On Mon, Jun 9, 2025 at 10:16 AM Chromestatus < ad...@cr-status.appspotmail.com> wrote:
> Contact emails jfernan...@igalia.com > > Explainer None > > Specification https://www.w3.org/TR/css-align-3/#baseline-align-content > > Summary > > This feature allows developers to align the content of the boxes > participating in row-like shared context by their last baseline, instead of > their first. This is done via the following property: align-content last > baseline; /* Table cells, Flex items or grid items */ > > Horray! The feature is somewhat non-trivial to implement, if you could share a document on how you are thinking of implementing - I'm also happy to jump on a VC to discuss how to implement it - it's quite complex/nuanced. > Blink component Blink>Layout > <https://issues.chromium.org/issues?q=customfield1222907:%22Blink%3ELayout%22> > > Motivation > > Both Firefox and Safari already implements this feature, as it's shown in > the wpt.fyi tests dashboard, hence this is an interoperability issue. > Additionally, Chrome already supports it for block containers, but it's > disabled at parsing time because of the lack of implementation for grid and > flex items. > > > Both Firefox and Safari already implements this feature This isn't true. The situation is relatively complex. See this testcase: https://www.software.hixie.ch/utilities/js/live-dom-viewer/?saved=13847 The layout modes which should support this are "flex", "grid", "table". Blink - supports parsing `align-content: baseline`. Doesn't support it in any layout mode. We explicitly didn't ship parsing for "align-content: last baseline" due to lack of layout support. Safari - supports parsing both `align-content: baseline` / `align-content: last baseline`. Doesn't support it in any layout mode. (Added parsing support for "last baseline" in https://webkit.org/blog/13591/webkit-features-in-safari-16-2/#:~:text=Features%20more%20often.-,Last%20Baseline,-CSS%20Alignment%20allows but it didn't add layout support for the feature). Gecko - supports parsing `align-content: baseline` / `align-content: last baseline`. Only supports it for "display: grid" *and* with block children, and *sometimes* correct for other children, but mostly broken. It might be worth raising a CSSWG issue to try and get the other browsers (and us) to unship parsing "align-content: baseline" until the feature is supported across all layout modes. Initial public proposal None > > TAG review None > > TAG review status Not applicable > > Risks > > > Interoperability and Compatibility > > This feature is marked as one of the interop-2025 tasks, since only Chrome > doesn't implement it. Safari has partial support, though, since it lacks > support for this feature in grid and flex. I don't see any interop risk > associated to this feature. > > There is potential compat risk. Basically everyone supports parsing this, but nobody implements it correctly. It has non-trivial performance costs so may affect sites which inadvertently rely on this rule, and/or rely on it not having any effect. > *Gecko*: Shipped/Shipping ( > https://developer.mozilla.org/en-US/docs/Web/CSS/align-content#browser_compatibility) > > > *WebKit*: Shipped/Shipping ( > https://webkit.org/blog/14885/release-notes-for-safari-technology-preview-185) > Implemented support for align-content on block containers; difficult to say > from the release notes how well the Baseline Content-Alignment is > supported, though. It shows "partial support" in "can-i-use" [1], mainly > due to partial implementation for flex and grid [2] [1] > https://caniuse.com/mdn-css_properties_align-content_flex_context_last_baseline > [2] https://bugs.webkit.org/show_bug.cgi?id=235005 > > *Web developers*: Positive This has been marked as one of the > interop-2025 issues to work on. > > *Other signals*: > > Ergonomics > > This feature will be used with Grid and Flexbox, so I'll make sure they > both support the feature before shipping it. > > > Activation > > In order to minimize the activation risks, we must be sure this feature is > supported in both Flexbox and Grid. > > @supports will be broken for this, so web-developers might have issues feature detecting it if engines don't unship parsing support. > > Security > > No security risks have been detected. > > > WebView application risks > > Does this intent deprecate or change behavior of existing APIs, such that > it has potentially high risk for Android WebView-based applications? > > No risks found. > > > Debuggability > > There is no need for changes in Dev tools in order to inspect this > feature. The new "last-baseline" value will be listed as valid in the CSS > inspector. > > > Is this feature fully tested by web-platform-tests > <https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md> > ? Yes > > There are already tests covering the "align-content: last-baseline", > mainly for block containers, but also for grid. > https://wpt.fyi/results/css?label=master&label=experimental&aligned&view=subtest&q=align-content-block%20or%20last-baseline%20or%20content-baseline%20or%20item-mixed-baseline > More tests will be added to properly support the feature in grid and flex. > > > Flag name on about://flags None > > Finch feature name None > > Non-finch justification None > > Requires code in //chrome? False > > Tracking bug https://issues.chromium.org/issues/341947689 > > Estimated milestones > > No milestones specified > > > Link to entry on the Chrome Platform Status > https://chromestatus.com/feature/5163497234890752?gate=5124964398923776 > > This intent message was generated by Chrome Platform Status > <https://chromestatus.com>. > > -- > You received this message because you are subscribed to the Google Groups > "blink-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to blink-dev+unsubscr...@chromium.org. > To view this discussion visit > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/684716ed.710a0220.d824b.055d.GAE%40google.com > <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/684716ed.710a0220.d824b.055d.GAE%40google.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "blink-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to blink-dev+unsubscr...@chromium.org. To view this discussion visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAJL3UpQPT-4hdzQaX9O38rVB9KD2%3D1%2B76j1hePRVcxf%2BU5hAng%40mail.gmail.com.
