Link types


I have “process trees” that I am rendering in JGO.
Some of the links in the tree are significant, in that they should be used to determine the layout of the tree. Other types of link are insignificant.
I have tested a multi-stage layout approach. I create the nodes and significant links and perform a layout as per normal.
I have subclassed JGoLayeredDigraphAutoLayout so that I can call methods like layoutLinks publicly. So after doing the first layout, I create the insignificant links, and then call my new public method to layout the new links. This fails with a null pointer exception (preconditions on layoutLinks not met I guess). What can I do to resolve?
Ideally I would want my tree layed out based upon the significant links. For the insignificant links I would want them routed around the “tree” so as to minimize crossings (particularly over nodes).


I’m not sure about how to do this–I can investigate this next week, after the holidays.


Hmmm. I can’t think of a good solution at this time. The layered-digraph layout doesn’t have the features one might want in a tree-layout.