org.apache.xindice.xml.dom.traversal
Class TreeWalkerImpl

java.lang.Object
  org.apache.xindice.xml.dom.traversal.TreeWalkerImpl

All Implemented Interfaces:

org.w3c.dom.traversal.NodeIterator, org.w3c.dom.traversal.TreeWalker

public final class TreeWalkerImpl

extends Object

implements org.w3c.dom.traversal.TreeWalker, org.w3c.dom.traversal.NodeIterator

TreeWalkerImpl

Version:

$Revision: 541508 $, $Date: 2007-05-24 21:54:12 -0400 (Thu, 24 May 2007) $

Field Summary

protected org.w3c.dom.Node	current
protected boolean	expand
protected org.w3c.dom.traversal.NodeFilter	filter
protected org.w3c.dom.Node	root
protected boolean	valid
protected int	whatToShow

Constructor Summary

TreeWalkerImpl(org.w3c.dom.Node root, int whatToShow, org.w3c.dom.traversal.NodeFilter filter, boolean entityReferenceExpansion)

Method Summary

void	detach() Detaches the iterator from the set which it iterated over, releasing any computational resources and placing the iterator in the INVALID state.
org.w3c.dom.Node	firstChild() Moves the TreeWalker to the first visible child of the current node, and returns the new node.
org.w3c.dom.Node	getCurrentNode() The node at which the TreeWalker is currently positioned.
boolean	getExpandEntityReferences() The value of this flag determines whether the children of entity reference nodes are visible to the iterator.
org.w3c.dom.traversal.NodeFilter	getFilter() The filter used to screen nodes.
org.w3c.dom.Node	getRoot() The root node of the Iterator, as specified when it was created.
int	getWhatToShow() This attribute determines which node types are presented via the iterator.
org.w3c.dom.Node	lastChild() Moves the TreeWalker to the last visible child of the current node, and returns the new node.
org.w3c.dom.Node	nextNode() Moves the TreeWalker to the next visible node in document order relative to the current node, and returns the new node.
org.w3c.dom.Node	nextSibling() Moves the TreeWalker to the next sibling of the current node, and returns the new node.
org.w3c.dom.Node	parentNode() Moves to and returns the closest visible ancestor node of the current node.
org.w3c.dom.Node	previousNode() Moves the TreeWalker to the previous visible node in document order relative to the current node, and returns the new node.
org.w3c.dom.Node	previousSibling() Moves the TreeWalker to the previous sibling of the current node, and returns the new node.
void	setCurrentNode(org.w3c.dom.Node currentNode)

Methods inherited from class java.lang.Object

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

Field Detail

valid

protected boolean valid

root

protected org.w3c.dom.Node root

current

protected org.w3c.dom.Node current

whatToShow

protected int whatToShow

filter

protected org.w3c.dom.traversal.NodeFilter filter

expand

protected boolean expand

Constructor Detail

TreeWalkerImpl

public TreeWalkerImpl(org.w3c.dom.Node root,
                      int whatToShow,
                      org.w3c.dom.traversal.NodeFilter filter,
                      boolean entityReferenceExpansion)
               throws org.w3c.dom.DOMException

Method Detail

getRoot

public org.w3c.dom.Node getRoot()

The root node of the Iterator, as specified when it was created.

Specified by:

getRoot in interface org.w3c.dom.traversal.TreeWalker

getWhatToShow

public int getWhatToShow()

This attribute determines which node types are presented via the iterator. The available set of constants is defined in the NodeFilter interface.

Specified by:

getWhatToShow in interface org.w3c.dom.traversal.TreeWalker

getFilter

public org.w3c.dom.traversal.NodeFilter getFilter()

The filter used to screen nodes.

Specified by:

getFilter in interface org.w3c.dom.traversal.TreeWalker

getExpandEntityReferences

public boolean getExpandEntityReferences()

The value of this flag determines whether the children of entity reference nodes are visible to the iterator. If false, they will be skipped over.
To produce a view of the document that has entity references expanded and does not expose the entity reference node itself, use the whatToShow flags to hide the entity reference node and set expandEntityReferences to true when creating the iterator. To produce a view of the document that has entity reference nodes but no entity expansion, use the whatToShow flags to show the entity reference node and set expandEntityReferences to false.

Specified by:

getExpandEntityReferences in interface org.w3c.dom.traversal.TreeWalker

detach

public void detach()

Detaches the iterator from the set which it iterated over, releasing any computational resources and placing the iterator in the INVALID state. Afterdetach has been invoked, calls to nextNode orpreviousNode will raise the exception INVALID_STATE_ERR.

Specified by:

detach in interface org.w3c.dom.traversal.NodeIterator

getCurrentNode

public org.w3c.dom.Node getCurrentNode()

The node at which the TreeWalker is currently positioned.
The value must not be null. Alterations to the DOM tree may cause the current node to no longer be accepted by the TreeWalker's associated filter. currentNode may also be explicitly set to any node, whether or not it is within the subtree specified by the root node or would be accepted by the filter and whatToShow flags. Further traversal occurs relative to currentNode even if it is not part of the current view by applying the filters in the requested direction (not changing currentNode where no traversal is possible).

Specified by:

getCurrentNode in interface org.w3c.dom.traversal.TreeWalker

Throws:

org.w3c.dom.DOMException - NOT_SUPPORTED_ERR: Raised if the specified currentNode isnull .

setCurrentNode

public void setCurrentNode(org.w3c.dom.Node currentNode)
                    throws org.w3c.dom.DOMException

Specified by:

setCurrentNode in interface org.w3c.dom.traversal.TreeWalker

Throws:

org.w3c.dom.DOMException

parentNode

public org.w3c.dom.Node parentNode()

Moves to and returns the closest visible ancestor node of the current node. If the search for parentNode attempts to step upward from the TreeWalker's root node, or if it fails to find a visible ancestor node, this method retains the current position and returns null.

Specified by:

parentNode in interface org.w3c.dom.traversal.TreeWalker

Returns:

The new parent node, or null if the current node has no parent in the TreeWalker's logical view.

firstChild

public org.w3c.dom.Node firstChild()

Moves the TreeWalker to the first visible child of the current node, and returns the new node. If the current node has no visible children, returns null , and retains the current node.

Specified by:

firstChild in interface org.w3c.dom.traversal.TreeWalker

Returns:

The new node, or null if the current node has no visible children in the TreeWalker's logical view.

lastChild

public org.w3c.dom.Node lastChild()

Moves the TreeWalker to the last visible child of the current node, and returns the new node. If the current node has no visible children, returns null , and retains the current node.

Specified by:

lastChild in interface org.w3c.dom.traversal.TreeWalker

Returns:

The new node, or null if the current node has no children in the TreeWalker's logical view.

previousSibling

public org.w3c.dom.Node previousSibling()

Moves the TreeWalker to the previous sibling of the current node, and returns the new node. If the current node has no visible previous sibling, returns null , and retains the current node.

Specified by:

previousSibling in interface org.w3c.dom.traversal.TreeWalker

Returns:

The new node, or null if the current node has no previous sibling in the TreeWalker's logical view.

nextSibling

public org.w3c.dom.Node nextSibling()

Moves the TreeWalker to the next sibling of the current node, and returns the new node. If the current node has no visible next sibling, returns null , and retains the current node.

Specified by:

nextSibling in interface org.w3c.dom.traversal.TreeWalker

Returns:

The new node, or null if the current node has no next sibling in the TreeWalker's logical view.

previousNode

public org.w3c.dom.Node previousNode()

Moves the TreeWalker to the previous visible node in document order relative to the current node, and returns the new node. If the current node has no previous node, or if the search for previousNode attempts to step upward from the TreeWalker's root node, returns null , and retains the current node.

Specified by:

previousNode in interface org.w3c.dom.traversal.TreeWalker

Returns:

The new node, or null if the current node has no previous node in the TreeWalker's logical view.

nextNode

public org.w3c.dom.Node nextNode()

Moves the TreeWalker to the next visible node in document order relative to the current node, and returns the new node. If the current node has no next node, or if the search for nextNode attempts to step upward from the TreeWalker's root node, returns null , and retains the current node.

Specified by:

nextNode in interface org.w3c.dom.traversal.TreeWalker

Returns:

The new node, or null if the current node has no next node in the TreeWalker's logical view.