How to: Customize a Layout Algorithm

To change the layout algorithm used by TreeMap, assign a new TreeMapLayoutAlgorithmBase class descendant object to the TreeMapControl.LayoutAlgorithm property. Optionally, for all predefined layout algorithms, it's possible to specify the fill direction using the TreeMapLayoutAlgorithm.Direction property.

<dxtm:TreeMapControl x:Name="treeMap"
                     LayoutAlgorithm="{Binding ElementName=lbLayoutAlgorithm, Path=SelectedValue}">
    <!-- endregion #LayoutAlgorithm-->
    <dxtm:TreeMapControl.Colorizer>
        <dxtm:TreeMapPaletteColorizer/>
    </dxtm:TreeMapControl.Colorizer>
    <dxtm:TreeMapItemStorage>
        <dxtm:TreeMapItem Label="Americas">
            <dxtm:TreeMapItem Label="United States" Value="17.418"/>
            <dxtm:TreeMapItem Label="Brazil" Value="2.353"/>
        </dxtm:TreeMapItem>
        <dxtm:TreeMapItem Label="Europe">
            <dxtm:TreeMapItem Label="Germany" Value="3.859"/>
            <dxtm:TreeMapItem Label="United Kingdom" Value="2.945"/>
            <dxtm:TreeMapItem Label="France" Value="2.846"/>
            <dxtm:TreeMapItem Label="Italy" Value="2.147"/>
            <dxtm:TreeMapItem Label="Russia" Value="1.857"/>
        </dxtm:TreeMapItem>
        <dxtm:TreeMapItem Label="Asia">
            <dxtm:TreeMapItem Label="China" Value="10.380"/>
            <dxtm:TreeMapItem Label="Japan" Value="4.616"/>
            <dxtm:TreeMapItem Label="India" Value="2.049"/>
        </dxtm:TreeMapItem>
    </dxtm:TreeMapItemStorage>
    <!--region #CloseTag-->
</dxtm:TreeMapControl>
<!--endregion #CloseTag-->
<Grid Grid.Column="1" Margin="4">
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto"/>
        <RowDefinition Height="Auto"/>
        <RowDefinition Height="Auto"/>
        <RowDefinition Height="Auto"/>
    </Grid.RowDefinitions>
    <TextBlock Grid.Row="0" 
               Margin="0,0,0,4"
               Text="Layout Algorithm:"/>
    <!--region #LayoutAlgorithmList-->
    <ListBox x:Name="lbLayoutAlgorithm"
             Grid.Row="1"
             DisplayMemberPath="LayoutAlgorithmName"
             SelectedValuePath="LayoutAlgorithm"
             SelectedIndex="0">
        <local:LayoutAlgorithmWarapper LayoutAlgorithmName="Slice and Dice">
            <dxtm:SliceAndDiceLayoutAlgorithm/>
        </local:LayoutAlgorithmWarapper>
        <local:LayoutAlgorithmWarapper LayoutAlgorithmName="Squarified">
            <dxtm:SquarifiedLayoutAlgorithm/>
        </local:LayoutAlgorithmWarapper>
        <local:LayoutAlgorithmWarapper LayoutAlgorithmName="Striped">
            <dxtm:StripedLayoutAlgorithm/>
        </local:LayoutAlgorithmWarapper>
    </ListBox>
    <ListBox x:Name="lbDirection"
             Grid.Row="3"
             DisplayMemberPath="DirectionName"
             SelectedValuePath="Direction"
             SelectedValue="{Binding Mode=TwoWay, ElementName=treeMap, Path=LayoutAlgorithm.Direction}">
        <local:LayoutDirectionWrapper DirectionName="Top-Left to Bottom-Right" 
                                      Direction="TopLeftToBottomRight"/>
        <local:LayoutDirectionWrapper DirectionName="Top-Right to Bottom-Left" 
                                      Direction="TopRightToBottomLeft"/>
        <local:LayoutDirectionWrapper DirectionName="Bottom-Left to Top-Right" 
                                      Direction="BottomLeftToTopRight"/>
        <local:LayoutDirectionWrapper DirectionName="Bottom-Right to Top-Left" 
                                      Direction="TopRightToBottomLeft"/>
    </ListBox>