Re: [xmlroff] FO and Area Tree browser proposal

[Tony G. <Ton...@Su...>]

Dave Malcolm wrote at  9 Mar 2003 13:29:23 +0000:
 > On Saturday 08 March 2003 20:43, Tony Graham wrote:
 > >  > Even without doing this, the browser should be a fairly simple job using
 > >  > GnomeCanvas.
 > >
 > > I had thought that a tree required GtkTree or similar, not a canvas
 > > widget.  What am I missing?
 > 
 > I was thinking of using the canvas to render rectangular areas that can be 
 > clicked and dragged etc; nice for visual inspection of the results.  Mind 

That would be simple to do (well, comparatively simple) if Pango's FT2
(or xft) backend could take the same PangoLayout as created by the
PDFlib backend.  Right now, I believe that the FT2 and xft backends
are too tied to 72dpi resolution.

 > you, a tree would be useful as well, for systematic "structural" browsing.  
 > (You probably want GtkTreeView for that; it's much better than the old GTK 
 > 1.* widgets)

Yes.  I installed GTK+ 2.2.0, and I've looked at the sample code in
gtk-demo.

 > > My blue-sky musing frequently concerns incremental updates: pushing a
 > > small change, e.g. one changed word, in the source XML through the
 > > XSLT transformation and through the XSL formatter without either
 > > transforming the whole document again or reformatting the whole
 > > document again.
 > 
 > I wasn't aware this was possible...  and if you manage to do it I'll be very 
 > interested in finding out how :-)  I've (briefly) looked for "incremental" 
 > XSLT engines but couldn't find any.

I haven't found any incremental XSLT engines either, but we are
speaking blue-sky, aren't we?

The first part of the story, alerting the XSLT engine to a change in
the source XML, could be done using something like DOM events [1].

The second part, going the incremental transformation, is left as an
exercise for the reader.

The third part, alerting the formatter, could also be based on DOM
events.

The fourth part, changing the formatted output, is not dissimilar from
what wil eventually have to be implemented for handling
page-number-citation and retrieve-marker and for handling the
area-tree adjustment phase.

So it's simple, really.

 > > Also, speaking as list administrator now, please only quote the parts
 > > of the previous message to which you are directly replying or only
 > > quote enough to establish the context.  Including entire copies of
 > > previous messages reduces the signal-to-noise ratio in SourceForge's
 > > one-thread-per-page mailing list archives.
 > 
 > Oops... sorry.

That's okay.  Some people's normal habits don't play well with
SourceForge's archive style, but you can't know that until you look in
the archives (or someone tells you).

Regards,


Tony Graham
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[1] http://www.w3.org/TR/DOM-Level-3-Events/events.html#Events-EventTypes-complete