can dia canvas help me with interactive graph drawing?

[Britton <fsblk aurora uaf edu>]

I'm just getting started on an interactive graph drawer for eiffel, and I
recently noticed that debian has split off a dia-newcanvas package.  I'm
trying to determine if the dia canvas can work for me.  I need to be able
to:

   1. Pop object nodes onto the screen (with 'ref: CLASS_NAME' labels).

   2. Allow user to move nodes around.  Edges would need to follow, of
      course.

   3. Get feedback on where nodes end up without too much pain.

   4. If there is a way to make certain drawn objects unmodifiable, that
      would be excellent, but shouldn't be strictly necessary, provided I
      can be sure they still exist and have certain outline features.

The obvious huge benefit of using the dia canvas for this is that users
would end up with diagrams that they could easily mark up to taste, with
all the power of dia.

If anyone can give me advice on how well the dia canvas is suited to this,
or if there is a better toolkit to use, I would greatly appreciate it.

Britton Kerin
__
GNU GPL: "The Source will be with you... always."