NEW 203681
Canvas layer not correct when -webkit-overflow-scrolling is set to touch on iOS 13 
https://bugs.webkit.org/show_bug.cgi?id=203681
Summary Canvas layer not correct when -webkit-overflow-scrolling is set to touch on i...
Yi Shen
Reported 2019-10-31 08:30:16 PDT
Created attachment 382463 [details] Demo to reproduce Hi, I'm one of the maintainer of Apache ECharts(incubating). It uses Canvas to draw charts. Recently a lot of our developers report to us, when running ECharts on iOS 13, Canvas in the container will cover the tooltip, which is a DIV and has larger z-index compared to canvas. Apparently they are having wrong layers. We found it only happens when -webkit-overflow-scrolling of top container is set to touch It seems this property has been eliminated since iOS 13 https://developer.apple.com/documentation/safari_release_notes/safari_13_release_notes index.html in the attachment is a minimal reproducible page. Step to reproduce: Open the index.html in attachment on iOS 13. Expected result: Black DIV should be on top of the red triangle, which is drawn by Canvas. Actual result: Red triangle is on top of the black DIV.
Attachments
Demo to reproduce (71.52 KB, application/zip)
2019-10-31 08:30 PDT, Yi Shen 		no flags
Details
View All Add attachment proposed patch, testcase, etc.
Radar WebKit Bug Importer
Comment 1 2019-10-31 23:38:45 PDT
<rdar://problem/56808427>
Simon Fraser (smfr)
Comment 2 2019-11-01 09:16:38 PDT
Are you seeing this on iPhone or iPad? The z-ordering side effects of -webkit-overflow-scrolling: touch differ (because iPad gets desktop content).
Yi Shen
Comment 3 2019-11-01 09:19:13 PDT
Hi, we were testing it on iPhone. Haven't tested iPad.
Simon Fraser (smfr)
Comment 4 2019-11-01 09:27:24 PDT
There should be no behavior change between iOS 12 and 13 on iPhone.
Note You need to log in before you can comment on or make changes to this bug.