itextpdf-master/itext/src/main/java/com/itextpdf/text/pdf/PdfIndirectReference.java
/*
 *
 * This file is part of the iText (R) project.
    Copyright (c) 1998-2022 iText Group NV
 * Authors: Bruno Lowagie, Paulo Soares, et al.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License version 3
 * as published by the Free Software Foundation with the addition of the
 * following permission added to Section 15 as permitted in Section 7(a):
 * FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY
 * ITEXT GROUP. ITEXT GROUP DISCLAIMS THE WARRANTY OF NON INFRINGEMENT
 * OF THIRD PARTY RIGHTS
 *
 * This program 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 Affero General Public License for more details.
 * You should have received a copy of the GNU Affero General Public License
 * along with this program; if not, see http://www.gnu.org/licenses or write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA, 02110-1301 USA, or download the license from the following URL:
 * http://itextpdf.com/terms-of-use/
 *
 * The interactive user interfaces in modified source and object code versions
 * of this program must display Appropriate Legal Notices, as required under
 * Section 5 of the GNU Affero General Public License.
 *
 * In accordance with Section 7(b) of the GNU Affero General Public License,
 * a covered work must retain the producer line in every PDF that is created
 * or manipulated using iText.
 *
 * You can be released from the requirements of the license by purchasing
 * a commercial license. Buying such a license is mandatory as soon as you
 * develop commercial activities involving the iText software without
 * disclosing the source code of your own applications.
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 */
package com.itextpdf.text.pdf;

import java.io.IOException;
import java.io.OutputStream;

/**
 * <CODE>PdfIndirectReference</CODE> contains a reference to a <CODE>PdfIndirectObject</CODE>.
 * <P>
 * Any object used as an element of an array or as a value in a dictionary may be specified
 * by either a direct object of an indirect reference. An <I>indirect reference</I> is a reference
 * to an indirect object, and consists of the indirect object's object number, generation number
 * and the <B>R</B> keyword.<BR>
 * This object is described in the 'Portable Document Format Reference Manual version 1.3'
 * section 4.11 (page 54).
 *
 * @see		PdfObject
 * @see		PdfIndirectObject
 */

public class PdfIndirectReference extends PdfObject {
    
    // membervariables
    
/** the object number */
    protected int number;
    
/** the generation number */
    protected int generation = 0;
    
    // constructors
    
    protected PdfIndirectReference() {
        super(0);
    }
    
/**
 * Constructs a <CODE>PdfIndirectReference</CODE>.
 *
 * @param		type			the type of the <CODE>PdfObject</CODE> that is referenced to
 * @param		number			the object number.
 * @param		generation		the generation number.
 */
    
    PdfIndirectReference(int type, int number, int generation) {
        super(0, new StringBuffer().append(number).append(" ").append(generation).append(" R").toString());
        this.number = number;
        this.generation = generation;
    }
    
/**
 * Constructs a <CODE>PdfIndirectReference</CODE>.
 *
 * @param		type			the type of the <CODE>PdfObject</CODE> that is referenced to
 * @param		number			the object number.
 */
    
    protected PdfIndirectReference(int type, int number) {
        this(type, number, 0);
    }
    
    // methods
    
/**
 * Returns the number of the object.
 *
 * @return		a number.
 */
    
    public int getNumber() {
        return number;
    }
    
/**
 * Returns the generation of the object.
 *
 * @return		a number.
 */
    
    public int getGeneration() {
        return generation;
    }
    
    public String toString() {
    	return new StringBuffer().append(number).append(" ").append(generation).append(" R").toString();
    }

    @Override
    public void toPdf(PdfWriter writer, OutputStream os) throws IOException {
        os.write(PdfEncodings.convertToBytes(toString(), null));
    }
}
