How to create a new shape for block diagrams?

[Günter Dannoritzer <dannoritzer web de>]

Hi,

I have been using dia now for a while and one drawing type I am using it
for quite often is that of block diagrams. Now I would like to get a new
shape that speeds up the drawing of these block diagrams and wonder how
to create one.

To give you an idea what type of block diagram I am looking for I picked
a data sheet from the web:

http://www.aldec.com/products/ipcores/_datasheets/Aldec/IC-DCT.pdf

On page 2 of that document they show a block diagram and I would like to
have a shape that supports the creation of these blocks.

I am using dia 0.96.1 and I know there is one shape, the data shape in
AADL, that comes pretty close to what I am looking for.

What is missing in that shape is that I can add the port name and it
gets displayed in the block.

Also I would like a text field for the block name, which is now
available in the AADL block, and a second text field outside the block
for the instance name.

A minor changed would be to move the arrow of the in port outside of the
block line and for an out port not have an arrow, just a connection
point I can connect a line to.

Now the cream would be to have a dialog that allows me to enter all the
ports that I want to add to that shape at once. I am not sure how
feasible that is?

I looked in the source under:

http://svn.gnome.org/viewcvs/dia/trunk/objects/AADL/

And it looks like I find what I am looking for in aadldata.c and aadlport.c.

In the source the author calls the objects a plug in. Could I also
create that as a Python plugin or does it need to be in C?

Thanks for your help.

Cheers,

Guenter