/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* $Id: UnionChildIterator.java,v 1.2.4.1 2005/09/14 19:45:20 jeffsuttor Exp $
*/
package com.sun.org.apache.xpath.internal.axes;
import com.sun.org.apache.xml.internal.dtm.DTMIterator;
import com.sun.org.apache.xpath.internal.XPathContext;
import com.sun.org.apache.xpath.internal.objects.XObject;
import com.sun.org.apache.xpath.internal.patterns.NodeTest;
/**
* This class defines a simplified type of union iterator that only
* tests along the child axes. If the conditions are right, it is
* much faster than using a UnionPathIterator.
*/
public class UnionChildIterator extends ChildTestIterator
{
static final long serialVersionUID = 3500298482193003495L;
/**
* Even though these may hold full LocPathIterators, this array does
* not have to be cloned, since only the node test and predicate
* portion are used, and these only need static information. However,
* also note that index predicates can not be used!
*/
private PredicatedNodeTest[] m_nodeTests = null;
/**
* Constructor for UnionChildIterator
*/
public UnionChildIterator()
{
super(null);
}
/**
* Add a node test to the union list.
*
* @param test reference to a NodeTest, which will be added
* directly to the list of node tests (in other words, it will
* not be cloned). The parent of this test will be set to
* this object.
*/
public void addNodeTest(PredicatedNodeTest test)
{
// Increase array size by only 1 at a time. Fix this
// if it looks to be a problem.
if (null == m_nodeTests)
{
m_nodeTests = new PredicatedNodeTest[1];
m_nodeTests[0] = test;
}
else
{
PredicatedNodeTest[] tests = m_nodeTests;
int len = m_nodeTests.length;
m_nodeTests = new PredicatedNodeTest[len + 1];
System.arraycopy(tests, 0, m_nodeTests, 0, len);
m_nodeTests[len] = test;
}
test.exprSetParent(this);
}
/**
* This function is used to fixup variables from QNames to stack frame
* indexes at stylesheet build time.
* @param vars List of QNames that correspond to variables. This list
* should be searched backwards for the first qualified name that
* corresponds to the variable reference qname. The position of the
* QName in the vector from the start of the vector will be its position
* in the stack frame (but variables above the globalsTop value will need
* to be offset to the current stack frame).
*/
public void fixupVariables(java.util.Vector vars, int globalsSize)
{
super.fixupVariables(vars, globalsSize);
if (m_nodeTests != null) {
for (int i = 0; i < m_nodeTests.length; i++) {
m_nodeTests[i].fixupVariables(vars, globalsSize);
}
}
}
/**
* Test whether a specified node is visible in the logical view of a
* TreeWalker or NodeIterator. This function will be called by the
* implementation of TreeWalker and NodeIterator; it is not intended to
* be called directly from user code.
* @param n The node to check to see if it passes the filter or not.
* @return a constant to determine whether the node is accepted,
* rejected, or skipped, as defined above .
*/
public short acceptNode(int n)
{
XPathContext xctxt = getXPathContext();
try
{
xctxt.pushCurrentNode(n);
for (int i = 0; i < m_nodeTests.length; i++)
{
PredicatedNodeTest pnt = m_nodeTests[i];
XObject score = pnt.execute(xctxt, n);
if (score != NodeTest.SCORE_NONE)
{
// Note that we are assuming there are no positional predicates!
if (pnt.getPredicateCount() > 0)
{
if (pnt.executePredicates(n, xctxt))
return DTMIterator.FILTER_ACCEPT;
}
else
return DTMIterator.FILTER_ACCEPT;
}
}
}
catch (javax.xml.transform.TransformerException se)
{
// TODO: Fix this.
throw new RuntimeException(se.getMessage());
}
finally
{
xctxt.popCurrentNode();
}
return DTMIterator.FILTER_SKIP;
}
}