Layout Manager for Prism v2

<UserControl x:Class="LayoutManager.Layout.LayoutControls.ThirdLayout"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:cal="http://www.codeplex.com/CompositeWPF">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition Height="*" />
            <RowDefinition Height="9" />
            <RowDefinition  Height="2*" />
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="3*" />
            <ColumnDefinition Width="9" />
            <ColumnDefinition Width="*" />
        </Grid.ColumnDefinitions>
        <ItemsControl Grid.Column="0"
                      Grid.Row="0"
                      Grid.ColumnSpan="3"
                      cal:RegionManager.RegionName="Menu">
            <ItemsControl.ItemsPanel>
                <ItemsPanelTemplate>
                    <DockPanel LastChildFill="True" />
                </ItemsPanelTemplate>
            </ItemsControl.ItemsPanel>
        </ItemsControl>
        <ItemsControl Grid.Column="0"
                      Grid.Row="1"
                      cal:RegionManager.RegionName="TopLeft">
            <ItemsControl.ItemsPanel>
                <ItemsPanelTemplate>
                    <DockPanel LastChildFill="True" />
                </ItemsPanelTemplate>
            </ItemsControl.ItemsPanel>
        </ItemsControl>
        <GridSplitter Grid.Column="0"
                      Grid.Row="2"
                      VerticalAlignment="Center"
                      HorizontalAlignment="Stretch"
                      Height="5"
                      Opacity="0.25" />
        <ItemsControl Grid.Column="0"
                      Grid.Row="3"
                      cal:RegionManager.RegionName="BottomLeft">
            <ItemsControl.ItemsPanel>
                <ItemsPanelTemplate>
                    <DockPanel LastChildFill="True" />
                </ItemsPanelTemplate>
            </ItemsControl.ItemsPanel>
        </ItemsControl>
        <GridSplitter Grid.Column="1"
                      Grid.Row="1"
                      Grid.RowSpan="3"
                      VerticalAlignment="Stretch"
                      HorizontalAlignment="Center"
                      Width="5"
                      Opacity="0.25" />
        <ItemsControl Grid.Column="2"
                      Grid.Row="1"
                      Grid.RowSpan="3"
                      cal:RegionManager.RegionName="Right">
            <ItemsControl.ItemsPanel>
                <ItemsPanelTemplate>
                    <DockPanel LastChildFill="True" />
                </ItemsPanelTemplate>
            </ItemsControl.ItemsPanel>
        </ItemsControl>
    </Grid>
</UserControl>