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Re: [css3-mediaqueries] tv and screen media types

From: Tab Atkins Jr. <jackalmage@gmail.com>
Date: Tue, 26 Oct 2010 15:08:48 -0700
Message-ID: <AANLkTinnpGtuO-qKtBwB6Zqb4=b2_y=g-iQji6u4Lm4y@mail.gmail.com>
To: David Singer <singer@apple.com>
Cc: fantasai <fantasai.lists@inkedblade.net>, www-style list <www-style@w3.org>
On Tue, Oct 26, 2010 at 2:46 PM, David Singer <singer@apple.com> wrote:
>
> On Oct 26, 2010, at 14:39 , Tab Atkins Jr. wrote:
>> On Tue, Oct 26, 2010 at 2:28 PM, fantasai <fantasai.lists@inkedblade.net> wrote:
>>> On 10/26/2010 11:45 AM, Tab Atkins Jr. wrote:
>>>>
>>>> According to an internal bug report that I cant' figure out how to
>>>> access, Google TV's browser will not respond to the TV media type,
>>>> because there are enough 'screen' stylesheets on the web that doing so
>>>> would produce too much breakage for Gtv users.
>>>>
>>>> The same applies to media types like 'handheld' and 'projection' -
>>>> Opera, I know, has to go through some ridiculous contortions to try
>>>> and respect them when they exist without breaking the web otherwise.
>>>>
>>>> I suggest that the 'tv', 'handheld', and 'projection' media types be
>>>> allowed to match at the same time as a 'screen' media type.  That way
>>>> Google TV could use both 'screen' and 'tv' media types.  As well,
>>>> Opera could use both 'screen' and 'projection' when the browser was
>>>> fullscreened, and both 'screen' and 'handheld' on phone browsers.
>>>> (Other browsers could as well, of course.)
>>>
>>> That would break anyone using these media types properly, i.e.
>>> expecting 'screen' not to apply when their 'handheld' sheet is
>>> enabled.
>>
>> Yes, it would.  The current state, though, means that you either have
>> to do silly contortions like Opera does, or just flat-out lie and just
>> masquerade as a screen, like Google TV's browser is doing.
>>
>> Do we have any information on how many sites actually use 'handheld'
>> and 'projection' in a way that would break if this were to change?
>
> I'm lost between two possible suggestions here.  Help?
>
> a) devices should be allowed to style to the 'tv' media-query(ies) if present, or else to 'screen' (a TV is a sub-type of screen, after all)
> b) devices should be allowed to apply rules from both 'tv' and 'screen' media types at the same time...
>
> The problem with (a) is that you have to scan the whole sheet first to see what media types it uses, which is...nasty...

Right; that's what Opera does, I believe, and I agree that it's nasty.


> perhaps we need a new media-type, 'generic-screen', which is true for TV and projection and any other type of electronic screen (basically, 'not print'?), and consider 'screen' to be really saying 'any kind of screen for which a more specific tag does not exist (such as TV or projection)'?

That won't help Google TV, as the stylesheets that specify
media=screen will still be required to be ignored by it.  Basically,
'screen' has become too polluted to be usable in this way.  As you
say, it basically just means "not print" now.  (Presumably it would
also still be okay to treat is as "not speech", "not braille", and
"not embossed", plus maybe "not tty".)

We could redefine 'screen' to be the generic type, and then create a
new type specifically for things that aren't tv, projection, or
handheld, but I don't see the value in the latter part.  All of these
support roughly the same stuff; any layout that works on a computer
monitor should work on a projector, a tv, or a handheld as well.  The
only problem would be viewport sizes, which you can separately
feature-test for.  (In fact, you *have* to separately feature-test for
it, since you can't rely on, say, 'handheld' always meaning
'significantly small screen'.  Is an iPad a handheld?)

I think we could get away with just genericizing 'screen', and then
you can specialize the media type to, for example, 'tv' to give
special styling (optimized for a lesser color depth, for example).

~TJ
Received on Tuesday, 26 October 2010 22:09:45 GMT

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