1798813 - [css-contain-2] filter effects and "relevant to the user" (for content-visibility:auto)

Status: NEW

(Core :: Layout, defect)

Description

[Mozilla Apprentice]

A resolution was made for csswg-drafts/#7711.

[css-contain-2] filter effects and "relevant to the user"

• RESOLVED: Add a SHOULD requirement for considering the filter effect extent and interaction with UA margin

Discussion.

Comment 1

[Daniel Holbert [:dholbert]]

Specific examples from the CSSWG discussion:

• if the viewport has some blur where e.g. a given pixel is a blurred average of pixels +/- N pixels away from it, then we need to be sure that offscreen content within that range is considered "relevant to the user" and gets rendered for the purpose of influencing blur.
• if there's a SVG displacement filter that causes offscreen content to be rendered on-screen, then that offscreen content needs to be considered relevant to the user

Comment 2

[Frédéric Wang]

This is a relatively recent change and it does not seem there is any WPT test for that yet ¿?. The added text at https://github.com/w3c/csswg-drafts/commit/e50cdcb0a3df08bbf54fd28044266b7d9404ada5 is quite generic, one would need to figure out precisely which filter can affect the rendering of a content-visibility: auto element in a way that makes part of it "onscreen" and when that happens.

Unless I'm missing something, this does not seem a blocker to ship an initial implementation of content-visibility though.

@Daniel: WDYT?

Comment 3

[Daniel Holbert [:dholbert]]

(In reply to Frédéric Wang from comment #2)

this does not seem a blocker to ship an initial implementation of content-visibility though.

Yup, agreed.