Re: [css3-ui] file formats for the cursor property

On 16 Mar 2015, at 09:39, Tantek Çelik <tantek@cs.stanford.edu> wrote:

Hi Tantek,

Thanks for chiming in, this is a tricky topic indeed.

> This is exactly why we have left cursor file formats unspecified and
> not required. The situation has not changed since we discussed it
> years ago.
> [...]
> This not a new issue (in general), HTML5 has (had?) the same issue
> with <video> and <audio>.

There are clearly many parts in the platform where we don't define
which file formats should or must be supported. However, most of the
time, this is because we could not do so, not because we prefer not
to do so. Video is a good example of that, and so is @font-face.

Referring to PNG and SVG is something we can do if we want to, and
so is requiring with a MUST all image static formats the UA already
supports for the <image> type (as used in 'background-image'),
or with a SHOULD the animated ones.

All browsers other than IE already do this MUST (and safari does
the SHOULD). Since we already cannot depend on IE to meet the spec's
CR exit criteria (it misses a number of other features), adding this
would not slow the spec down.

> For any such format we'd like to suggest, even as a should, we need
> * an open spec we can normatively reference.

As I mentioned it in my initial mail, I agree with you that the lack of
a spec we can reference for .ico and .cur is an problem.

At the same time,
> Multiple implementations implementing a cursor file format is
> *insufficient* to making such a format a must (or even a should).

All browsers support this pair of formats, and since this pair of
format is alone in being supported by all browsers, by and large
that's what content uses.

Being able to be spec compliant without being interoperable is only
moderately useful, so we would be doing a disservice to new
User Agents (Servo?) by leaving .ico and .cur out.

 - Florian

Received on Monday, 16 March 2015 17:31:00 UTC