[pointerevents] Need clarification with `MouseEvent::mouseleave` (#624)

yezhizhen has just created a new issue for https://github.com/w3c/pointerevents:

== Need clarification with `MouseEvent::mouseleave` ==
It would be nice to clarify in current [spec](https://w3c.github.io/uievents/#event-type-mouseleave) what happens when

1. mouse move out of viewport
2. the mouse is static within the viewport, but swap to another window with keyboard shortcut.

For both case 1 & 2, I see 
- FireFox not firing `mouseleave` event.
- Chromium fires `mouseleave` event

But for [mouseout](https://w3c.github.io/uievents/#event-type-mouseout) event, the behaviour is consistent as spec is quite clear.

Please view or discuss this issue at https://github.com/w3c/pointerevents/issues/624 using your GitHub account


-- 
Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config

Received on Monday, 12 January 2026 22:04:41 UTC