Re: New Shapeset -- What Will I Need To Do...?

[Lars Clausen <lrclause cs uiuc edu>]

On Thu, 29 Aug 2002, Tim Ellis wrote:
> We (DBAs that use UML shapeset to create Database ERDs) have finally come
> to an impasse. The UML shapeset simply doesn't have all the checkboxes
> and dropdowns that we need to express ourselves. Problems have become
> intractable without a new shapeset.
>
> However, the two of us that actually feel like we might tackle the
> problem have both tried GTK programming in the past, and both have
> suffered catastrophic failure.
[...]
> Does anyone have any advice for a GTK/Dia novice about how I could create
> a whole new Dia shapeset, (where the shapes are extremely similar to
> UML)?  The more RAD-tool-oriented the solution, the better...
>
> Oh, and just asking this question terrifies me. Please be gentle.

It's your first time, as well? :)

First thing to do is to try avoiding GTK whatsoever.  If you can create the
dialogues using just the standard properties, you can avoid much pain.
Look to chronogram/chronoline to see how some more complex things can be
implemented.  Do *not* look at the UML class dialog, it's horrible and
outdated. 

Unfortunately, your example above indicates that you want fancier controls
than the properties can give you.  Before you decide to go down the road of
GTK dialogs, you should write out (on paper) the attributes you want your
shapes to have.  I would recommend starting off without complex
interactions, even if it makes usage clunkier.  Once you have the shapes
working, you can try them out and figure out what you want happening that
properties doesn't provide.

I cannot repeat this often enough:  Be very sure that you need GTK before
you try using it.  Plus, if you make a couple non-GTK shapes first, you
learn the Dia internals without the extra confusion of GTK.  For your
information, only three of the programmed shapes use GTK (and I'm hoping to
get two of those out).

-Lars

-- 
Lars Clausen (http://shasta.cs.uiuc.edu/~lrclause)| Hårdgrim 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?