Adds the specified items to an existing drag session.
- iOS 11.0+
The collection view from which the drag operation originated.
The current drag session object.
The index path of the item to add to the drag.
The point that the user touched. This point is in the coordinate space of the collection view.
An array of
UIDrag objects containing the items to add to the current drag session. Return an empty array to prevent the items from being added to the drag session.
Implement this method when you want to allow the user to add items to an active drag session. If you do not implement this method, taps in the collection view trigger the selection of items or other behaviors. However, when a drag session is active and a tap occurs, the collection view calls this method to give you an opportunity to add the underlying item to the drag session.
In your implementation, create one or more
UIDrag objects for the item at the specified
index. Normally, you return only one drag item, but if the specified item has children or cannot be dragged without one or more associated items, include those items as well.