Reference to the part in PMObject

[Luis Carvalho]

Hi!

Andreas, as you may recall, I'm changing the library so that we can edit a 
library object through drag'n'drop.

Currently the library browser has no reference to any part. It doesn't make 
any sense to associate the library browser to any specific part. However, in 
order to provide drag'n'drop for the library, I need to load the objects 
contained in the library object. Since the constructor of PMObject and 
descendants requires a reference to a PMPart I'm a bit stuck, as the objects 
will be created by the Library Browser who doesn't know any part.

Is there a change to have PMObject fallback to a default PMPrototypeManager 
and PMInsertRuleSystem if no part is given? Or, since PMObject only uses the 
part to get the prototype manager and the insert rule system, we could change 
the constructor to receive a pointer to the two managers eliminating the 
reference to PMPart. That way, I can create copies of the managers owned by 
the library browser that will be passed when I load the file.

Another thing I need to handle is objects created by plugins. I'll add a 
"requires" field to the library object to identify wich plugins have to be 
available to handle the library object. If a library object requires a 
certain plugin that is unavailable, I'll refuse to open the file.

What do you think?

Regards,
Luis