Index of visible element in a ZapPanel

Hi,

I'm using a ListBox with a ZapPanel, just like in the ZapPanel example. So there's one item visible in the front while the other items are fade out or invisible. The problem is now that the focus may be on a different element when using the scroll bar. So the user may think, he selected an item, but the focus (an the SelectedIndex of the ListBox) may be on another, yet invisible item. This will be confusing and so I like to synchronize the visible item with the focussed item.

Unfortunaltely I didn't find a ZapPanel property to do this, FocalIndex is bound to SelectedIndex of the ListBox.

Any ideas?

Thanks and bye,