Why gnome-office needs libSVG

[Martin Sevior <msevior mccubbin ph unimelb edu au>]

Hi everyone,
	    I think gnome needs a libSVG to render SVG graphics onto a
variety of backends the way gnome-print renders to postscript and PDF.

If constructed correctly this library would render onto a GTK graphics
context, the gnome-print graphics system or the Abiword XP graphics
context. I volenteer to do the Abi GC backend :-).

Why do we need this? 

1. Documents containing embedded components need a fast way of rendering
the object to screen. Say we have a math compoenent embedded in Abiword. I
typically have lots of equations in my document that I don't need to
overhead of parsing and contructing. If the math component was already
rendered into SVD graphics via, say, gnomeprint this could be displayed
quickly via this library. Of course when I click on the equation the
embedded component would go "live" and enable the math editor.  The same
argument could be made of GUPPI charts or Gnumeric spreadsheets. Anything
embedded into anything else should also carry this SVG image of itself to
enable fast display.

2. We all want people with gnome-office to seamlessly interoperate with
other users in a MS environment. How then does someone send a document
with a math or GUPPI emabbed graphic to a MS excell or Word user? The MS
office format requires both a serilaized description of the embedded
component plus a WMF graphic of said object. So on our end to read these
compound documents we can at least display the embedded graphics using a
WMF to SVG converter and libSVG. We will also need to make a Vector
graphics repesentation of our components, convert these to WMF's and embed
these in the OLE stream for MS format export.

3. By employing AbiWord as the Word Processor for gnome office we can
create compound docs based on the *.abw file format. If these contain both
XML description of the component plus an SVG rendered image of the
embedded image these can be viewed by Abiword users on arbitary platforms.

So your friends and colleagues working on Windows, MAc, QNX and BeoS can
at least view gnome generated compound documents. 

I think that code for rendering SVG graphics is scattered around the gnome
project. It would be in everyone's interest for this code to be
collected into a libSVG which would be employed by all gnome-office apps.

Cheers

Martin Sevior