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 * without modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain copyright statements and notices. Redistributions
 * must also contain a copy of this document.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of
 * conditions and the following disclaimer in the documentation and/or other materials provided with
 * the distribution.
 *
 * 3. The name "Exolab" must not be used to endorse or promote products derived from this Software
 * without prior written permission of Intalio, Inc. For written permission, please contact
 * info@exolab.org.
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 * 4. Products derived from this Software may not be called "Exolab" nor may "Exolab" appear in
 * their names without prior written permission of Intalio, Inc. Exolab is a registered trademark of
 * Intalio, Inc.
 *
 * 5. Due credit should be given to the Exolab Project (http://www.exolab.org/).
 *
 * THIS SOFTWARE IS PROVIDED BY INTALIO, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESSED OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
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 * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Copyright 2001 (C) Intalio, Inc. All Rights Reserved.
 *
 * $Id$
 */

package org.exolab.castor.xml.schema;

import java.util.Enumeration;
import java.util.Vector;

/**
 * A class that represents the XML Schema Union simple-type.
 *
 * @author <a href="mailto:kvisco@intalio.com">Keith Visco</a>
 * @version $Revision$ $Date: 2006-04-14 04:14:43 -0600 (Fri, 14 Apr 2006) $
 **/
public class Union extends SimpleType {
  /** SerialVersionUID */
  private static final long serialVersionUID = -1389185884142578168L;

  /**
   * The local annotation for this Union
   **/
  private Annotation _annotation = null;

  /**
   * The id attribute for this Union
   **/
  private String _id = null;

  /**
   * The simpleType members of this Union. No sense in having a union of only one (1), but we choose
   * a low number, like two (2) or three (3) since most unions will only have at most a few members.
   **/
  private final Vector<SimpleType> _simpleTypes = new Vector<>(3);

  private boolean _hasReferencedTypes = false;

  /**
   * Creates a new Union type.
   *
   * @param schema the Schema for this Union (Cannot be null)
   **/
  public Union(Schema schema) throws SchemaException {
    super();

    if (schema == null) {
      String err = "The Schema argument to the constructor of Union " + "may not be null.";
      throw new IllegalArgumentException(err);
    }
    super.setSchema(schema);
  } // -- Union

  /**
   * Adds the given SimpleType reference as a member of this Union. An exception will be thrown
   * during a call to #getMemberTypes if this reference cannot be resolved.
   *
   * @param typeName the name of the SimpleType to add.
   **/
  public void addMemberType(String typeName) {
    if (typeName == null)
      return;
    addMemberType(new SimpleTypeReference(getSchema(), typeName));
  } // -- addMemberType

  /**
   * Adds the given SimpleType as a member of this Union
   *
   * @param simpleType the SimpleType to add to this Union.
   **/
  public void addMemberType(SimpleType simpleType) {
    if (simpleType == null)
      return;

    if (simpleType instanceof SimpleTypeReference) {
      if (simpleType.getType() != null) {
        simpleType = (SimpleType) simpleType.getType();
      } else
        _hasReferencedTypes = true;
    }
    _simpleTypes.add(simpleType);
  } // -- addMemberType

  /**
   * Returns the id for this Union, or null if no id has been set.
   *
   * @return the id for this Union, or null if no id has been set..
   **/
  public String getId() {
    return _id;
  } // -- getId

  /**
   * Returns the annotation which appears local to this Union, or null if no local annotation has
   * been set.
   *
   * @return the annotation which is local to this Union.
   **/
  public Annotation getLocalAnnotation() {
    return _annotation;
  } // -- getLocalAnnotation

  /**
   * Returns an Enumeration of all the SimpleTypes that are members of this Union.
   *
   * @return an Enumeration of all member SimpleTypes.
   **/
  public Enumeration<SimpleType> getMemberTypes() {
    // -- clear any referenced types (if necessary)
    if (_hasReferencedTypes) {
      _hasReferencedTypes = false;
      for (int i = 0; i < _simpleTypes.size(); i++) {
        Object obj = _simpleTypes.elementAt(i);
        if (obj instanceof SimpleTypeReference) {
          SimpleType simpleType = (SimpleType) obj;
          if (simpleType.getType() != null) {
            _simpleTypes.setElementAt(resolveReference(simpleType), i);
          } else {
            // -- XXXX
            // -- we should really throw an exception here
            // -- but for now...just re-mark as having
            // -- an unresolved referred type.
            _hasReferencedTypes = true;
          }
        }
      }
    }
    return _simpleTypes.elements();
  } // -- getMemberTypes;

  /**
   * Returns the type of this Schema Structure
   * 
   * @return the type of this Schema Structure
   **/
  public short getStructureType() {
    return Structure.UNION;
  } // -- getStructureType

  /**
   * Sets the Schema for this Union. This method overloads the SimpleType#setSchema method to
   * prevent the Schema from being changed.
   *
   * @param schema the schema that this Union belongs to.
   **/
  public void setSchema(Schema schema) {
    if (schema != getSchema()) {
      String err = "The Schema of an Union cannot be changed.";
      throw new IllegalStateException(err);
    }
  } // -- void setSchema

  /**
   * Sets the id for this Union.
   * 
   * @param id the unique id for this Union. Must be globally unique within the scope of the Schema.
   **/
  public void setId(String id) {
    _id = id;
  } // -- setId

  /**
   * Sets an annotation which is local to this Union.
   *
   * @param annotation the local annotation to set for this Union.
   **/
  public void setLocalAnnotation(Annotation annotation) {
    _annotation = annotation;
  } // -- setLocalAnnotation

} // -- class: Union
