gnu.xml.dom

Class DomNodeIterator

Implemented Interfaces:
NodeIterator, TreeWalker

public class DomNodeIterator
extends java.lang.Object
implements NodeIterator, TreeWalker

Node iterator and tree walker.

Constructor Summary

DomNodeIterator(Node root, int whatToShow, NodeFilter filter, boolean entityReferenceExpansion, boolean walk)

Method Summary

void
detach()
Detaches the NodeIterator from the set which it iterated over, releasing any computational resources and placing the NodeIterator in the INVALID state.
Node
firstChild()
Moves the TreeWalker to the first visible child of the current node, and returns the new node.
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 NodeIterator.
NodeFilter
getFilter()
The NodeFilter used to screen nodes.
Node
getRoot()
The root node of the NodeIterator, as specified when it was created.
int
getWhatToShow()
This attribute determines which node types are presented via the NodeIterator.
Node
lastChild()
Moves the TreeWalker to the last visible child of the current node, and returns the new node.
Node
nextNode()
Returns the next node in the set and advances the position of the NodeIterator in the set.
Node
nextSibling()
Moves the TreeWalker to the next sibling of the current node, and returns the new node.
Node
parentNode()
Moves to and returns the closest visible ancestor node of the current node.
Node
previousNode()
Returns the previous node in the set and moves the position of the NodeIterator backwards in the set.
Node
previousSibling()
Moves the TreeWalker to the previous sibling of the current node, and returns the new node.
void
setCurrentNode(Node current)
The node at which the TreeWalker is currently positioned.

Constructor Details

DomNodeIterator

public DomNodeIterator(Node root,
                       int whatToShow,
                       NodeFilter filter,
                       boolean entityReferenceExpansion,
                       boolean walk)

Method Details

detach

public void detach()
Detaches the NodeIterator from the set which it iterated over, releasing any computational resources and placing the NodeIterator in the INVALID state. After detach has been invoked, calls to nextNode or previousNode will raise the exception INVALID_STATE_ERR.
Specified by:
detach in interface NodeIterator


firstChild

public 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 TreeWalker

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


getCurrentNode

public Node getCurrentNode()
The node at which the TreeWalker is currently positioned.
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; if no traversal is possible, currentNode is not changed.
Specified by:
getCurrentNode in interface TreeWalker


getExpandEntityReferences

public boolean getExpandEntityReferences()
The value of this flag determines whether the children of entity reference nodes are visible to the NodeIterator. If false, these children and their descendants will be rejected. Note that this rejection takes precedence over whatToShow and the filter. Also note that this is currently the only situation where NodeIterators may reject a complete subtree rather than skipping individual nodes.

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 NodeIterator. 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 NodeIterator
getExpandEntityReferences in interface TreeWalker


getFilter

public NodeFilter getFilter()
The NodeFilter used to screen nodes.
Specified by:
getFilter in interface NodeIterator
getFilter in interface TreeWalker


getRoot

public Node getRoot()
The root node of the NodeIterator, as specified when it was created.
Specified by:
getRoot in interface NodeIterator
getRoot in interface TreeWalker


getWhatToShow

public int getWhatToShow()
This attribute determines which node types are presented via the NodeIterator. The available set of constants is defined in the NodeFilter interface. Nodes not accepted by whatToShow will be skipped, but their children may still be considered. Note that this skip takes precedence over the filter, if any.
Specified by:
getWhatToShow in interface NodeIterator
getWhatToShow in interface TreeWalker


lastChild

public 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 TreeWalker

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


nextNode

public Node nextNode()
            throws DOMException
Returns the next node in the set and advances the position of the NodeIterator in the set. After a NodeIterator is created, the first call to nextNode() returns the first node in the set.
Specified by:
nextNode in interface NodeIterator
nextNode in interface TreeWalker

Returns:
The next Node in the set being iterated over, or null if there are no more members in that set.

Throws:
DOMException - INVALID_STATE_ERR: Raised if this method is called after the detach method was invoked.


nextSibling

public 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 TreeWalker

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


parentNode

public 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 TreeWalker

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


previousNode

public Node previousNode()
            throws DOMException
Returns the previous node in the set and moves the position of the NodeIterator backwards in the set.
Specified by:
previousNode in interface NodeIterator
previousNode in interface TreeWalker

Returns:
The previous Node in the set being iterated over, or null if there are no more members in that set.

Throws:
DOMException - INVALID_STATE_ERR: Raised if this method is called after the detach method was invoked.


previousSibling

public 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 TreeWalker

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


setCurrentNode

public void setCurrentNode(Node current)
            throws DOMException
The node at which the TreeWalker is currently positioned.
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; if no traversal is possible, currentNode is not changed.
Specified by:
setCurrentNode in interface TreeWalker

Throws:
DOMException - NOT_SUPPORTED_ERR: Raised if an attempt is made to set currentNode to null.