/*
 * @(#)XmlChars.java    1.1 00/08/05
 *
 * Copyright (c) 1998 Sun Microsystems, Inc. All Rights Reserved.
 */

package com.sun.msv.scanner.dtd;

import java.util.EventListener;

import org.xml.sax.Locator;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;

/**
 * All DTD parsing events are signaled through this interface.
 */
public interface DTDEventListener extends EventListener {

    public void setDocumentLocator( Locator loc );
    
    /**
     * Receive notification of a Processing Instruction.
     * Processing instructions contain information meaningful
     * to the application.
     *
     * @param target The target of the proceessing instruction
     *               which should have meaning to the application.
     * @param data   The instruction itself which should contain
     *               valid XML characters.
     *
     * @throws SAXException
     */
    public void processingInstruction(String target, String data)
                throws SAXException;

    /**
     * Receive notification of a Notation Declaration.
     * Notation declarations are used by elements and entities
     * for identifying embedded non-XML data.
     *
     * @param name     The notation name, referred to by entities and
     *                 elements.
     * @param publicId The public identifier 
     * @param systemId The system identifier
     */
    public void notationDecl(String name, String publicId, String systemId)
        throws SAXException;

    /**
     * Receive notification of an unparsed entity declaration.
     * Unparsed entities are non-XML data.
     *
     * @param name         The name of the unparsed entity.
     * @param publicId     The public identifier 
     * @param systemId     The system identifier
     * @param notationName The associated notation
     */
    public void unparsedEntityDecl(String name, String publicId, 
                                   String systemId, String notationName)
        throws SAXException;

    /**
     * Receive notification of a internal general entity declaration event.
     *
     * @see #externalGeneralEntityDecl(String, String, String)
     *
     * @param name  The internal general entity name.
     * @param value The value of the entity, which may include unexpanded
     *                entity references.  Character references will have been 
     *              expanded.
     *
     * @exception SAXException
     */
    public void internalGeneralEntityDecl (String name, String value)
        throws SAXException;

    /**
     * Receive notification of an external parsed general entity 
     * declaration event.
     *
     * <p>If a system identifier is present, and it is a relative URL, the
     * parser will have resolved it fully before passing it through this
     * method to a listener.</p>
     *
     * @see #unparsedEntityDecl(String, String, String, String)
     *
     * @param name     The entity name.
     * @param publicId The entity's public identifier, or null if
     *                 none was given.
     * @param systemId The entity's system identifier.
     *
     * @exception SAXException
     */
    public void externalGeneralEntityDecl(String name, String publicId, 
                                          String systemId)
        throws SAXException;

    /**
     * Receive notification of a internal parameter entity declaration 
     * event.
     *
     * @see #externalParameterEntityDecl(String, String, String)
     *
     * @param name  The internal parameter entity name.
     * @param value The value of the entity, which may include unexpanded
     *                entity references.  Character references will have been 
     *              expanded.
     *
     * @exception SAXException
     */
    public void internalParameterEntityDecl (String name, String value)
        throws SAXException;

    /**
     * Receive notification of an external parameter entity declaration 
     * event.
     *
     * <p>If a system identifier is present, and it is a relative URL, the
     * parser will have resolved it fully before passing it through this
     * method to a listener.</p>
     *
     * @see #unparsedEntityDecl(String, String, String, String)
     *
     * @param name     The parameter entity name.
     * @param publicId The entity's public identifier, or null if
     *                 none was given.
     * @param systemId The entity's system identifier.
     *
     * @exception SAXException
     */
    public void externalParameterEntityDecl (String name, String publicId, 
                                             String systemId)
        throws SAXException;

    /**
     * Receive notification of the beginning of the DTD.
     *
     * @param in  Current input entity.  
     * @see #endDTD()
     */
    public void startDTD(InputEntity in)
        throws SAXException;

    /**
     * Receive notification of the end of a DTD.  The parser will invoke
     * this method only once.
     *
     * @see #startDTD(InputEntity)
     *
     * @exception SAXException
     */
    public void endDTD()
        throws SAXException;

    /**
     * Receive notification that a comment has been read.
     *
     * <P> Note that processing instructions are the mechanism designed
     * to hold information for consumption by applications, not comments.
     * XML systems may rely on applications being able to access information
     * found in processing instructions; this is not true of comments, which
     * are typically discarded.
     *
     * @param text the text within the comment delimiters.
     *
     * @exception SAXException
     */
    public void comment (String text)
        throws SAXException;

    /**
     * Receive notification of character data.
     *
     * <p>The Parser will call this method to report each chunk of
     * character data.  SAX parsers may return all contiguous character
     * data in a single chunk, or they may split it into several
     * chunks; however, all of the characters in any single event
     * must come from the same external entity, so that the Locator
     * provides useful information.</p>
     *
     * <p>The application must not attempt to read from the array
     * outside of the specified range.</p>
     *
     * <p>Note that some parsers will report whitespace using the
     * ignorableWhitespace() method rather than this one (validating
     * parsers must do so).</p>
     *
     * @param ch     The characters from the DTD.
     * @param start  The start position in the array.
     * @param length The number of characters to read from the array.
     * @exception SAXException
     *            
     * @see #ignorableWhitespace(char[], int, int)
     */
    public void characters (char ch[], int start, int length)
        throws SAXException;


    /**
     * Receive notification of ignorable whitespace in element content.
     *
     * <p>Validating Parsers must use this method to report each chunk
     * of ignorable whitespace (see the W3C XML 1.0 recommendation,
     * section 2.10): non-validating parsers may also use this method
     * if they are capable of parsing and using content models.</p>
     *
     * <p>SAX parsers may return all contiguous whitespace in a single
     * chunk, or they may split it into several chunks; however, all of
     * the characters in any single event must come from the same
     * external entity, so that the Locator provides useful
     * information.</p>
     *
     * <p>The application must not attempt to read from the array
     * outside of the specified range.</p>
     *
     * @param ch     The characters from the DTD.
     * @param start  The start position in the array.
     * @param length The number of characters to read from the array.
     *
     * @exception SAXException
     * @see #characters(char[], int, int)
     */
    public void ignorableWhitespace (char ch[], int start, int length)
        throws SAXException;

    /**
     * Receive notification that a CDATA section is beginning.  Data in a
     * CDATA section is is reported through the appropriate event, either
     * <em>characters()</em> or <em>ignorableWhitespace</em>.
     *
     * @see #endCDATA()
     *
     * @exception SAXException 
     */
    public void startCDATA () throws SAXException;


    /**
     * Receive notification that the CDATA section finished.
     *
     * @see #startCDATA()
     *
     * @exception SAXException
     */
    public void endCDATA () throws SAXException;


    public void fatalError(SAXParseException e) 
           throws SAXException;

    public void error(SAXParseException e) throws SAXException;

    public void warning(SAXParseException err) throws SAXException;

    public final short CONTENT_MODEL_EMPTY        = 0;
    public final short CONTENT_MODEL_ANY        = 1;
    public final short CONTENT_MODEL_MIXED        = 2;
    public final short CONTENT_MODEL_CHILDREN    = 3;
    
    /**
     * receives notification that parsing of content model is beginning.
     * 
     * @param elementName
     *        name of the element whose content model is going to be defined.
     * @param contentModelType
     *        {@link #CONTENT_MODEL_EMPTY}
     *            this element has EMPTY content model. This notification
     *            will be immediately followed by the corresponding endContentModel.
     *        {@link #CONTENT_MODEL_ANY}
     *            this element has ANY content model. This notification
     *            will be immediately followed by the corresponding endContentModel.
     *        {@link #CONTENT_MODEL_MIXED}
     *            this element has mixed content model. #PCDATA will not be reported.
     *            each child element will be reported by mixedElement method.
     *        {@link #CONTENT_MODEL_CHILDREN}
     *            this elemen has child content model. The actual content model will
     *            be reported by childElement, startModelGroup, endModelGroup, and
     *            connector methods. Possible call sequences are:
     * 
     *            START := MODEL_GROUP
     *            MODEL_GROUP := startModelGroup TOKEN (connector TOKEN)* endModelGroup
     *            TOKEN := childElement
     *                   | MODEL_GROUP
     *            
     */
    public void startContentModel( String elementName, short contentModelType ) throws SAXException;
    
    /** receives notification that parsing of content model is finished. */
    public void endContentModel( String elementName, short contentModelType ) throws SAXException;

    public final short USE_NORMAL        = 0;
    public final short USE_IMPLIED        = 1;
    public final short USE_FIXED        = 2;
    public final short USE_REQUIRED        = 3;
    /**
     * For each entry in an ATTLIST declaration,
     * this event will be fired.
     * 
     * <p>
     * DTD allows the same attributes to be declared more than
     * once, and in that case the first one wins. I think
     * this method will be only fired for the first one,
     * but I need to check.
     */
    public void attributeDecl(
        String elementName, String attributeName, String attributeType,
        String[] enumeration, short attributeUse, String defaultValue ) throws SAXException;
    
    public void childElement( String elementName, short occurence ) throws SAXException;
    
    /**
     * receives notification of child element of mixed content model.
     * this method is called for each child element.
     * 
     * @see #startContentModel(String, short)
     */
    public void mixedElement( String elementName ) throws SAXException;
    
    public void startModelGroup() throws SAXException;
    public void endModelGroup( short occurence ) throws SAXException;
    
    public final short CHOICE    = 0;
    public final short SEQUENCE    = 1;
    /**
     * Connectors in one model group is guaranteed to be the same.
     * 
     * <p>
     * IOW, you'll never see an event sequence like (a|b,c)
     * 
     * @return
     *      {@link #CHOICE} or {@link #SEQUENCE}.
     */
    public void connector( short connectorType ) throws SAXException;
    
    public final short OCCURENCE_ZERO_OR_MORE    = 0;
    public final short OCCURENCE_ONE_OR_MORE    = 1;
    public final short OCCURENCE_ZERO_OR_ONE    = 2;
    public final short OCCURENCE_ONCE            = 3;
}
