net.sf.saxon.tree.wrapper
Class VirtualCopy.VirtualCopier

java.lang.Object
  net.sf.saxon.tree.wrapper.VirtualCopy.VirtualCopier

All Implemented Interfaces:

SequenceIterator, AxisIterator, UnfailingIterator

Direct Known Subclasses:

VirtualUntypedCopy.VirtualUntypedCopier

Enclosing class:

VirtualCopy

protected class VirtualCopy.VirtualCopier
extends Object
implements AxisIterator

VirtualCopier implements the XPath axes as applied to a VirtualCopy node. It works by applying the requested axis to the node of which this is a copy. There are two complications: firstly, all nodes encountered must themselves be (virtually) copied to give them a new identity. Secondly, axes that stray outside the subtree rooted at the original copied node must be truncated.

Field Summary

protected AxisIterator	base
protected NodeInfo	subtreeRoot

Fields inherited from interface net.sf.saxon.om.SequenceIterator

GROUNDED, LAST_POSITION_FINDER, LOOKAHEAD

Constructor Summary

VirtualCopy.VirtualCopier(AxisIterator base, VirtualCopy parent, NodeInfo subtreeRoot)

Method Summary

Value	atomize() Return the atomized value of the current node.
void	close() Close the iterator.
protected VirtualCopy	createCopy(NodeInfo node, NodeInfo root) Method to create the virtual copy of a node encountered when navigating.
NodeInfo	current() Get the current item in the sequence.
AxisIterator	getAnother() Get another iterator over the same sequence of items, positioned at the start of the sequence
int	getProperties() Get properties of this iterator, as a bit-significant integer.
CharSequence	getStringValue() Return the string value of the current node.
AxisIterator	iterateAxis(byte axis, NodeTest test) Return an iterator over an axis, starting at the current node.
boolean	moveNext() Move to the next node, without returning it.
NodeInfo	next() Get the next item in the sequence.
int	position() Get the current position

Methods inherited from class java.lang.Object

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

Field Detail

base

protected AxisIterator base

subtreeRoot

protected NodeInfo subtreeRoot

Constructor Detail

VirtualCopy.VirtualCopier

public VirtualCopy.VirtualCopier(AxisIterator base,
                                 VirtualCopy parent,
                                 NodeInfo subtreeRoot)

Method Detail

moveNext

public boolean moveNext()

Move to the next node, without returning it. Returns true if there is a next node, false if the end of the sequence has been reached. After calling this method, the current node may be retrieved using the current() function.

Specified by:

moveNext in interface AxisIterator

Returns:

true if there is a next node, false if the end of the sequence has been reached

next

public NodeInfo next()

Get the next item in the sequence.

Specified by:

next in interface SequenceIterator

Specified by:

next in interface AxisIterator

Specified by:

next in interface UnfailingIterator

Returns:

the next Item. If there are no more nodes, return null.

current

public NodeInfo current()

Get the current item in the sequence.

Specified by:

current in interface SequenceIterator

Specified by:

current in interface AxisIterator

Specified by:

current in interface UnfailingIterator

Returns:

the current item, that is, the item most recently returned by next()

position

public int position()

Get the current position

Specified by:

position in interface SequenceIterator

Specified by:

position in interface UnfailingIterator

Returns:

the position of the current item (the item most recently returned by next()), starting at 1 for the first node

close

public void close()

Description copied from interface: SequenceIterator

Close the iterator. This indicates to the supplier of the data that the client does not require any more items to be delivered by the iterator. This may enable the supplier to release resources. After calling close(), no further calls on the iterator should be made; if further calls are made, the effect of such calls is undefined.

(Currently, closing an iterator is important only when the data is being "pushed" in another thread. Closing the iterator terminates that thread and means that it needs to do no additional work. Indeed, failing to close the iterator may cause the push thread to hang waiting for the buffer to be emptied.)

Specified by:

close in interface SequenceIterator

iterateAxis

public AxisIterator iterateAxis(byte axis,
                                NodeTest test)

Return an iterator over an axis, starting at the current node.

Specified by:

iterateAxis in interface AxisIterator

Parameters:

axis - the axis to iterate over, using a constant such as Axis.CHILD

test - a predicate to apply to the nodes before returning them.

Returns:

an iterator over an axis, starting at the current node

Throws:

NullPointerException - if there is no current node

atomize

public Value atomize()
              throws XPathException

Return the atomized value of the current node.

Specified by:

atomize in interface AxisIterator

Returns:

the atomized value.

Throws:

NullPointerException - if there is no current node

XPathException - if the current node cannot be atomized, for example because it is an element node with element-only content.

getStringValue

public CharSequence getStringValue()

Return the string value of the current node.

Specified by:

getStringValue in interface AxisIterator

Returns:

the string value, as an instance of CharSequence.

Throws:

NullPointerException - if there is no current node

getAnother

public AxisIterator getAnother()

Get another iterator over the same sequence of items, positioned at the start of the sequence

Specified by:

getAnother in interface SequenceIterator

Specified by:

getAnother in interface AxisIterator

Specified by:

getAnother in interface UnfailingIterator

Returns:

a new iterator over the same sequence

getProperties

public int getProperties()

Get properties of this iterator, as a bit-significant integer.

Specified by:

getProperties in interface SequenceIterator

Returns:

the properties of this iterator. This will be some combination of properties such as SequenceIterator.GROUNDED, SequenceIterator.LAST_POSITION_FINDER, and SequenceIterator.LOOKAHEAD. It is always acceptable to return the value zero, indicating that there are no known special properties. It is acceptable for the properties of the iterator to change depending on its state.

createCopy

protected VirtualCopy createCopy(NodeInfo node,
                                 NodeInfo root)

Method to create the virtual copy of a node encountered when navigating. This method is separated out so that it can be overridden in a subclass.

Parameters:

node - the node to be copied

root - the root of the tree

Returns:

the virtual copy