New issue
Advanced search Search tips
Note: Color blocks (like or ) mean that a user may not be available. Tooltip shows the reason.

Issue 849343 link

Starred by 1 user

Issue metadata

Status: WontFix
Owner: ----
Closed: Jun 2018
Cc:
Components:
EstimatedDays: ----
NextAction: ----
OS: Android
Pri: 2
Type: Compat



Sign in to add a comment

scroll anchoring should work on live blogs

Reported by billdill...@gmail.com, Jun 4 2018

Issue description

Example URL:

Steps to reproduce the problem:
I was on The Verge's WWDC live blog earlier and the page kept jumping/shifting as I was trying to read (because new posts being added), it was a horrible experience and I just gave up. Isn't scroll anchoring supposed to 'fix' stuff like this?

What is the expected behavior?

What went wrong?
here is the URL if that's any help https://live.theverge.com/apple-wwdc-live-blog-keynote-2018/?_ga=2.53734056.1865542238.1528136784-1428338024.1527882054

Also I assume this isn't just an issue with Chrome for Android, Windows/Linux/macOS/ChromeOS too 

Does it occur on multiple sites: N/A

Is it a problem with a plugin? N/A 

Did this work before? N/A 

Does this work in other browsers? N/A

Chrome version: 67  Channel: stable
OS Version: 8.0
Flash Version:
 
Components: Blink>Scroll
Labels: Needs-triage-Mobile
Cc: sandeepkumars@chromium.org
Labels: Triaged-Mobile Needs-Feedback
Tested the issue using #67.0.3396.68 on Android Pixel; 8.1.0 as per the steps mentioned below and could not reproduce the issue.

Steps:
1. Launched Browser
2. Navigated to The Verge's page
3. Played random videos
4. No issue is seen.

Note: Unable to test this issue on The Verge's WWDC live blog as no live video available at this moment.

@Reporter: Could you please help us with the details of device for further triaging?

Thanks!!
@ comment 3, the live blog is not taking place right now so of course you cannot repro just by going to the URL. The issue is this: during the live blog, as new posts/updates are added at the top, the content is shifting/jumping and you can't read or keep track of where you are, it's a very bad experience. 
Project Member

Comment 5 by sheriffbot@chromium.org, Jun 5 2018

Labels: -Needs-Feedback
Thank you for providing more feedback. Adding the requester to the cc list.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot
Labels: Needs-Feedback
It maybe an issue related live.theverge. I just wrote a simple page to simulate the live behavior: keep insert div to the top of page but can not reproduce.

Does this work in other browsers?

If you can, please provide a example for us. Thank you.

2.html
499 bytes View Download
Can't test at the moment but isn't scroll anchoring supposed to fix issues like this?
Project Member

Comment 8 by sheriffbot@chromium.org, Jun 7 2018

Cc: chaopeng@chromium.org
Labels: -Needs-Feedback
Thank you for providing more feedback. Adding the requester to the cc list.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot
The Verge will have several live blogs in the coming days for E3, it's a good chance to see the issue for yourself. I emailed the Verge and they weren't very helpful but if I'm not mistaken, scroll anchoring should work with existing websites and shouldn't require any changes from web devs. Live blogs should probably be the best example of scroll anchoring improving the experience so I really hope something can be done about this. (I noticed the issue in Chrome for Android, my friend said he didn't have the issue in Chrome for Windows) 
Cc: skobes@chromium.org
My mistake, I think it will be the Verges sister video game site Polygon for the live blogs, they use the same system though https://www.polygon.com

Comment 12 by bokan@chromium.org, Jun 16 2018

Cc: bokan@chromium.org
Yes, scroll anchoring should try to keep the currently visible element in view. Perhaps we're anchoring to the wrong element? It's also possible for the page to turn it off.

skobes@, are you aware of issues like this?

Comment 13 by bokan@chromium.org, Jun 21 2018

ping skobes@

Unfortunately, without a local repro this isn't very actionable.
Status: WontFix (was: Unconfirmed)
Yes, scroll anchoring is, generally speaking, intended to fix things like this.  You can see scroll anchoring working correctly in chaopeng's test case in #6.  Scroll anchoring is enabled for existing websites on all platforms.  Web devs do not need to do anything to utilize scroll anchoring.

In some situations, we suppress scroll anchoring.  For example, if new content is inserted, and styles on the <body> are modified at the same time, we will not do any scroll anchoring.

In some situations, web developers explicitly disable scroll anchoring.

In some situations, scroll anchoring fails to mitigate a content shift, because the insertion of new content triggering the shift happens within, or partially within, the viewport.  Scroll anchoring "anchors", roughly speaking, to the top of the viewport.  So if new content drops in at (scrollY + 1) and your eyes are at the center, the thing you're looking at will shift.  Scroll anchoring only mitigates shifts from content insertions that are entirely above the viewport.

I tested, in devtools with mobile emulation, dynamic removal and re-insertion of one of the ".entry" divs near the top of the feed on the reported URL, with the page scrolled so that the entry was entirely above the viewport.  In this test, scroll anchoring worked correctly.

Based on the above I'm going to close this report but if you have a test case that demonstrates scroll anchoring behaving other than as described please feel free to reopen / re-file.

Sign in to add a comment