CompositeGraphMaker

Superclass

GraphMaker

Subclasses

none

Referenced By

GraphMaker

This class is created when an arithmetic operation must be performed on two graph
specifications.  Therefore its result is the operation of the result of the first and the
result of the second.  When either of the two children changes its results, it is kept in
the database.  When the other child also changes, then the results are recalculated and a
changed message is sent.

Instance Variables:
operator   <Symbol>	The name of the method name to call.  It must take one argument.
firstMaker   <GraphMaker>	
secondMaker   <GraphMaker>	
changedChildren   <GraphMaker>	Keeps track of the child that has sent and update message.  Once the other updates, it returns to nil.

Developed By Jee Ku (jku@cat.ncsa.uiuc.edu) and Joseph W. Yoder (yoder@cs.uiuc.edu)