Intent to Ship: Unprefixed Touch rotationAngle

54 views
Skip to first unread message

Mustaq Ahmed

unread,
May 28, 2015, 12:38:40 PM5/28/15
to blink-dev, Rick Byers

Contact emails

mus...@chromium.org


Spec

http://rawgit.com/w3c/touch-events/master/touchevents.html#touch-interface


Summary

Enable the unprefixed version of the touch rotation angle attribute in Touch Events spec extension. Touch.rotationAngle gives the orientation (clockwise in degrees) of the elliptical touch surface described by Touch.radiusX and Touch.radiusY.


Link to “Intent to Implement” blink-dev discussion

https://groups.google.com/a/chromium.org/forum/#!searchin/blink-dev/webkitrotationangle/blink-dev/ewIxA2P3bks/aClnxtRIXcUJ


Is this feature supported on all six Blink platforms (Windows, Mac, Linux, Chrome OS, Android, and Android WebView)?

Yes.


Demo link

https://plus.google.com/+RickByers/posts/EcxNyw5WHg8


Debuggability

Developers can easily check the attribute through devtools, as in the case for other Touch attributes.


Compatibility Risk

Low. The prefixed version of the attribute (Touch.webkitRotationAngle) is available since M39.


OWP launch tracking bug?

http://crbug.com/493199


Link to entry on the feature dashboard

N/A.


Rick Byers

unread,
May 28, 2015, 12:44:57 PM5/28/15
to Mustaq Ahmed, blink-dev
Agree we should unprefix Touch.webkitRotationAngle (which we have shipped for a long time).  Thanks!

Note that I screwed this up when I unprefixed radiusX/radiusY and force.  I thought there was no value in rotationAngle, but I was wrong (see my demo).

Rick

Chris Harrelson

unread,
May 28, 2015, 12:48:21 PM5/28/15
to Rick Byers, Mustaq Ahmed, blink-dev
I assume the unprefixed variant is identical in semantics?

Also, how about deprecating the old one? Is it UseCounted?

To unsubscribe from this group and stop receiving emails from it, send an email to blink-dev+...@chromium.org.

Mustaq Ahmed

unread,
May 28, 2015, 1:02:58 PM5/28/15
to Chris Harrelson, Rick Byers, blink-dev
Yes, the unprefixed attribute is identical to the prefixed one.

I will send an "intent to deprecate" in a few hours, for 4 prefixed Touch attributes (rotationAngle, radiusX, radiusY, force). They are all UseCounted, current stats: https://www.chromestatus.com/metrics/feature/popularity#PrefixedTouchRotationAngle

Mustaq

Chris Harrelson

unread,
May 28, 2015, 1:06:52 PM5/28/15
to Mustaq Ahmed, Rick Byers, blink-dev
Have you investigated whether it's appropriate to try to remove the prefixed one and replace with non-prefixed in one release? 0.02% is low.

Rick Byers

unread,
May 28, 2015, 1:15:22 PM5/28/15
to Chris Harrelson, Mustaq Ahmed, blink-dev
On Thu, May 28, 2015 at 1:06 PM, Chris Harrelson <chri...@chromium.org> wrote:
Have you investigated whether it's appropriate to try to remove the prefixed one and replace with non-prefixed in one release? 0.02% is low.

They're all at 0.03% - right on our line.  My opinion was that it wasn't worth the compat risk - might as well have at least one or two releases with a deprecation warning.   That said I'd be very surprised if anything actually broke in practice for any of these properties. rotationAngle in particular is rarely non-zero (Nexus10 is the only common device I'm aware of that supports it).  So if you'd prefer to bypass deprecation and go straight to removal (for just rotationAngle or even for the other properties too), that's OK with me.

Philip Jägenstedt

unread,
May 28, 2015, 2:56:24 PM5/28/15
to Mustaq Ahmed, blink-dev, Rick Byers
Obviously LGTM to ship Touch.rotationAngle!

Can someone check what the usage for webkitRadiusX, webkitRadiusY, webkitRotationAngle and webkitForce look like on Android?

I think these existed for a very long time prefixed only, so I would expect a lot of content to only use the prefixed variants. Use counters for the unprefixed variants don't help if people write `event.radiusX || event.webkitRadiusX` so probably the best way to figure this out is to analyze a random sample from httparchive.

Mustaq Ahmed

unread,
May 28, 2015, 4:57:49 PM5/28/15
to Philip Jägenstedt, blink-dev, Rick Byers
The usage percentages on Android are perhaps confidential, but I can assure you that they are "very low".

Mustaq

Mustaq Ahmed

unread,
May 28, 2015, 5:11:17 PM5/28/15
to Philip Jägenstedt, blink-dev, Rick Byers
Just sent a separate "intent to deprecate" mail, not sure if it was necessary at all. I will merge the two "intents" into a single patch if we have consensus here.

TAMURA, Kent

unread,
May 29, 2015, 4:05:09 AM5/29/15
to Mustaq Ahmed, blink-dev, Rick Byers
LGTM2.

--
TAMURA Kent
Software Engineer, Google


Philip Jägenstedt

unread,
May 29, 2015, 12:57:01 PM5/29/15
to TAMURA, Kent, Mustaq Ahmed, blink-dev, Rick Byers
I created an entry on the feature dashboard:

(Needs one more LGTM.)

Chris Harrelson

unread,
May 29, 2015, 1:04:19 PM5/29/15
to Mustaq Ahmed, Rick Byers, blink-dev
LGTM3.

Let's go with ship and deprecate as separate steps.

Jacob Rossi

unread,
Jun 2, 2015, 1:07:40 PM6/2/15
to Chris Harrelson, Mustaq Ahmed, Rick Byers, blink-dev

Have you seen any interest from other browsers in implementing this?  This isn’t on our roadmap at the moment and I hadn’t seen signs from Mozilla or Apple either.

 

-Jacob

Mustaq Ahmed

unread,
Jun 2, 2015, 2:40:19 PM6/2/15
to Jacob Rossi, Chris Harrelson, Rick Byers, blink-dev
WebKit has expressed interest in exposing basic radius: https://bugs.webkit.org/show_bug.cgi?id=133642. We haven't heard anything from other browsers.


Reply all
Reply to author
Forward
0 new messages