218860 2020-11-12 11:09:54 -0800 Events delivered when all event listeners in the ancestor chain are passive should be cancelable=false 2022-09-12 14:40:54 -0700 1 1 1 Unclassified WebKit DOM Safari Technology Preview Unspecified Unspecified NEW https://bugs.webkit.org/show_bug.cgi?id=218861 BrowserCompat, InRadar, WPTImpact P2 Normal --- 1 simon.fraser webkit-unassigned ahmad.saleem792 cdumez emilio rniwa simon.fraser webkit-bug-importer oldest_to_newest 1706931 0 simon.fraser 2020-11-12 11:09:54 -0800 Wheel/touch events delivered to passive event listeners should have their `cancelable` property set to false. 1706932 1 webkit-bug-importer 2020-11-12 11:10:19 -0800 <rdar://problem/71334287> 1706935 2 simon.fraser 2020-11-12 11:11:41 -0800 Note that Chrome does this, Gecko does not. 1707029 3 emilio 2020-11-12 14:42:20 -0800 Should the cancelability of the event really depend on the listener? What do we do for other events, or if there are both passive and non-passive listeners? 1707040 4 cdumez 2020-11-12 14:56:52 -0800 https://w3c.github.io/touch-events/#cancelability """ In particular, a user agent may generate only uncancelable touch events when it observes that there are no non-passive listeners for the event. """ 1707041 5 cdumez 2020-11-12 14:58:23 -0800 Corresponding spec for Wheel events: https://w3c.github.io/uievents/#cancelability-of-wheel-events 1707043 6 simon.fraser 2020-11-12 15:08:08 -0800 I filed https://github.com/w3c/uievents/issues/282 on clarifying this for wheel events. 1707054 7 simon.fraser 2020-11-12 16:09:32 -0800 Looking at blink code, it appears (for touch events at least) to set the event to non-cancelable if all the event listeners in the ancestor chain of the target element have passive listeners. My testing suggests that the same is true for wheel event listeners. 1707117 8 rniwa 2020-11-12 21:33:15 -0800 Changing the event type based on the type of event listeners seem very strange & weird. 1711847 9 simon.fraser 2020-12-03 15:05:47 -0800 We'll do this now if the event starts in the passive event listener region. 1898010 10 ahmad.saleem792 2022-09-12 14:40:54 -0700 Safari is failing quite a few tests: https://wpt.fyi/results/dom/events/non-cancelable-when-passive?label=master&label=experimental&aligned&view=subtest&q=non-cancelable