915474 - sticky position layers "flicker" while scrolling on Android

Status: RESOLVED WORKSFORME

(Core :: Layout, defect)

Description

[Corey Ford [:coyotebush]]

(As I mentioned in bug 897105 comment 47 and comment 55:)

When scrolling a page with sticky elements on Android (with the patches from bug 897105), the sticky elements appear to "flicker" on what appears to be each content update.

I'm guessing this is because the asynchronous (AsyncCompositionManager::AlignFixedAndStickyLayers) and synchronous (StickyScrollContainer::ScrollPositionDidChange) scrolling code for sticky positioning are not completely in sync with each other. I've seen logging output to suggest that ScrollPositionDidChange gets called several times with slightly different scroll positions each time this happens.

Comment 1

[Corey Ford [:coyotebush]]

Attachment: sticky-flicker.zip

Some video frames of interest while scrolling the html5rocks demo page on a Nexus 4 with Android 4.3. Note that often part of the element appears to move up; when scrolling up, it usually appears to flicker down.

Comment 2

[Corey Ford [:coyotebush]]

Looks okay to me now, on the same hardware with Android 4.4.2. I don't have other devices handy to test on, unfortunately.

Comment 3

[Kazumasa Hasegawa (Kazz)]

Me too.
With Android 4.1.2

Comment 4

[Corey Ford [:coyotebush]]

Yeah, Release still shows the problem on my phone but Beta doesn't, so it must have been fixed by some other work during 27.