On 1 Dec 2011, at 13:29, James Montgomerie wrote:
>
> > As I've posted before, I'm using libCSS in an ebook/ePub rendering
> project ('libEucalyptus'). I've recently come across the need to parse
> @font-face rules.
> >
> > Attached is a patch that does this, following (or attempting to :-)
> the CSS 3 spec. It extends the parser to parse font-face rules (which
> use a slightly different grammar to the regular CSS, of course...),
> and adds support to the selection engine to query font-faces by family
> name. The support is limited - at the moment it supports 'src:',
> 'font-family:', 'font-style', and 'font-weight:' rules. It should be
> fairly easily extensible to the other font-face directives in the
> future (unicode-range etc.).
Excellent!
> > When parsing, it 'correctly' handles other unsupported directives by
> ignoring them. I've tried to keep the font-face handling well
> compartmentalised into its own files, although I have extended a
> couple of the parsing util routines where I thought that made sense.
Sounds fine to me.
> > On the selection side, for the client, the new css_select_font_faces
> function will take a font family name and media and provide a list of
> font-face results that specify the font-faces that match. I've
> deliberately not tried to filter this list further than by family name
> and doing some sorting by specificity, so that the user agent can
> apply its own logic to the font selection and fallback This logic is
> - mostly - specified in the CSS spec, of course, but it's rather vague
> places, but more importantly also depends so much on installed fonts
> and OS capabilities in rendering that I thought it best to leave it to
> the client.
Yeah; that matches what we did with font-families, so I've no objection
to this approach. After all, the client is the only place that is
capable of making a fully informed decision here :)
> > I hope the patch meets with approval. Criticism and changes are
> appreciated, and I'm very happy to receive constructive feedback (or
> bug fixes :-). While I am using this in its current state in a
> product now, I would very much like to keep my libCSS unforked - and I
> hope this will also be useful to others in the future.
I've had a relatively quick look through it. It appears mostly fine, but
it's been a while since I last looked at the CSS3 Fonts module. I'll
endeavour to give it a proper look at the weekend.
Cheers,
J.
