com.github.stephenc.javaisotools.rockridge.impl.SystemUseEntryHandler Maven / Gradle / Ivy

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/*
 * Copyright (c) 2010. Stephen Connolly.
 * Copyright (C) 2007. Jens Hatlak 
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

package com.github.stephenc.javaisotools.rockridge.impl;

import java.util.Stack;

import com.github.stephenc.javaisotools.sabre.ContentHandler;
import com.github.stephenc.javaisotools.sabre.DataReference;
import com.github.stephenc.javaisotools.sabre.Element;
import com.github.stephenc.javaisotools.sabre.Fixup;
import com.github.stephenc.javaisotools.sabre.HandlerException;
import com.github.stephenc.javaisotools.sabre.impl.ByteDataReference;
import com.github.stephenc.javaisotools.sabre.impl.ChainingStreamHandler;
import com.github.stephenc.javaisotools.sabre.StructureHandler;
import com.github.stephenc.javaisotools.sabre.impl.ByteArrayDataReference;

public class SystemUseEntryHandler extends ChainingStreamHandler {

    private Stack elements;
    private int length = 0;
    private Fixup lengthFixup;

    public SystemUseEntryHandler(StructureHandler chainingStructureHandler, ContentHandler chainingContentHandler) {
        super(chainingStructureHandler, chainingContentHandler);
        this.elements = new Stack();
    }

    public void startElement(Element element) throws HandlerException {
        elements.push(element);
        if (element instanceof SystemUseEntryElement) {
            SystemUseEntryElement sue = (SystemUseEntryElement) element;

            // Reset byte counter
            length = 0;

            // Signature Word
            data(new ByteArrayDataReference(sue.getSignatureWord()));

            // Length (including Signature Word, Length, Version and Data)
            lengthFixup = fixup(new ByteDataReference(0));

            // Version
            data(new ByteDataReference(sue.getVersion()));
        }

        super.startElement(element);
    }

    public void data(DataReference reference) throws HandlerException {
        length += reference.getLength();
        super.data(reference);
    }

    public Fixup fixup(DataReference reference) throws HandlerException {
        length += reference.getLength();
        return super.fixup(reference);
    }

    public void endElement() throws HandlerException {
        Element element = (Element) elements.pop();
        if (element instanceof SystemUseEntryElement) {
            // Write and close Entry Length Fixup
            if (length > 255) {
                throw new RuntimeException("Invalid System Use Entry length: " + length);
            }
            lengthFixup.data(new ByteDataReference(length));
            lengthFixup.close();
        }
        super.endElement();
    }
}