VisClient/org/dronus/graph/Graph.java

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package org.dronus.graph;


import java.io.BufferedReader;
import java.io.IOException;
import java.io.PrintStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.StringTokenizer;

public class Graph  {   
        public List<Node> nodes= new ArrayList<Node>();
        public HashSet<Edge> edges= new HashSet<Edge>();

    protected HashMap<Integer,Node> nodeIDRegistry = new HashMap<Integer,Node>();
        // ...........

    Node root;
    
    public Graph() {}
    
        public Graph(BufferedReader r, boolean silent) throws IOException {
                load(r, silent);
        }
    
    public int nodeCount() {
        return nodes.size(); 
    }

   
    public void addNode( Node node ) {
        int id=node.id;
        if ( findNode(id) == null ) { // doesn't already exist
            nodeIDRegistry.put(id,node);                                
            nodes.add(node);
            if(root==null) root=node;
        } else throw new RuntimeException("node ID '"+id+"' already exists.");        
    }

    public void addEdge( Edge edge ) {
        if ( edge == null ) return;
        if(!edges.contains(edge)) {
            edges.add(edge);
            edge.getFrom().addEdge(edge);
            edge.getTo().addEdge(edge);
        }
    }

    public Node findNode(int id ) {
        //if ( id == 0 ) return null; // ignore
        return nodeIDRegistry.get(id);
    }
    
    
    public Edge findEdge( Node from, Node to ) {
        for (Edge e: from.getEdges()) {
            if (e.getTo() == to) return e;
        }
        return null;
    }

    public boolean deleteEdge( Edge edge ) {
        synchronized(edges) {
            if ( edge == null ) return false;
            if (!edges.remove(edge)) return false;
            edge.getFrom().removeEdge(edge);
            edge.getTo().removeEdge(edge);
            return true;
        }
    }

    synchronized public boolean removeNode( Node node ) {
        if ( node == null ) return false;
        if (!nodes.remove(node)) return false;
        int id = node.id;
        if (id != 0) nodeIDRegistry.remove(id); 
        return true;
    }

    synchronized public boolean deleteNode( Node node ) {
        if ( node == null ) return false;
        if ( !nodes.remove(node) ) return false;
        int id = node.id;
        if (id != 0 ) nodeIDRegistry.remove(id); 
        for (Edge e: node.getEdges() ) {
            if ( e.getFrom() == node ) {
                edges.remove(e);
                e.getTo().removeEdge(e);
            } else if ( e.getTo() == node ) {
                edges.remove(e);
                e.getFrom().removeEdge(e);
            }
        }
        return true;
    }

    public Node getRoot(){
        return root;
    }
    
        synchronized public void clearAll() {
                nodes.clear();
                edges.clear();
                nodeIDRegistry.clear();
    }
        
        void load(BufferedReader r, boolean silent) throws IOException{
                String line;
                
                //read all nodes.
                while(!(line=r.readLine()).equals("") && line.length()>0)       {
                        StringTokenizer tok=new StringTokenizer(line,"\t");
                        String id=tok.nextToken(), name=tok.nextToken(), type=tok.nextToken();
                        Node n=new Node(id, unescape(name), type);
                        if(findNode(id.hashCode())==null) 
                                addNode(n);             
                }
                
                if(!silent)  System.out.print(nodeCount()+" Nodes; ");                  
                
                //read all edges. 
                while((line=r.readLine())!=null && line.length()>0)     {
                        StringTokenizer tok=new StringTokenizer(line,"\t");
                        String id=tok.nextToken(), n1=tok.nextToken(), n2=tok.nextToken();
                    
                        String name=tok.nextToken();                            
                        Node node1=findNode(n1.hashCode()), node2=findNode(n2.hashCode());
                        
                        Edge e=new Edge(node1,node2, id,name);
                        if (node1!=null && node2!=null) addEdge(e); //add edge only if nodes exist!
                        else
                                System.out.println("\n Edge damaged: "+id+" from "+n1+" to "+n2);
                }
                if(!silent)  System.out.println(edges.size()+" Edges.");
                
//              fill fake set edges (not transfered)
                if (getRoot()!=null && getRoot().type.equals("Set")){
                        Node set=getRoot();
                        for (Node n: nodes)
                                addEdge(new Edge(n, set, null,"in"));
                }
        }                       
        
        public void dump(PrintStream p){
                for (Node n : nodes)
                        p.println(n.id+"\t"+n.text+"\t"+n.type+"\t");
                p.println();
                for (Edge e: edges)
                        p.println(e.id+"\t"+e.from.id+"\t"+e.to.id+"\t"+e.type);
        }
        
        String unescape(String escaped){
                return escaped.replace("\\n", "\n");
        }
} 

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