1 /*
   2  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 /*
  26  * Copyright (C) 2004-2011
  27  *
  28  * Permission is hereby granted, free of charge, to any person obtaining a copy
  29  * of this software and associated documentation files (the "Software"), to deal
  30  * in the Software without restriction, including without limitation the rights
  31  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  32  * copies of the Software, and to permit persons to whom the Software is
  33  * furnished to do so, subject to the following conditions:
  34  *
  35  * The above copyright notice and this permission notice shall be included in
  36  * all copies or substantial portions of the Software.
  37  *
  38  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  39  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  40  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  41  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  42  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  43  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  44  * THE SOFTWARE.
  45  */
  46 package com.sun.xml.internal.rngom.binary.visitor;
  47 
  48 import com.sun.xml.internal.rngom.binary.Pattern;
  49 import com.sun.xml.internal.rngom.nc.NameClass;
  50 
  51 import java.util.HashSet;
  52 import java.util.Set;
  53 
  54 /**
  55  * Visits a pattern and creates a list of possible child elements.
  56  *
  57  * <p>
  58  * One can use a similar technique to introspect a pattern.
  59  *
  60  * @author Kohsuke Kawaguchi (kk@kohsuke.org)
  61  */
  62 public class ChildElementFinder extends PatternWalker {
  63 
  64     private final Set children = new HashSet();
  65 
  66     /**
  67      * Represents a child element.
  68      */
  69     public static class Element {
  70         public final NameClass nc;
  71         public final Pattern content;
  72 
  73         public Element(NameClass nc, Pattern content) {
  74             this.nc = nc;
  75             this.content = content;
  76         }
  77 
  78         public boolean equals(Object o) {
  79             if (this == o) return true;
  80             if (!(o instanceof Element)) return false;
  81 
  82             final Element element = (Element) o;
  83 
  84             if (content != null ? !content.equals(element.content) : element.content != null) return false;
  85             if (nc != null ? !nc.equals(element.nc) : element.nc != null) return false;
  86 
  87             return true;
  88         }
  89 
  90         public int hashCode() {
  91             int result;
  92             result = (nc != null ? nc.hashCode() : 0);
  93             result = 29 * result + (content != null ? content.hashCode() : 0);
  94             return result;
  95         }
  96     }
  97 
  98     /**
  99      * Returns a set of {@link Element}.
 100      */
 101     public Set getChildren() {
 102         return children;
 103     }
 104 
 105     public void visitElement(NameClass nc, Pattern content) {
 106         children.add(new Element(nc,content));
 107     }
 108 
 109     public void visitAttribute(NameClass ns, Pattern value) {
 110         // there will be no element inside attribute,
 111         // so don't go in there.
 112     }
 113 
 114     public void visitList(Pattern p) {
 115         // there will be no element inside a list,
 116         // so don't go in there.
 117     }
 118 }