Open Bug 1460032 Opened 4 years ago Updated 3 years ago

Twitch box art images flicker when scrolling on desktop


(Core :: Graphics, defect, P3)




Tracking Status
firefox-esr60 --- affected
firefox60 --- affected
firefox61 --- affected
firefox62 --- affected
firefox64 --- wontfix
firefox65 --- affected
firefox66 --- affected


(Reporter: cpeterson, Unassigned)




(Whiteboard: [gfx-noted])

1. Load
2. Slowly scroll down the page.

As each row of box art images scrolls into view, all the images on the page flicker as the high-res images are loaded.

This is not a new problem. I can reproduce the flickering in Firefox builds as old as 55 on both Windows and macOS. The images don't flicker in Chrome, Edge, or IE11 on Windows or Chrome or Safari on macOS, so this problem is unique to Firefox.
See Also: → 1446239
As noted in the original bug, I expect this is in part caused by the recreation of the DOM elements and us getting a paint in before the images have loaded in the new element.
Priority: -- → P3
Whiteboard: [gfx-noted]

This is reproducible on Android device (Note 9) with today's Nightly build (01-16-2019).

See Also: → 1548376

Still reproduces in Fennec and Fenix.

Hey Jamie - curious if this gets better when we enable WR? Just wondering if WR makes a positive impact here.

Flags: needinfo?(jnicol)

Jessie - On a Pixel 2 in Fenix & Fenix Nightly, it's much worse of a problem. Right after scrolling the first bit, the page starts automatically scrolling quickly and loading all the title images uncontrollably.

Fennec is still showing the same issue as reported.

The scrolling issue is a scroll anchoring bug. Setting layout.css.scroll-anchoring=false fixes it. cc Emilio (sorry!) - Is there a metabug we should file a bug and block against?

I can indeed reproduce the original issue in Fennec, but not in Fenix or Fenix nightly. It looks like it could be to do with the image cache being purged - Andrew, has the cache limit changed post-68?

Flags: needinfo?(jnicol)
Flags: needinfo?(emilio)
Flags: needinfo?(aosmond)

Hmm, is it? That's a bit surprising, but I guess it may make sense.

Is there any chance of doing a proper bisect? Looking at the JS code in the page, it does a bunch of stuff off scroll event listeners, which with scroll anchoring may trigger other scroll events.

Bug 1561450 comes to mind as something that could've fixed this as well.

Flags: needinfo?(emilio)

To clarify, the flickering that this bug was originally about is fixed in current Fenix. The scrolling issue is still present (and I think we should file a separate bug about it).

See Also: → 1586909

Ah, gotcha, hadn't seen comment 5. I filed bug 1586909 about the scrolling issue in particular.

No longer blocks: scroll-anchoring

Thanks Emilio!

I actually take back what I said in comment 6 and 8 about it being fixed in Fenix - I had webrender enabled. It does indeed seem to be fixed by webrender, but I can still reproduce with webrender disabled.

Flags: needinfo?(aosmond)

The scrolling issue should be fixed, fwiw.

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