1212322 - Set the scrollbar fade duration to 0

Status: RESOLVED FIXED

(Firefox OS Graveyard :: General, defect)

Description

[vnicolas]

I noticed that the scrollbar is generating a lot of frames in the profiler. Changing its animation duration to 0 reduce that to 2 frames (one when it appears, one when it dissapears). And tbh the difference is hardly noticeable...

Comment 1

[vnicolas]

Attachment: scrollbar.fade.duration.0.patch

Comment 2

[[:fabrice] Fabrice Desré]

How much/what do we gain from that concretely? I kind of like our current scrollbars...

Comment 3

[[:fabrice] Fabrice Desré]

well, they should not be xul elements and move into the gfx stack instead but that's another issue!

Comment 4

[vnicolas]

(In reply to [:fabrice] Fabrice Desré from comment #2)
> How much/what do we gain from that concretely? I kind of like our current
> scrollbars...

In the profiler I see 9 refreshes generated for scrollbars.

Each of them  have a very small restyle (under 1ms), a very small rasterization (under 1ms) but an expensive display list building (11 to 13ms).

With the patch I see 2 refreshes for scrollbars. Values are the same.

So it may save some load times. It is hard to predict which metrics will be affected exactly has it depends on the app logic.
I also believe that it will save some battery.

Comment 5

[vnicolas]

(In reply to [:fabrice] Fabrice Desré from comment #3)
> well, they should not be xul elements and move into the gfx stack instead
> but that's another issue!

That's an old debate but as moving it to gfx should shape the display list calculation I tend to think that killing xul will make it cheaper to have a prettier effect. But yeah that's another issue.

Comment 6

[[:fabrice] Fabrice Desré]

Comment on attachment 8670776 [details] [diff] [review]
scrollbar.fade.duration.0.patch

Review of attachment 8670776 [details] [diff] [review]:
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Did you try to just use a shorter duration while not using 0? like 100 or 50?

Comment 7

[vnicolas]

I tried but this is very hard to see an animation at all.

Comment 8

[Pulsebot]

https://hg.mozilla.org/integration/b2g-inbound/rev/43350e8da63e

Comment 9

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/43350e8da63e