Re: [touch-events] Spec should be explicit on whether the of elements in TouchLists is relevant (#13)

I don't think we'd ever want to leave gaps no.  We should test to see if
all existing implementations maintain order in the simple case of no
touchstart/touchend.  If so, that might at least be worth a note - with a
warning saying you shouldn't rely on it.  The fact that a site was relying
on this caught us by surprise (though it's of course not surprising in
retrospect) - seems like the sort of thing worth documenting somewhere
unless at least one major implementation wants to take the hit of
intentionally shuffling the ordering.

On Fri, May 8, 2015 at 1:22 PM, Scott González <notifications@github.com>
wrote:

> I also don't think we should specify an order for existing touches.
>
> On Fri, May 8, 2015 at 1:19 PM, Patrick H. Lauke <notifications@github.com
> >
> wrote:
>
>
> > My gut feeling is that no, the spec should clarify that the order/index
> > may change and that authors should rely only on the id.
> >
> > I've not had a chance to test it, but: if i put 3 fingers on the screen
> in
> > sequence, and then remove the second one, is the expectation from devs
> that
> > you'd still see a touch point on 0 and 2 in the touchlist? what would
> index
> > 1 contain, then? null?
> >
> > p
> > --
> > Patrick H. Lauke
> >
> >
> >
> > > On 8 May 2015, at 16:59, Rick Byers <notifications@github.com> wrote:
> > >
> > > I believe the order of TouchList entries is supposed to be irrelevant.
> > However some sites (eg. this one) make assumptions about a given touch ID
> > remaining at the same index in the TouchList from event to event. There
> was
> > a special case in blink where we weren't preserving order, and we're
> going
> > to fix this.
> > >
> > > In what cases is the ordering preserved in existing browsers? Should we
> > just make that part of the spec so that sites can depend on it? It can
> > certainly simplify some coding patterns.
> > >
> > > —
> > > Reply to this email directly or view it on GitHub.
> > >
> >
> > —
> > Reply to this email directly or view it on GitHub
> > <https://github.com/w3c/touch-events/issues/13#issuecomment-100302942>.
>
> >
>
> —
> Reply to this email directly or view it on GitHub
> <https://github.com/w3c/touch-events/issues/13#issuecomment-100303366>.
>


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