org.apache.xml.dtm.ref
Class DTMDefaultBaseTraversers.DescendantTraverser

java.lang.Object
  org.apache.xml.dtm.DTMAxisTraverser
      org.apache.xml.dtm.ref.DTMDefaultBaseTraversers.IndexedDTMAxisTraverser
          org.apache.xml.dtm.ref.DTMDefaultBaseTraversers.DescendantTraverser

Direct Known Subclasses:

DTMDefaultBaseTraversers.DescendantFromRootTraverser, DTMDefaultBaseTraversers.DescendantOrSelfFromRootTraverser, DTMDefaultBaseTraversers.DescendantOrSelfTraverser, DTMDefaultBaseTraversers.FollowingTraverser

Enclosing class:

DTMDefaultBaseTraversers

private class DTMDefaultBaseTraversers.DescendantTraverser
extends DTMDefaultBaseTraversers.IndexedDTMAxisTraverser

Implements traversal of the Ancestor access, in reverse document order.

Constructor Summary

private

DTMDefaultBaseTraversers.DescendantTraverser()

Method Summary

protected boolean	axisHasBeenProcessed(int axisRoot) Tell if the axis has been fully processed to tell if a the wait for an arriving node should terminate.
int	first(int context, int expandedTypeID) By the nature of the stateless traversal, the context node can not be returned or the iteration will go into an infinate loop.
protected int	getFirstPotential(int identity) Get the first potential identity that can be returned.
protected int	getSubtreeRoot(int handle) Get the subtree root identity from the handle that was passed in by the caller.
protected boolean	isAfterAxis(int axisRoot, int identity) Tell if a node is outside the axis being traversed.
protected boolean	isDescendant(int subtreeRootIdentity, int identity) Tell if this node identity is a descendant.
int	next(int context, int current) Traverse to the next node after the current node.
int	next(int context, int current, int expandedTypeID) Traverse to the next node after the current node that is matched by the expanded type ID.

Methods inherited from class org.apache.xml.dtm.ref.DTMDefaultBaseTraversers.IndexedDTMAxisTraverser

getNextIndexed, isIndexed

Methods inherited from class org.apache.xml.dtm.DTMAxisTraverser

first

Methods inherited from class java.lang.Object

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

Constructor Detail

DTMDefaultBaseTraversers.DescendantTraverser

private DTMDefaultBaseTraversers.DescendantTraverser()

Method Detail

getFirstPotential

protected int getFirstPotential(int identity)

Get the first potential identity that can be returned. This should be overridded by classes that need to return the self node.

Parameters:

identity - The node identity of the root context of the traversal.

Returns:

The first potential node that can be in the traversal.

axisHasBeenProcessed

protected boolean axisHasBeenProcessed(int axisRoot)

Tell if the axis has been fully processed to tell if a the wait for an arriving node should terminate.

Specified by:

axisHasBeenProcessed in class DTMDefaultBaseTraversers.IndexedDTMAxisTraverser

Parameters:

axisRoot - The root identity of the axis.

Returns:

true if the axis has been fully processed.

getSubtreeRoot

protected int getSubtreeRoot(int handle)

Get the subtree root identity from the handle that was passed in by the caller. Derived classes may override this to change the root context of the traversal.

Parameters:

handle - handle to the root context.

Returns:

identity of the root of the subtree.

isDescendant

protected boolean isDescendant(int subtreeRootIdentity,
                               int identity)

Tell if this node identity is a descendant. Assumes that the node info for the element has already been obtained. %REVIEW% This is really parentFollowsRootInDocumentOrder ... which fails if the parent starts after the root ends. May be sufficient for this class's logic, but misleadingly named!

Parameters:

subtreeRootIdentity - The root context of the subtree in question.

identity - The index number of the node in question.

Returns:

true if the index is a descendant of _startNode.

isAfterAxis

protected boolean isAfterAxis(int axisRoot,
                              int identity)

Tell if a node is outside the axis being traversed. This method must be implemented by derived classes, and must be robust enough to handle any node that occurs after the axis root.

Specified by:

isAfterAxis in class DTMDefaultBaseTraversers.IndexedDTMAxisTraverser

Parameters:

axisRoot - The root identity of the axis.

identity - The node in question.

Returns:

true if the given node falls outside the axis being traversed.

first

public int first(int context,
                 int expandedTypeID)

By the nature of the stateless traversal, the context node can not be returned or the iteration will go into an infinate loop. So to traverse an axis, the first function must be used to get the first node.

This method needs to be overloaded only by those axis that process the self node. <\p>

Overrides:

first in class DTMAxisTraverser

Parameters:

context - The context node of this traversal. This is the point of origin for the traversal -- its "root node" or starting point.

expandedTypeID - The expanded type ID that must match.

Returns:

the first node in the traversal.

next

public int next(int context,
                int current)

Traverse to the next node after the current node.

Specified by:

next in class DTMAxisTraverser

Parameters:

context - The context node of this iteration.

current - The current node of the iteration.

Returns:

the next node in the iteration, or DTM.NULL.

See Also:

DTMAxisTraverser.first(int)

next

public int next(int context,
                int current,
                int expandedTypeID)

Traverse to the next node after the current node that is matched by the expanded type ID.

Specified by:

next in class DTMAxisTraverser

Parameters:

context - The context node of this iteration.

current - The current node of the iteration.

expandedTypeID - The expanded type ID that must match.

Returns:

the next node in the iteration, or DTM.NULL.

See Also:

DTMAxisTraverser.first(int,int)