Bug 283846

Summary:

[css-contain-2] content skipped with `content-visibility: auto` should still be findable

Product:

WebKit

Reporter:

Nathan Knowler <nathan>

Component:

CSS

Assignee:

alan <zalan>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

karlcow, koivisto, lwarlow, m.goleb+bugzilla, mike, ntim, thorton, webkit-bug-importer, wenson_hsieh, woodlxf00, zalan

Priority:

Keywords:

HasReduction, InRadar

Version:

Safari 18

Hardware:

All

OS:

All

Bug Depends on:

290490

Bug Blocks:

Attachments:

Description	Flags
Reduced test with some off-screen content skipped with `content-visibility: auto`.	none
Reference video for matching content with a text fragment in Safari 18.3	none
WIP TextIterator changes	none
Patch	none
Patch	none
[fast-cq]Patch	none

Nathan Knowler

Reported 2024-11-29 23:19:05 PST

Created attachment 473400 [details] Reduced test with some off-screen content skipped with `content-visibility: auto`. Content skipped with `content-visibility: auto` should still be findable with find-in-page features and in Safari it’s not. I did confirm that content is still accessible in VoiceOver (e.g. if the skipped content includes a link, it’ll surface in the Web Rotor). Latest draft spec (this is not a recent change): https://drafts.csswg.org/css-contain/#valdef-content-visibility-auto macOS Version: 15.1.1 (24B2091) Safari version 18.1.1 (20619.2.8.11.12) Safari Tech Preview Release 208 (Safari 18.2, WebKit 20621.1.5.1)

Attachments
Reduced test with some off-screen content skipped with `content-visibility: auto`. (888 bytes, text/html) 2024-11-29 23:19 PST, Nathan Knowler	no flags	Details
Reference video for matching content with a text fragment in Safari 18.3 (126.14 KB, video/mp4) 2025-02-13 11:05 PST, Nathan Knowler	no flags	Details
WIP TextIterator changes (4.95 KB, patch) 2025-02-19 08:04 PST, Tim Nguyen (:ntim)	no flags	Details Formatted Diff Diff
Patch (16.28 KB, patch) 2025-03-26 20:05 PDT, alan	no flags	Details Formatted Diff Diff
Patch (17.63 KB, patch) 2025-03-29 09:46 PDT, alan	no flags	Details Formatted Diff Diff
[fast-cq]Patch (17.63 KB, patch) 2025-03-29 14:38 PDT, alan	no flags	Details Formatted Diff Diff
Show Obsolete (3) View All Add attachment proposed patch, testcase, etc.

Radar WebKit Bug Importer

Comment 1 2024-12-06 23:20:14 PST

<rdar://problem/141086607>

Nathan Knowler

Comment 2 2025-02-13 11:05:05 PST

Created attachment 474222 [details] Reference video for matching content with a text fragment in Safari 18.3 I’m adding a video demonstration of how text fragment URLs relate to this bug in Safari 18.3. The behaviour is slightly different than find-in-page. The page scrolls to the location of the match. The matched text displays briefly, before disappearing. This means that content with `content-visibility: auto` that is within the viewport is still hidden.

Tim Nguyen (:ntim)

Comment 3 2025-02-18 23:29:56 PST

rdar://141237620

Tim Nguyen (:ntim)

Comment 4 2025-02-19 08:04:39 PST

Created attachment 474285 [details] WIP TextIterator changes My TextIterator changes should be correct, but I'm missing some other part of the puzzle that I can't seem to pinpoint atm.

alan

Comment 5 2025-03-26 20:05:25 PDT

Created attachment 474731 [details] Patch

alan

Comment 6 2025-03-27 08:59:29 PDT

fullyClipsContents change is not quite right. I think what we need here is to run the forced layout without applying implicit size containment on c-v auto content so that c-v auto block containers don't get collapsed.

alan

Comment 7 2025-03-27 09:01:36 PDT

(as it is difficult to differentiate actual collapsed containers from containers with zero height caused by applying (c-v a) size containment)

alan

Comment 8 2025-03-29 09:46:40 PDT

Created attachment 474757 [details] Patch

alan

Comment 9 2025-03-29 14:38:22 PDT

Created attachment 474759 [details] [fast-cq]Patch

EWS

Comment 10 2025-03-30 19:21:35 PDT

Committed 292919@main (d1074e32ca2f): <https://commits.webkit.org/292919@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 474759 [details].

alan

Comment 11 2025-03-30 19:22:07 PDT

oops, forgot to submit the test. will do it in a bit.

alan

Comment 12 2025-03-31 12:24:49 PDT

(In reply to zalan from comment #11) > oops, forgot to submit the test. will do it in a bit. https://commits.webkit.org/292949@main

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