org.locationtech.jts.planargraph

Class PlanarGraph

java.lang.Object

org.locationtech.jts.planargraph.PlanarGraph

Direct Known Subclasses:

LineMergeGraph

public abstract class PlanarGraph
extends Object

Represents a directed graph which is embeddable in a planar surface.

This class and the other classes in this package serve as a framework for building planar graphs for specific algorithms. This class must be subclassed to expose appropriate methods to construct the graph. This allows controlling the types of graph components (DirectedEdges, Edges and Nodes) which can be added to the graph. An application which uses the graph framework will almost always provide subclasses for one or more graph components, which hold application-specific data and graph algorithms.

Version:

1.7

Constructor Summary

Constructors

Constructor and Description
PlanarGraph() Constructs a empty graph.

Method Summary

Modifier and Type	Method and Description
boolean	contains(DirectedEdge de) Tests whether this graph contains the given DirectedEdge
boolean	contains(Edge e) Tests whether this graph contains the given Edge
Iterator	dirEdgeIterator() Returns an Iterator over the DirectedEdges in this PlanarGraph, in the order in which they were added.
Iterator	edgeIterator() Returns an Iterator over the Edges in this PlanarGraph, in the order in which they were added.
Node	findNode(Coordinate pt) Returns the Node at the given location, or null if no Node was there.
List	findNodesOfDegree(int degree) Returns all Nodes with the given number of Edges around it.
Collection	getEdges() Returns the Edges that have been added to this PlanarGraph
Collection	getNodes()
Iterator	nodeIterator() Returns an Iterator over the Nodes in this PlanarGraph.
void	remove(DirectedEdge de) Removes a DirectedEdge from its from-Node and from this graph.
void	remove(Edge edge) Removes an Edge and its associated DirectedEdges from their from-Nodes and from the graph.
void	remove(Node node) Removes a node from the graph, along with any associated DirectedEdges and Edges.

Methods inherited from class java.lang.Object

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

Constructor Detail

PlanarGraph

public PlanarGraph()

Constructs a empty graph.

Method Detail

findNode

public Node findNode(Coordinate pt)

Returns the Node at the given location, or null if no Node was there.

Parameters:

pt - the location to query

Returns:

the node found or null if this graph contains no node at the location

nodeIterator

public Iterator nodeIterator()

Returns an Iterator over the Nodes in this PlanarGraph.

contains

public boolean contains(Edge e)

Tests whether this graph contains the given Edge

Parameters:

e - the edge to query

Returns:

true if the graph contains the edge

contains

public boolean contains(DirectedEdge de)

Tests whether this graph contains the given DirectedEdge

Parameters:

de - the directed edge to query

Returns:

true if the graph contains the directed edge

getNodes

public Collection getNodes()

dirEdgeIterator

public Iterator dirEdgeIterator()

Returns an Iterator over the DirectedEdges in this PlanarGraph, in the order in which they were added.

See Also:

add(Edge), add(DirectedEdge)

edgeIterator

public Iterator edgeIterator()

Returns an Iterator over the Edges in this PlanarGraph, in the order in which they were added.

See Also:

add(Edge)

getEdges

public Collection getEdges()

Returns the Edges that have been added to this PlanarGraph

See Also:

add(Edge)

remove

public void remove(Edge edge)

Removes an Edge and its associated DirectedEdges from their from-Nodes and from the graph. Note: This method does not remove the Nodes associated with the Edge, even if the removal of the Edge reduces the degree of a Node to zero.

remove

public void remove(DirectedEdge de)

Removes a DirectedEdge from its from-Node and from this graph. This method does not remove the Nodes associated with the DirectedEdge, even if the removal of the DirectedEdge reduces the degree of a Node to zero.

remove

public void remove(Node node)

Removes a node from the graph, along with any associated DirectedEdges and Edges.

findNodesOfDegree

public List findNodesOfDegree(int degree)

Returns all Nodes with the given number of Edges around it.