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[css-device-adapt] CSS Device Adaptation and legacy meta tags and doctypes

From: Kenneth Rohde Christiansen <kenneth.christiansen@gmail.com>
Date: Fri, 25 May 2012 01:02:57 +0200
Message-ID: <CAEC208sm1_V5OV0Qikxn2jVAFYSxTfnhm8TwT2f0=2+S03UbTA@mail.gmail.com>
To: Øyvind Stenhaug <oyvinds@opera.com>, florianr@opera.com
Cc: www-style list <www-style@w3.org>, Peter Beverloo <peter@chromium.org>, Hugo Parente Lima <hugo.lima@openbossa.org>, Ojan Vafai <ojan@chromium.org>, Rune Lillesveen <rune@opera.com>, John Mellor <johnme@chromium.org>
Hi there,

TabAtkins told me that the CSS Device Adaption spec changed hands, so
I am adding the new editors to this thread.

Cheers,
Kenneth

> On Mon, May 14, 2012 at 4:25 PM, John Mellor <johnme@chromium.org> wrote:
>> I wrote a set of test pages to determine what browsers support
>> these: jsbin.com/uyojoj/2
>>
>> And tested using the following browser versions:
>> - (Legacy) Android Browser on Nexus S running ICS 4.0.4
>> - Chrome for Android beta 2 on Nexus S running ICS 4.0.4
>> - Firefox Aurora 14.0a2 (2012-05-13) on Nexus S running ICS 4.0.4
>> - Internet Explorer Mobile 9 on Nokia Lumia 800 running WP7.5
>> - Nokia Browser for N9 on Nokia N9 running MeeGo 1.2 Harmattan
>> - Opera Mobile 12.00.ADR-1204201824 on Nexus S running ICS 4.0.4
>> - Mobile Safari on iPod touch (4th gen) running iOS 5.1.1
>>
>> Here are the viewport widths that the browsers calculated on the 4 test
>> pages:
>>
>> Test: \ Browser:|Android|Chrome |Firefox|  IE   | Nokia | Opera |Safari |
>> ----------------+-------+-------+-------+-------+-------+-------+-------+
>> Default         |  980  |  980  |  800? | 1024  |  980  |  980? |  980  |
>> XHTML-MP        |  320  |  320  |  320  |  320  |  320  |  320  |  320  |
>> HandheldFriendly|  320  |  320  |  800? |  320  |  320  |  980? |  980  |
>> MobileOptimized |  320  |  320  |  800? |  320  |  320  |  980? |  980  |
>>
>> (there are question marks next to the Firefox and Opera widths since
>> window.innerWidth did not match the observed viewport width, so I had to
>> estimate these by eye)
>>
>> It seems that all browsers already treat the XHTML-MP doctype as equivalent
>> to a width=device-width viewport, so I agree with Kenneth that it would make
>> sense for the Device Adaptation spec to explicitly formalize this defacto
>> standard in a normative section.
>>
>> Handling of legacy HandheldFriendly and MobileOptimized viewport tags is
>> less consistent, but adding these to the specification could also be useful,
>> to improve interoperability.
>>
>> In both cases the order of precedence Kenneth suggested (whereby modern
>> standards override legacy ones, irrespective of document order) seems wise,
>> as it reduces the risk of supporting the legacy methods.
>>
>> Cheers,
>> John
>>
>>
>> On Wed, May 9, 2012 at 11:49 AM, Kenneth Rohde Christiansen
>> <kenneth.christiansen@gmail.com> wrote:
>>>
>>> Hi there,
>>>
>>> Following a discussion on webkit-dev [1], we would like to have added
>>> a nomative section in the CSS Device Adaptation spec [2], specifying
>>> how to handle legacy viewport tags, such as HandheldFriendly.
>>>
>>> The spec already briefly talks about XHTML-MP in the following:
>>>
>>> "Certain DOCTYPEs (for instance XHTML Mobile Profile) are used to
>>> recognize
>>> mobile documents which are assumed to be designed for handheld devices,
>>> hence
>>> using the viewport size as the initial containing block size."
>>>
>>> The Nokia N9 browser, WP7 Internet Explorer and Android already
>>> implement such support. And testing shows that iOS at least does
>>> similar things for XHTML-MP.
>>>
>>> The IE team even has a blog post explaining how it works [3]
>>>
>>> Basically there is a priority:
>>>
>>> XHTML-MP doctype (overrides default configuration)
>>> HandheldFriendly meta tag (overrides XHTML-MP doctype)
>>> MobileOptimized (overrides HandheldFriendly, etc)
>>> viewport (overrides MobileOptimized etc)
>>>
>>> The XHTML-MP doctype would correspond to the following viewport meta
>>> tag: <meta name="viewport" content="width=device-width,
>>> height=device-height, initial-scale=1">
>>>
>>> The same counts for HandheldFriendly (and MobileOptimized, in the case
>>> the content attribute is missing or not parseable)
>>>
>>> Else <meta name="MobileOptimized" content="320"> would to correspond
>>> to  <meta name="viewport" content="width=320, initial-scale=1">
>>>
>>> Cheers,
>>> Kenneth
>>>
>>> [1] http://thread.gmane.org/gmane.os.opendarwin.webkit.devel/20536
>>> [2] http://www.w3.org/TR/css-device-adapt/
>>> [3]
>>> http://blogs.msdn.com/b/iemobile/archive/2010/11/22/the-ie-mobile-viewport-on-windows-phone-7.aspx
>>>
>>> --
>>> Kenneth Rohde Christiansen
>>> Senior Engineer
>>> Nokia Mobile Phones, Browser / WebKit team
>>> Phone  +45 4093 0598 / E-mail kenneth at webkit.org
>>>
>>> http://codeposts.blogspot.com ﹆﹆﹆
>>
>>
>
>
>
> --
> Kenneth Rohde Christiansen
> Senior Engineer
> Nokia Mobile Phones, Browser / WebKit team
> Phone  +45 4093 0598 / E-mail kenneth at webkit.org
>
> http://codeposts.blogspot.com ﹆﹆﹆



-- 
Kenneth Rohde Christiansen
Senior Engineer
Nokia Mobile Phones, Browser / WebKit team
Phone  +45 4093 0598 / E-mail kenneth at webkit.org

http://codeposts.blogspot.com ﹆﹆﹆
Received on Thursday, 24 May 2012 23:03:47 GMT

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