Artemis/src/Artemis.UI.Shared/Controls/GradientPicker.xaml

<UserControl x:Class="Artemis.UI.Shared.GradientPicker"
             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:shared="clr-namespace:Artemis.UI.Shared"
             mc:Ignorable="d"
             d:DesignHeight="450" d:DesignWidth="800">
    <UserControl.Resources>
        <ResourceDictionary>
            <shared:ColorGradientToGradientStopsConverter x:Key="ColorGradientToGradientStopsConverter" />
            <VisualBrush x:Key="Checkerboard" TileMode="Tile" Stretch="Uniform" ViewportUnits="Absolute" Viewport="0,0,10,10">
                <VisualBrush.Visual>
                    <Grid Width="10" Height="10">
                        <Grid.RowDefinitions>
                            <RowDefinition />
                            <RowDefinition />
                        </Grid.RowDefinitions>
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition />
                            <ColumnDefinition />
                        </Grid.ColumnDefinitions>
                        <Rectangle Grid.Row="0" Grid.Column="0" Fill="Gray" />
                        <Rectangle Grid.Row="0" Grid.Column="1" Fill="White" />
                        <Rectangle Grid.Row="1" Grid.Column="0" Fill="White" />
                        <Rectangle Grid.Row="1" Grid.Column="1" Fill="Gray" />
                    </Grid>
                </VisualBrush.Visual>
            </VisualBrush>
        </ResourceDictionary>
    </UserControl.Resources>

    <Border Height="15"
            BorderBrush="{DynamicResource NormalBorderBrush}"
            BorderThickness="1"
            HorizontalAlignment="Stretch"
            Background="{StaticResource Checkerboard}">
        <Rectangle Stroke="{DynamicResource NormalBorderBrush}" Cursor="Hand" MouseUp="UIElement_OnMouseUp">
            <Rectangle.Fill>
                <LinearGradientBrush
                    GradientStops="{Binding ColorGradient, Mode=OneWay, RelativeSource={RelativeSource AncestorType={x:Type UserControl}}, Converter={StaticResource ColorGradientToGradientStopsConverter}}"
                    EndPoint="1,0"
                    StartPoint="0,0" />
            </Rectangle.Fill>
        </Rectangle>
    </Border>

</UserControl>