1383531 - The Preferences tab opening tab animation is janky

Status: RESOLVED WORKSFORME

(Firefox :: Settings UI, defect, P3)

Description

[Vlad Filippov (:vladikoff)]

Attachment: about:preference animation

Opening the about:preferences from hamburger menu or old new tab "Preferences" button lags the tab animation. Please see attached .gif for details. Maybe it has something to do with the changing <title> of the tab (From about:preferences to "Preferences")?



Mike, could you please help triage this?  


Details:
I have Stylo / Servo pref enabled.
56.0a1 (2017-07-23) (64-bit)

Comment 1

[Mike Conley (:mconley) (:⚙️)]

Thanks!

Comment 2

[Mike Conley (:mconley) (:⚙️)]

I'll note that the old Preferences UI (toggle-able with browser.preferences.useOldOrganization) does not have so much jank.

Hey timdream, is this something your team would have cycles to look at?

Comment 3

[Tim Guan-tin Chien [:timdream] (please needinfo)]

This is pretty sad. Given that Preferences lives in the Chrome process, it will block the tab animation when itself blocks. I don't think there is a lot other things to do in this bug -- we should address bug 1382170 and it's dependency and see if tab animation become smoother.

(I see paint flash when tab animates; I assume that means to don't use OMTA there.)

Comment 4

[Tim Guan-tin Chien [:timdream] (please needinfo)]

This is likely fixed already. Let me verify.

Comment 5

[Tim Guan-tin Chien [:timdream] (please needinfo)]

I can still see that with today's artifect build & clean profile. Let me test again once bug 1375870 lands.

Comment 6

[Tim Guan-tin Chien [:timdream] (please needinfo)]

I am fairing confident the only way to fix this is to fix bug 1375978.

Comment 7

[Tim Guan-tin Chien [:timdream] (please needinfo)]

(In reply to Tim Guan-tin Chien [:timdream] (please needinfo) from comment #6)
> I am fairing confident the only way to fix this is to fix bug 1375978.

Been playing around this today and compare the new pref with the old one.

The good news is that the time it takes in bug 1375978 would greatly reduce if you open the Preferences for the second time. However, it still takes a non-trivial time to do it.

Another thing is that the function documented in bug 1389550 takes a longer on new pref than old pref; presumably, because the DOM is more complex here.

We could further remove the jank by moving appUpdater away from DOMContentLoaded, but that won't save a lot.

The bottom line is we cannot completely remove the jank (which is actually also present on old pref too) unless we employ the logic like bug 1384830 to completely async-ify init_all(). I am not sure if that's worth doing.

Or, we could delay init_all() until the completion of tab animation -- the timing can be guessed by looking checking the value returned by performance.now() -- but I don't think it's a better experience. I actually can't reproduce this bug on my regular profile because DOMContentLoaded always happens after tab animation; I, unfortunately, don't understand XUL and browser enough to tell what happens before DOMContentLoaded that didn't block the tab animation (and what would).

I will look at bug 1389550 for now.

Comment 8

[Marius Coman [:mcoman], Ecosystem QA]

User Agent 	Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:57.0) Gecko/20100101 Firefox/57.0 
Firefox: 57.0a1, Build ID 	20170822100529

I have tested this issue on latest Firefox release (55.0.2) and latest Nightly (57.0a1) build. 
I have managed to reproduce it using the steps provided in the description. As I was searching for a regression window I found out that this issue is not a regression because this behaviour could be observed since build 20140518030203, and when i went further, to the build 20140517030204, "about:preferences" opens in a dialog box and not in a tab.

Considering this I will remove the regressionwindow-wanted keyword.

Comment 10

[Tim Guan-tin Chien [:timdream] (please needinfo)]

I can no longer observe this bug on Nightly.

Comment 11

[Marco Castelluccio [:marco]]

It still feels slow to me, although much faster than before.
One source of perceived jankiness is the fact that the tab title starts as "about:preferences" and quickly turns to "Preferences".

Comment 12

[Florian Quèze [:florian]]

(In reply to Marco Castelluccio [:marco] from comment #11)

> One source of perceived jankiness is the fact that the tab title starts as
> "about:preferences" and quickly turns to "Preferences".

The patch in bug 1362774 would fix that, but it's unclear at this point if we can still get it landed in 57.