Evolving TouchEvents within the W3C

Changing subject to reflect the much broader scope (which frankly has
probably deserved a thread on this list for while <grin> - we talked about
it in a recent PEWG telcon, but not on the list).

+Anne since we had some good discussions about this at BlinkOn

On Fri, Jun 6, 2014 at 9:02 AM, Sangwhan Moon <smoon@opera.com> wrote:

> On Fri, Jun 6, 2014 at 12:37 PM, Rick Byers <rbyers@google.com> wrote:
>
>> Thanks Matt.  I've made the following changes and pushed an update here
>> <https://dvcs.w3.org/hg/webevents/raw-file/tip/touchevents.html>:
>>
>>    - added rotationAngle back, and updated text for radiusX to indicate
>>    that it's along the axis specified by rotationAngle, while radiusY is
>>    perpendicular to that axis.
>>    - changed unsupported radius value from 1 to 0
>>    - changed radius units from long to float (matching proposed
>>    screenX/screenY changes in the v1-errata spec)
>>    - updated document date
>>    - added myself as an editor (I assume since these changes are
>>    non-trivial that's the right procedure, let me know otherwise).
>>
>> Any feedback?
>>
>
> Regarding rotation and radius, while I wasn't a huge fan myself, the
> biggest reason for dropping those properties was to ensure interoperability
> across implementations. Considering the fact that:
>
> 1. WebKit will most likely not change.
> 2. Gecko's values are dummies values, which can be removed.
> 3. Presto will not change.
> 4. IE will most likely not implement.
>
> Unless Mozilla is actually intending to implement it with real values, I
> really think existing implementations should drop support for radius and
> angle and move that over to the scope of the next iteration of
> PointerEvents rather than try to completely scatter interoperability
> around. Chromium being the only implementation of a already dead spec that
> will break interoperability doesn't sound like a good direction to drive
> towards.
>
> So the only implementation that has even a remote possibility of getting
> these changes implemented is Gecko, and unless Mozilla will implement a
> patch to a dead spec I don't think we should do this - I would actually
> vote on trying to *remove* these properties on existing implementations and
> move it into the scope of PE where we can get at least one more
> implementation to ship. Changing it and making Chromium the only compliant
> implementation doesn't seem right.
>
> That said, I probably won't (or more of, can't) proactively try to remove
> it on Chromium upstream. (Although there is a chance that I might suggest
> removal within the scope of Opera.)
>

I understand your concern.  We're in a tough place here with evolving input
in blink.  The top priority for blink right now is to make our
implementation of the web platform on mobile more competitive with native
mobile platforms.  This involves urgently improving input APIs.
 Radius/rotation definitely aren't important here, but I think it's most
valuable to have this discussion on the abstract principle since the
argument also applies to things that are important.  Interoperability here
is definitely key, but unfortunately the #1 browser on mobile isn't
interested in implementing pointer PointerEvents, so for maximum
interoperability we feel we must also work to improve TouchEvents (and
we're having some limited success engaging with Apple on this front -
eg. fractional
co-ordinates <https://bugs.webkit.org/show_bug.cgi?id=133180> [1]).

I don't think the strategies are mutually exclusive.  I intend to continue
to work in the PEWG, and hopefully someday we'll have an API that all major
browsers implement (or at a minimum, have the key pieces such that
high-quality JavaScript implementations are possible).

But in parallel we feel we absolutely must continue to incrementally evolve
TouchEvents in blink.  There are lots of other parts of the web we'd throw
out and replace with something brand new if we could, but that's just not
how evolution of the web normally works.  Our deepest hope is that at least
some of the other members of the TECG will be interested in collaborating
with us on improving TouchEvents.  But if this doesn't align with the
strategic priorities for Opera, Firefox or IE then I understand, and I'm
sure we'll still be able to collaborate on other places where input
improvements are needed (I'm quite excited by the long list of ideas we
came up with for the upcoming face-to-face).

Rick

[1] https://bugs.webkit.org/show_bug.cgi?id=133180

-- 
> Sangwhan Moon [Opera Software ASA]
> Software Engineer | Tokyo, Japan
>