net.sourceforge.esw.graph.context
Class SameValueNodeContextFactory

java.lang.Object
  |
  +--net.sourceforge.esw.graph.context.PrototypeNodeContextFactory
        |
        +--net.sourceforge.esw.graph.context.SameValueNodeContextFactory

All Implemented Interfaces:

INodeContextFactory, IPrototypeNodeContextFactory, java.io.Serializable

public class SameValueNodeContextFactory

extends PrototypeNodeContextFactory

Provides same-value context for creation of a single INode instance, or a graph of INode instances.

INodeContextFactory implementors can use this factory to control creational behavior and patterns for INode instances. It allows the program to specifiy the semantics used when creating a graph of INode instances, or a single INode instance. It allows a one-step indirection for INode creation beyond the NodeFactory.

A typical use of an IPrototypeNodeContextFactory instance is to predefine a data structure to be used for a graph, then using the getGraph() method to clone that predefined data structure, or prototype, to fill in the details of the graph.

This IPrototypeNodeContextFactory interface extends the INodeContextFactory interface by providing prototypes to the context factory. A prototype follows the Prototype design pattern. The cloning semantics are an implementation detail of the implementor of the IPrototypeNodeContextFactory interface.

Intended to be used when the same graph needs to be used over and over again. For example, use this when the columns of a 2 dimensonal structure are always the same but the data in those columns change from row to row. To save object instantiation costs, use a SameValueNodeContextFactory instance and each call made to getGraph will return a reference to the same object, allowing the instance to be filled in without creating new INode instances. Understand that this means that only one "row" of data can be filled in at a time, and can only be used during a single thread of execution or the data will be replaced.

See Also:

INode, Serialized Form

Fields inherited from class net.sourceforge.esw.graph.context.PrototypeNodeContextFactory

prototype

Constructor Summary

SameValueNodeContextFactory()

Method Summary

INode	getGraph() Returns a graph of newly created INode instances.
INode	getSingleNode() Returns a newly created INode instance.

Methods inherited from class net.sourceforge.esw.graph.context.PrototypeNodeContextFactory

getPrototype, setPrototype

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SameValueNodeContextFactory

public SameValueNodeContextFactory()

Method Detail

getGraph

public INode getGraph()

Returns a graph of newly created INode instances.

This implementation returns the exact prototype that was set on this SameValueNodeContextFactory instance.

Overrides:

getGraph in class PrototypeNodeContextFactory

getSingleNode

public INode getSingleNode()

Returns a newly created INode instance.

Implementors can use this method to allow single INode instances to be added to a graph that follow the semantics of the INode instances created via the getGraph method.

This implementation returns a single INode instance returned from a call to NodeFactory.createNode().

Overrides:

getSingleNode in class PrototypeNodeContextFactory