Hi Paul,
The current version of the GUI designer does not support configuring cell editors. That being said column's already have a default cell editor appropriate for its data type. If you want to change the cell editor or create a new one, then you will need to do this in XAML.
<xcdg:DataGridControl x:Name="OrdersGrid"
ItemsSource="{Binding Source={StaticResource cvs_orders}}">
<xcdg:DataGridControl.Columns>
<xcdg:Column FieldName="ShipVia">
<xcdg:Column.CellEditor>
<xcdg:CellEditor>
<xcdg:CellEditor.EditTemplate>
<DataTemplate>
<Slider Value="{xcdg:CellEditorBinding}" Minimum="1" Maximum="3"/>
</DataTemplate>
</xcdg:CellEditor.EditTemplate>
<xcdg:CellEditor.ActivationGestures>
<xcdg:KeyActivationGesture Key="Right"/>
<xcdg:KeyActivationGesture Key="Left"/>
</xcdg:CellEditor.ActivationGestures>
</xcdg:CellEditor>
</xcdg:Column.CellEditor>
</xcdg:Column>
</xcdg:DataGridControl.Columns>
</xcdg:DataGridControl>
Technical Writer - Xceed Software
Of all the things I've lost, I miss my mind the most. - Mark Twain