Bug 552994

Summary: [CSS][Dark] Delay in background rendering
Product: [Eclipse Project] Platform Reporter: Karsten Thoms <karsten.thoms>
Component: UIAssignee: Platform-UI-Inbox <Platform-UI-Inbox>
Status: NEW --- QA Contact:
Severity: normal    
Priority: P3 CC: Lars.Vogel
Version: 4.14Keywords: helpwanted
Target Milestone: ---   
Hardware: All   
OS: Mac OS X   
Whiteboard:
Attachments:
Description Flags
Screen Recording none

Description Karsten Thoms CLA 2019-11-13 07:58:00 EST
Created attachment 280623 [details]
Screen Recording

In the breadcrump menu there is a recognizable delay of styling the background color, see attached screencast. At first a different background is applied and then with a delay a darker background.
I recognized while debugging that the CSS engine multiple times sets the background color while applying styling with the CSS engine.
Comment 1 Lars Vogel CLA 2019-11-13 08:01:06 EST
Reducing the number of CSS calls of the same widget will be a huge value.
Comment 2 Lars Vogel CLA 2020-05-25 04:47:07 EDT
Karsten, is this still the case on the Mac? I cannot see a delay on Linux in the most recent release.
Comment 3 Karsten Thoms CLA 2020-06-28 18:37:06 EDT
I did not see this with the breadcrumps now. But in general I do observe a kind of flickering sometimes, e.g. in tab folders.

The problem I see here is that if multiple styles are assigned to an element, this happens synchronously. So when one style is overridden by another, the first is applied and shortly after the second one.

I think we need to come to a more atomic why to apply styles when theming elements.