If, during editing, you use layers where the amount of unique value info's in drawing info is big then the standard template picker (stackpanel with series of textblock+templatepanel) can become quite large. I tried to change the default templatepicker to make use of an accordion. So that only one layer's symbols are visible at one time and such reducing the space the templatepicker occupies. I did not manage to get this to work properly. Has anybody else (hopefully with more templating knowledge) tried this ?
I tried to replace the StackPanel with an Accordion and played around with AccordionItems, etc. but this did not work good.
<Style x:Key="TemplatePickerGrid8x8" TargetType="esri:TemplatePicker">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="esri:TemplatePicker">
<ItemsControl ItemsSource="{TemplateBinding TemplateGroups}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Vertical">
<TextBlock Text="{Binding Name}" Foreground="White" FontWeight="Bold"/>
<esriPrimitives:TemplatePanel Templates="{Binding Templates}" StackCount="8" StackDirection="Vertical">
<esriPrimitives:TemplatePanel.ItemTemplate>
<DataTemplate>
<Grid>
<Button HorizontalContentAlignment="Center" Margin="2" Command="{Binding Editor.Add}" CommandParameter="{Binding TypeID}" ToolTipService.ToolTip="{Binding Name}">
<StackPanel HorizontalAlignment="Center" VerticalAlignment="Center" Orientation="Vertical">
<esriPrimitives:SymbolDisplay Height="20" Width="20" Symbol="{Binding Symbol}" />
</StackPanel>
</Button>
</Grid>
</DataTemplate>
</esriPrimitives:TemplatePanel.ItemTemplate>
</esriPrimitives:TemplatePanel>
</StackPanel>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>