iTextSharp-LGPL/src/core/iTextSharp/text/pdf/PdfIndirectObject.cs

using System;
using System.IO;

using iTextSharp.text;

/*
 * $Id: PdfIndirectObject.cs,v 1.3 2008/05/13 11:25:21 psoares33 Exp $
 * 
 *
 * Copyright 1999, 2000, 2001, 2002 Bruno Lowagie
 *
 * The contents of this file are subject to the Mozilla Public License Version 1.1
 * (the "License"); you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the License.
 *
 * The Original Code is 'iText, a free JAVA-PDF library'.
 *
 * The Initial Developer of the Original Code is Bruno Lowagie. Portions created by
 * the Initial Developer are Copyright (C) 1999, 2000, 2001, 2002 by Bruno Lowagie.
 * All Rights Reserved.
 * Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer
 * are Copyright (C) 2000, 2001, 2002 by Paulo Soares. All Rights Reserved.
 *
 * Contributor(s): all the names of the contributors are added in the source code
 * where applicable.
 *
 * Alternatively, the contents of this file may be used under the terms of the
 * LGPL license (the "GNU LIBRARY GENERAL PUBLIC LICENSE"), in which case the
 * provisions of LGPL are applicable instead of those above.  If you wish to
 * allow use of your version of this file only under the terms of the LGPL
 * License and not to allow others to use your version of this file under
 * the MPL, indicate your decision by deleting the provisions above and
 * replace them with the notice and other provisions required by the LGPL.
 * If you do not delete the provisions above, a recipient may use your version
 * of this file under either the MPL or the GNU LIBRARY GENERAL PUBLIC LICENSE.
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the MPL as stated above or under the terms of the GNU
 * Library General Public License as published by the Free Software Foundation;
 * either version 2 of the License, or 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 Library general Public License for more
 * details.
 *
 * If you didn't download this code from the following link, you should check if
 * you aren't using an obsolete version:
 * http://www.lowagie.com/iText/
 */

namespace iTextSharp.text.pdf {
/**
 * <CODE>PdfIndirectObject</CODE> is the Pdf indirect object.
 * <P>
 * An <I>indirect object</I> is an object that has been labeled so that it can be referenced by
 * other objects. Any type of <CODE>PdfObject</CODE> may be labeled as an indirect object.<BR>
 * An indirect object consists of an object identifier, a direct object, and the <B>endobj</B>
 * keyword. The <I>object identifier</I> consists of an integer <I>object number</I>, an integer
 * <I>generation number</I>, and the <B>obj</B> keyword.<BR>
 * This object is described in the 'Portable Document Format Reference Manual version 1.3'
 * section 4.10 (page 53).
 *
 * @see        PdfObject
 * @see        PdfIndirectReference
 */

public class PdfIndirectObject {
    
        // membervariables
        
    /** The object number */
        protected int number;
        
    /** the generation number */
        protected int generation = 0;
        
        internal static byte[] STARTOBJ = DocWriter.GetISOBytes(" obj\n");
        internal static byte[] ENDOBJ = DocWriter.GetISOBytes("\nendobj\n");
        internal static int SIZEOBJ = STARTOBJ.Length + ENDOBJ.Length;
        internal PdfObject objecti;
        internal PdfWriter writer;
        
        // constructors
        
    /**
    * Constructs a <CODE>PdfIndirectObject</CODE>.
    *
    * @param        number            the objecti number
    * @param        objecti            the direct objecti
    */
        
        internal PdfIndirectObject(int number, PdfObject objecti, PdfWriter writer) : this(number, 0, objecti, writer) {
        }
        
        internal PdfIndirectObject(PdfIndirectReference refi, PdfObject objecti, PdfWriter writer) : this(refi.Number,refi.Generation,objecti,writer) {
        }
    /**
    * Constructs a <CODE>PdfIndirectObject</CODE>.
    *
    * @param        number            the objecti number
    * @param        generation        the generation number
    * @param        objecti            the direct objecti
    */
        
        internal PdfIndirectObject(int number, int generation, PdfObject objecti, PdfWriter writer) {
            this.writer = writer;
            this.number = number;
            this.generation = generation;
            this.objecti = objecti;
            PdfEncryption crypto = null;
            if (writer != null)
                crypto = writer.Encryption;
            if (crypto != null) {
                crypto.SetHashKey(number, generation);
            }
        }
        
        // methods
        
    /**
    * Returns a <CODE>PdfIndirectReference</CODE> to this <CODE>PdfIndirectObject</CODE>.
    *
    * @return        a <CODE>PdfIndirectReference</CODE>
    */
        
        public PdfIndirectReference IndirectReference {
            get {
                return new PdfIndirectReference(objecti.Type, number, generation);
            }
        }
        
    /**
    * Writes eficiently to a stream
    *
    * @param os the stream to write to
    * @throws IOException on write error
    */
        internal void WriteTo(Stream os) {
            byte[] tmp = DocWriter.GetISOBytes(number.ToString());
            os.Write(tmp, 0, tmp.Length);
            os.WriteByte((byte)' ');
            tmp = DocWriter.GetISOBytes(generation.ToString());
            os.Write(tmp, 0, tmp.Length);
            os.Write(STARTOBJ, 0, STARTOBJ.Length);
            objecti.ToPdf(writer, os);
            os.Write(ENDOBJ, 0, ENDOBJ.Length);
        }
    }
}