Package org.locationtech.jts.planargraph
Class PlanarGraph
- java.lang.Object
-
- org.locationtech.jts.planargraph.PlanarGraph
-
- Direct Known Subclasses:
LineMergeGraph
,PolygonizeGraph
public abstract class PlanarGraph extends java.lang.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 (
DirectedEdge
s,Edge
s andNode
s) 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 Description PlanarGraph()
Constructs a empty graph.
-
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description protected void
add(DirectedEdge dirEdge)
Adds the Edge to this PlanarGraph; only subclasses can add DirectedEdges, to ensure the edges added are of the right class.protected void
add(Edge edge)
Adds the Edge and its DirectedEdges with this PlanarGraph.protected void
add(Node node)
Adds a node to the map, replacing any that is already at that location.boolean
contains(DirectedEdge de)
Tests whether this graph contains the givenDirectedEdge
boolean
contains(Edge e)
Tests whether this graph contains the givenEdge
java.util.Iterator
dirEdgeIterator()
Returns an Iterator over the DirectedEdges in this PlanarGraph, in the order in which they were added.java.util.Iterator
edgeIterator()
Returns an Iterator over the Edges in this PlanarGraph, in the order in which they were added.Node
findNode(Coordinate pt)
java.util.List
findNodesOfDegree(int degree)
Returns all Nodes with the given number of Edges around it.java.util.Collection
getEdges()
Returns the Edges that have been added to this PlanarGraphjava.util.Collection
getNodes()
java.util.Iterator
nodeIterator()
Returns an Iterator over the Nodes in this PlanarGraph.void
remove(DirectedEdge de)
Removes aDirectedEdge
from its from-Node
and from this graph.void
remove(Edge edge)
Removes anEdge
and its associatedDirectedEdge
s 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.
-
-
-
Field Detail
-
edges
protected java.util.Set edges
-
dirEdges
protected java.util.Set dirEdges
-
nodeMap
protected NodeMap nodeMap
-
-
Method Detail
-
findNode
public Node findNode(Coordinate pt)
- Parameters:
pt
- the location to query- Returns:
- the node found
or
null
if this graph contains no node at the location
-
add
protected void add(Node node)
Adds a node to the map, replacing any that is already at that location. Only subclasses can add Nodes, to ensure Nodes are of the right type.- Parameters:
node
- the node to add
-
add
protected void add(Edge edge)
Adds the Edge and its DirectedEdges with this PlanarGraph. Assumes that the Edge has already been created with its associated DirectEdges. Only subclasses can add Edges, to ensure the edges added are of the right class.
-
add
protected void add(DirectedEdge dirEdge)
Adds the Edge to this PlanarGraph; only subclasses can add DirectedEdges, to ensure the edges added are of the right class.
-
nodeIterator
public java.util.Iterator nodeIterator()
Returns an Iterator over the Nodes in this PlanarGraph.
-
contains
public boolean contains(Edge e)
Tests whether this graph contains the givenEdge
- 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 givenDirectedEdge
- Parameters:
de
- the directed edge to query- Returns:
true
if the graph contains the directed edge
-
getNodes
public java.util.Collection getNodes()
-
dirEdgeIterator
public java.util.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 java.util.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 java.util.Collection getEdges()
Returns the Edges that have been added to this PlanarGraph- See Also:
add(Edge)
-
remove
public void remove(Edge edge)
-
remove
public void remove(DirectedEdge de)
Removes aDirectedEdge
from its from-Node
and from this graph. This method does not remove theNode
s 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 java.util.List findNodesOfDegree(int degree)
Returns all Nodes with the given number of Edges around it.
-
-