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Re: [css3-mediaqueries] Touch enabled devices

From: Tab Atkins Jr. <jackalmage@gmail.com>
Date: Tue, 27 Apr 2010 08:55:17 -0700
Message-ID: <k2jdd0fbad1004270855n787d2bfm2d86076bd31ed057@mail.gmail.com>
To: Simon Fraser <smfr@me.com>
Cc: Gregers Gram Rygg <gregersrygg@gmail.com>, Mikko Rantalainen <mikko.rantalainen@peda.net>, www-style@w3.org
On Mon, Apr 26, 2010 at 10:33 AM, Simon Fraser <smfr@me.com> wrote:
> On Apr 26, 2010, at 10:16 AM, Gregers Gram Rygg wrote:
>
>> On Fri, Apr 23, 2010 at 12:38 PM, Mikko Rantalainen
>> <mikko.rantalainen@peda.net> wrote:
>>> pointer-precision: <len> | step;
>>>
>>> The user is expected to be able to hit targets of size <len> without
>>> huge effort. The <len> should be expressed in "px", "em" or "ch" unit.
>>
>> That depends on how flexible this needs to be. Using a value instead
>> of an input method will make this feature more complicated for browser
>> developers and web developers. But I wouldn't mind, as long as there
>> are some predefined keywords for different input devices. Example:
>> "pointer-precision: touch", where touch could be specified to 8mm.
>>
>> Shouldn't <len> rather be specified in a physical unit (in, cm, mm, pt
>> or pc)? A value in px might vary depending on the resolution for the
>> device, and em/ch depend on the font in use.
>>
>> Example:
>> @media screen and (pointer-precision: 10mm) {
>>    a { padding: 3mm; }
>>    ul.autocomplete li { padding: 3mm; }
>>    div.touchController { display: block; }
>>    div.nonTouchController { display: none; }
>> }
>
>
> This seems like way too much resolution. Imagine a hardware vendor tweaking the display
> resolution of a device in a revision, and this causing web content to fall over a threshold
> here.
>
> I think it's quite sufficient to simply identify the primary input method. I can imagine
> the following input methods:
>
> pointer: mouse input (maybe include stylus?)
> touch: finger-based interaction
> keypad: up/down/left/right/enter navigation only

Agreed.  I don't think I'd ever vary my display enough to need an
actual length value there.  As far as we know, there are only two
precisions, that of a mouse/stylus and that of a finger.

As well, a length-based variable ignores alternate input methods that
could be usefully handled, like keyboard navigation, as Simon points
out.  I could see offering a slightly different presentation to
keyboard users, such as show/hiding useful anchors.

~TJ
Received on Tuesday, 27 April 2010 15:56:10 GMT

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