java.lang.Object
- org.jgrapht.traverse.AbstractGraphIterator<V,E>

Type Parameters:

V - the graph vertex type

E - the graph edge type

All Implemented Interfaces:

Iterator<V>, GraphIterator<V,E>

Direct Known Subclasses:

CrossComponentIterator, DegeneracyOrderingIterator, LexBreadthFirstIterator, MaximumCardinalityIterator, TopologicalOrderIterator
```
public abstract class AbstractGraphIterator<V,E>
extends Object
implements GraphIterator<V,E>
```
An empty implementation of a graph iterator to minimize the effort required to implement graph iterators.

Author:

Barak Naveh

Field Summary

Fields
Modifier and Type	Field	Description
`protected boolean`	`crossComponentTraversal`
`protected Graph<V,E>`	`graph`
`protected int`	`nListeners`
`protected org.jgrapht.traverse.AbstractGraphIterator.FlyweightEdgeEvent<E>`	`reusableEdgeEvent`
`protected org.jgrapht.traverse.AbstractGraphIterator.FlyweightVertexEvent<V>`	`reusableVertexEvent`
`protected boolean`	`reuseEvents`

Constructor Summary

Constructors
Constructor Description

AbstractGraphIterator(Graph<V,E> graph)
Create a new iterator

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`addTraversalListener(TraversalListener<V,E> l)`	Adds the specified traversal listener to this iterator.
`protected EdgeTraversalEvent<E>`	`createEdgeTraversalEvent(E edge)`	Create an edge traversal event.
`protected VertexTraversalEvent<V>`	`createVertexTraversalEvent(V vertex)`	Create a vertex traversal event.
`protected void`	`fireConnectedComponentFinished(ConnectedComponentTraversalEvent e)`	Informs all listeners that the traversal of the current connected component finished.
`protected void`	`fireConnectedComponentStarted(ConnectedComponentTraversalEvent e)`	Informs all listeners that a traversal of a new connected component has started.
`protected void`	`fireEdgeTraversed(EdgeTraversalEvent<E> e)`	Informs all listeners that a the specified edge was visited.
`protected void`	`fireVertexFinished(VertexTraversalEvent<V> e)`	Informs all listeners that a the specified vertex was finished.
`protected void`	`fireVertexTraversed(VertexTraversalEvent<V> e)`	Informs all listeners that a the specified vertex was visited.
`Graph<V,E>`	`getGraph()`	Get the graph being traversed.
`boolean`	`isCrossComponentTraversal()`	Test whether this iterator is set to traverse the graph across connected components.
`boolean`	`isReuseEvents()`	Tests whether the `reuseEvents` flag is set.
`void`	`remove()`	Unsupported.
`void`	`removeTraversalListener(TraversalListener<V,E> l)`	Removes the specified traversal listener from this iterator.
`void`	`setCrossComponentTraversal(boolean crossComponentTraversal)`	Sets the cross component traversal flag - indicates whether to traverse the graph across connected components.
`void`	`setReuseEvents(boolean reuseEvents)`	Sets a value the `reuseEvents` flag.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.Iterator
forEachRemaining, hasNext, next

- Field Detail
  - nListeners
```
protected int nListeners
```
  - reusableEdgeEvent
```
protected final org.jgrapht.traverse.AbstractGraphIterator.FlyweightEdgeEvent<E> reusableEdgeEvent
```
  - reusableVertexEvent
```
protected final org.jgrapht.traverse.AbstractGraphIterator.FlyweightVertexEvent<V> reusableVertexEvent
```
  - graph
```
protected final Graph<V,E> graph
```
  - crossComponentTraversal
```
protected boolean crossComponentTraversal
```
  - reuseEvents
```
protected boolean reuseEvents
```
- Constructor Detail
  - AbstractGraphIterator
```
public AbstractGraphIterator(Graph<V,E> graph)
```
    Create a new iterator
    
    Parameters:
    
    graph - the graph
    
    Throws:
    
    NullPointerException - if argument is null
- Method Detail
  - getGraph
```
public Graph<V,E> getGraph()
```
    Get the graph being traversed.
    
    Returns:
    
    the graph being traversed
  - setCrossComponentTraversal
```
public void setCrossComponentTraversal(boolean crossComponentTraversal)
```
    Sets the cross component traversal flag - indicates whether to traverse the graph across connected components.
    
    Parameters:
    
    crossComponentTraversal - if true traverses across connected components.
    
    Throws:
    
    IllegalArgumentException - if the argument is invalid for this iterator
  - isCrossComponentTraversal
```
public boolean isCrossComponentTraversal()
```
    Test whether this iterator is set to traverse the graph across connected components.
    
    Specified by:
    
    isCrossComponentTraversal in interface GraphIterator<V,E>
    
    Returns:
    
    true if traverses across connected components, otherwise false.
  - setReuseEvents
```
public void setReuseEvents(boolean reuseEvents)
```
    Description copied from interface: GraphIterator
    
    Sets a value the reuseEvents flag. If the reuseEvents flag is set to true this class will reuse previously fired events and will not create a new object for each event. This option increases performance but should be used with care, especially in multithreaded environment.
    
    Specified by:
    
    setReuseEvents in interface GraphIterator<V,E>
    
    Parameters:
    
    reuseEvents - whether to reuse previously fired event objects instead of creating a new event object for each event.
  - isReuseEvents
```
public boolean isReuseEvents()
```
    Description copied from interface: GraphIterator
    
    Tests whether the reuseEvents flag is set. If the flag is set to true this class will reuse previously fired events and will not create a new object for each event. This option increases performance but should be used with care, especially in multithreaded environment.
    
    Specified by:
    
    isReuseEvents in interface GraphIterator<V,E>
    
    Returns:
    
    the value of the reuseEvents flag.
  - addTraversalListener
```
public void addTraversalListener(TraversalListener<V,E> l)
```
    Description copied from interface: GraphIterator
    
    Adds the specified traversal listener to this iterator.
    
    Specified by:
    
    addTraversalListener in interface GraphIterator<V,E>
    
    Parameters:
    
    l - the traversal listener to be added.
  - remove
```
public void remove()
```
    Description copied from interface: GraphIterator
    
    Unsupported.
    
    Specified by:
    
    remove in interface GraphIterator<V,E>
    
    Specified by:
    
    remove in interface Iterator<V>
    
    Throws:
    
    UnsupportedOperationException - always since operation is not supported
  - removeTraversalListener
```
public void removeTraversalListener(TraversalListener<V,E> l)
```
    Description copied from interface: GraphIterator
    
    Removes the specified traversal listener from this iterator.
    
    Specified by:
    
    removeTraversalListener in interface GraphIterator<V,E>
    
    Parameters:
    
    l - the traversal listener to be removed.
  - fireConnectedComponentFinished
```
protected void fireConnectedComponentFinished(ConnectedComponentTraversalEvent e)
```
    Informs all listeners that the traversal of the current connected component finished.
    
    Parameters:
    
    e - the connected component finished event.
  - fireConnectedComponentStarted
```
protected void fireConnectedComponentStarted(ConnectedComponentTraversalEvent e)
```
    Informs all listeners that a traversal of a new connected component has started.
    
    Parameters:
    
    e - the connected component started event.
  - fireEdgeTraversed
```
protected void fireEdgeTraversed(EdgeTraversalEvent<E> e)
```
    Informs all listeners that a the specified edge was visited.
    
    Parameters:
    
    e - the edge traversal event.
  - fireVertexTraversed
```
protected void fireVertexTraversed(VertexTraversalEvent<V> e)
```
    Informs all listeners that a the specified vertex was visited.
    
    Parameters:
    
    e - the vertex traversal event.
  - fireVertexFinished
```
protected void fireVertexFinished(VertexTraversalEvent<V> e)
```
    Informs all listeners that a the specified vertex was finished.
    
    Parameters:
    
    e - the vertex traversal event.
  - createVertexTraversalEvent
```
protected VertexTraversalEvent<V> createVertexTraversalEvent(V vertex)
```
    Create a vertex traversal event.
    
    Parameters:
    
    vertex - the vertex
    
    Returns:
    
    the event
  - createEdgeTraversalEvent
```
protected EdgeTraversalEvent<E> createEdgeTraversalEvent(E edge)
```
    Create an edge traversal event.
    
    Parameters:
    
    edge - the edge
    
    Returns:
    
    the event

Class AbstractGraphIterator<V,​E>

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface java.util.Iterator

Field Detail

nListeners

reusableEdgeEvent

reusableVertexEvent

graph

crossComponentTraversal

reuseEvents

Constructor Detail

AbstractGraphIterator

Method Detail

getGraph

setCrossComponentTraversal

isCrossComponentTraversal

setReuseEvents

isReuseEvents

addTraversalListener

remove

removeTraversalListener

fireConnectedComponentFinished

fireConnectedComponentStarted

fireEdgeTraversed

fireVertexTraversed

fireVertexFinished

createVertexTraversalEvent

createEdgeTraversalEvent

Class AbstractGraphIterator<V,E>