Bug 252665

Summary:	touch-action doesn't apply if element has overflow properties
Product:	WebKit	Reporter:	Adam Gamble <adam.gamble>
Component:	CSS	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Minor	CC:	graouts, simon.fraser, webkit-bug-importer, wenson_hsieh, zalan
Priority:	P2	Keywords:	InRadar
Version:	Safari 16
Hardware:	iPhone / iPad
OS:	iOS 16

Description Adam Gamble 2023-02-21 07:56:35 PST

Basic steps:

 - Set `touch-action: none;` on html and body tags.
 - Any child elements that set overflow-x or overflow-y will still have touch actions enabled.

Example repro: https://jsfiddle.net/e3hbd2L9/

The computed styles on child nodes is `touch-action: auto` so perhaps this is expected (?) behaviour. Unsure why adding overflow should make a difference though.

Comment 1 Adam Gamble 2023-02-21 07:59:20 PST

Ok, perhaps expected considering https://bugs.chromium.org/p/chromium/issues/detail?id=674872#c2

Comment 2 Simon Fraser (smfr) 2023-02-21 12:30:39 PST

Are you saying that `touch-action: none` is still allowing overflow regions to scroll, or that other touch interactions also work?

Comment 3 Adam Gamble 2023-02-22 02:47:32 PST

Yes that's right, other touch interactions such as pinch-zoom will still work inside overflow regions (but are otherwise prevented).

This might be intentionally the case as I hadn't realised that `touch-action` isn't inherited. Just that the behaviour appeared inconsistent at first.

Comment 4 Radar WebKit Bug Importer 2023-02-28 07:57:20 PST

<rdar://problem/106031820>