1620749 - Use ReflowChildFlags::ApplyRelativePositioning flag in ReflowFlexItem

Status: RESOLVED FIXED

(Core :: Layout: Flexbox, task)

Description

[Ting-Yu Lin [:TYLin] (PDT, UTC-7)]

This is a followup to bug 1547759 to remove the conversion before calling FinishReflowChild() in nsFlexContainerFrame::ReflowFlexItem. Instead we should use ReflowChildFlags::ApplyRelativePositioning flag.

Comment 1

[Ting-Yu Lin [:TYLin] (PDT, UTC-7)]

Attachment: Bug 1620749 - Adjust FinishReflowChild()'s relative positioning conversion, to make it a writing-mode-agnostic API.

Currently, when using ReflowChildFlags::ApplyRelativePositioning flag in
FinishReflowChild(), we (implicitly) force the callers to pass aWM and
aPos in the same writing-mode as the reflow input, i.e. the child's
writing-mode. This results in an unintuitive LogicalPoint conversion
mContainerSize - mMetrics.PhysicalSize() in
nsBlockReflowContext::PlaceBlock().

We should allow the callers to use their preferred aWM and aPos (either
in parent's wm or child's wm), and doing the necessary conversion in
FinishReflowChild() (like we did to convert aDesiredSize from
ReflowOutput's wm to aWM).

Also, correct the documentation for aWM in ReflowChild() and
FinishReflowChild(). aWM doesn't need to be the containing frame's
writing-mode. It can be any as long as it is the writing-mode that aPos
is used.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/0d3c7f7727b4
Adjust FinishReflowChild()'s relative positioning conversion, to make it a writing-mode-agnostic API. r=dholbert

Comment 3

[Oana Pop-Rus]

https://hg.mozilla.org/mozilla-central/rev/0d3c7f7727b4