Boundary header does not respect top section content inset

Number:rdar://FB9842880 Date Originated:2022-01-12
Status:Open Resolved:No
Product:UIKit Product Version:iOS 15 SDK
Classification:Bug Reproducible:
When using `UICollectionViewCompositionalLayout` with a header boundary supplementary view, `NSCollectionLayoutSection`’s `supplementariesFollowContentInsets` does not behave according to the documentation.

The documentation states:

“A Boolean value that indicates whether the section's supplementary items follow the specified content insets for the section.

The default value of this property is true.”

Setting this to true causes the supplementary view header to be inset from the leading / trailing edge of the section geometry, but not from the top (or the bottom in the case of footer boundary supplementary items).


Either the documentation is wrong or there is a bug. It should be made clear that this property causes boundary supplementary views to respect only horizontal content insets on the section, not vertical (top/bottom).

I’m hoping that this is indeed a bug, as I need a way to inset headers from the top edge by a certain number of points. I would then like to inset the items in the section using the group containing them, effectively giving me full control over the padding above the section header and the space between the section header and the first group of items in the section.

Attached is a sample project that demonstrates the issue.


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