Re: TouchEvent sub-pixel precision

On Wed, May 21, 2014 at 9:44 AM, Simon Pieters <simonp@opera.com> wrote:

> On Tue, 20 May 2014 21:09:43 +0900, Sangwhan Moon <smoon@opera.com> wrote:
>
>  While it makes sense, the IDL as it looks like today was mostly because of
>> interoperability with the existing implementations. In practice, this will
>> make very little difference in the code that makes use of the events so
>> it's probably very safe to make the changes. (I can't think of any cases
>> this would break content from the back of my head, at least)
>>
>
> See https://www.w3.org/Bugs/Public/show_bug.cgi?id=24159#c2 for
> MouseEvents compat.


Note that even though there were some edge cases like this, IE still
unconditionally supplies fractional mouse co-ordinates in standards mode:
http://blogs.msdn.com/b/ie/archive/2012/02/17/sub-pixel-rendering-and-the-css-object-model.aspx.
 So I'm optimistic doing the same for TouchEvent will be relatively safe.

 I'm not sure if we can get all implementations to agree on this (I know one
>> that probably won't change, which is why we had to pull some of the stuff
>> out to the extensions note..) - and sadly I don't think we'll ever
>> implement fractional coordinates on Presto. Will Gecko adopt these changes
>> as well? (Opera 20+ sadly does not count as a independent implementation,
>> afaik - if Blink is the only implementation that is intending to implement
>> the change - personal opinion is to keep it as is, even if it's not very
>> pretty)
>>
>
> WebKit recently implemented sub-pixel return values for some things, I'm
> not sure if it included TouchEvents or not.
>
> As Rick says in the bug referenced above, we will probably get a better
> understanding of the Web compat situation here soon from WebKit and Blink
> trying it out.


>
> --
> Simon Pieters
> Opera Software
>