Here's a small PR for a bug that I think has just gone unnoticed because we've never used the sectionInset property of the UICollectionViewFlowLayout, and we've never used the contentInset property of UICollectionView.

The issues looks to be that the layout's sectionInset property is applied on a per-section basis, but the collection view's contentInset was not being honoured.

It was also calculated using insetBy(dx:dy:), which will modify the width by -dx * 2, which would double the expected insets.

Partial fix for #31

Added to work around https://bugs.swift.org/browse/SR-14103

Overall this is pretty minor but when dealing with a lot of SingleElementSections that are infrequently updated is does start to slow down.

I thought a faster approach would be to use generics on replace(element:) to only check for nil when the value is Optional, but generics don't allow for this kind of overload.

Also added some basic tests. The performance tests show a ~9% performance increase.

Replacing https://github.com/composed-swift/ComposedUI/pull/15

This PR is being used to diff between the OpenNet fork.

Hopefully other PRs will be merged before this (e.g. https://github.com/composed-swift/Composed/pull/21), which should lead to this PR having no changes and purely to ensure some of the history is not lost.

We've discussed returning -1 not being great previously, but now we have the 2.0 branch we can make this change :)

@bill201207 found that UINib(nibName:bundle:) is a big part of the poor performance when our app launches.

Ultimately batching updates will help with a lot of things like this, but really that'll just be masking some of the performance issues so it's useful to find issues like this now.

This adds the ComposedLayout and ComposedUI packages, which will close #16.

The base for this is 2.0-beta, which we can use for testing new changes, which can also break API.

If you go to the repo settings you can (temporarily) set the default branch to 2.0-beta and we can add a note to the README stating this is the beta release and the stable release is available in the master branch.

Once merged and these changes are made the READMEs for ComposedLayout and ComposedUI repos can be updated to point to this repo and their repos archived.

This is a new type of section that is similar to ComposedSectionProvider, but rather than flattening each of the children in to a single SectionProvider it flattens them in to a single Section.

The ComposedUI side of this has been updated to support multiple cells per section, with a convenience for FlatSection that delegates the calls to each of the flattened sections.

This is a breaking change since the protocol requirements have changed. I have set the base of the PR to merge-all-libraries since that's also a breaking change and this PR relies on those changes.

edit: We've moved to our own fork to allow for more rapid development. The latest changes are in https://github.com/opennetltd/Composed/tree/feature/FlatSection, which will eventually be merged back in to this repo once some of the other PRs/issues have been resolved.