746705 - Do abspos child reflow in a separate pass after in-flow layout

Status: NEW

(Core :: Layout: Positioned, defect)

Description

[Boris Zbarsky [:bzbarsky]]

Now that we can update overflow areas without doing a reflow (thanks to bug 524925), we should consider doing abspos reflow off something like post-reflow callbacks instead of when finishing up layout of the containing block.  The main benefit is that we can then have the final correct size of the containing block (letting us fix bug 63895), up-to-date placeholder positions (important for cases like the one described in bug 641341 comment 43), etc.

Thoughts?

Ehsan, I'm not sure how much this intersects with the work you're doing on this stuff already....

Comment 1

[(no longer active)]

(In reply to Boris Zbarsky (:bz) from comment #0)
> Ehsan, I'm not sure how much this intersects with the work you're doing on
> this stuff already....

I'm not currently working on this at all, but I think this generally makes sense.

But I should also say that I've seen problems with UpdateOverflow in bug 157681 comment 92.  It would be nice if we ensure that UpdateOverflow works correctly before relying on it here too.

Comment 2

[Mayank Bansal]

Is this still needed?

Comment 3

[Daniel Holbert [:dholbert]]

It's not on anyone's radar at the moment, but it might still be a good idea in theory, so might as well leave it open.

CC jwatt who's currently working on anchor positioning which is in the guts of absolutely-positioned reflow, in case he develops thoughts about this proposal as part of that work. (But no action needed here for now.)