001/*
002 * $Id: PdfIndirectObject.java 4784 2011-03-15 08:33:00Z blowagie $
003 *
004 * This file is part of the iText (R) project.
005 * Copyright (c) 1998-2011 1T3XT BVBA
006 * Authors: Bruno Lowagie, Paulo Soares, et al.
007 *
008 * This program is free software; you can redistribute it and/or modify
009 * it under the terms of the GNU Affero General Public License version 3
010 * as published by the Free Software Foundation with the addition of the
011 * following permission added to Section 15 as permitted in Section 7(a):
012 * FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY 1T3XT,
013 * 1T3XT DISCLAIMS THE WARRANTY OF NON INFRINGEMENT OF THIRD PARTY RIGHTS.
014 *
015 * This program is distributed in the hope that it will be useful, but
016 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
017 * or FITNESS FOR A PARTICULAR PURPOSE.
018 * See the GNU Affero General Public License for more details.
019 * You should have received a copy of the GNU Affero General Public License
020 * along with this program; if not, see http://www.gnu.org/licenses or write to
021 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
022 * Boston, MA, 02110-1301 USA, or download the license from the following URL:
023 * http://itextpdf.com/terms-of-use/
024 *
025 * The interactive user interfaces in modified source and object code versions
026 * of this program must display Appropriate Legal Notices, as required under
027 * Section 5 of the GNU Affero General Public License.
028 *
029 * In accordance with Section 7(b) of the GNU Affero General Public License,
030 * a covered work must retain the producer line in every PDF that is created
031 * or manipulated using iText.
032 *
033 * You can be released from the requirements of the license by purchasing
034 * a commercial license. Buying such a license is mandatory as soon as you
035 * develop commercial activities involving the iText software without
036 * disclosing the source code of your own applications.
037 * These activities include: offering paid services to customers as an ASP,
038 * serving PDFs on the fly in a web application, shipping iText with a closed
039 * source product.
040 *
041 * For more information, please contact iText Software Corp. at this
042 * address: sales@itextpdf.com
043 */
044package com.itextpdf.text.pdf;
045
046import java.io.IOException;
047import java.io.OutputStream;
048
049import com.itextpdf.text.DocWriter;
050
051/**
052 * <CODE>PdfIndirectObject</CODE> is the Pdf indirect object.
053 * <P>
054 * An <I>indirect object</I> is an object that has been labeled so that it can be referenced by
055 * other objects. Any type of <CODE>PdfObject</CODE> may be labeled as an indirect object.<BR>
056 * An indirect object consists of an object identifier, a direct object, and the <B>endobj</B>
057 * keyword. The <I>object identifier</I> consists of an integer <I>object number</I>, an integer
058 * <I>generation number</I>, and the <B>obj</B> keyword.<BR>
059 * This object is described in the 'Portable Document Format Reference Manual version 1.7'
060 * section 3.2.9 (page 63-65).
061 *
062 * @see         PdfObject
063 * @see         PdfIndirectReference
064 */
065
066public class PdfIndirectObject {
067    
068    // membervariables
069    
070/** The object number */
071    protected int number;
072    
073/** the generation number */
074    protected int generation = 0;
075    
076    static final byte STARTOBJ[] = DocWriter.getISOBytes(" obj\n");
077    static final byte ENDOBJ[] = DocWriter.getISOBytes("\nendobj\n");
078    static final int SIZEOBJ = STARTOBJ.length + ENDOBJ.length;
079    PdfObject object;
080    PdfWriter writer;
081    
082    // constructors
083    
084/**
085 * Constructs a <CODE>PdfIndirectObject</CODE>.
086 *
087 * @param               number                  the object number
088 * @param               object                  the direct object
089 */
090    
091    PdfIndirectObject(int number, PdfObject object, PdfWriter writer) {
092        this(number, 0, object, writer);
093    }
094    
095    PdfIndirectObject(PdfIndirectReference ref, PdfObject object, PdfWriter writer) {
096        this(ref.getNumber(),ref.getGeneration(),object,writer);
097    }
098/**
099 * Constructs a <CODE>PdfIndirectObject</CODE>.
100 *
101 * @param               number                  the object number
102 * @param               generation              the generation number
103 * @param               object                  the direct object
104 */
105    
106    PdfIndirectObject(int number, int generation, PdfObject object, PdfWriter writer) {
107        this.writer = writer;
108        this.number = number;
109        this.generation = generation;
110        this.object = object;
111        PdfEncryption crypto = null;
112        if (writer != null)
113            crypto = writer.getEncryption();
114        if (crypto != null) {
115            crypto.setHashKey(number, generation);
116        }
117    }
118    
119    // methods
120    
121/**
122 * Return the length of this <CODE>PdfIndirectObject</CODE>.
123 *
124 * @return              the length of the PDF-representation of this indirect object.
125 */
126    
127//    public int length() {
128//        if (isStream)
129//            return bytes.size() + SIZEOBJ + stream.getStreamLength(writer);
130//        else
131//            return bytes.size();
132//    }
133    
134    
135/**
136 * Returns a <CODE>PdfIndirectReference</CODE> to this <CODE>PdfIndirectObject</CODE>.
137 *
138 * @return              a <CODE>PdfIndirectReference</CODE>
139 */
140    
141    public PdfIndirectReference getIndirectReference() {
142        return new PdfIndirectReference(object.type(), number, generation);
143    }
144    
145/**
146 * Writes efficiently to a stream
147 *
148 * @param os the stream to write to
149 * @throws IOException on write error
150 */
151    void writeTo(OutputStream os) throws IOException
152    {
153        os.write(DocWriter.getISOBytes(String.valueOf(number)));
154        os.write(' ');
155        os.write(DocWriter.getISOBytes(String.valueOf(generation)));
156        os.write(STARTOBJ);
157        object.toPdf(writer, os);
158        os.write(ENDOBJ);
159    }
160}