I have (or hope to have) a custom view with a bipartite graph in it.
Strictly, the model consists of only the labeled nodes and edges. But the user can move the nodes around to better visualize some aspect currently under study. When re-opening the document the XY locations of each node should remain the same as when it was last saved.
I plan to use NSKeyedArchiver.
In a preliminary version, I've included the XY location of each node in the model, but in general this doesn't seem right. This seems to me like data that should be included, perhaps, in a mediating controller, but not in the model itself.
I can think of various ways this might be done, but none seem very "elegant".
Any suggestions?