serein-flow/Workbench/Views/FlowCanvasView.xaml

<UserControl x:Class="Serein.Workbench.Views.FlowCanvasView"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             xmlns:local="clr-namespace:Serein.Workbench.Views"
             xmlns:converter="clr-namespace:Serein.Workbench.Converters"
             xmlns:vm="clr-namespace:Serein.Workbench.ViewModels"
             mc:Ignorable="d" 
             d:DesignHeight="450" 
             d:DesignWidth="800"
             d:DataContext="{d:DesignInstance vm:FlowCanvasViewModel}">

    <UserControl.Resources>
        <converter:RightThumbPositionConverter x:Key="RightThumbPositionConverter" />
        <converter:BottomThumbPositionConverter x:Key="BottomThumbPositionConverter" />
        <converter:VerticalCenterThumbPositionConverter x:Key="VerticalCenterThumbPositionConverter" />
        <converter:HorizontalCenterThumbPositionConverter x:Key="HorizontalCenterThumbPositionConverter" />
    </UserControl.Resources>

    <DockPanel x:Name="FlowChartStackPanel"
               ClipToBounds="True">
      
        <Canvas  ClipToBounds="True"
                 x:Name="FlowChartCanvas" 
                 Background="#FFFFFF"
                 AllowDrop="True" 
                 Width="{Binding Model.Width, Mode=TwoWay}"
                 Height="{Binding Model.Height, Mode=TwoWay}"
                 MouseLeftButtonDown ="FlowChartCanvas_MouseLeftButtonDown"
                 MouseLeftButtonUp="FlowChartCanvas_MouseLeftButtonUp"
                 MouseDown="FlowChartCanvas_MouseDown"
                 MouseUp="FlowChartCanvas_MouseUp"
                 MouseMove="FlowChartCanvas_MouseMove"
                 MouseWheel="FlowChartCanvas_MouseWheel"
                 Drop="FlowChartCanvas_Drop" 
                 DragOver="FlowChartCanvas_DragOver"
                 >

            <Rectangle x:Name="SelectionRectangle" 
                               Stroke="Blue" 
                               StrokeThickness="2" 
                               Fill="LightBlue" 
                               Opacity="0.2" 
                               Panel.ZIndex="999999"
                               Visibility="Collapsed"/>

            <!-- Top-Left Thumb -->
            <!--<Thumb x:Name="TopLeftThumb" 
                           Width="10" Height="10"
                           DragDelta="Thumb_DragDelta_TopLeft"
                           Cursor="SizeNWSE"
                           Canvas.Left="0" Canvas.Top="0"/>-->

            <!-- Top-Right Thumb -->
            <!--<Thumb x:Name="TopRightThumb" 
                           Width="10" Height="10"
                           DragDelta="Thumb_DragDelta_TopRight"
                           Cursor="SizeNESW"
                           Canvas.Left="{Binding ActualWidth, ElementName=FlowChartCanvas, Mode=OneWay, Converter={StaticResource RightThumbPositionConverter}}" 
                           Canvas.Top="0"/>-->

            <!-- Bottom-Left Thumb -->
            <!--<Thumb x:Name="BottomLeftThumb" 
                           Width="10" Height="10"
                           DragDelta="Thumb_DragDelta_BottomLeft"
                           Cursor="SizeNESW"
                           Canvas.Left="0" 
                           Canvas.Top="{Binding ActualHeight, ElementName=FlowChartCanvas, Mode=OneWay, Converter={StaticResource BottomThumbPositionConverter}}"/>-->

            <!-- Left Thumb -->
            <!--<Thumb x:Name="LeftThumb" 
                           Width="10" Height="10"
                           DragDelta="Thumb_DragDelta_Left"
                           Cursor="SizeWE"
                           Canvas.Left="0" 
                           Canvas.Top="{Binding ActualHeight, ElementName=FlowChartCanvas, Mode=OneWay, Converter={StaticResource VerticalCenterThumbPositionConverter}}"/>-->

            <!-- Right Thumb -->

            <!-- Top Thumb -->
            <!--<Thumb x:Name="TopThumb" 
                           Width="10" Height="10"
                           DragDelta="Thumb_DragDelta_Top"
                           Cursor="SizeNS"
                           Canvas.Left="{Binding ActualWidth, ElementName=FlowChartCanvas, Mode=OneWay, Converter={StaticResource HorizontalCenterThumbPositionConverter}}" 
                           Canvas.Top="0"/>-->

            <!-- Bottom Thumb -->
            <!-- Bottom-Right Thumb -->
            <Thumb x:Name="BottomRightThumb" 
                           Width="15" Height="15"
                           DragDelta="Thumb_DragDelta_BottomRight"
                           Cursor="SizeNWSE"
                           Canvas.Left="{Binding ActualWidth, Converter={StaticResource RightThumbPositionConverter}, ElementName=FlowChartCanvas, Mode=OneWay}" 
                           Canvas.Top="{Binding ActualHeight, Converter={StaticResource BottomThumbPositionConverter}, ElementName=FlowChartCanvas, Mode=OneWay}"/>

            <!--Canvas.Left="{Binding ActualWidth, ElementName=FlowChartCanvas, Mode=OneWay, Converter={StaticResource RightThumbPositionConverter}}" 
Canvas.Top="{Binding ActualHeight, ElementName=FlowChartCanvas, Mode=OneWay, Converter={StaticResource VerticalCenterThumbPositionConverter}}"-->
            <Thumb x:Name="RightThumb" Width="5" Cursor="SizeWE" Canvas.Top="0" Canvas.Right="0" DragDelta="Thumb_DragDelta_Right">
                <Thumb.Template>
                    <ControlTemplate>
                        <Border Background="#B1B9F8" Width="5" Height="{Binding ActualHeight, RelativeSource={RelativeSource AncestorType={x:Type Canvas}}}" />
                    </ControlTemplate>
                </Thumb.Template>
            </Thumb>

            <!--Canvas.Left="{Binding ActualWidth, ElementName=FlowChartCanvas, Mode=OneWay, Converter={StaticResource HorizontalCenterThumbPositionConverter}}" 
 Canvas.Top="{Binding ActualHeight, ElementName=FlowChartCanvas, Mode=OneWay, Converter={StaticResource BottomThumbPositionConverter}}"-->
            <Thumb x:Name="BottomThumb" Height="5" Cursor="SizeNS" Canvas.Bottom="0" Canvas.Left="0"  DragDelta="Thumb_DragDelta_Bottom">
                <Thumb.Template>
                    <ControlTemplate>
                        <Border Background="#B1B9F8" Height="5" Width="{Binding ActualWidth, RelativeSource={RelativeSource AncestorType={x:Type Canvas}}}" />
                    </ControlTemplate>
                </Thumb.Template>
            </Thumb>
        </Canvas>


    </DockPanel>

</UserControl>