/**
 * Redistribution and use of this software and associated documentation ("Software"), with or
 * 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.
 *
 * 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
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTALIO, INC. OR ITS
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
 * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Copyright 1999 (C) Intalio, Inc. All Rights Reserved.
 *
 * $Id$
 */

package org.exolab.castor.xml.schema.reader;

// -- imported classes and packages
import org.exolab.castor.xml.schema.Resolver;
import org.xml.sax.AttributeList;
import org.xml.sax.DocumentHandler;
import org.xml.sax.Locator;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;

/**
 * The base class for unmarshallers
 * 
 * @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 abstract class SaxUnmarshaller implements DocumentHandler, org.xml.sax.ErrorHandler {


  // --------------------/
  // - Member Variables -/
  // --------------------/

  /**
   * The document locator
   **/
  protected Locator _locator = null;

  /**
   * The resolver to be used for resolving id references
   **/
  private Resolver _resolver;

  // ----------------/
  // - Constructors -/
  // ----------------/

  public SaxUnmarshaller() {
    super();
  } // -- SaxUnmarshaller

  // -----------/
  // - Methods -/
  // -----------/

  /**
   * Returns the name of the element that this SaxUnmarshaller handles
   * 
   * @return the name of the element that this SaxUnmarshaller handles
   **/
  public abstract String elementName();

  /**
   * Returns the Object created by this Unmarshaller
   * 
   * @return the Object created by this Unmarshaller
   **/
  public abstract Object getObject();

  /**
   * Called to signal an end of unmarshalling. This method should be overridden to perform any
   * necessary clean up by an unmarshaller
   **/
  public void finish() throws SAXException {}

  public Locator getDocumentLocator() {
    return _locator;
  } // -- getLocator

  /**
   * Returns the resolver used for resolving id references.
   * 
   * @return the resolver used for resolving id references.
   **/
  public Resolver getResolver() {
    return _resolver;
  } // -- getResolver

  /**
   * Sets the Resolver to be used for resolving id references
   * 
   * @param resolver the Resolver to be used for resolving id references
   **/
  public void setResolver(Resolver resolver) {
    _resolver = resolver;
  } // -- setResolver

  /**
   * Determines if the given sequence of characters consists of whitespace characters
   * 
   * @param chars an array of characters to check for whitespace
   * @param start the start index into the character array
   * @param length the number of characters to check
   * @return true if the characters specficied consist only of whitespace characters
   **/
  public static boolean isWhiteSpace(char[] chars, int start, int length) {
    int max = start + length;
    for (int i = start; i < max; i++) {
      char ch = chars[i];
      switch (ch) {
        case ' ':
        case '\n':
        case '\t':
        case '\r':
          break;
        default:
          return false;
      }
    }
    return true;
  } // -- isWhiteSpace

  /**
   * This method is called for a general error.
   * 
   * @param err the error message to report
   * @exception org.xml.sax.SAXException always thrown.
   **/
  public void error(String err) throws org.xml.sax.SAXException {

    if (_locator != null) {
      err += "\n   line: " + _locator.getLineNumber();
    }

    throw new SAXException(err);
  } // -- error

  /**
   * This method is called when an illegal Attribute is encountered.
   * 
   * @param attName the name of the illegal attribute.
   * @exception org.xml.sax.SAXException always thrown.
   **/
  public void illegalAttribute(String attName) throws org.xml.sax.SAXException {
    String err = "Illegal attribute '" + attName + "' found on element <" + elementName() + ">.";

    if (_locator != null) {
      err += "\n   line: " + _locator.getLineNumber();
    }

    throw new SAXException(err);
  } // -- illegalAttribute

  /**
   * This method is called when an illegal Element is encountered.
   * 
   * @param name the name of the illegal element
   * @exception org.xml.sax.SAXException always thrown.
   **/
  public void illegalElement(String name) throws org.xml.sax.SAXException {
    String err = "Illegal element '" + name + "' found as child of <" + elementName() + ">.";

    if (_locator != null) {
      err += "\n   line: " + _locator.getLineNumber();
    }

    throw new SAXException(err);
  } // -- illegalElement


  /**
   * This method is called when an element which may only be defined once, is redefined.
   * 
   * @param name the name of the element
   * @exception org.xml.sax.SAXException always thrown.
   **/
  public void redefinedElement(String name) throws org.xml.sax.SAXException {
    redefinedElement(name, null);
  } // -- redefinedElement

  /**
   * This method is called when an element which may only be defined once, is redefined.
   * 
   * @param name the name of the element
   * @exception org.xml.sax.SAXException always thrown.
   **/
  public void redefinedElement(String name, String xtraInfo) throws org.xml.sax.SAXException {
    String err = "redefintion of element '" + name + "' within element <" + elementName() + ">.";

    if (_locator != null) {
      err += "\n   line: " + _locator.getLineNumber();
    }

    if (xtraInfo != null) {
      err += "\n   " + xtraInfo;
    }

    throw new SAXException(err + "\n");
  } // -- redefinedElement

  /**
   * This method is called when an out of order element is encountered
   * 
   * @exception org.xml.sax.SAXException always thrown.
   **/
  public void outOfOrder(String name) throws org.xml.sax.SAXException {
    StringBuffer err = new StringBuffer("out of order element <");
    err.append(name);
    err.append("> found in <");
    err.append(elementName());
    err.append(">.");
    throw new SAXException(err.toString());
  }

  /**
   * Converts the given String to an int
   * 
   * @param str the String to convert to an int
   * @return the int derived from the given String
   * @exception IllegalArgumentException when the given String does not represent a valid int
   **/
  public static int toInt(String str) throws IllegalArgumentException {
    try {
      return Integer.parseInt(str);
    } catch (NumberFormatException nfe) {
      String err = str + " is not a valid integer. ";
      throw new IllegalArgumentException(err);
    }
  } // -- toInt


  // ---------------------------------------/
  // - org.xml.sax.DocumentHandler methods -/
  // ---------------------------------------/

  public void characters(char[] ch, int start, int length) throws org.xml.sax.SAXException {
    // -- do nothing

  } // -- characters

  public void endDocument() throws org.xml.sax.SAXException {
    // -- do nothing

  } // -- endDocument

  public void endElement(String name) throws org.xml.sax.SAXException {
    // -- do nothing

  } // -- endElement


  public void ignorableWhitespace(char[] ch, int start, int length)
      throws org.xml.sax.SAXException {
    // -- do nothing

  } // -- ignorableWhitespace

  public void processingInstruction(String target, String data) throws org.xml.sax.SAXException {
    // -- do nothing

  } // -- processingInstruction

  public void setDocumentLocator(Locator locator) {
    this._locator = locator;
  } // -- setDocumentLocator

  public void startDocument() throws org.xml.sax.SAXException {
    // -- do nothing

  } // -- startDocument


  public void startElement(String name, AttributeList atts) throws org.xml.sax.SAXException {
    // -- do nothing

  } // -- startElement


  // ------------------------------------/
  // - org.xml.sax.ErrorHandler methods -/
  // ------------------------------------/

  public void error(SAXParseException exception) throws org.xml.sax.SAXException {
    throw exception;

  } // -- error

  public void fatalError(SAXParseException exception) throws org.xml.sax.SAXException {
    throw exception;

  } // -- fatalError


  public void warning(SAXParseException exception) throws org.xml.sax.SAXException {
    throw exception;

  } // -- warning

} // -- SaxUnmarshaller

