Package org.graphstream.graph

Class Path

java.lang.Object
org.graphstream.graph.Path
All Implemented Interfaces:
Structure
public class Path
extends Object
implements Structure
Path description.

A path is a class that stores ordered lists of nodes and links that are adjacent. Such a path may be manipulated with nodes and/or edges added or removed. This class is designed as a dynamic structure that is, to add edges during the construction of the path. Only edges need to be added, the nodes list is maintained automatically.

The two lists (one for nodes, one for edges) may be acceded at any moment in constant time.

The constraint of this class is that it needs to know the first node of the path (the root). This root can be set with the setRoot(Node) method or by using the add(Node, Edge) method.

The normal use with this class is to first use the setRoot(Node) method to initialize the path; then to use the add(Edge) method to grow it and the popEdge() or popNode().

  • Constructor Summary

    Constructors 
    Constructor Description
    Path()
    New empty path.

  • Method Summary

    Modifier and Type Method Description
    void add​(Edge edge)
    Adds an edge to the path.
    void add​(Node from, Edge edge)
    Adds a node and an edge to the path.
    void clear()
    Clears the path;
    boolean contains​(Edge edge)
    Says whether the path contains this edge or not.
    boolean contains​(Node node)
    Says whether the path contains this node or not.
    Stream<Edge> edges()  
    boolean empty()
    Returns true if the path is empty.
    boolean equals​(Path p)
    Compare the content of the current path and the specified path to decide weather they are equal or not.
    Path getACopy()
    Get a copy of this path
    int getEdgeCount()
    Number of edges in this graph.
    List<Edge> getEdgePath()
    Returns the list of edges representing the path.
    <T extends Edge>
    Collection<T>    		 getEdgeSet()  
    int getNodeCount()
    Returns the size of the path.
    List<Node> getNodePath()
    Construct an return a list of nodes that represents the path.
    <T extends Node>
    Collection<T>    		 getNodeSet()  
    Double getPathWeight​(String characteristic)
    It returns the sum of the characteristic given value in the Edges of the path.
    Node getRoot()
    Get the root (the first node) of the path.
    Stream<Node> nodes()  
    Edge peekEdge()
    Looks at the edge at the top of the stack without removing it from the stack.
    Node peekNode()
    Looks at the node at the top of the stack without removing it from the stack.
    Edge popEdge()
    This methods pops the 2 stacks (edgePath and nodePath) and returns the removed edge.
    Node popNode()
    This methods pops the 2 stacks (edgePath and nodePath) and returns the removed node.
    void push​(Edge edge)
    A synonym for add(Edge).
    void push​(Node from, Edge edge)
    A synonym for add(Edge).
    void removeLoops()
    Remove all parts of the path that start at a given node and pass a new at this node.
    void setRoot​(Node root)
    Set the root (first node) of the path.
    int size()
    Returns the size of the path
    String toString()
    Returns a String description of the path.

    Methods inherited from class java.lang.Object

    equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

  • Constructor Details

    • Path

      public Path()
      New empty path.

  • Method Details

    • getRoot

      public Node getRoot()
      Get the root (the first node) of the path.
      Returns:
      the root of the path.

    • setRoot

      public void setRoot​(Node root)
      Set the root (first node) of the path.
      Parameters:
      root - The root of the path.

    • contains

      public boolean contains​(Node node)
      Says whether the path contains this node or not.
      Parameters:
      node - The node tested for existence in the path.
      Returns:
      true if the path contains the node.

    • contains

      public boolean contains​(Edge edge)
      Says whether the path contains this edge or not.
      Parameters:
      edge - The edge tested for existence in the path.
      Returns:
      true if the path contains the edge.

    • empty

      public boolean empty()
      Returns true if the path is empty.
      Returns:
      true if the path is empty.

    • size

      public int size()
      Returns the size of the path

    • getPathWeight

      public Double getPathWeight​(String characteristic)
      It returns the sum of the characteristic given value in the Edges of the path.
      Parameters:
      characteristic - The characteristic.
      Returns:
      Sum of the characteristics.

    • getEdgePath

      public List<Edge> getEdgePath()
      Returns the list of edges representing the path.
      Returns:
      The list of edges representing the path.

    • getNodePath

      public List<Node> getNodePath()
      Construct an return a list of nodes that represents the path.
      Returns:
      A list of nodes representing the path.

    • add

      public void add​(Node from, Edge edge)
      Adds a node and an edge to the path. If root is not set, the node will be set as root. Otherwise from node must be the same as the head node of the path.
      Parameters:
      from - The start node.
      edge - The edge used.

    • add

      public void add​(Edge edge)
      Adds an edge to the path.
      Parameters:
      edge - The edge to add to the path.

    • push

      public void push​(Node from, Edge edge)
      A synonym for add(Edge).

    • push

      public void push​(Edge edge)
      A synonym for add(Edge).

    • popEdge

      public Edge popEdge()
      This methods pops the 2 stacks (edgePath and nodePath) and returns the removed edge.
      Returns:
      The edge that have just been removed.

    • popNode

      public Node popNode()
      This methods pops the 2 stacks (edgePath and nodePath) and returns the removed node.
      Returns:
      The node that have just been removed.

    • peekNode

      public Node peekNode()
      Looks at the node at the top of the stack without removing it from the stack.
      Returns:
      The node at the top of the stack.

    • peekEdge

      public Edge peekEdge()
      Looks at the edge at the top of the stack without removing it from the stack.
      Returns:
      The edge at the top of the stack.

    • clear

      public void clear()
      Clears the path;

    • getACopy

      public Path getACopy()
      Get a copy of this path
      Returns:
      A copy of this path.

    • removeLoops

      public void removeLoops()
      Remove all parts of the path that start at a given node and pass a new at this node.

    • equals

      public boolean equals​(Path p)
      Compare the content of the current path and the specified path to decide weather they are equal or not.
      Parameters:
      p - A path to compare to the curent one.
      Returns:
      True if both paths are equal.

    • toString

      public String toString()
      Returns a String description of the path.
      Overrides:
      toString in class Object
      Returns:
      A String representation of the path.

    • getNodeCount

      public int getNodeCount()
      Returns the size of the path. Identical to size().
      Specified by:
      getNodeCount in interface Structure
      Returns:
      The size of the path.

    • getEdgeCount

      public int getEdgeCount()
      Description copied from interface: Structure
      Number of edges in this graph.
      Specified by:
      getEdgeCount in interface Structure
      Returns:
      The number of edges.

    • nodes

      public Stream<Node> nodes()
      Specified by:
      nodes in interface Structure

    • edges

      public Stream<Edge> edges()
      Specified by:
      edges in interface Structure

    • getNodeSet

      public <T extends Node> Collection<T> getNodeSet()

    • getEdgeSet

      public <T extends Edge> Collection<T> getEdgeSet()