1 /*
   2  * reserved comment block
   3  * DO NOT REMOVE OR ALTER!
   4  */
   5 /*
   6  * Copyright 2001-2004 The Apache Software Foundation.
   7  *
   8  * Licensed under the Apache License, Version 2.0 (the "License");
   9  * you may not use this file except in compliance with the License.
  10  * You may obtain a copy of the License at
  11  *
  12  *      http://www.apache.org/licenses/LICENSE-2.0
  13  *
  14  * Unless required by applicable law or agreed to in writing, software
  15  * distributed under the License is distributed on an "AS IS" BASIS,
  16  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  17  * See the License for the specific language governing permissions and
  18  * limitations under the License.
  19  */
  20 
  21 package com.sun.org.apache.xerces.internal.impl.xs.models;
  22 
  23 import com.sun.org.apache.xerces.internal.xni.QName;
  24 import com.sun.org.apache.xerces.internal.impl.xs.SubstitutionGroupHandler;
  25 import com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaException;
  26 
  27 import java.util.Vector;
  28 import java.util.ArrayList;
  29 
  30 /**
  31  * XSEmptyCM is a derivative of the abstract content model base class that
  32  * handles a content model with no chilren (elements).
  33  *
  34  * This model validated on the way in.
  35  *
  36  * @xerces.internal
  37  *
  38  * @author Elena Litani, Lisa Martin
  39  * @author IBM
  40  * @version $Id: XSEmptyCM.java,v 1.7 2009/07/28 15:18:11 spericas Exp $
  41  */
  42 public class XSEmptyCM  implements XSCMValidator {
  43 
  44     //
  45     // Constants
  46     //
  47 
  48     // start the content model: did not see any children
  49     private static final short STATE_START = 0;
  50 
  51     private static final Vector EMPTY = new Vector(0);
  52 
  53     //
  54     // Data
  55     //
  56 
  57     //
  58     // XSCMValidator methods
  59     //
  60 
  61     /**
  62      * This methods to be called on entering a first element whose type
  63      * has this content model. It will return the initial state of the content model
  64      *
  65      * @return Start state of the content model
  66      */
  67     public int[] startContentModel(){
  68         return (new int[] {STATE_START});
  69     }
  70 
  71 
  72     /**
  73      * The method corresponds to one transaction in the content model.
  74      *
  75      * @param elementName the qualified name of the element
  76      * @param currentState Current state
  77      * @param subGroupHandler the substitution group handler
  78      * @return element index corresponding to the element from the Schema grammar
  79      */
  80     public Object oneTransition (QName elementName, int[] currentState, SubstitutionGroupHandler subGroupHandler){
  81 
  82         // error state
  83         if (currentState[0] < 0) {
  84             currentState[0] = XSCMValidator.SUBSEQUENT_ERROR;
  85             return null;
  86         }
  87 
  88         currentState[0] = XSCMValidator.FIRST_ERROR;
  89         return null;
  90     }
  91 
  92 
  93     /**
  94      * The method indicates the end of list of children
  95      *
  96      * @param currentState Current state of the content model
  97      * @return true if the last state was a valid final state
  98      */
  99     public boolean endContentModel (int[] currentState){
 100         boolean isFinal =  false;
 101         int state = currentState[0];
 102 
 103         // restore content model state:
 104 
 105         // error
 106         if (state < 0) {
 107             return false;
 108         }
 109 
 110 
 111         return true;
 112     }
 113 
 114     /**
 115      * check whether this content violates UPA constraint.
 116      *
 117      * @param subGroupHandler the substitution group handler
 118      * @return true if this content model contains other or list wildcard
 119      */
 120     public boolean checkUniqueParticleAttribution(SubstitutionGroupHandler subGroupHandler) throws XMLSchemaException {
 121         return false;
 122     }
 123 
 124     /**
 125      * Check which elements are valid to appear at this point. This method also
 126      * works if the state is in error, in which case it returns what should
 127      * have been seen.
 128      *
 129      * @param state  the current state
 130      * @return       a Vector whose entries are instances of
 131      *               either XSWildcardDecl or XSElementDecl.
 132      */
 133     public Vector whatCanGoHere(int[] state) {
 134         return EMPTY;
 135     }
 136 
 137     public ArrayList checkMinMaxBounds() {
 138         return null;
 139     }
 140 
 141 } // class XSEmptyCM