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Re: [css-device-adapt] @viewport vs. Media Queries.

From: Rune Lillesveen <rune@opera.com>
Date: Fri, 01 Mar 2013 14:14:57 +0100
To: "www-style@w3.org" <www-style@w3.org>, "Simon Sapin" <simon.sapin@kozea.fr>
Message-ID: <op.ws9q27pj8isf1p@id-c1005.oslo.osa>
On Fri, 01 Mar 2013 09:51:24 +0100, Rune Lillesveen <rune@opera.com> wrote:

> On Thu, 28 Feb 2013 13:06:24 +0100, Simon Sapin <simon.sapin@kozea.fr>  
> wrote:

>> Section 7 on css-device-adapt describes how @viewport rules interact  
>> with Media Queries, which may be based on the viewport size.
>>
>> Three comments:
>>
>>
>> 1.
>>
>> Editorial: This section uses the word "recommended". It is fine when  
>> addressed to authors, but the meaning is unclear when addressed at  
>> implementation. Does it make the sentence non-normative? I suggest  
>> either:
>> * If it’s a normative requirement, use "must" or general statements  
>> like "This is what happens."
>> * If it’s not, move to a note or have something like "This section is  
>> non-normative."
>
> I'm fine with making it a "must".

Changed ED.

>> 2.
>>
>> Next is described hot to apply @viewport rules first, then style rules.  
>> This needs to mention every other at-rule. I think the intended  
>> behavior is:
>>
>> 1. Apply @import rules, conditional rules (including @media) and  
>> @viewport rules. Media queries are based on the initial viewport.
>> 2. Apply all rules but @viewport. Conditionals are resolved again with  
>> MQs based on the actual viewport.
>
> This was written before Conditionals (reading it a second time, it seems  
> you mean everything relying on viewport size). I'd prefer a wording that  
> is more forward compatible with future specs and @-rules.
>
> How about:
>
> 1. Cascade all @viewport rules using the initial viewport size for  
> values and evaluations which rely on viewport size.
> 2. Compute the actual viewport from the cascaded viewport descriptors.
> 3. Cascade all other properties and descriptors using the actual  
> viewport size.

Changed ED.

>> 3.
>>
>> At the end of the section: "The next example illustrates possible  
>> circular dependencies […] If the media queries were based on the actual  
>> viewport […]"
>>
>> This is a justification of why the spec is written as it is, by showing  
>> that the other behavior would not make sense, right? It’s a bit  
>> confusing to describe a behavior that is not the one specified. This  
>> example needs a big warning.
>
> Yes, it's a justification.
>
> I'd prefer to just remove the last paragraph + example instead.

Removed from ED.

-- 
Rune Lillesveen
Received on Friday, 1 March 2013 13:15:29 GMT

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