1373662 - [Form Autofill] Dropdown UI flickers when first time opening form autofill popup after browser launched

Status: NEW

(Toolkit :: Form Autofill, enhancement, P3)

Description

[Ray Lin[:ralin]]

This issue occurs only for the first time opening form autofill popup. 
The appearance of popup transforms from normal autocomplete layout to autofill's layout in a very short time, and it's observable by naked eyes. 
I think it's because we insert our stylesheet at "FormAutoComplete:MaybeOpenPopup" and that might too late for our binding being attached prior to showing up. 
Also, this issue might cause some of the test cases unstable as we could not tell which binding is actually attached right after popup opened.

Perhaps, we should consider inserting stylesheet a bit earlier to mitigate this issue? maybe when input being "focusin"?  

* This issue barely happens on Windows.

Comment 1

[Ray Lin[:ralin]]

Attachment: Bug 1373662 - An experiment to test whether formautofill binding has actually attached right after the popup is opened.

Review commit: https://reviewboard.mozilla.org/r/150066/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/150066/

Comment 2

[Ray Lin[:ralin]]

Added a browser chrome test to validate this issue, please see the attachment 8878737 [details] and try result: https://treeherder.mozilla.org/#/jobs?repo=try&revision=a3338ac1c9dafe5bdd4e6cfa33bff7686efcaf22

The experiment is basically to check the @actualtype of the list items, that @actualtype will only be set to "formautofill" in our binding's constructor. If actual value got "" rather than "formautofill", then we can say our binding hasn't really attached yet at that point.

Comment 4

[Timea Cernea [:tbabos][inactive]]

The flicker is slightly reproducible on Windows 7/10 but I am more concerned about MacOS because it displays a scrollable dropdown even if there is only 1 CC suggestion displayed, check it out here: https://streamable.com/ek6sos