com.vividsolutions.jts.planargraph
Class PlanarGraph
java.lang.Object
com.vividsolutions.jts.planargraph.PlanarGraph
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 and
Node
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.
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.
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protected void | add(Edge edge) - Adds the Edge and its DirectedEdges with this PlanarGraph.
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protected void | add(Node node) - Adds a node to the map, replacing any that is already at that location.
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boolean | contains(DirectedEdge de) - Tests whether this graph contains the given
DirectedEdge
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boolean | contains(Edge e) - Tests whether this graph contains the given
Edge
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Iterator | dirEdgeIterator() - Returns an Iterator over the DirectedEdges in this PlanarGraph, in the order in which they
were added.
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Iterator | edgeIterator() - Returns an Iterator over the Edges in this PlanarGraph, in the order in which they
were added.
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Node | findNode(Coordinate pt) - Returns the
Node at the given location,
or null if no Node was there.
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List | findNodesOfDegree(int degree) - Returns all Nodes with the given number of Edges around it.
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Collection | getEdges() - Returns the Edges that have been added to this PlanarGraph
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Collection | getNodes()
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Iterator | nodeIterator() - Returns an Iterator over the Nodes in this PlanarGraph.
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void | remove(DirectedEdge de) - Removes DirectedEdge from its from-Node and from this PlanarGraph.
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void | remove(Edge edge) - Removes an
Edge and its associated DirectedEdge s
from their from-Nodes and from the graph.
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void | remove(Node node) - Removes a node from the graph, along with any associated DirectedEdges and
Edges.
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dirEdges
protected Set dirEdges
PlanarGraph
public PlanarGraph()
Constructs a empty graph.
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.
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(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.
contains
public boolean contains(DirectedEdge de)
de
- the directed edge to query
true
if the graph contains the directed edge
contains
public boolean contains(Edge e)
Tests whether this graph contains the given
Edge
true
if the graph contains the edge
dirEdgeIterator
public Iterator dirEdgeIterator()
Returns an Iterator over the DirectedEdges in this PlanarGraph, in the order in which they
were added.
edgeIterator
public Iterator edgeIterator()
Returns an Iterator over the Edges in this PlanarGraph, in the order in which they
were added.
findNode
public Node findNode(Coordinate pt)
Returns the
Node
at the given location,
or null if no
Node
was there.
pt
- the location to query
findNodesOfDegree
public List findNodesOfDegree(int degree)
Returns all Nodes with the given number of Edges around it.
getEdges
public Collection getEdges()
Returns the Edges that have been added to this PlanarGraph
getNodes
public Collection getNodes()
nodeIterator
public Iterator nodeIterator()
Returns an Iterator over the Nodes in this PlanarGraph.
remove
public void remove(DirectedEdge de)
Removes DirectedEdge from its from-Node and from this PlanarGraph.
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(Edge edge)
Removes an
Edge
and its associated
DirectedEdge
s
from their from-Nodes and from the graph.
Note: This method does not remove the
Node
s associated
with the
Edge
, even if the removal of the
Edge
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.