willTransition(from:to:)
Tells the element that the layout object of the collection view is about to change.
Declaration
@MainActor optional func willTransition(from oldLayout: NSCollectionViewLayout, to newLayout: NSCollectionViewLayout)Parameters
- oldLayout:
The current layout object used by the collection view.
- newLayout:
The new layout object that is about to be used by the collection view.
Discussion
The default implementation of this method does nothing. Subclasses can override it and use it to prepare for the change in layouts.
Special Considerations
In OS X 10.11, this method is never called.