- From: Arthur Barstow <art.barstow@nokia.com>
- Date: Thu, 05 May 2011 08:21:10 -0400
- To: ext Matt Brubeck <mbrubeck@mozilla.com>, "public-webevents@w3.org" <public-webevents@w3.org>
All - please send feedback on Matt's questions i.e should the spec say
something here and if so, what should it say?
Matt - is there some related work or precedences we can
use/leverage/consider?
(Note to reader: the examples below reflect earlier versions of the spec
so if you are referencing the latest spec, you need to
s/identifiedPoint/identifiedTouches/).
On Apr/26/2011 1:39 PM, ext Matt Brubeck wrote:
> Should the Touch Events standard specify whether certain operations
> return the same object?
>
>
> Example 1: Should changedTouches and targetTouches refer to the same
> objects as the "touches" attribute for the same event?
>
> window.addEventListener("touchstart", function(e) {
> var changedTouch = e.changedTouches[0];
> var id = changedTouch.identifier;
>
> var touch = e.touches.identifiedPoint(id);
> var targetTouch = e.targetTouches.identifiedPoint(id);
>
> // Should these be true?
> assert(touch == changedTouch);
> assert(touch == targetTouch);
> });
>
>
> Example 2: Should different touch events refer to the same objects?
>
> window.addEventListener("touchstart", function(e0) {
> var touch0 = e0.touches[0];
> var id = touch.identifier;
>
> window.addEventListener("touchmove", function(e1) {
> var touch1 = e1.touches.identifiedPoint(id);
> assert(touch0 == touch1); // Should this be true?
> });
> });
>
>
> Leaving these implementation-defined might lead to content depending
> on one behavior, and breaking if the implementation changes. For a
> similar example, see:
> http://www.quirksmode.org/blog/archives/2010/02/persistent_touc.html
>
Received on Thursday, 5 May 2011 12:21:41 UTC