prs/prs.desktop/Panels/Quotes/QuoteDesigns.xaml

<UserControl x:Class="PRSDesktop.QuoteDesigns"
             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:PRSDesktop"
             xmlns:syncfusion="http://schemas.syncfusion.com/wpf"
             mc:Ignorable="d"
             d:DesignHeight="450" d:DesignWidth="800">
    <UserControl.Resources>
        <ControlTemplate x:Key="VerticalSplitter">
            <Grid Background="{TemplateBinding Background}" Width="4">
                <Button x:Name="PART_Left" Visibility="Collapsed" />
                <Button x:Name="PART_Right" Visibility="Collapsed" />
                <StackPanel Margin="0" Orientation="Vertical" VerticalAlignment="Center" HorizontalAlignment="Center">
                    <Ellipse Fill="Silver" HorizontalAlignment="Center" Height="2" Width="2" Opacity="1"
                             Margin="0,2,0,0" />
                    <Ellipse Fill="Silver" HorizontalAlignment="Center" Height="2" Width="2" Opacity="1"
                             Margin="0,2,0,0" />
                    <Ellipse Fill="Silver" HorizontalAlignment="Center" Height="2" Width="2" Opacity="1"
                             Margin="0,2,0,0" />
                    <Ellipse Fill="Silver" HorizontalAlignment="Center" Height="2" Width="2" Opacity="1"
                             Margin="0,2,0,0" />
                    <Ellipse Fill="Silver" HorizontalAlignment="Center" Height="2" Width="2" Opacity="1"
                             Margin="0,2,0,0" />
                    <Ellipse Fill="Silver" HorizontalAlignment="Center" Height="2" Width="2" Opacity="1"
                             Margin="0,2,0,0" />
                    <Ellipse Fill="Silver" HorizontalAlignment="Center" Height="2" Width="2" Opacity="1"
                             Margin="0,2,0,0" />
                </StackPanel>
            </Grid>
        </ControlTemplate>
    </UserControl.Resources>

    <Grid>

        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="350" />
            <ColumnDefinition Width="4" />
            <ColumnDefinition Width="*" />
        </Grid.ColumnDefinitions>

        <local:QuoteDesignGrid Grid.Column="0" x:Name="Designs" />

        <syncfusion:SfGridSplitter Grid.Column="1" Grid.ColumnSpan="2" Name="PART_DetailSplitter"
                                   ResizeBehavior="PreviousAndNext" Height="4" Background="Transparent"
                                   Template="{StaticResource VerticalSplitter}">

            <syncfusion:SfGridSplitter.PreviewStyle>
                <Style TargetType="Control">
                    <Setter Property="Background" Value="Gray" />
                    <Setter Property="Template">
                        <Setter.Value>
                            <ControlTemplate TargetType="Control">
                                <Grid x:Name="Root" Opacity="0.5">
                                    <Rectangle Fill="{TemplateBinding Background}" />
                                </Grid>
                            </ControlTemplate>
                        </Setter.Value>
                    </Setter>
                </Style>
            </syncfusion:SfGridSplitter.PreviewStyle>

        </syncfusion:SfGridSplitter>

        <local:QuoteDesignItemGrid Grid.Column="2" x:Name="Items" />

    </Grid>
</UserControl>