Re: [css-device-adapt] Number or percentage values for zoom values

On Fri, 01 Mar 2013 19:49:20 +0100, Tab Atkins Jr. <>  

> On Fri, Mar 1, 2013 at 8:29 AM, Simon Sapin <> wrote:
>> Le 01/03/2013 17:08, Rune Lillesveen a écrit :
>>> currently both <number> and <percentage> values are allowed for the
>>> various zoom descriptors in @viewport. A long time ago, an issue was
>>> raised about this ("Issue 4: Should both numbers and percentages be
>>> allowed?"). According to the complaint there is no tradition in CSS for
>>> having two different ways of expressing the same value.
>> Well, font-size and line-height both accept percentages that do the  
>> same as
>> the em unit. Obviously we can’t change these now, but *maybe* this is a  
>> not
>> pattern we want to repeat with new features?
> It is normally a bad idea to have two different ways of doing the same
> thing.  It's confusing to authors, and it closes off easy expansion
> opportunities in the future.
> However, in this case it's appropriate.  The meta viewport uses
> numbers, so people are familiar with that, but it's conceptually a
> percentage, so that's appropriate as well.  I don't see a good reason
> to believe we'll want to expand this feature in the future with a
> similar functionality, so losing the easy expansion is fine.

I cannot see any negative reactions to this, so I'll mark the issue as  
resolved and keep both percentage and numbers in the spec.

Rune Lillesveen

Received on Thursday, 2 May 2013 08:26:56 UTC