1402458 - When clicking "show sidebars", resulting in not smooth page content shifting then resizing

Status: NEW

(Firefox :: General, defect, P3)

Description

[Mohammad Maruf Rahman]

Attachment: transition of 'activity stream' is not smooth

Build ID   : 20170921100141
User Agent : Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:57.0) Gecko/20100101 
             Firefox/57.0
OS         : Windows 7, 64 Bit!

Steps to Reproduce : 
          
             1. Open Firefox Nightly and go to about:newtab
             2. Click the 'show sidebars' button 
             
Actual result      :

             If you click the 'show sidebars' button, the activity stream portion 
             gets shifted little-bite towards the right side and if you close 
             sidebars, then the activity stream backs to its original space. But 
             this transition of 'activity stream' from one place to another is 
             not smooth. It look likes, the the activity stream goes bit ahead 
             of its desired position and then comes back to its desired place, 
             which is not very convincing looking.    

Expected result    : 
  
             The transition of 'activity stream' from one place to another 
             should be smooth.

Comment 1

[Ed Lee :Mardak]

How is this different from showing the sidebar for any other page? E.g., on this bugzilla page, opening pushes the content to the right then resizes.

Comment 2

[Valentina Claudia Ona]

Sorry, I added the wrong component

Comment 3

[Florian Quèze [:florian]]

This is ugly indeed. What happens is that when we open or close the sidebar it pushes the browser horizontally. The browser gets painted in a new position, but without the page being updated. Then a couple frames later (2 in a screen recording I just did), the page gets re-painted again at the right dimension, giving the impression that everything flickers on the page.

I wonder if there's a way to prevent the browser from being repainted before the page itself has repainted.

Putting back the photon-performance whiteboard for now (we removed it because when looking at the video in attachment 8911329 [details] it seemed to be an activity stream bug).

Comment 6

[Albert Scheiner [:alberts]]

Is there a proton equivalent to [reserve-photon-performance] ? The sidebar would be nicer to use, if it would feel more integral.