Package org.locationtech.jts.planargraph

Class Subgraph

  • public class Subgraph
extends Object
    A subgraph of a PlanarGraph. A subgraph may contain any subset of Edges from the parent graph. It will also automatically contain all DirectedEdges and Nodes associated with those edges. No new objects are created when edges are added - all associated components must already exist in the parent graph.

    • Field Detail

      • edges

        protected Set edges

      • dirEdges

        protected List dirEdges

      • nodeMap

        protected NodeMap nodeMap

    • Constructor Detail

      • Subgraph

        public Subgraph​(PlanarGraph parentGraph)
        Creates a new subgraph of the given PlanarGraph
        Parameters:
        parentGraph - the parent graph

    • Method Detail

      • getParent

        public PlanarGraph getParent()
        Gets the PlanarGraph which this subgraph is part of.
        Returns:
        the parent PlanarGraph

      • add

        public void add​(Edge e)
        Adds an Edge to the subgraph. The associated DirectedEdges and Nodes are also added.
        Parameters:
        e - the edge to add

      • dirEdgeIterator

        public Iterator dirEdgeIterator()
        Returns an Iterator over the DirectedEdges in this graph, in the order in which they were added.
        Returns:
        an iterator over the directed edges
        See Also:
        add(Edge)

      • edgeIterator

        public Iterator edgeIterator()
        Returns an Iterator over the Edges in this graph, in the order in which they were added.
        Returns:
        an iterator over the edges
        See Also:
        add(Edge)

      • nodeIterator

        public Iterator nodeIterator()
        Returns an Iterator over the Nodes in this graph.
        Returns:
        an iterator over the nodes

      • contains

        public boolean contains​(Edge e)
        Tests whether an Edge is contained in this subgraph
        Parameters:
        e - the edge to test
        Returns:
        true if the edge is contained in this subgraph