Re: Proposals for OO and GO commonalities

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

On Sat, 18 Nov 2000, Jody Goldberg wrote:

> On Fri, Nov 17, 2000 at 06:32:16AM -0100, Rodrigo Moya wrote:
> > 
> > So, again, shall we start talking about common stuff so that we all go in the
> > same direction? For example:
> > * common UI look&feel: a good place for placing widgets and other UI related
> >   stuff could be libgal, if not a new libgnomeoffice
> GAL is definitely appropriate for the GO components.  This is what
> it was intended for.  It not likely to offer much to the OO codebase.
> 
> > * CORBA: we should also start to talk about common higher-level office
> >   components, to be implemented by all the different GO components.
> Agreed.  This would be an excellent starting point.
> 
> > * common file formats: filters for file formats should be also implemented
> >   in a common place, so that all GO components can make use of them, to
> >   allow REAL compatibility between them.
> Depends on what you mean by 'file format'.  It has been my
> experience that the file format for an application closely mirrors
> its internal data structures and implementation philosophies.
> Even if everyone uses xml, having two similar applications using
> the same file format seems very unlikely.  I'd recommend starting
> with something 'simpler'.  There has been alot of discussion on how
> to handle structured files for OO.  This is definitely an area that
> Gnumeric is ripe to explore.  We need a way to save embedded objects
> and images.  How does Abi handle this ?

Here are my ideas for Abi side of Bonobo support. This all seems straight
forward to me. I've discussed them briefly with Dom over IRC but I haven't
spelled them out to Abi list so I'm CCing AbiWord-dev this reply. Please
feel free to tell me if this sounds like it is not going to work. It will
save everyone a lot of time. Basically to Abi, a Bonobo object can be just
another rectangular piece of screen. We already have a machanism to deal
with this through our image support. The file format I envision for a
bonobo object would closely match that for an image within Abi. ie

<bonobo
dataid="seviorpc.ph.unimelb.edu.au:/home/msevior/marks.gnumeric"
props="height:3.0in;width=1.36in> ... rest of document

<data>
<d
name="seviorpc.ph.unimelb.edu.au:/home/msevior/marks.gnumeric" mime-type="
bonobo/gnumeric">
<gnumeric XML file of marks.gnumeric here>
</d>

I imagine it would be possible to recursively generate object within
objects with each container calling new containers this way.
 
Within Abi we could create a new subclass of our Piece Table fragment
frag_object with known dimensions. This is just like our Image and
Piece Table Field support.  Then all the formatting code would treat this
bonobo object just the same as an embedded image. We reuse all this code.
All that is left is to actually render the bonobo object on our Abi
canvas. I think I can work out how this magic will be done and Dom assures
me he knows how to do this (handwave, handwave). We will use the
gnome-print architure to print embedded object. Once rendered the object
can be manipulated by our standard scrolling mechanisms until off the
screen.

Cheers

Martin