Re: Preview - more haggling

[Lauris Kaplinski <lauris ximian com>]

Hello!

I'll jump in with some probably quite unrelated comments...
If generic intra-file vector preview format will ever be considered, it 
should be SVG ;)

On Tue, 2001-12-11 at 09:07, Michael Meeks wrote:
>         Possibly we should have two aspect ratios, portrait and landscape
> - just to make life difficult for you :-)

I would say whatever aspect ratio with full viewport attribute set ;)

>         As background - Windows saves a 'wfm' file - a Word Meta file,
> essentialy an API dump of the rendering primatives. Thus if you have a
> complex document - it can take forever to render, and is somewhat of a
> pain.

This is the problem, that makes Nautilus (more) unusable for me (than
for many others). It can be done - use out-of-process rendering lalala,
but makes things much more complex.

>         _But_ - this does have some advantages - namely, that when the
> document loads; it's not neccessary for eg. Word to fire up Excel - it can
> just use the wmf stream to render it. This can equate to quite a large
> saving I imagine.

It is.
Plus some extra sugar - say, you have complex doc generated by someone,
but do not have all components installed (in proprietary world you may
have financial reasons for that). Having generic preview format in
everywhere gives you at minimum knowledge about what is there, only
activation (i.e. editing) is missing.
Or, if document has some standardized viewport/pagination specification,
you can embed it even without having component available - just like
embedding (set of) image(s) - with the extra sugar, that someone having
that comp. installed will be available to edit it.

>         So - yes a png is a very nice way to do the serialization - but
> it's possible that we want to store a gnome print meta-file in there
> instead :-) - either way - we would want to generate the image with
> gnome-print almost certainly in the first place.

Gnome-print-metafile as it currently is, is more a joke. For external 
image format I see 3 possibilities:
a) Standardize gnome-print-metafile and make it extensible.
b) Use SVG
c) use PDF
I'd prefer (b), as most document formats are xml-based anyways,
and SVG fits nicely into those. Plus that makes documents viewable
not only be some-yet-to-be-written gnome preview library/component,
but (if done correctly) many more programs (imagine they being
automatically previewable by web-browsers ;)
SVG disadvantages are:
a) No standard CMYK color system (but the same stands for current 
   gnome-print as well
b) Complexity (but it is still more logical and easier to parse than 
   PDF)
c) Ambiguity - but this can be reduced at least to PDF level by
   careful image construction.

Best wishes,
Lauris Kaplinski