org.apache.xml.dtm.ref
Class DTMAxisIteratorBase

java.lang.Object
  |
  +--org.apache.xml.dtm.ref.DTMAxisIteratorBase
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.


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.
 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()
           
 void setRestartable(boolean isRestartable)
           
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

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()
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)
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.


Copyright 2006 Apache XML Project. All Rights Reserved.