Bug 257119

Summary: onpointerdown event not firing on position: fixed elements at certain scroll position
Product: WebKit Reporter: shuangqiu2
Component: UI EventsAssignee: Nobody <webkit-unassigned>
Status: NEW    
Severity: Normal CC: a_protyasha, simon.fraser, webkit-bug-importer, wenson_hsieh
Priority: P2 Keywords: InRadar
Version: Safari 16   
Hardware: iPhone / iPad   
OS: Other   
Attachments:
Description Flags
screen recording of the reproduction none

shuangqiu2
Reported 2023-05-22 04:52:04 PDT
Created attachment 466446 [details] screen recording of the reproduction Tapping an element doesn't fire the pointer down event in this setup: 1. The button itself has "position: fixed" set 2. The ancestors have "height: 100%" set 3. The page has a viewport meta tag set (seems to happen only on a small-ish viewport width. If I set the width to 1200, it works testing on an ipad mini) You could find the reproduction sandbox here: https://codesandbox.io/s/young-moon-4uhybj?file=/public/index.html. Attached is a video of my reproduction on an ipad mini with iPadOS 16.3.1: the button has an onpointerdown callback that will update the number on the button. When I scroll to the bottom and scroll back up a bit, tapping doesn't update the value until I scroll to a different position. It works if I change one of the conditions above, or if I use onclick instead.
Attachments
screen recording of the reproduction (533.36 KB, video/quicktime)
2023-05-22 04:52 PDT, shuangqiu2 		no flags
Details
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Radar WebKit Bug Importer
Comment 1 2023-05-22 12:09:46 PDT
<rdar://problem/109671417>
shuangqiu2
Comment 2 2023-05-23 06:28:57 PDT
> 2. The ancestors have "height: 100%" set Just tested with the sandbox again, the same bug persists with the 100% height removed as well.
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