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      1 /*
      2  * Licensed to the Apache Software Foundation (ASF) under one
      3  * or more contributor license agreements. See the NOTICE file
      4  * distributed with this work for additional information
      5  * regarding copyright ownership. The ASF licenses this file
      6  * to you under the Apache License, Version 2.0 (the  "License");
      7  * you may not use this file except in compliance with the License.
      8  * You may obtain a copy of the License at
      9  *
     10  *     http://www.apache.org/licenses/LICENSE-2.0
     11  *
     12  * Unless required by applicable law or agreed to in writing, software
     13  * distributed under the License is distributed on an "AS IS" BASIS,
     14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     15  * See the License for the specific language governing permissions and
     16  * limitations under the License.
     17  */
     18 /*
     19  * $Id: Function3Args.java 468655 2006-10-28 07:12:06Z minchau $
     20  */
     21 package org.apache.xpath.functions;
     22 
     23 import org.apache.xalan.res.XSLMessages;
     24 import org.apache.xpath.Expression;
     25 import org.apache.xpath.ExpressionOwner;
     26 import org.apache.xpath.XPathVisitor;
     27 
     28 /**
     29  * Base class for functions that accept three arguments.
     30  * @xsl.usage advanced
     31  */
     32 public class Function3Args extends Function2Args
     33 {
     34     static final long serialVersionUID = 7915240747161506646L;
     35 
     36   /** The third argument passed to the function (at index 2).
     37    *  @serial  */
     38   Expression m_arg2;
     39 
     40   /**
     41    * Return the third argument passed to the function (at index 2).
     42    *
     43    * @return An expression that represents the third argument passed to the
     44    *         function.
     45    */
     46   public Expression getArg2()
     47   {
     48     return m_arg2;
     49   }
     50 
     51   /**
     52    * This function is used to fixup variables from QNames to stack frame
     53    * indexes at stylesheet build time.
     54    * @param vars List of QNames that correspond to variables.  This list
     55    * should be searched backwards for the first qualified name that
     56    * corresponds to the variable reference qname.  The position of the
     57    * QName in the vector from the start of the vector will be its position
     58    * in the stack frame (but variables above the globalsTop value will need
     59    * to be offset to the current stack frame).
     60    */
     61   public void fixupVariables(java.util.Vector vars, int globalsSize)
     62   {
     63     super.fixupVariables(vars, globalsSize);
     64     if(null != m_arg2)
     65       m_arg2.fixupVariables(vars, globalsSize);
     66   }
     67 
     68   /**
     69    * Set an argument expression for a function.  This method is called by the
     70    * XPath compiler.
     71    *
     72    * @param arg non-null expression that represents the argument.
     73    * @param argNum The argument number index.
     74    *
     75    * @throws WrongNumberArgsException If the argNum parameter is greater than 2.
     76    */
     77   public void setArg(Expression arg, int argNum)
     78           throws WrongNumberArgsException
     79   {
     80 
     81     if (argNum < 2)
     82       super.setArg(arg, argNum);
     83     else if (2 == argNum)
     84     {
     85       m_arg2 = arg;
     86       arg.exprSetParent(this);
     87     }
     88     else
     89 		  reportWrongNumberArgs();
     90   }
     91 
     92   /**
     93    * Check that the number of arguments passed to this function is correct.
     94    *
     95    *
     96    * @param argNum The number of arguments that is being passed to the function.
     97    *
     98    * @throws WrongNumberArgsException
     99    */
    100   public void checkNumberArgs(int argNum) throws WrongNumberArgsException
    101   {
    102     if (argNum != 3)
    103       reportWrongNumberArgs();
    104   }
    105 
    106   /**
    107    * Constructs and throws a WrongNumberArgException with the appropriate
    108    * message for this function object.
    109    *
    110    * @throws WrongNumberArgsException
    111    */
    112   protected void reportWrongNumberArgs() throws WrongNumberArgsException {
    113       throw new WrongNumberArgsException(XSLMessages.createXPATHMessage("three", null));
    114   }
    115 
    116   /**
    117    * Tell if this expression or it's subexpressions can traverse outside
    118    * the current subtree.
    119    *
    120    * @return true if traversal outside the context node's subtree can occur.
    121    */
    122    public boolean canTraverseOutsideSubtree()
    123    {
    124     return super.canTraverseOutsideSubtree()
    125     ? true : m_arg2.canTraverseOutsideSubtree();
    126    }
    127 
    128   class Arg2Owner implements ExpressionOwner
    129   {
    130     /**
    131      * @see ExpressionOwner#getExpression()
    132      */
    133     public Expression getExpression()
    134     {
    135       return m_arg2;
    136     }
    137 
    138 
    139     /**
    140      * @see ExpressionOwner#setExpression(Expression)
    141      */
    142     public void setExpression(Expression exp)
    143     {
    144     	exp.exprSetParent(Function3Args.this);
    145     	m_arg2 = exp;
    146     }
    147   }
    148 
    149 
    150   /**
    151    * @see org.apache.xpath.XPathVisitable#callVisitors(ExpressionOwner, XPathVisitor)
    152    */
    153   public void callArgVisitors(XPathVisitor visitor)
    154   {
    155   	super.callArgVisitors(visitor);
    156   	if(null != m_arg2)
    157   		m_arg2.callVisitors(new Arg2Owner(), visitor);
    158   }
    159 
    160   /**
    161    * @see Expression#deepEquals(Expression)
    162    */
    163   public boolean deepEquals(Expression expr)
    164   {
    165   	if(!super.deepEquals(expr))
    166   		return false;
    167 
    168   	if(null != m_arg2)
    169   	{
    170   		if(null == ((Function3Args)expr).m_arg2)
    171   			return false;
    172 
    173   		if(!m_arg2.deepEquals(((Function3Args)expr).m_arg2))
    174   			return false;
    175   	}
    176   	else if (null != ((Function3Args)expr).m_arg2)
    177   		return false;
    178 
    179   	return true;
    180   }
    181 
    182 
    183 }
    184