Make mouseenter/mouseleave behavior optional

In the compatibility with mouse events section [1], the pointer events
draft dictates when mouseenter and mouseleave events should be
dispatched.  However, I believe today only IE and Opera support these
events [2].  Can we add an 'if supported by the UA' to the wording to
make it clear that some UAs won't dispatch these events?    Of course
the wording around  mouseover/mouseout (which are universally
supported) should not change.

Bigger picture, I'm curious to hear why 'pointerenter' and
'pointerleave' weren't included in the pointer event design for IE.
I've heard some web developers say that they prefer the enter/leave
semantics (non-bubbling) to the over/out semantics.



Received on Tuesday, 20 November 2012 18:24:20 UTC