BlorbMetadataHandler.java

/*
 * $Id: BlorbMetadataHandler.java 536 2008-02-19 06:03:27Z weiju $
 * 
 * Created on 2006/03/04
 * Copyright 2005-2008 by Wei-ju Wu
 * This file is part of The Z-machine Preservation Project (ZMPP).
 *
 * ZMPP is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * ZMPP 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 for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with ZMPP.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.zmpp.blorb;

import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

import org.xml.sax.Attributes;
import org.xml.sax.helpers.DefaultHandler;
import org.zmpp.base.Memory;
import org.zmpp.iff.Chunk;
import org.zmpp.iff.FormChunk;
import org.zmpp.media.InformMetadata;
import org.zmpp.media.StoryMetadata;

/**
 * This class parses the metadata chunk in the Blorb file and converts it into a
 * Treaty of Babel metadata object.
 *
 * @author Wei-ju Wu
 * @version 1.0
 */
public class BlorbMetadataHandler extends DefaultHandler {

    private StoryMetadata story;
    private StringBuilder buffer;
    private boolean processAux;

    public BlorbMetadataHandler(FormChunk formchunk) {
        extractMetadata(formchunk);
    }

    public InformMetadata getMetadata() {
        return (story == null) ? null : new InformMetadata(story);
    }

    private void extractMetadata(final FormChunk formchunk) {
        final Chunk chunk = formchunk.getSubChunk("IFmd".getBytes());
        if (chunk != null) {
            final Memory chunkmem = chunk.getMemory();
            final MemoryInputStream meminput
                    = new MemoryInputStream(chunkmem, Chunk.CHUNK_HEADER_LENGTH,
                            chunk.getSize() + Chunk.CHUNK_HEADER_LENGTH);

            try {

                final SAXParser parser = SAXParserFactory.newInstance().newSAXParser();
                parser.parse(meminput, this);

            } catch (Exception ex) {

                ex.printStackTrace();
            }
        }
    }

  // **********************************************************************
    // **** Parsing meta data
    // *********************************
    public void startElement(final String uri, final String localName,
            final String qname, final Attributes attributes) {

        if ("story".equals(qname)) {
            story = new StoryMetadata();
        }
        if ("title".equals(qname)) {
            buffer = new StringBuilder();
        }
        if ("headline".equals(qname)) {
            buffer = new StringBuilder();
        }
        if ("author".equals(qname)) {
            buffer = new StringBuilder();
        }
        if ("genre".equals(qname)) {
            buffer = new StringBuilder();
        }
        if ("description".equals(qname)) {
            buffer = new StringBuilder();
        }
        if (isPublishYear(qname)) {
            buffer = new StringBuilder();
        }
        if ("auxiliary".equals(qname)) {
            processAux = true;
        }
        if ("coverpicture".equals(qname)) {
            buffer = new StringBuilder();
        }
        if ("group".equals(qname)) {
            buffer = new StringBuilder();
        }
    }

    public void endElement(final String uri, final String localName,
            final String qname) {
        if ("title".equals(qname)) {
            story.setTitle(buffer.toString());
        }
        if ("headline".equals(qname)) {
            story.setHeadline(buffer.toString());
        }
        if ("author".equals(qname)) {
            story.setAuthor(buffer.toString());
        }
        if ("genre".equals(qname)) {
            story.setGenre(buffer.toString());
        }
        if ("description".equals(qname) && !processAux) {
            story.setDescription(buffer.toString());
        }
        if (isPublishYear(qname)) {
            story.setYear(buffer.toString());
        }
        if ("group".equals(qname)) {
            story.setGroup(buffer.toString());
        }
        if ("coverpicture".equals(qname)) {
            final String val = buffer.toString().trim();
            try {
                story.setCoverPicture(Integer.parseInt(val));
            } catch (NumberFormatException ex) {
                System.err.println("NumberFormatException in cover picture: " + val);
            }
        }
        if ("auxiliary".equals(qname)) {
            processAux = false;
        }
        if ("br".equals(qname) && buffer != null) {

            buffer.append("\n");
        }
    }

    public void characters(final char[] ch, final int start, final int length) {
        if (buffer != null) {

            final StringBuilder partbuilder = new StringBuilder();
            for (int i = start; i < start + length; i++) {

                partbuilder.append(ch[i]);
            }
            buffer.append(partbuilder.toString().trim());
        }
    }

    /**
     * Unfortunately, year was renamed to firstpublished between the preview
     * metadata version of Inform 7 and the Treaty of Babel version, so we
     * handle both here.
     *
     * @param str the qname
     * @return true if matches, false, otherwise
     */
    private boolean isPublishYear(String str) {
        return "year".equals(str) || "firstpublished".equals(str);
    }
}