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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

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package com.sun.tools.internal.xjc.reader.internalizer;

import com.sun.xml.internal.bind.unmarshaller.DOMScanner;

import org.w3c.dom.Document;

import org.w3c.dom.Element;

import org.w3c.dom.Node;

import org.xml.sax.Attributes;

import org.xml.sax.ContentHandler;

import org.xml.sax.Locator;

import org.xml.sax.SAXException;

import org.xml.sax.helpers.XMLFilterImpl;

/**

 * Produces a complete series of SAX events from any DOM node

 * in the DOMForest.

 *

 * <p>

 * This class hides a logic of re-associating {@link Locator}

 * to the generated SAX event stream.

 *

 * @author

 *     Kohsuke Kawaguchi (kohsuke.kawaguchi@sun.com)

 */

public class DOMForestScanner {

    private final DOMForest forest;

    /**

     * Scans DOM nodes of the given forest.

     *

     * DOM node parameters to the scan method must be a part of

     * this forest.

     */

    public DOMForestScanner( DOMForest _forest ) {

        this.forest = _forest;

    }

    /**

     * Generates the whole set of SAX events by treating

     * element e as if it's a root element.

     */

    public void scan( Element e, ContentHandler contentHandler ) throws SAXException {

        DOMScanner scanner = new DOMScanner();

        // insert the location resolver into the pipe line

        LocationResolver resolver = new LocationResolver(scanner);

        resolver.setContentHandler(contentHandler);

        // parse this DOM.

        scanner.setContentHandler(resolver);

        scanner.scan(e);

    }

    /**

     * Generates the whole set of SAX events from the given Document

     * in the DOMForest.

     */

    public void scan( Document d, ContentHandler contentHandler ) throws SAXException {

        scan( d.getDocumentElement(), contentHandler );

    }

    /**

     * Intercepts the invocation of the setDocumentLocator method

     * and passes itself as the locator.

     *

     * If the client calls one of the methods on the Locator interface,

     * use the LocatorTable to resolve the source location.

     */

    private class LocationResolver extends XMLFilterImpl implements Locator {

        LocationResolver( DOMScanner _parent ) {

            this.parent = _parent;

        }

        private final DOMScanner parent;

        /**

         * Flag that tells us whether we are processing a start element event

         * or an end element event.

         *

         * DOMScanner's getCurrentLocation method doesn't tell us which, but

         * this information is necessary to return the correct source line information.

         *

         * Thus we set this flag appropriately before we pass an event to

         * the next ContentHandler, thereby making it possible to figure

         * out which location to return.

         */

        private boolean inStart = false;

        @Override

        public void setDocumentLocator(Locator locator) {

            // ignore one set by the parent.

            super.setDocumentLocator(this);

        }

        @Override

        public void endElement(String namespaceURI, String localName, String qName) throws SAXException {

            inStart = false;

            super.endElement(namespaceURI, localName, qName);

        }

        @Override

        public void startElement(String namespaceURI, String localName, String qName, Attributes atts)

            throws SAXException {

            inStart = true;

            super.startElement(namespaceURI, localName, qName, atts);

        }

        private Locator findLocator() {

            Node n = parent.getCurrentLocation();

            if( n instanceof Element ) {

                Element e = (Element)n;

                if( inStart )

                    return forest.locatorTable.getStartLocation( e );

                else

                    return forest.locatorTable.getEndLocation( e );

            }

            return null;

        }

        //

        //

        // Locator methods

        //

        //

        public int getColumnNumber() {

            Locator l = findLocator();

            if(l!=null)     return l.getColumnNumber();

            return          -1;

        }

        public int getLineNumber() {

            Locator l = findLocator();

            if(l!=null)     return l.getLineNumber();

            return          -1;

        }

        public String getPublicId() {

            Locator l = findLocator();

            if(l!=null)     return l.getPublicId();

            return          null;

        }

        public String getSystemId() {

            Locator l = findLocator();

            if(l!=null)     return l.getSystemId();

            return          null;

        }

    }

}