CSS Inline `text-box`, `text-box-trim`, and `text-box-edge` properties

[kojiishi]

こんにちは TAG-さん!

I'm requesting a TAG review of CSS Inline text-box, text-box-trim, and text-box-edge properties.

To achieve optical balance of text content, the text-box-trim and text-box-edge properties, along with the text-box shorthand property, make finer control of vertical alignment of text possible.

• Explainer¹: https://kojiishi.github.io/explainers/text-box-trim
• Specification: https://drafts.csswg.org/css-inline-3/#leading-trim
• WPT Tests: https://wpt.fyi/results/css/css-inline/text-box-trim?label=master&label=experimental&aligned
• User research:
• Security and Privacy self-review²:
• GitHub repo:
• Primary contacts:
  • @fantasai, Apple, spec editor.
  • @kojiishi, Google, Chromium implementor
  • @atanassov, Microsoft, CSS WG Chair
  • @astearns, Adobe, CSS WG Chair
• Organization/project driving the specification:
• Multi-stakeholder support³:
  • Chromium comments: Positive.
  • Mozilla comments: CSS text-box, text-box-trim, text-box-edge mozilla/standards-positions#1105
  • WebKit comments: CSS Inline text-box, text-box-trim, text-box-edge WebKit/standards-positions#432
  • Microsoft Design: Published an article.
  • Figma: Launched their implementation.
• Status/issue trackers for implementations⁴:
  • https://chromestatus.com/feature/5174589850648576, crbug.com/40254880, available as Experimental Web Platform features.
  • WebKit available under a runtime flag.

Further details:

• I have reviewed the TAG's Web Platform Design Principles
• Relevant time constraints or deadlines:
• The group where the work on this specification is currently being done: CSS WG
• The group where standardization of this work is intended to be done (if different from the current group):
• Major unresolved issues with or opposition to this specification:
• This work is being funded by:

[xiaochengh]

Hi @kojiishi, we discussed this at a TAG breakout today and are generally positive about it.

There's one concern. While solving vertical alignment, this feature changes the sizes of the boxes, which leads to interactions with background, highlights, borders, outlines and etc. Have the CSSWG assessed these interactions, or considered any alternatives that do not affect the sizes?

Besides, it will be better if the explainer is placed next to the spec.

[kojiishi]

Hi @xiaochengh, thank you for the comments.

There's one concern. While solving vertical alignment, this feature changes the sizes of the boxes, which leads to interactions with background, highlights, borders, outlines and etc. Have the CSSWG assessed these interactions, or considered any alternatives that do not affect the sizes?

I think so, it's intentional. If you have specific cases, can you file to https://github.com/w3c/csswg-drafts/issues ?

Besides, it will be better if the explainer is placed next to the spec.

I'm sorry but I couldn't understand what this means. Can you please expand?