On Apr 30, 2008, at 12:41 AM, Charles Iliya Krempeaux wrote:
Hello,
On Wed, Apr 30, 2008 at 12:19 AM, Maciej Stachowiak <[EMAIL PROTECTED]>
wrote:
On Apr 29, 2008, at 11:54 PM, Charles Iliya Krempeaux wrote:
[...]
In practice, these things usually do not matter when using an icon
in the user interface. But the sizes available do matter. I would
not want to download a 512x512 icon for use as an iPhone homescreen
icon (it's not anywhere near the right size) but it is irrelevant
whether the compression is lossy or how colors are represented. I
would prefer a multisize icon with a wide size range for Mac OS X or
Windows Vista but not for Windows XP or most mobile platforms.
True... for an iPhone that might be the case. Or even Mac OS X or
Windows Vista. But it might become important in usages of this
metadata beyond just icons.
For example, consider a photo blogging example...
<link rel="enclosure" type="image/png" width="64" height="48"
compressioning="lossless" coloring="paletted" href="A.png">
<link rel="enclosure" type="image/png" width="640" height="480"
compressioning="lossless" coloring="truecolor" href="B.png">
<link rel="enclosure" type="image/png" width="640" height="480"
compressioning="lossless" coloring="grayscale" href="C.png">
<link rel="enclosure" type="image/jpeg" width="2560" height="1920"
compressioning="lossy" coloring="truecolor" href="D.jpg">
(The bottom <link> if the original image. The 2 640x480 onews are
scaled version... one color and one grayscale. And the top one is a
thumbnail.)
Has anyone actually asked for this kind of functionality or is this a
hypothetical use case? I don't think we should tie solving a real
problem (the need to specify icons at different sizes and let the UA
know these sizes) to an open-ended metadata annotation mechanism.
If we have this new attribute(s) available on the <link> element,
then it is very likely going to be used for other things besides
just icons.
You could use width and height for videos too. What if video wants
to be able to "declare" that the video has "closed captioning"
embedded or not?! Or what language the video file has audio for?!
("hreflang" would almost work for that... if it let you specify more
than one language.) Or`what "ratings" that version of the video is?!
What I was getting at with this suggestion is that if we start
adding the ability to specify all sorts of metadata about what's
being linked to and go along the path of #1, then we likely need to
create a kind of complex language to describe this. (Something
approaching the complexity of CSS.) And perhaps that's complicating
the <link> element too much.
Maybe it's simpler to (do #2 and) just create a <link> for each thing.
I'm not sure I understand this. Your proposal amounts to adding two
new attributes to the <link> element, "width" and "height" (and
possibly specifying a link of the same type to the same item
multiple times). My proposal involves a single new attribute on
<link>, with essentially the same information conveyed in a more
compact way. Why does my proposal lead to a CSS-like general-purpose
metadata language, but yours does not?
It leads to a CSS-like language only if we start adding more
metadata in there besides just the width and height.
For example, this...
<link rel="enclosure" type="image/xxx" width="640" height="480"
compressioning="lossy" coloring="truecolor" href="A.xxx">
<link rel="enclosure" type="image/xxx" width="1280" height="960"
compressioning="lossy" coloring="truecolor" href="A.xxx">
<link rel="enclosure" type="image/xxx" width="2560" height="1920"
compressioning="lossy" coloring="truecolor" href="A.xxx">
... could become...
<link rel="enclosure" type="image/xxx" metadata="size:640x480,
1280x960, 2560x1920; compressioning:lossy; coloring:truecolor;"
href="A.xxx">
The "metadata" attribute is where you start to get a CSS-like
language. (Which seems to complicate the <link> element.)
I'm not in favor of a CSS-like metadata language or a metadata
attribute. I don't think your suggested extra attributes are very
useful either so I am not sure how it is relevant to discuss different
syntax alternatives for them. That being said, this:
<link rel="enclosure" type="image/xxx" sizes="640x480 1280x960
2560x1920" compressioning="lossy" coloring="truecolor" href="A.xxx">
Does not introduce a CSS-like metadata language any more than your
first alternative. So I still do not see your point.
Regards,
Maciej
