Re: Feedback on "CSS Device Adaptation" draft 5/10/11

On Tue, 24 May 2011 19:35:39 +0200, <mike.sierra@nokia.com> wrote:

> These are a couple of minor concerns about the CSS viewport spec, not  
> necessarily "problems" per se, but issues that should be thought through  
> as potential uncharted territory for CSS:
>
> * In current implementations, the viewport is applied once at page load  
> and can't be modified therafter. This seems like a special case that's  
> much different than other at-rules and properties. I didn't see any  
> obvious discussion of the issue within the spec.

No, I think that it can be modified afterwards in both existing viewport  
meta implementation, and in Opera's @-o-viewport implementation. Changing  
the zoom/initial-scale value will not change zoom, though. I haven't  
specifically tested for that now, but typically, if the user has changed  
the zoom factor interactively, changes to the zoom/initial-scale factor in  
css/meta-viewport will not change the zoom factor. The spec should  
probably say something about it, though.

> * The various zoom-related properties don't affect the content itself,  
> but rather constrains how the browser displays the content.  I  
> understand the web-app use case for zoom control, but it may be a bit of  
> a reach for CSS. It seems analogous to letting CSS control display of  
> bookmark/URL/status bars within desktop browsers.

I see your point. It can be seen analogues to controlling the intial  
scroll position which is supported through scripting (CSSOM View) and not  
through stylesheets.

If you look at the Conformance section, a conforming UA may ignore the  
zoom related properties for presentation.

One concern is that this intends to replace the functionality introduced  
with viewport meta, which gives you this possibility without scripting.

-- 
Rune Lillesveen
Senior Core Developer / Architect
Opera Software ASA

Received on Wednesday, 25 May 2011 09:50:27 UTC