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StepIterator.javaAPI DocJava SE 5 API4269Fri Aug 26 14:55:40 BST 2005com.sun.org.apache.xalan.internal.xsltc.dom

StepIterator

public class StepIterator extends DTMAxisIteratorBase
A step iterator is used to evaluate expressions like "BOOK/TITLE". A better name for this iterator would have been ParentIterator since both "BOOK" and "TITLE" are steps in XPath lingo. Step iterators are constructed from two other iterators which we are going to refer to as "outer" and "inner". Every node from the outer iterator (the one for BOOK in our example) is used to initialize the inner iterator. After this initialization, every node from the inner iterator is returned (in essence, implementing a "nested loop").
author
Jacek Ambroziak
author
Santiago Pericas-Geertsen
author
Erwin Bolwidt
author
Morten Jorgensen

Fields Summary
protected DTMAxisIterator
_source
A reference to the "outer" iterator.
protected DTMAxisIterator
_iterator
A reference to the "inner" iterator.
private int
_pos
Temp variable to store a marked position.
Constructors Summary
public StepIterator(DTMAxisIterator source, DTMAxisIterator iterator)


         
	_source = source;
	_iterator = iterator;
// System.out.println("SI source = " + source + " this = " + this);
// System.out.println("SI iterator = " + iterator + " this = " + this);
Methods Summary
public com.sun.org.apache.xml.internal.dtm.DTMAxisIteratorcloneIterator()

	_isRestartable = false;
	try {
	    final StepIterator clone = (StepIterator) super.clone();
	    clone._source = _source.cloneIterator();
	    clone._iterator = _iterator.cloneIterator();
	    clone._iterator.setRestartable(true); 	// must be restartable
	    clone._isRestartable = false;
	    return clone.reset();
	}
	catch (CloneNotSupportedException e) {
	    BasisLibrary.runTimeError(BasisLibrary.ITERATOR_CLONE_ERR,
				      e.toString());
	    return null;
	}
public voidgotoMark()

	_source.gotoMark();
	_iterator.gotoMark();
	//_position = _pos;
public intnext()

	for (int node;;) {
	    // Try to get another node from the right-hand iterator
	    if ((node = _iterator.next()) != END) {
		return returnNode(node);
	    }
	    // If not, get the next starting point from left-hand iterator...
	    else if ((node = _source.next()) == END) {
		return END;
	    }
	    // ...and pass it on to the right-hand iterator
	    else {
		_iterator.setStartNode(node);
	    }
	}
public com.sun.org.apache.xml.internal.dtm.DTMAxisIteratorreset()

	_source.reset();
	// Special case for //* path - see ParentLocationPath
	_iterator.setStartNode(_includeSelf ? _startNode : _source.next());
	return resetPosition();
public voidsetMark()

	_source.setMark();
	_iterator.setMark();
	//_pos = _position;
public voidsetRestartable(boolean isRestartable)

	_isRestartable = isRestartable;
	_source.setRestartable(isRestartable);
	_iterator.setRestartable(true); 	// must be restartable
public com.sun.org.apache.xml.internal.dtm.DTMAxisIteratorsetStartNode(int node)

	if (_isRestartable) {
	    // Set start node for left-hand iterator...
	    _source.setStartNode(_startNode = node);

	    // ... and get start node for right-hand iterator from left-hand,
	    // with special case for //* path - see ParentLocationPath
	    _iterator.setStartNode(_includeSelf ? _startNode : _source.next());
	    return resetPosition();
	}
	return this;