Bug 285713 – Scroll to view doesn't take sticky elements in consideration, so the focused element can remain invisible on GitHub and elsewhere

• Component: Scrolling
• Status: NEW

Steps to reproduce:

1. Press Tab or just simply scroll down to the middle of the page.

2. Confirm current visible port's focus is highlighted.

3. Press shift-tab to do the back tabbing from bottom to top.

4. Expected behavior: the visible focus should be follow the cursor and make the screen move to focus as when you tabbing.

4.1 Actual behavior: the visible focus will lost when cursor reach out to the top element on your current screen, and when you keep shift-tabing, the visible focus will eventually moved up, experiencing a kind of delay on the focus moving.

This was found on both Chrome and Safari.

[Alexey Proskuryakov]

Thank you for the report. I don't think that I can reproduce this issue on this page in Safari. Could you please provide more details, and/or a screen recording?

Created attachment 473860 [details]
A sample screen shot regarding this issue on Chrome

This is a sample screenshot took on Chrome, for Safari I need to setup something before I can take the screenshot but this shows the issue.

When back-tabing(shift-tab), you can found on the top left corner there is a helptext message shows up "Open Admin User Preview", this is actually a help text for a button/clickable link.
It indicates that the current cursor already reached to this place but the screen focus was not there yet, after several more shift-tabbing, my screen finally moved and the focus resumed.

[Alexey Proskuryakov]

This is probably content specific. Assuming that we cannot get access to this website, we may need to have a standalone test case to investigate.

(In reply to Alexey Proskuryakov from comment #4)
> This is probably content specific. Assuming that we cannot get access to
> this website, we may need to have a standalone test case to investigate.

Hi Alexey, thanks for following up with this. I can reproduce this on a github PR page, with the very similar behavior, thus we think this is not the site issue but might be a webkit issue.
And we check the taborder/tabindex but no recent change shows up.

I just tried on a public website(slackoverflow) and found the same behavior, the help text of some button already shows up on the top part of my screen but the focus delayed, require a few more shift-tab to actually focus to it.

I tried to upload a 1.1MB screenshot but it gave me error mentioning the entity too large.

[Alexey Proskuryakov]

Re-titled to describe the issue that I can indeed reproduce on GitHub. Steps to reproduce:

1. Open a PR like https://github.com/WebKit/WebKit/pull/38816
2. Scroll down to comments field, and click on it.
3. Start pressing Shift-Tab.

From time to time, it will seem as if the focus simply disappears, because the focused element will be below the sticky header.

[Radar WebKit Bug Importer]

<rdar://problem/143088712>