Bug 249094 – Implement baseline-source CSS property

• Status: NEW
• Component: CSS

[Tim Nguyen (:ntim)]

https://drafts.csswg.org/css-inline-3/#baseline-source

Allows choosing between first or last baseline (or auto behavior).

WPT being added by https://github.com/web-platform-tests/wpt/pull/37443/

[Radar WebKit Bug Importer]

<rdar://problem/103495495>

Created attachment 465773 [details]
A HTML file showcasing alignment issues with textareas

Textareas are a problematic area with regards to "vertical-align: baseline".

I'd expect elements with "vertical-align: baseline" in the same row of a table to be aligned together. As can be seen using the attached HTML file, the label, and the input texts are aligned, but the textarea text isn't.

Using "baseline-source: first" solves this issue in Chrome, it would be nice to have the same possibility in webkit. Firefox textareas don't have this issue.

Created attachment 465774 [details]
Screenshot of the textarea alignment issue

[Šime Vidas]

It’s worth mentioning that <textarea> does not have this issue in flex layouts with align-items: baseline. I have created a test page with flex layout instead of <table>:

https://jsbin.com/cijerob/edit?css,output

So it seems that baseline-source would be useful in <table>, but it’s not really needed in flex layouts.

[Karl Dubost]

This makes fail a couple of tests in 
https://wpt.fyi/results/css/css-inline/baseline-source