/*
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 2001, 2002 The Apache Software Foundation.  
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 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 end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:  
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Xerces" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written 
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``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 THE APACHE SOFTWARE FOUNDATION 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation and was
 * originally based on software copyright (c) 1999, International
 * Business Machines, Inc., http://www.apache.org.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

package org.apache.xerces.xni.parser;

import java.io.IOException;
import org.apache.xerces.xni.XNIException;

/**
 * This interface defines a generic DTD scanner. This interface
 * allows a scanner to be used interchangably in existing parser
 * configurations.
 * <p>
 * If the parser configuration uses a DTD scanner that implements
 * this interface, components should be able to query the scanner
 * instance from the component manager using the following property 
 * identifier:
 * <blockquote>
 *  "http://apache.org/xml/properties/internal/dtd-scanner"
 * </blockquote>
 *
 * @author Andy Clark, IBM
 *
 * @version $Id: XMLDTDScanner.java,v 1.5 2002/11/19 01:41:38 twl Exp $
 */
public interface XMLDTDScanner 
    extends XMLDTDSource, XMLDTDContentModelSource {

    //
    // XMLDTDScanner methods
    //

    /** 
     * Sets the input source. 
     *
     * @param inputSource The input source or null.
     *
     * @throws IOException Thrown on i/o error.
     */
    public void setInputSource(XMLInputSource inputSource) throws IOException;

    /** 
     * Scans the internal subset of the document.
     *
     * @param complete True if the scanner should scan the document
     *                 completely, pushing all events to the registered
     *                 document handler. A value of false indicates that
     *                 that the scanner should only scan the next portion
     *                 of the document and return. A scanner instance is
     *                 permitted to completely scan a document if it does
     *                 not support this "pull" scanning model.
     * @param standalone True if the document was specified as standalone.
     *                   This value is important for verifying certain
     *                   well-formedness constraints.
     * @param hasExternalDTD True if the document has an external DTD.
     *                       This allows the scanner to properly notify
     *                       the handler of the end of the DTD in the
     *                       absence of an external subset.
     *
     * @return True if there is more to scan, false otherwise.
     */
    public boolean scanDTDInternalSubset(boolean complete, boolean standalone,
                                         boolean hasExternalSubset)
        throws IOException, XNIException;

    /**
     * Scans the external subset of the document.
     *
     * @param complete True if the scanner should scan the document
     *                 completely, pushing all events to the registered
     *                 document handler. A value of false indicates that
     *                 that the scanner should only scan the next portion
     *                 of the document and return. A scanner instance is
     *                 permitted to completely scan a document if it does
     *                 not support this "pull" scanning model.
     *
     * @return True if there is more to scan, false otherwise.
     */
    public boolean scanDTDExternalSubset(boolean complete) 
        throws IOException, XNIException;

} // interface XMLDTDScanner
