File	Doc	Category	Size	Date	Package
DTMAxisIteratorBase.java	API Doc	Java SE 5 API	7527	Fri Aug 26 14:56:00 BST 2005	com.sun.org.apache.xml.internal.dtm.ref

DTMAxisIteratorBase

• java.lang.Object

Fields Summary
protected int	_last The position of the last node within the iteration, as defined by XPath. Note that this is _not_ the node's handle within the DTM. Also, don't confuse it with the current (most recently returned) position.
protected int	_position The position of the current node within the iteration, as defined by XPath. Note that this is _not_ the node's handle within the DTM!
protected int	_markedNode The position of the marked node within the iteration; a saved itaration state that we may want to come back to. Note that only one mark is maintained; there is no stack.
protected int	_startNode The handle to the start, or root, of the iteration. Set this to END to construct an empty iterator.
protected boolean	_includeSelf True if the start node should be considered part of the iteration. False will cause it to be skipped.
protected boolean	_isRestartable True if this iteration can be restarted. False otherwise (eg, if we are iterating over a stream that can not be re-scanned, or if the iterator was produced by cloning another iterator.)

Constructors Summary

Methods Summary
public com.sun.org.apache.xml.internal.dtm.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. return a deep copy of this iterator. try { final DTMAxisIteratorBase clone = (DTMAxisIteratorBase) super.clone(); clone._isRestartable = false; // return clone.reset(); return clone; } catch (CloneNotSupportedException e) { throw new com.sun.org.apache.xml.internal.utils.WrappedRuntimeException(e); }
public int	getAxis() Returns the axis being iterated, if it is known. return Axis.CHILD, etc., or -1 if the axis is not known or is of multiple types. return -1;
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. return The number of nodes in this iterator (forward) or 1 (reverse). if (_last == -1) // Not previously established { // Note that we're doing both setMark() -- which saves _currentChild // -- and explicitly saving our position counter (number of nodes // yielded so far). // // %REVIEW% Should position also be saved by setMark()? // (It wasn't in the XSLTC version, but I don't understand why not.) final int temp = _position; // Save state setMark(); reset(); // Count the nodes found by this iterator do { _last++; } while (next() != END); gotoMark(); // Restore saved state _position = temp; } return _last;
public int	getNodeByPosition(int position) Return the node at the given position. param position The position return The node at the given position. if (position > 0) { final int pos = isReverse() ? getLast() - position + 1 : position; int node; while ((node = next()) != DTMAxisIterator.END) { if (pos == getPosition()) { return node; } } } return END;
public int	getPosition() return The position of the current node within the set, as defined by XPath. Note that this is one-based, not zero-based. return _position == 0 ? 1 : _position;
public int	getStartNode() Get start to END should 'close' the iterator, i.e. subsequent call to next() should return END. return The root node of the iteration. return _startNode;
public com.sun.org.apache.xml.internal.dtm.DTMAxisIterator	includeSelf() Set the flag to include the start node in the iteration. return 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.) _includeSelf = true; return this;
public boolean	isDocOrdered() Returns true if all the nodes in the iteration well be returned in document order. return true as a default. return true;
public boolean	isReverse() return true if this iterator has a reversed axis, else false return false;
public com.sun.org.apache.xml.internal.dtm.DTMAxisIterator	reset() return A DTMAxisIterator which has been reset to the start node, which may or may not be the same as this iterator. final boolean temp = _isRestartable; _isRestartable = true; setStartNode(_startNode); _isRestartable = temp; return this;
protected final com.sun.org.apache.xml.internal.dtm.DTMAxisIterator	resetPosition() Reset the position to zero. NOTE that this does not change the iteration state, only the position number associated with that state. %REVIEW% Document when this would be used? return This instance. _position = 0; return this;
protected final int	returnNode(int node) Do any final cleanup that is required before returning the node that was passed in, and then return it. The intended use is return returnNode(node); %REVIEW% If we're calling it purely for side effects, should we really be bothering with a return value? Something like accept(node); return node; would probably optimize just about as well and avoid questions about whether what's returned could ever be different from what's passed in. param node Node handle which iteration is about to yield. return The node handle passed in. _position++; return node;
public void	setRestartable(boolean isRestartable) _isRestartable = isRestartable;