Re: A patch to support creating network diagrams using programs

[Lars Clausen <lars raeder dk>]

On Fri, 2005-05-20 at 08:49 +0100, Aaron Trevena wrote:
> On 5/19/05, Lars Clausen <lars raeder dk> wrote:
> > On Mon, 2005-05-16 at 08:25 -0400, Michael Tiemann wrote:
> > > I'm writing some scripts to extract data from spreadsheets and build
> > > network flow diagrams.  I assumed that if I created a line that
> > > connected handle A to handle B that dia would figure out where to put
> > > the line and display it.  It did not (instead defaulting to position 0,0
> > > and bounding box 0,0,0,0).  Here's a patch so that locations and bb's
> > > can be inferred by what they connect.
> > 
> > A nice idea, but not quite that easy.  You implementation has a couple
> > problems (assuming that all objects have handles, assuming that
> > connectionpoint 0 is always connected on the objects we want to fix),
> > but also a more serious problem:  When you do move_handle, you're not
> > guaranteed that the connection will go to the connection point it was
> > originally on, but rather on the connection point that is on top at that
> > place.  Hopefully a generated diagram would not have many overlaps like
> > that, though.
> 
> Those problems are minimal compared to the current situation. I had to
> give up connecting shapes in Autodia because it was near impossible to
> work out the positions of the connectors, so now it has a trimmed
> sprout of lines from each shape that connect only when the shape they
> connect to moves. This is far from satisfactory.

I guess only doing this for connectors at 0,0 with BB 0x0 would prevent
most problems.  However, this patch is still a kludge.  It may be the
necessary kludge, but I'd like to think a bit about alternatives.

> Umbrello manages this OK, I think. Yes I know Dia isn't umbrello but
> there is little point having an XML file format if you can't create
> that XML and have it JustWork(TM) :)

Ah, the magic of XML:)  IMHO, XML is way overrated in many situations
(Native XML databases?), and it's not something that JustWorks[TM] any
more than keyword-value or binary dumps.  

-Lars

-- 
Lars Clausen <lars raeder dk>