Returns the layout information for the supplementary view at the specified index path.
- macOS 10.11+
The kind of the supplementary view whose attributes you want. The layout object defines the kinds of supplementary views it supports. This parameter must not be
The index path of the supplementary view. Normally, this path
The layout attributes of the supplementary view or
nil if no item exists at the specified path.
This method updates the layout information as needed before returning the specified attributes. Always use this method to retrieve the layout attributes for supplementary views in the collection view. Do not query the layout object directly.