/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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: Counter.java 468645 2006-10-28 06:57:24Z minchau $
*/
package org.apache.xalan.transformer;
import javax.xml.transform.TransformerException;
import org.apache.xalan.templates.ElemNumber;
import org.apache.xml.dtm.DTM;
import org.apache.xpath.NodeSetDTM;
import org.apache.xpath.XPathContext;
/**
* A class that does incremental counting for support of xsl:number.
* This class stores a cache of counted nodes (m_countNodes).
* It tries to cache the counted nodes in document order...
* the node count is based on its position in the cache list
* @xsl.usage internal
*/
public class Counter
{
/**
* Set the maximum ammount the m_countNodes list can
* grow to.
*/
static final int MAXCOUNTNODES = 500;
/**
* The start count from where m_countNodes counts
* from. In other words, the count of a given node
* in the m_countNodes vector is node position +
* m_countNodesStartCount.
*/
int m_countNodesStartCount = 0;
/**
* A vector of all nodes counted so far.
*/
NodeSetDTM m_countNodes;
/**
* The node from where the counting starts. This is needed to
* find a counter if the node being counted is not immediatly
* found in the m_countNodes vector.
*/
int m_fromNode = DTM.NULL;
/**
* The owning xsl:number element.
*/
ElemNumber m_numberElem;
/**
* Value to store result of last getCount call, for benifit
* of returning val from CountersTable.getCounterByCounted,
* who calls getCount.
*/
int m_countResult;
/**
* Construct a counter object.
*
* @param numberElem The owning xsl:number element.
* @param countNodes A vector of all nodes counted so far.
*
* @throws TransformerException
*/
Counter(ElemNumber numberElem, NodeSetDTM countNodes) throws TransformerException
{
m_countNodes = countNodes;
m_numberElem = numberElem;
}
/**
* Construct a counter object.
*
* @param numberElem The owning xsl:number element.
*
* @throws TransformerException
*
Counter(ElemNumber numberElem) throws TransformerException
{
m_numberElem = numberElem;
}*/
/**
* Try and find a node that was previously counted. If found,
* return a positive integer that corresponds to the count.
*
* @param support The XPath context to use
* @param node The node to be counted.
*
* @return The count of the node, or -1 if not found.
*/
int getPreviouslyCounted(XPathContext support, int node)
{
int n = m_countNodes.size();
m_countResult = 0;
for (int i = n - 1; i >= 0; i--)
{
int countedNode = m_countNodes.elementAt(i);
if (node == countedNode)
{
// Since the list is in backwards order, the count is
// how many are in the rest of the list.
m_countResult = i + 1 + m_countNodesStartCount;
break;
}
DTM dtm = support.getDTM(countedNode);
// Try to see if the given node falls after the counted node...
// if it does, don't keep searching backwards.
if (dtm.isNodeAfter(countedNode, node))
break;
}
return m_countResult;
}
/**
* Get the last node in the list.
*
* @return the last node in the list.
*/
int getLast()
{
int size = m_countNodes.size();
return (size > 0) ? m_countNodes.elementAt(size - 1) : DTM.NULL;
}
}