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Re: [css-device-adapt] MSFT feedback on latest editor's draft

From: Kenneth Rohde Christiansen <kenneth.christiansen@gmail.com>
Date: Mon, 9 Dec 2013 22:24:19 +0100
Message-ID: <CAEC208tHwXvAKx7DuE==7b4vZoy8S=x_gugSCw2+wXX1S5YmiQ@mail.gmail.com>
To: Matt Rakow <marakow@microsoft.com>
Cc: "www-style@w3.org" <www-style@w3.org>
As I understood it, without having reread the latest spec, 'auto'
should be the same as using the US sheet default, so if your UA sheet
says @viewport { min-width: 1024px; max-width: 100%; }, auto has the
behavior that you want. This example also shows the use of the min and
max values.

I don't like magic values like initial-width etc. I rather have the
developer understand the feature they are using and quickly see when
they are doing something wrong. It should be quite easy to educate
them and tooling (like the Chrome Web Inspector etc) can also help.

Kenneth

On Mon, Dec 9, 2013 at 10:12 PM, Matt Rakow <marakow@microsoft.com> wrote:
> Although these are functionally equivalent, I still think there is some value in providing some more explicit named value which indicates the desired behavior.  I don't think percent or vw units seem like a natural go-to for a developer who is looking to disable automatic scaling.
>
> The other side that I am interested in is that the "auto" value seems to be equivalent to "100%" in the latest ED (unless I am misinterpreting steps 6-8 of the constraining procedure).
>
> Thanks,
> -Matt
>
>> -----Original Message-----
>> From: Kenneth Rohde Christiansen
>> [mailto:kenneth.christiansen@gmail.com]
>> Sent: Monday, December 9, 2013 1:03 PM
>> To: Matt Rakow
>> Cc: www-style@w3.org
>> Subject: Re: [css-device-adapt] MSFT feedback on latest editor's draft
>>
>> These values 100vw and 100% are relative to the initial viewport (which might
>> be affected by page zoom as defined in CSSOM Views).
>>
>> Kenneth
>>
>> On Mon, Dec 9, 2013 at 9:55 PM, Kenneth Rohde Christiansen
>> <kenneth.christiansen@gmail.com> wrote:
>> > Hi there,
>> >
>> > 1. device-width and device-height are being replaced by 100% or 100vw/vh.
>> >
>> > Kenneth
>> >
>> > On Mon, Dec 9, 2013 at 9:49 PM, Matt Rakow <marakow@microsoft.com>
>> wrote:
>> >> Hi all,
>> >>
>> >> I've been getting caught up recently on the edits made to the Device
>> Adaptation ED and wanted to provide some feedback.
>> >>
>> >> 1. Explicit values for initial viewport width and height In the
>> >> latest ED the named values of "device-width" and "device-height" have
>> been removed, and instead declaring a width or height of "auto" is intended
>> to provide equivalent behavior.  However, "auto" is already the default
>> value, indicating that the UA's default behavior may apply - the behavior just
>> changes if you explicitly set the width or height to "auto".
>> >>
>> >> IE uses "auto" to reflect the default behavior of the browser (i.e. actual
>> viewport is minimum 1024px by default), whereas "device-width" and
>> "device-height" map to the dimensions of the initial viewport (matching the
>> current WD).  I'd like to add the named values back so we can keep these
>> concepts distinct, and so that "auto" only has a single meaning.
>> >>
>> >> I agree that device-width/device-height are probably not the right
>> vocabulary to use though.  Perhaps a renaming would be appropriate
>> ("initial-viewport-width"?  "window-width"?  "css-pixel-width"?).
>> >>
>> >>
>> >> 2. min- and max- width and height
>> >> Currently, there are two ways to provide a viewport "range."  These are
>> the min- and max- prefixes for the width and height properties, and the
>> interaction of @viewport with width and height media queries.  Having both
>> of these mechanisms adds a pretty significant amount of complexity to the
>> ways this feature can be applied, especially if both are used simultaneously.
>> >>
>> >> I'd argue that the min- and max- prefixes for the width and height
>> properties are not necessary for the scenarios developers are interested in,
>> and that equivalent functionality can be built using only media queries for
>> range constraints.  For example, consider the two following rules:
>> >>
>> >> /* Example A */
>> >> @viewport {
>> >>     min-width: 640px;
>> >>     max-width: 960px;
>> >> }
>> >>
>> >> /* Example B */
>> >> @media (min-width: 640px) and (max-width: 960px) {
>> >>     @viewport { width: device-width; } }
>> >>
>> >> Both of these rules suggest the author has done the work necessary to
>> ensure their site works well for widths between 640 and 960px, and both are
>> equivalent for initial viewports within that range.  However, outside of that
>> range the behavior differs.  The primary difference is that Example A forces
>> scaling for all window sizes outside of the designed-for range, while Example
>> B leaves the UA in charge of what happens to those sizes.  I see Example B as
>> the better option, as the potentially unbounded scaling of Example A will
>> likely end up with an unintended result for extreme viewport sizes.  Consider
>> the ~200% scaling that would occur on a 1080p monitor, for example.
>> >>
>> >> I'd be interested in removing the min/max option from the spec, if there
>> is not a particular scenario they are required for.
>> >>
>> >> Thanks,
>> >> -Matt
>> >>
>> >>
>> >
>> >
>> >
>> > --
>> > Kenneth Rohde Christiansen
>> > Web Platform Architect, Intel Corporation.
>> > Phone  +45 4294 9458 ﹆﹆﹆
>>
>>
>>
>> --
>> Kenneth Rohde Christiansen
>> Web Platform Architect, Intel Corporation.
>> Phone  +45 4294 9458 ﹆﹆﹆



-- 
Kenneth Rohde Christiansen
Web Platform Architect, Intel Corporation.
Phone  +45 4294 9458 ﹆﹆﹆
Received on Monday, 9 December 2013 21:24:47 UTC

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