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Re: Question about px: Relative size?

From: Charles McCathieNevile <charles@sidar.org>
Date: Fri, 22 Apr 2005 00:00:20 +0200
To: "Sailesh Panchang" <sailesh.panchang@deque.com>, w3c-wai-ig@w3.org, "WebAIM Discussion List" <webaim-forum@list.webaim.org>, "Tim Boland" <frederick.boland@nist.gov>
Message-ID: <op.splreu1lw5l938@researchsft>

On Thu, 21 Apr 2005 18:34:11 +0200, Sailesh Panchang  
<sailesh.panchang@deque.com> wrote:

> Tim and all,
>  I note from the W3C doc on basic data types in CSS2  (1) that  Relative  
> units include:
> px: pixels, relative to the viewing device
...
> Is there a difference in terminology here? Ppixels are
> relative/scalable in regards to "physical" viewing devices, as are em &  
> % units. But the following: "Make content scalable by using relative  
> measures like em, px, percentages for specifying characteristics like  
> sizes, width,
> etc." could lead a developer to believe that their text will be  
> scalable, or rather sizable, within the content when viewed in a  
> browser. While this is true with em & % units, it is not with px, right?

More or less right. (Many systems now allow the user some gross definition  
of the screen size which is a change from the "actual" one, and browers  
like Opera that zoom allow for further changes. The way this interacts  
with CSS means that it is still not the same thing as with em or similar...

see http://lists.w3.org/Archives/Public/w3c-wai-ig/2005JanMar/0028.html  
for a discussion of the history of this checkpoint, the erratum I proposed  
many moons ago to try ad clear it up, etc.

cheers

Chaals

-- 
Charles McCathieNevile                      Fundacion Sidar
charles@sidar.org   +61 409 134 136    http://www.sidar.org
Received on Thursday, 21 April 2005 22:00:40 GMT

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