Bug 213618

Summary:

[iOS] Event region briefly missing editable element after typing second character in question field on discussions.apple.com

Product:

WebKit

Reporter:

Daniel Bates <dbates>

Component:

Layout and Rendering

Assignee:

Daniel Bates <dbates>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

bfulgham, changseok, esprehn+autocc, ews-watchlist, fred.wang, glenn, koivisto, kondapallykalyan, pdr, simon.fraser, webkit-bug-importer, zalan

Priority:

Keywords:

InRadar, PlatformOnly

Version:

WebKit Local Build

Hardware:

Unspecified

OS:

Unspecified

URL:

https://discussions.apple.com

See Also:

https://bugs.webkit.org/show_bug.cgi?id=213564

Attachments:

Description	Flags
Test case	none
Test case (shows it affects touch-action region too!)	none
Patch	none
To land	none

Description Daniel Bates 2020-06-25 13:57:56 PDT

This is visually observable with the editable regions debug overlay enabled: defaults key WebKitDebugVisibleDebugOverlayRegions has bit 3 enabled.

Steps to reproduce:

1. Visit <https://discussions.apple.com>.
2. Type 'f' into the question field

Notice the field has purple overlay, which indicates that it's in the editable region.

3. Type 'f'.

Then the overlay briefly vanishes until search results come back.

Comment 1 Daniel Bates 2020-06-25 13:59:03 PDT

Created attachment 402807 [details]
Test case

Comment 2 Daniel Bates 2020-06-25 13:59:22 PDT

This also affects touch-action!

Comment 3 Daniel Bates 2020-06-25 13:59:41 PDT

Created attachment 402808 [details]
Test case (shows it affects touch-action region too!)

Comment 4 Daniel Bates 2020-06-25 14:01:35 PDT

How do I use ^^^ tests?

Easiest way is to just ensure WebKitDebugVisibleDebugOverlayRegions has TouchActionRegion and EditableElementRegion set. Here's the enum for reference:

[[

enum DebugOverlayRegionFlags {
    NonFastScrollableRegion = 1 << 0,
    WheelEventHandlerRegion = 1 << 1,
    TouchActionRegion = 1 << 2,
    EditableElementRegion = 1 << 3,
};

]]
<https://trac.webkit.org/browser/trunk/Source/WebCore/page/SettingsBase.h?rev=263316#L65>

Comment 5 Daniel Bates 2020-06-25 14:02:54 PDT

<rdar://problem/62656131>

Comment 6 Daniel Bates 2020-06-25 14:09:28 PDT

Note that bug #213564 will mitigate *this* bug (on https://discussions.apple.com), but that's only because the repro steps require focusing the search field. The root cause of this bug is that the event region is not updated for the foreground layer (if it exists) and could be triggered just like in the attached test case (0 interaction required!)

Comment 7 Daniel Bates 2020-06-25 14:23:18 PDT

Created attachment 402810 [details]
Patch

Comment 8 Daniel Bates 2020-06-25 15:38:24 PDT

Oops forgot to include the updated expected results for iOS...

Comment 9 Daniel Bates 2020-06-25 15:40:26 PDT

Created attachment 402820 [details]
To land

Comment 10 Daniel Bates 2020-06-25 15:41:27 PDT

Comment on attachment 402820 [details]
To land

Clearing flags on attachment: 402820

Committed r263538: <https://trac.webkit.org/changeset/263538>

Comment 11 Daniel Bates 2020-06-25 15:41:30 PDT

All reviewed patches have been landed.  Closing bug.