triggers>
            <Trigger Property="Selector.IsSelected" Value="True">
              <Setter TargetName="ItemDecorator" Property="ShowDecorator" Value="True"/>
            </Trigger>
          </ControlTemplate.Triggers>
        </ControlTemplate>
      </Setter.Value>
    </Setter>
  </Style>


</ResourceDictionary>