1995348 - Implement parsing for masonry using placeholder `display:grid-lanes` / `inline-grid-lanes`

Status: ASSIGNED

(Core :: Layout: Grid, enhancement)

Description

[Daniel Holbert [:dholbert]]

Spinning this off from bug 1991204 to implement masonry as a display value.

The actual value is TBD - it's currently display:something in the spec :) -- but the existing WPTs use[1] display:masonry and display:inline-masonry, so we should use that (behind a pref, because that's not what will actually ship) to enable the appropriate behavior for those tests.

[1] see e.g. here: https://searchfox.org/firefox-main/source/testing/web-platform/tests/css/css-grid/masonry/tentative/alignment/masonry-align-content-001.html#23
and here: https://searchfox.org/firefox-main/source/testing/web-platform/tests/css/css-grid/masonry/tentative/baseline/masonry-grid-item-content-baseline-001.html#20

Comment 1

[Daniel Holbert [:dholbert]]

(In reply to Daniel Holbert [:dholbert] from comment #0)

the existing WPTs use[1] display:masonry and display:inline-masonry, so we should use that (behind a pref, because that's not what will actually ship) to enable the appropriate behavior for those tests.

(As noted in the spec "issue 2" box (https://drafts.csswg.org/css-grid-3/#issue-1224e16e ), the discussion about the actual final display value is happening in https://github.com/w3c/csswg-drafts/issues/12022 . But that'll just be a trivial switcheroo once that's settled.)

Comment 2

[Ting-Yu Lin [:TYLin] (PST, UTC-8)]

For other masonry related properties, I saw in the css-grid-3's recent changes section https://drafts.csswg.org/css-grid-3/#recent-changes

Introduced item-flow and the item-* longhands, replacing masonry-flow and related properties. (Issue 11480)

So it appears that the parsing tests for masonry-flow, etc in https://wpt.fyi/results/css/css-masonry/tentative/parsing?label=master&label=experimental&aligned&q=masonry are out-of-date.

Comment 3

[Ting-Yu Lin [:TYLin] (PST, UTC-8)]

RESOLVED: masonry switch will be display: grid-lanes

https://github.com/w3c/csswg-drafts/issues/12022#issuecomment-3525043825

Comment 4

[Tiaan Louw [:tlouw]]

Attachment: Bug 1995348 - Implement the "grid-lanes" value for the "display" property r=#layout

Use the "display: grid-lanes" value to conform to current usage in web
platform tests.

See: https://drafts.csswg.org/css-grid-3/#masonry-model

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/74e86f72e209
https://hg.mozilla.org/integration/autoland/rev/ce817bfc7b96
Implement the "grid-lanes" value for the "display" property r=layout-reviewers,dholbert

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/d839523e0358
https://hg.mozilla.org/integration/autoland/rev/6fb14d9268d3
Revert "Bug 1995348 - Implement the "grid-lanes" value for the "display" property r=layout-reviewers,dholbert" for causing assertion failures @ nsCSSFrameConstructor.cpp

Comment 7

[Sandor Molnar[:smolnar]]

Backed out for causing assertion failures @ nsCSSFrameConstructor.cpp

Backout link: https://hg.mozilla.org/integration/autoland/rev/6fb14d9268d3e32063cc78c1c5246980488aec70

Push with failures

Failure log -> Assertion failure: display->mDisplay == StyleDisplay::Block || display->mDisplay == StyleDisplay::FlowRoot (Unhandled display type for root element), at /builds/worker/checkouts/gecko/layout/base/nsCSSFrameConstructor.cpp