Re: @font-face and slow downloading

I'd propose that we first agree on
   Q1. whether the tentative drawing behavior is at UA's discretion or not
and then on
   Q2. how the spec wording should be.

As to Q1, I think it must be at UA's discretion (rather than document
authors').

Rationale:
1. Through the discussion so far, it seems to be very difficult to find a
common ground with that everyone is reasonably happy. Hence mandating
a behavior doesn't look reasonable.
2. Allowing authors to control this tentative and transitional behavior
seems to be an overcommitment for me, especially as a browser developer.

As to Q2, I'd propose the following, deriving from David's:

"when a downloadable font is used in a stylesheet, UA may, after waiting for
download completion as long as it wants,
first use the fallback font for rendering as if all downloading have
failed and then use the downloadable font
when the download completes.
It is recommended to the document author that the fallback font(s) have 'as
similar metrics as possible'
to the downloadable font, so that, if the page is first rendered with a
fallback and later with the downloadable font,
the degree of visual change, re-layout etc., is as small as possible."

Yuzo

On Sat, Oct 23, 2010 at 3:50 AM, David Singer <singer@apple.com> wrote:


> On Oct 22, 2010, at 0:22 , Yuzo Fujishima wrote:

> >
> > Hi, David,
> >
> > Sorry if I was unclear.
> >
> > I think the temporary substitute and the permanent fallback should be  
> the
> same if possible.
> >
> > Put differently, I think the temporary substitute should be the same  
> font
> as the font that
> > is used when all downloads failed.
> >
> > Yuzo

> Hi, no problem.  We already have syntax for fallback, so we can document
> that it can also be used as a 'temporary' substitute (with no formal
> definition of how long temporary can be).

> So, should the specification say that "when a downloaded font is used in a
> stylesheet, a local fallback font must (should?) also be specified, and  
> that
> the fallback font may be used by the UA when/while the downloaded font is
> unavailable.  It is (strongly?) recommended that the fallback font(s) have
> 'as similar metrics as possible' to the downloaded font, so that, if the
> page is first rendered with a fallback and later with the downloaded font,
> the degree of visual change, re-layout etc., is as small as possible."

> David Singer
> Multimedia and Software Standards, Apple Inc.