WPF Gadget Container Control

<Window x:Class="GadgetPrototype.Window1"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:GadgetPrototype="clr-namespace:GadgetPrototype"
        xmlns:GadgetLibrary="clr-namespace:GadgetLibrary;assembly=GadgetLibrary"
        xmlns:Weather="clr-namespace:GadgetPrototype.Weather"
        xmlns:Picture="clr-namespace:GadgetPrototype.Picture"
        Background="#4d6a73"
        Title="Window1"
        Height="600"
        Width="800">
    <Window.Resources>
        <Weather:WeatherGadget x:Key="_TestGadget" />
        <Picture:PictureGadget x:Key="_PictureGadget" />
    </Window.Resources>
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition Height="*" />
        </Grid.RowDefinitions>
        <Menu Grid.Row="0"
              Height="22"
              Name="_MainMenu">
            <Menu.Items>
            <MenuItem Header="Background">
                <MenuItem.Items>
                    <MenuItem Header="Solid Color"
                              x:Name="_SolidColorMenu"
                              Click="_SolidColorMenu_Click" />
                    <MenuItem Header="Abstract"
                              x:Name="_AbstractBackgroundMenu"
                              Click="_AbstractBackgroundMenu_Click" />
                    <MenuItem Header="Nature"
                              x:Name="_NatureBackgroundMenu"
                              Click="_NatureBackgroundMenu_Click" />
                </MenuItem.Items>
            </MenuItem>
                <MenuItem Header="Add Gadget">
                    <MenuItem.Items>
                        <MenuItem Header="Weather"
                                  x:Name="_AddWeatherGadget"
                                  Click="_AddWeatherGadget_Click" />
                        <MenuItem Header="Picture"
                                  x:Name="_AddPictureGadget"
                                  Click="_AddPictureGadget_Click" />
                    </MenuItem.Items>
                </MenuItem>
                </Menu.Items>
        </Menu>
        <GadgetLibrary:SnapCanvas x:Name="_SnapCanvas"
                                  Grid.Row="1"
                                  AllowDragging="True"
                                  SnapThreshold="20"
                                  AllowDragOutOfView="False">
        </GadgetLibrary:SnapCanvas>
    </Grid>
</Window>