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

    <Style x:Key="gridSplitterStyle"  TargetType="{x:Type GridSplitter}">
        <Style.Resources>
            <local:LessThanConverter x:Key="LessThanConverter"/>
        </Style.Resources>
        <!--    <Setter Property="TextElement.Foreground" Value="{StaticResource GlyphBrush}" />
        <Setter Property="Panel.Background" Value="{StaticResource ControlBackgroundBrush}" /> -->
        <Setter Property="UIElement.SnapsToDevicePixels" Value="True" />
        <Setter Property="UIElement.Focusable" Value="False" />
        <Setter Property="ShowsPreview" Value="True"/>

        <Setter Property="Control.Template">
            <Setter.Value>
                <ControlTemplate>

                    <Border x:Name="Root" BorderThickness="{TemplateBinding Border.BorderThickness}" BorderBrush="{TemplateBinding Border.BorderBrush}" Background="{TemplateBinding Panel.Background}">
                        <Grid>
                            <StackPanel  x:Name="Grip"  VerticalAlignment="Center" Orientation="Horizontal" HorizontalAlignment="Center">
                                <Ellipse Fill="LightGray" Width="4" Height="4" Margin="2 0 2 0"  />
                                <Ellipse Fill="LightGray" Width="4" Height="4" Margin="2 0 2 0"  />
                                <Ellipse Fill="LightGray" Width="4" Height="4" Margin="2 0 2 0"  />
                            </StackPanel>
                        </Grid>
                    </Border>
                    <ControlTemplate.Triggers>
                        <DataTrigger Value="True"  Binding="{Binding RelativeSource={RelativeSource Self}, Path=ActualWidth, Converter={StaticResource LessThanConverter}, ConverterParameter=20}">
                            <Setter TargetName="Grip" Property="Visibility" Value="Collapsed"/>
                        </DataTrigger>

                        <Trigger Property="VerticalAlignment" Value="Stretch">
                            <Setter TargetName="Grip" Property="Orientation" Value="Vertical"/>
                            <Setter TargetName="Grip" Property="Visibility" Value="Visible"/>
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>




</ResourceDictionary>
Grammar Composition System
