content: /*
   * 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 mf.org.apache.xerces.stax;
  
  import java.util.Collections;
  import java.util.Iterator;
  import java.util.NoSuchElementException;
  
  import mf.javax.xml.XMLConstants;
  import mf.javax.xml.namespace.NamespaceContext;
  
  /**
   * <p>A <code>NamespaceContext</code> which only
   * contains bindings for the xml and xmlns prefixes.</p>
   *
   * @author Michael Glavassevich, IBM
   * @version $Id: DefaultNamespaceContext.java 730672 2009-01-02 06:15:08Z mrglavas $
   * @xerces.internal
   */
  public final class DefaultNamespaceContext implements NamespaceContext {
  
      /**
       * Singleton instance.
       */
      private static final DefaultNamespaceContext DEFAULT_NAMESPACE_CONTEXT_INSTANCE
              = new DefaultNamespaceContext();
  
      private DefaultNamespaceContext() {
      }
  
      /**
       * Returns the one and only instance of this class.
       */
      public static DefaultNamespaceContext getInstance() {
          return DEFAULT_NAMESPACE_CONTEXT_INSTANCE;
      }
  
      @Override
      public String getNamespaceURI(String prefix) {
          if (prefix == null) {
              throw new IllegalArgumentException("Prefix cannot be null.");
          } else if (XMLConstants.XML_NS_PREFIX.equals(prefix)) {
              return XMLConstants.XML_NS_URI;
          } else if (XMLConstants.XMLNS_ATTRIBUTE.equals(prefix)) {
              return XMLConstants.XMLNS_ATTRIBUTE_NS_URI;
          }
          return XMLConstants.NULL_NS_URI;
      } // getNamespaceURI(String)
  
      @Override
      public String getPrefix(String namespaceURI) {
          if (namespaceURI == null) {
              throw new IllegalArgumentException("Namespace URI cannot be null.");
          } else if (XMLConstants.XML_NS_URI.equals(namespaceURI)) {
              return XMLConstants.XML_NS_PREFIX;
          } else if (XMLConstants.XMLNS_ATTRIBUTE_NS_URI.equals(namespaceURI)) {
              return XMLConstants.XMLNS_ATTRIBUTE;
          }
          return null;
      } // getPrefix(String)
  
      @Override
      public Iterator getPrefixes(String namespaceURI) {
          if (namespaceURI == null) {
              throw new IllegalArgumentException("Namespace URI cannot be null.");
          } else if (XMLConstants.XML_NS_URI.equals(namespaceURI)) {
              return new Iterator() {
                  boolean more = true;
  
                  @Override
                  public boolean hasNext() {
                      return more;
                  }
  
                  @Override
                  public Object next() {
                      if (!hasNext()) {
                          throw new NoSuchElementException();
                      }
                      more = false;
                      return XMLConstants.XML_NS_PREFIX;
                  }
  
                  @Override
                  public void remove() {
                      throw new UnsupportedOperationException();
                  }
              };
          } else if (XMLConstants.XMLNS_ATTRIBUTE_NS_URI.equals(namespaceURI)) {
              return new Iterator() {
                  boolean more = true;
  
                  @Override
                  public boolean hasNext() {
                      return more;
                  }
  
                  @Override
                  public Object next() {
                      if (!hasNext()) {
                          throw new NoSuchElementException();
                      }
                      more = false;
                      return XMLConstants.XMLNS_ATTRIBUTE;
                  }
  
                  @Override
                  public void remove() {
                      throw new UnsupportedOperationException();
                  }
              };
          }
          return Collections.EMPTY_LIST.iterator();
      } // getPrefixes(String)
  }
  