An array of the visible items in the collection view.
- iOS 10.0+
- Mac Catalyst 13.0+
- tvOS 10.0+
The value of this property is an unsorted array of
NSIndex objects, each of which corresponds to a visible cell in the collection view. This array does not include any supplementary views that are currently visible. If there are no visible items, the value of this property is an empty array.