Re: [compositing] isolation property should be renamed

On Dec 4, 2014, at 12:39 PM, Erik Dahlström <ed@opera.com> wrote:

> On Thu, 04 Dec 2014 03:54:19 +0100, Rik Cabanier <cabanier@gmail.com> wrote:
> 
>> On Tue, Dec 2, 2014 at 11:24 AM, Elliott Sprehn <esprehn@gmail.com> wrote:
>> 
>>> If all the isolation property does is create a stacking context [1][2]
>>> then it seems like it should be called stacking-context: true to reveal
>>> it's purpose,
>>> 
>> 
>> Its purpose is not to create stacking context. It's designed to limit the
>> backdrop for its children with blending.
>> The fact that the spec says to do this using a stacking context, is for
>> implementors; not authors.
>> 
>> As Erik Dahlström noted, this property also applies to SVG which has no
>> stacking contexts. [1]
>> 
>> 
>>> otherwise we're just going to have blog posts about the "secret css hacks"
>>> to create stacking contexts using isolation: isolate as stacking contexts
>>> have all kinds of other side effects.
>>> 
>> 
>> How would this be different from "will-change: transform;"?
>> That creates a stacking context with the same side effects.
>> 
>> 
>>> The property also does not seem to be specific to blending, and the
>>> isolation naming is confusing given that there's talk of layout/style
>>> isolation, bidi isolation, and now blend isolation.
>>> 
>> 
>> It's meant to be used with blending and filters but as with many other
>> properties, it has side effects.
>> 
>> The next level of the spec will also reintroduce support for non-isolated
>> blending. Since this is expensive, authors will be able to opt into this
>> with this same property. Non-isolated blending will not introduce a
>> stacking context.
>> 
>> I agree that the name is somewhat confusing. We (= mailing list + css
>> group) went over different options a couple of years ago and this was the
>> one that we eventually settled on.
>> 
>> 1:
>> https://groups.google.com/a/chromium.org/d/msg/blink-dev/WoLwgoPB-GE/LITzZ2ifVVsJ
> 
> Was having a 'blend-' prefix ever discussed (as in: blend-isolation)? I couldn't find any mentions of it when searching through the w3 mailinglists.
> 
> Would 'blend-isolation' be an acceptable new name?

‘isolation' will likely isolate for compositing as well. Compositing is not part of level 1 but will be added into future specs eventually. This is one reason why we decided to have the mix- prefix for blending. 

I agree with Rik here that the purpose of 'isolation' is not related to having a stacking context. It may cause the creation of a stacking context just like filter, transform, opacity and many other properties may do.

As a note: We have two more implementations beside Blink which support the ‘isolation’ property. One (Safari/WebKit) is shipping with it in a release version already and another (Firefox) is about to ship in the stable branch soon. IMO this is the worst timing to change names or even functionality.

Greetings,
Dirk

> 
> 
> -- 
> Erik Dahlstrom, Web Technology Developer, Opera Software
> Co-Chair, W3C SVG Working Group
>

Received on Thursday, 4 December 2014 12:53:31 UTC