Does not use passive listeners to improve scrolling performance

[mauriciolauffer]

OpenUI5 version: all

Browser/version (+device/version): Google Chrome

URL (minimal example if possible):
https://openui5.hana.ondemand.com/test-resources/sap/m/demokit/master-detail/webapp/test/mockServer.html

Steps to reproduce the problem:

1. Open Master-Detail Template App in Google Chrome
2. Open Developer Tools (F12)
3. Select Audits tab
4. Run Audits
5. Check results' Best Practices section

What is the expected result?
Message "Does not use passive listeners to improve scrolling performance" should not be listed.

What happens instead?
Message "Does not use passive listeners to improve scrolling performance" is listed.

Any other information? (attach screenshot if possible)

https://developers.google.com/web/tools/lighthouse/audits/passive-event-listeners

[Shtilianova]

Hello @mauriciolauffer ,
Thank you for sharing this finding. I've created an internal incident 1880716535. The status of the issue will be updated here in GitHub.
Regards, Diana

[matz3]

@mauriciolauffer In the example I can see two different places where the warning is triggered from.
One in the general event handler within sap/ui/core/UIArea and one within sap/m/SearchField.

The one in the SearchField can't be changed as the handler calls "preventDefault" (see

openui5/src/sap.m/src/sap/m/SearchField.js

Line 400 in b280b11

oEvent.preventDefault();

).

The one in UIArea is using jQuery, which is currently not even capable of using "passive:true" (see jquery/jquery#2871). And even when we would switch to native events (which doesn't seem to be straight-forward), we would need to know whether any of the event handlers requires to call "preventDefault".

So I don't see any easy solution to this. Closing this as "wontfix" but I'm open for any other ideas or feedback. Maybe I missed something here.