org.apache.xml.dtm.ref
Class DTMAxisIteratorBase

java.lang.Object
  org.apache.xml.dtm.ref.DTMAxisIteratorBase

All Implemented Interfaces:

java.lang.Cloneable, DTMAxisIterator

Direct Known Subclasses:

AbsoluteIterator, CachedNodeListIterator, ClonedNodeListIterator, CurrentNodeListIterator, DTMDefaultBaseIterators.InternalAxisIteratorBase, DupFilterIterator, FilterIterator, ForwardPositionIterator, KeyIndex, MatchingIterator, MultiValuedNodeHeapIterator, NthIterator, SimpleResultTreeImpl.SimpleIterator, SimpleResultTreeImpl.SingletonIterator, SingletonIterator, SortingIterator, StepIterator

public abstract class DTMAxisIteratorBase
extends java.lang.Object
implements DTMAxisIterator

This class serves as a default base for implementations of mutable DTMAxisIterators.

Field Summary

Fields inherited from interface org.apache.xml.dtm.DTMAxisIterator

END

Constructor Summary

DTMAxisIteratorBase()

Method Summary

DTMAxisIterator	cloneIterator() Returns a deep copy of this iterator.
int	getAxis() Returns the axis being iterated, if it is known.
int	getLast() Returns the position of the last node within the iteration, as defined by XPath.
int	getNodeByPosition(int position) Return the node at the given position.
int	getPosition()
int	getStartNode() Get start to END should 'close' the iterator, i.e. subsequent call to next() should return END.
DTMAxisIterator	includeSelf() Set the flag to include the start node in the iteration.
boolean	isDocOrdered() Returns true if all the nodes in the iteration well be returned in document order.
boolean	isReverse()
DTMAxisIterator	reset() Resets the iterator to the last start node.
void	setRestartable(boolean isRestartable) Set if restartable.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.xml.dtm.DTMAxisIterator

gotoMark, next, setMark, setStartNode

Constructor Detail

DTMAxisIteratorBase

public DTMAxisIteratorBase()

Method Detail

getStartNode

public int getStartNode()

Get start to END should 'close' the iterator, i.e. subsequent call to next() should return END.

Specified by:

getStartNode in interface DTMAxisIterator

Returns:

The root node of the iteration.

reset

public DTMAxisIterator reset()

Description copied from interface: DTMAxisIterator

Resets the iterator to the last start node.

Specified by:

reset in interface DTMAxisIterator

Returns:

A DTMAxisIterator which has been reset to the start node, which may or may not be the same as this iterator.

includeSelf

public DTMAxisIterator includeSelf()

Set the flag to include the start node in the iteration.

Returns:

This default method returns just returns this DTMAxisIterator, after setting the flag. (Returning "this" permits C++-style chaining of method calls into a single expression.)

getLast

public int getLast()

Returns the position of the last node within the iteration, as defined by XPath. In a forward iterator, I believe this equals the number of nodes which this iterator will yield. In a reverse iterator, I believe it should return 1 (since the "last" is the first produced.) This may be an expensive operation when called the first time, since it may have to iterate through a large part of the document to produce its answer.

Specified by:

getLast in interface DTMAxisIterator

Returns:

The number of nodes in this iterator (forward) or 1 (reverse).

getPosition

public int getPosition()

Specified by:

getPosition in interface DTMAxisIterator

Returns:

The position of the current node within the set, as defined by XPath. Note that this is one-based, not zero-based.

isReverse

public boolean isReverse()

Specified by:

isReverse in interface DTMAxisIterator

Returns:

true if this iterator has a reversed axis, else false

cloneIterator

public DTMAxisIterator cloneIterator()

Returns a deep copy of this iterator. Cloned iterators may not be restartable. The iterator being cloned may or may not become non-restartable as a side effect of this operation.

Specified by:

cloneIterator in interface DTMAxisIterator

Returns:

a deep copy of this iterator.

isDocOrdered

public boolean isDocOrdered()

Returns true if all the nodes in the iteration well be returned in document order.

Returns:

true as a default.

getAxis

public int getAxis()

Returns the axis being iterated, if it is known.

Returns:

Axis.CHILD, etc., or -1 if the axis is not known or is of multiple types.

setRestartable

public void setRestartable(boolean isRestartable)

Description copied from interface: DTMAxisIterator

Set if restartable.

Specified by:

setRestartable in interface DTMAxisIterator

getNodeByPosition

public int getNodeByPosition(int position)

Return the node at the given position.

Specified by:

getNodeByPosition in interface DTMAxisIterator

Parameters:

position - The position

Returns:

The node at the given position.