No unique IDs for objects??

[Lennon Day-Reynolds <lennon kestrel edu>]

In trying to add text annotation support for several plugin object 
types, I've come up against a bit of a quandry, which I hope someone 
here will be able to answer for me. First off, I can't seem to find 
where the numeric 'id' attribute values present in the Dia XML output 
are generated; I'm assuming they're simply assigned in a linear fashion 
by iterating through the objects in each layer, but haven't found the 
code where it happens. Secondly, assuming that my assumption about how 
the id attribute is assigned is valid, I'm sort of stuck on trying to 
get annotations working in general fashion.

Ideally, I'd like to have an identifier (number, string, or otherwise) 
that would stay with an object through its entire lifecycle (create, 
save, load, etc.); this would help immensely in keeping the annotation 
text tied to a certain object, as well as in trying to process the 
output files with an external filter. At this point, I'm thinking that I 
may just have to define a new AnnotatedObject type, which has an 'id' 
property which I can use to correlate objects to notes from outside the 
standard property editor. That, however, means I lose access to the 
SVG-defined object types for my plugin.

Would it be too extreme a change for me to dig into the base Object type 
definition and operations, and add a simple integer ID field? As a 
starting point, the values could just be generated by incrementing a 
counter in the current diagram. Are there any other areas of the 
application that could benefit from this kind of secondary handle to an 
object?

Thanks,

Lennon Day-Reynolds
Software Engineer
Kestrel Institute