SharpDevelop/samples/XamlDesigner2/SharpDevelop.XamlDesigner/PropertyGrid/Editors/BrushEditor/GradientSlider.xaml

<UserControl x:Name="root"
             x:Class="SharpDevelop.XamlDesigner.PropertyGrid.Editors.BrushEditor.GradientSlider"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:BrushEditor="clr-namespace:SharpDevelop.XamlDesigner.PropertyGrid.Editors.BrushEditor">

    <UserControl.Resources>

        <Style TargetType="{x:Type BrushEditor:GradientThumb}">
            <Setter Property="BrushEditor:NormalizedPanel.X"
                    Value="{Binding Offset}" />
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type BrushEditor:GradientThumb}">
                        <StackPanel>
                            <Path x:Name="thumb"
                                  Data="m 0 0 l 6 -5 l 6 5"
                                  Stroke="Black"
                                  Fill="White" />
                            <Border BorderBrush="Black"
                                    BorderThickness="1"
                                    Width="12"
                                    Height="12">
                                <Border BorderThickness="1"
                                        BorderBrush="White"
                                        Background="{DynamicResource ChessBrush}">
                                    <Border>
                                        <Border.Background>
                                            <SolidColorBrush Color="{Binding Color}" />
                                        </Border.Background>
                                    </Border>
                                </Border>
                            </Border>
                        </StackPanel>
                        <ControlTemplate.Triggers>
                            <Trigger Property="Selector.IsSelected"
                                     Value="True">
                                <Setter TargetName="thumb"
                                        Property="Fill"
                                        Value="Orange" />
                            </Trigger>
                        </ControlTemplate.Triggers>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>

        <Style x:Key="StripStyle"
               TargetType="Thumb">
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="Thumb">
                        <Border BorderThickness="1"
                                BorderBrush="{DynamicResource BackgroundBrush}"
                                Background="{DynamicResource ChessBrush}">
                            <Border>
                                <Border.Background>
                                    <LinearGradientBrush EndPoint="1 0"
                                                         GradientStops="{Binding InternalValue.GradientStops}" />
                                </Border.Background>
                            </Border>
                        </Border>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>

    </UserControl.Resources>

    <Grid>

        <Thumb x:Name="strip"
               Style="{StaticResource StripStyle}"
               VerticalAlignment="Top"
               Height="20"
               Margin="6 0 6 0" />

        <BrushEditor:GradientItemsControl x:Name="itemsControl"
                                          ItemsSource="{Binding GradientStops, ElementName=root}"
                                          Margin="6 28 6 10">
            <ItemsControl.ItemsPanel>
                <ItemsPanelTemplate>
                    <BrushEditor:NormalizedPanel />
                </ItemsPanelTemplate>
            </ItemsControl.ItemsPanel>
        </BrushEditor:GradientItemsControl>

    </Grid>

</UserControl>