1186765 - Scrolling is janky on specific page when zoomed in

Status: RESOLVED WORKSFORME

(Firefox for Android Graveyard :: Toolbar, defect)

Description

[Swarnava Sengupta (:Swarnava)]

Go to: http://gerrit.aospal.com/#/c/1155/4/packages/SystemUI/src/com/android/systemui/BatteryMeterView.java: 

try to zoom in/out and scroll down/up

Result: 

the browser become unresponsive sometime.

Comment 1

[u279076]

Reproduced with today's Fennec Nightly on a Sony Xperia Z3 running Android 5.0.2. Chrome 43 seems to perform much better although I still notice some slight jank.

Comment 2

[Michael Comella (:mcomella) [needinfo or I won't see it]]

Snorp, what can we do about this?

Comment 3

[James Willcox (:snorp) ([e-mail]) (he/him)]

This another instance of synchronous subframe scrolling biting us.

Comment 4

[Kartikaya Gupta (email:[e-mail])]

I think the URL is invalid now, it goes to some hosting company's website instead of (presumably) a java code file.

Comment 5

[Swarnava Sengupta (:Swarnava)]

hmm, here is a new  url http://review.cyanogenmod.org/#/c/122385/1/doze/src/com/cyanogenmod/settings/device/MotoDozeService.java

you can check this on any gerrit code review repo

Comment 6

[James Willcox (:snorp) ([e-mail]) (he/him)]

This is improved now with APZ, but still seems to be pretty janky -- especially when you are zoomed in.

Comment 7

[Kartikaya Gupta (email:[e-mail])]

Agreed, when zoomed it appears to jank when a repaint comes in, or something. Not entirely sure, we will need to investigate. I'm marking this as blocking APZ riding the trains on Fennec just so we make sure we look into what's going on before we ship it.

Comment 8

[Kartikaya Gupta (email:[e-mail])]

Bug 1241917 will probably help here.

Comment 9

[Kartikaya Gupta (email:[e-mail])]

I don't see a lot of jank when APZ-scrolling on this anymore. I do see other issues however. It looks like there are actually two scrolling subframes which are "linked", so scrolling one will scroll the other. This "linking" is a scroll-linked effect which is laggy with APZ and makes it look janky. We have bug 1246290 as a backup plan for that issue, if it becomes too bad.

On top of that, this is a CodeMirror code window, which has it's own set of problems (bug 1249090) with respect to checkerboarding. It also had jankiness issues (bug 1239615, fixed by bug 1243589). When zooming in it looks like there's still some checkerboard-like behaviour going on, which we can track with bug 1249090.

Basically, the jank seems to be fixed, so I'm going to close this bug. If there's more issues that are not covered by the above-referenced bugs, please file a new bug. Thanks!