root/trunk/Node.java

// Node.java
//
// stores all the information about a node that the searching algorithm
// will know about.

import java.io.*;
import java.util.*;

public abstract class Node implements Serializable {
        static final long serialVersionUID = 3897565286366276995L;
        Node(int id) {
                this.id = id;
        }
        
        Node(int id, String name, String description) {
                this.id = id;
                this.name = name;
                this.description = description;
        }
        // returns a new (modifiable) cost smaller than the actual cost required
        //      to reach the destination.
        // called by a search algorithm, or possibly by edges (as part of a search)
        // this must be overridden by all subclasses
        public abstract Cost computeHCost(Search s, Node previousNode);

        // note - eventually there will be methods to handle naming of nodes
        // it was not necessary in this demo, however.

        public boolean equals(Object o) {
                return (o instanceof Node) && (((Node)o).id == id);
        }

        public int hashCode() {
                return id;
        }

        // for debug purposes
        public String toString() {
                return "Node\n" + infoToString();
        }

        public String infoToString() {
                return "\tid=" + id + "\n\tname=" + name + "\n\tdescription=" + description + "\n";     
        }
        
        private void readObject(java.io.ObjectInputStream in) throws IOException, ClassNotFoundException {
                in.defaultReadObject();
                edges = new LinkedList();
        }

        public void setDescription(String desc) { description = desc; }
        public String getDescription() { return description; }

        public String getName() { return name; }
        // changing the name of a node will break lookup by name in the graph
        // that contains the node, however, this breakage won't be persistant
        // across saves, so it's not a problem.
        public void setName(String s) {
                name = s;
        }
        
        // returns whether the node should be displayed with the given map
        public boolean isOnMap(BackgroundMap m) {
                return true;
        }

        // this must be unique within a graph for serialization to work
        public final int id;


        // this is encouraged to be unique per graph, so lookup by name works
        private String name = "";
        
        // this need not be unique, or in any specific format, and is designed
        // for human consumption.
        private String description = "";
        

        //TODO:  make get/set functions for this
        public transient Collection edges = new LinkedList();
}