[gef-dev] [C]DAG layout algorithms released to CVS example

[Randy Hudson <hudsonr@xxxxxxxxxx>]

Any suggestions are welcome on how to
name and structure the graph layout classes.  It is currently done
like this:
Data structures:
  -DirectedGraph
  -CompoundDirectedGraph (extends
DirectedGraph)
  -Node
  -Subgraph (extends Node)
  -Edge
  -Ranks

The nodes and edges store the input
data for the graph, but they *also* contain fields for working data required
by the algorithms.  These fields will be marked as internal in the
JavaDOC, as only the layout results (x,y,width,height, index, and rank)
should be accessed.

Each step of the layout is implemented
as a graph "visitor".  There are lots of steps, so a convenience
class called DirectedGraphLayout also exists which runs all visitors.  Prior
to the 3.0 release, we may not be able to commit on the API/names for the
various steps to the layout.  But, this is the whole purpose of reaching
out, defining good class names, and understanding how the layout will be
used and or extended.

-Randy