Re: Proposed new API for libgnomeui

[Dave Malcolm <david davemalcolm demon co uk>]

On Tuesday 17 September 2002 16:48, Alexander Larsson wrote:

<snip>

>
> As a bonus I've added pluggable thumbnailing scripts.
> By putting this:
> video/x-msvideo: /home/alex/bin/avithumbnailer %i %o
> application/pdf,application/postscript: gs  -sDEVICE=png16m -r11
> -dFirstPage=1 -dLastPage=1 -sOutputFile=%o -dBATCH -dNOPAUSE %i
>
> in ~/.gnome2/thumbnailrc i was able to get this:
> http://people.redhat.com/alexl/files/thumbnails2.png
>

<snip>

Excellent - a few thoughts:
(i) For the pdf/postcript files, you might want to add "-dSAFER" for 
paranoia's sake; also -sDEVICE=png256 was a lot faster for me when I was 
playing around with this, with no appreciable loss of quality (on my test 
cases, at any rate)

(ii) Is ~/.gnome2/thumbnailrc just a temporary staging area?  We'd want to be 
able to install new thumbnail generators on a per-mimetype and possibly 
per-user basis.

(iii)  I've got a heavily hacked version of libole2 for extracting thumbnails 
out of MS Office docs.   Where should I be sending patches etc?

<bluesky-mode>
(iv) ultimately it might be better to implement thumbnailing as a component 
rather than script-based system; you ask an activation framework to give you 
a reference to an object that can thumbnail a particular mime-type.  That way 
you can amortise startup costs when e.g. generating 10 thumbnails involving 
something complex e.g. StarOffice, and hopefully avoid them altogether if 
StarOffice's already been launched (you can hopefully ask it to generate some 
thumbnails for you, without having to launch it yourself).   Though I'm not 
familiar enought with Bonobo to implement this myself :-(

(v)  taking things further, this could be generalised to per-mimetype 
metadata providers:   the component we've launched might be able to tell us 
the page count of a document, the author, the dimensions in pixels etc.  
(These could then be displayed in Nautilus - page count is probably more 
interesting to users like my mother than size in bytes).  Recent versions of 
the WIn32 Shell Namespace and Explorer collaborate to provide this kind of 
functionality.
</bluesky-mode>

Dave