Re: [csswg-drafts] [css-grid-3][Masonry] Behavior of repeat(auto-fit, auto) in Masonry (#12485)

> In css-grid-3, there is a proposal to add support for repeat(auto-fit, auto). However, what should happen for this in Masonry? In Masonry, placement hasn't happened by the time we size tracks, so currently, all items contribute to the size of every track (unless explicitly placed). If a track has no item, should that track still be collapsed in this case? If so, we won't know this during track sizing.

The heuristic in https://drafts.csswg.org/css-grid-3/#repeat-auto-fit should help with the not knowing item placement during track sizing piece. But I think there are still a piece that could use clarity in the spec:

Should collapsing of tracks happen during the track sizing pass for `repeat(auto-fit, auto)`, and should that impact the number of auto repeaters that we calculate, or should that only happen after in the true pass?

My guess is that collapsed tracks shouldn't impact the number of repeaters that are computed for auto. That likely means that we should not collapse tracks during the track sizing pass to compute the number of auto repetitions because we could for some reason end up with those all being fully collapsed, and then calculate the number of auto repetitions against a 0px sized auto track.

So I suspect we'll want to update the spec to note that tracks shouldn't be collapsed when making this computation for `repeat(auto-fit, auto)`

-- 
GitHub Notification of comment by alisonmaher
Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/12485#issuecomment-3110210463 using your GitHub account


-- 
Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config

Received on Wednesday, 23 July 2025 21:22:22 UTC