/*
    * 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.
   */
  package org.apache.commons.jxpath.ri.model.beans;
  
  import java.util.Locale;
  
  import org.apache.commons.jxpath.JXPathContext;
  import org.apache.commons.jxpath.ri.QName;
  import org.apache.commons.jxpath.ri.model.NodePointer;
  
  /**
   * Pointer whose value is <code>null</code>.
   * @author Dmitri Plotnikov
   * @version $Revision: 652915 $ $Date: 2008-05-02 23:12:57 +0200 (Fr, 02 Mai 2008) $
   */
  public class NullPointer extends PropertyOwnerPointer {
      private QName name;
      private String id;
  
      private static final long serialVersionUID = 2193425983220679887L;
  
      /**
       * Create a new NullPointer.
       * @param name node name
       * @param locale Locale
       */
      public NullPointer(QName name, Locale locale) {
          super(null, locale);
          this.name = name;
      }
  
      /**
       * Used for the root node.
       * @param parent parent pointer
       * @param name node name
       */
      public NullPointer(NodePointer parent, QName name) {
          super(parent);
          this.name = name;
      }
  
      /**
       * Create a new NullPointer.
       * @param locale Locale
       * @param id String
       */
      public NullPointer(Locale locale, String id) {
          super(null, locale);
          this.id = id;
      }
  
      public QName getName() {
          return name;
      }
  
      public Object getBaseValue() {
          return null;
      }
  
      public boolean isCollection() {
          return false;
      }
  
      public boolean isLeaf() {
          return true;
      }
  
      public boolean isActual() {
          return false;
      }
  
      public PropertyPointer getPropertyPointer() {
          return new NullPropertyPointer(this);
      }
  
      public NodePointer createPath(JXPathContext context, Object value) {
          if (parent != null) {
              return parent.createPath(context, value).getValuePointer();
          }
          throw new UnsupportedOperationException(
              "Cannot create the root object: " + asPath());
      }
  
      public NodePointer createPath(JXPathContext context) {
          if (parent != null) {
             return parent.createPath(context).getValuePointer();
         }
         throw new UnsupportedOperationException(
             "Cannot create the root object: " + asPath());
     }
 
     public NodePointer createChild(
         JXPathContext context,
         QName name,
         int index) {
         return createPath(context).createChild(context, name, index);
     }
 
     public NodePointer createChild(
         JXPathContext context,
         QName name,
         int index,
         Object value) {
         return createPath(context).createChild(context, name, index, value);
     }
 
     public int hashCode() {
         return name == null ? 0 : name.hashCode();
     }
 
     public boolean equals(Object object) {
         if (object == this) {
             return true;
         }
 
         if (!(object instanceof NullPointer)) {
             return false;
         }
 
         NullPointer other = (NullPointer) object;
         return name == other.name || name != null && name.equals(other.name);
     }
 
     public String asPath() {
         if (id != null) {
             return "id(" + id + ")";
         }
         return parent == null ? "null()" : super.asPath();
     }
 
     public int getLength() {
         return 0;
     }
 }