prefuse.data.util
Class BreadthFirstIterator

java.lang.Object
  prefuse.data.util.BreadthFirstIterator

All Implemented Interfaces:

java.util.Iterator

public class BreadthFirstIterator
extends java.lang.Object
implements java.util.Iterator

Provides a distance-limited breadth first traversal over nodes, edges, or both, using any number of traversal "roots".

Author:

jeffrey heer

Field Summary

protected int	m_depth
protected boolean	m_includeEdges
protected boolean	m_includeNodes
protected Queue	m_queue
protected int	m_traversal

Constructor Summary

BreadthFirstIterator()
Create an uninitialized BreadthFirstIterator.

BreadthFirstIterator(java.util.Iterator it, int depth, int traversal)
Create a new BreadthFirstIterator starting from the given source nodes.

BreadthFirstIterator(Node n, int depth, int traversal)
Create a new BreadthFirstIterator starting from the given source node.

Method Summary

int	getDepth(Tuple t) Get the traversal depth at which a particular tuple was encountered.
protected java.util.Iterator	getEdges(Node n) Determines which edges are traversed for a given node.
boolean	hasNext()
void	init(java.lang.Object o, int depth, int traversal) Initialize (or re-initialize) this iterator.
java.lang.Object	next()
void	remove()

Methods inherited from class java.lang.Object

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

Field Detail

m_queue

protected Queue m_queue

m_depth

protected int m_depth

m_traversal

protected int m_traversal

m_includeNodes

protected boolean m_includeNodes

m_includeEdges

protected boolean m_includeEdges

Constructor Detail

BreadthFirstIterator

public BreadthFirstIterator()

Create an uninitialized BreadthFirstIterator. Use the init(Object, int, int) method to initialize the iterator.

BreadthFirstIterator

public BreadthFirstIterator(Node n,
                            int depth,
                            int traversal)

Create a new BreadthFirstIterator starting from the given source node.

Parameters:

n - the source node from which to begin the traversal

depth - the maximum graph distance to traverse

traversal - the traversal type, one of Constants.NODE_TRAVERSAL, Constants.EDGE_TRAVERSAL, or Constants.NODE_AND_EDGE_TRAVERSAL

BreadthFirstIterator

public BreadthFirstIterator(java.util.Iterator it,
                            int depth,
                            int traversal)

Create a new BreadthFirstIterator starting from the given source nodes.

Parameters:

it - an Iterator over the source nodes from which to begin the traversal

depth - the maximum graph distance to traverse

traversal - the traversal type, one of Constants.NODE_TRAVERSAL, Constants.EDGE_TRAVERSAL, or Constants.NODE_AND_EDGE_TRAVERSAL

Method Detail

init

public void init(java.lang.Object o,
                 int depth,
                 int traversal)

Initialize (or re-initialize) this iterator.

Parameters:

o - Either a source node or iterator over source nodes

depth - the maximum graph distance to traverse

traversal - the traversal type, one of Constants.NODE_TRAVERSAL, Constants.EDGE_TRAVERSAL, or Constants.NODE_AND_EDGE_TRAVERSAL

remove

public void remove()

Specified by:

remove in interface java.util.Iterator

See Also:

Iterator.remove()

hasNext

public boolean hasNext()

Specified by:

hasNext in interface java.util.Iterator

See Also:

Iterator.hasNext()

getEdges

protected java.util.Iterator getEdges(Node n)

Determines which edges are traversed for a given node.

Parameters:

n - a node

Returns:

an iterator over edges incident on the node

getDepth

public int getDepth(Tuple t)

Get the traversal depth at which a particular tuple was encountered.

Parameters:

t - the tuple to lookup

Returns:

the traversal depth of the tuple, or -1 if the tuple has not been visited by the traversal.

next

public java.lang.Object next()

Specified by:

next in interface java.util.Iterator

See Also:

Iterator.next()