DataTemplateSelector in SemanticZoom.ZoomedOutView

Question

I have a set of groups of different types of item, all inheriting form a common base type (ItemBase). Each of my groups has an Items collection of type ObservableCollection<ItemBase>.

In my SemanticZoom.ZoomedInView, I can set a DataTemplateSelector, and in SelectTemplateCore() I can cast the item parameter to detrmine which template to apply.

In my zoomed out view, though, the objects are passed around as DependencyObjects, and I can't for the life of me figure out how I can take the data passsed in to determine which template to use.

To set the items source of the GridView in the zoomed out view, I use

(semZm.ZoomedOutView as ListViewBase).ItemsSource = this.groupedItemsViewSource.View.CollectionGroups;

as this appears to be the only way to get the zoomedin and zoomedout views to synchronise (when you click on a group in the zoomed out view it should take me to the appropriate place in the zoomedinview to see that group's detail.

So, am I missing something obvious in terms of getting the actual group in SelectTemplateCore(), or failing that is there a better way of binding my ItemsSource of the ZoomedOutView?

Answer 1

For the appropriate way to handle casting of the DependencyObject to a usable type, see the answer to This question.

Essentially, cast it to ICollectionViewGroup to access the members.