Improve performance of contentSize by not using a list to back it

[kyleve]

This PR refactors how ListView.contentSize is implemented, by switching to manually allocating a layout and measuring it, instead of using a static measurement / template view. This has significant performance improvement benefits on its own of about 50%, because we're not going through the entire diff and layout loop to update the measurement view – just creating a layout and measuring it.

To allow this, a few changes happened:

1. Updated the list layout APIs to work without a needed UICollectionView – you really just need the layout objects and the information about the layout frame, so I cleaned that up. This involved removing references to UICollectionView, making the delegate optional.
2. Move ListSizing to the BlueprintUILists module – it's only used there anyway.
3. Some small cleanup things as I went.

[kyleve]

Fixes build warnings in tests

[kylebshr]

This is pretty silly, feel free to leave as-is, but do you think top-aligning illustrates what will actually happen better?

[kyleve]

I'm going to ignore this given it was the same as before in the old file and I want to get this in SPOS tonight

[kylebshr]

Please do 😂

…

On Mar 29, 2021, at 8:01 PM, Kyle Van Essen ***@***.***> wrote:  @kyleve commented on this pull request. In BlueprintUILists/Sources/ListSizing.swift: > +/// .fillParent: +/// ┌───────────┐ +/// │┌─────────┐│ +/// ││ ││ +/// ││ ││ +/// ││ ││ +/// ││ ││ +/// ││ ││ +/// │└─────────┘│ +/// └───────────┘ +/// +/// .measureContent +/// ┌───────────┐ +/// │ │ +/// │ │ +/// │┌─────────┐│ I'm going to ignore this given it was the same as before in the old file and I want to get this in SPOS tonight — You are receiving this because your review was requested. Reply to this email directly, view it on GitHub, or unsubscribe.