Re: using dia for graphs (as in graph theory)

[Lars Clausen <lrclause cs uiuc edu>]

On 11 Aug 2003, ml knorke in-berlin de wrote:
> On Mon, Aug 11, 2003 at 05:34:46AM -0500, Lars Clausen wrote:
> > There's the basic shapes always shown in the toolbox.  The boxes and
> > circles there don't allow parenting right now, but could be made to by
> > setting a single flag.  
>
> Just for fun I set obj->can_parent = TRUE for the UML actor.
> It works great.  Another important feature for graphing, I
> cannot yet find in dia: Allowing connections only between
> certain objects, e.g. not allow UML class inheritance
> between SDL state and network cloud. 

I don't think the objects should say anything about whether they can
connect to unknown other objects.  I'd hate to try to set up an unorthodox
diagram only to find that the editor says no for no good reason.  What we
could do, and I'd like to see, is have connections verify whether they make
sense within their own sheet, so e.g. realizes doesn't point to a class.
Preferably it should not forbid it, but indicate that it's a connection
that doesn't make sense (like a text editor doesn't prevent you from making
spelling errors).  We'd need to allow connections to check before they're
connected for that to work.

-Lars

-- 
Lars Clausen (http://shasta.cs.uiuc.edu/~lrclause)| HÃrdgrim of Numenor
"I do not agree with a word that you say, but I   |----------------------------
will defend to the death your right to say it."   | Where are we going, and
    --Evelyn Beatrice Hall paraphrasing Voltaire  | what's with the handbasket?