RE: Pointer cancel event dispatching

Hi Nick,

The case you call out is possible and OK. The Pointer Events spec does not define the triggers for behaviors like panning. So such a "touch action" could kick in at any time (even after move events have fired).  The spec text you link to is saying that, if you have already fired pointerdown and are now about to perform a touch action then you must fire pointercancel. In other words, we want to make sure that if the page sees a pointerdown, then it is guaranteed to see either a pointerup or a pointercancel.

-Jacob

From: Nikolay Lebedev [mailto:nicklebedev37@gmail.com]
Sent: Tuesday, February 4, 2014 4:58 AM
To: public-pointer-events@w3.org
Subject: Pointer cancel event dispatching

Hello,

may i ask a question about pointer cancel event dispatching:
Is it proper spec behavior If the browser would dispatch the following sequence of events:
[pointerdown, pointermove (a few times), pointercancel] in the following case: user starts panning a scrollable div with the touch-action value = auto ?

I'm not an expert on the dom/events spec stuff but when i firstly looked at the section [1] i misintepreted it and understood that only pointerdown/pointercancel events are allowed but not the pointermove for the case described above.

[1] https://dvcs.w3.org/hg/pointerevents/raw-file/tip/pointerEvents.html#the-touch-action-css-property

Thanks,
Nick