Bug 220899

Summary:	long-press/callout - weird foreground/background colors applied to links. bailing out of callout leaves :hover styles sticking
Product:	WebKit	Reporter:	Patrick H. Lauke <redux>
Component:	UI Events	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Normal	CC:	dino, hi, megan_gardner, redux, simon.fraser, smoley, thorton, webkit-bug-importer, wenson_hsieh
Priority:	P2	Keywords:	InRadar
Version:	Safari 14
Hardware:	iPhone / iPad
OS:	iOS 14

Description Patrick H. Lauke 2021-01-24 04:39:37 PST

First identified as a bug in Bootstrap - see https://github.com/twbs/bootstrap/issues/31315

This seems due to some weird heuristics (which don't seem to be documented anywhere?) of how iOS/Safari decides to style a link when it's being long-pressed, just before the callout/context menu is shown. In the case of Bootstrap, this results in outline button styled links to momentarily have a "white-on-white" style on links, which makes it look like a bug.

Additionally, after bailing out of the callout, iOS/Safari leaves the :hover styles applied until another control is tapped. Is this intentional behavior, or a bug?

reduced test case: https://codepen.io/patrickhlauke/pen/ExgBxwv

video of the bug: https://www.youtube.com/watch?v=_xCNSgieCuY

Comment 1 Smoley 2021-01-27 17:58:02 PST

This does not reproduce for me using the codepen but I can reproduce it using the page shown in the video: getbootstrap.com. I'm seeing it on iOS 13.6.1 as well as the latest 14.4 beta.

Comment 2 Radar WebKit Bug Importer 2021-01-27 17:58:13 PST

<rdar://problem/73688837>

Comment 3 Tim Horton 2021-01-27 18:42:08 PST

(FWIW if anyone wants to dig in, this is all about the background color + snapshot that TextIndicator computes and that we hand to the UITargetedPreview for the long press/context menu/etc. preview; the heuristic is nontrivial, so probably requires debugging to understand what's gone wrong).

Separately, I *believe* that :hover sticking is intentional, that's how our touch-hover adaptation works (otherwise things hidden behind hover are unusable).

Comment 4 Patrick H. Lauke 2021-01-28 00:38:40 PST

On the :hover sticking...I thought there was a heuristic that checked if there was some form of document mutation (new content appearing etc) - but maybe I'm getting confused with the "generate mouse and click events as result of touch" JS handling.

Comment 5 Patrick H. Lauke 2021-01-28 00:41:38 PST

Regarding repro on the codepen - sorry, try the debug view of the pen https://cdpn.io/patrickhlauke/debug/ExgBxwv