itextpdf-master/xtra/src/main/java/com/itextpdf/text/pdf/mc/StructureObject.java
/*
 *
 * This file is part of the iText (R) project.
    Copyright (c) 1998-2022 iText Group NV
 * Authors: Bruno Lowagie, 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.mc;

import com.itextpdf.text.exceptions.InvalidPdfException;
import com.itextpdf.text.pdf.*;

/**
 * A StructureItem that refers to an object from an OBJR dictionary.
 */
public class StructureObject extends StructureItem {

	/** The structure element of which the properties are stored. */
	protected PdfDictionary structElem;
	/** The reference of the structure element of which the properties are stored. */
	protected PdfIndirectReference ref;
	/** An object referred to by an OBJR dictionary. */
	protected PdfObject obj;
	/** The reference to the object. */
	protected PdfIndirectReference objref;
	/** The StructParent value of the object. */
	protected int structParent;

	/**
	 * Creates a StructureObject for an OBJR dictionary.
	 * @param structElem	the parent structure element
	 * @param ref			the reference of the parent structure element
	 * @param dict			the object reference dictionary
	 */
	public StructureObject(PdfDictionary structElem, PdfIndirectReference ref, PdfDictionary dict) throws InvalidPdfException {
		this.structElem = structElem;
		this.ref = ref;
		this.obj = dict.getDirectObject(PdfName.OBJ);
		this.objref = dict.getAsIndirectObject(PdfName.OBJ);
		PdfNumber sp = ((PdfDictionary)obj).getAsNumber(PdfName.STRUCTPARENT);
		if(sp == null)
			throw new InvalidPdfException("");
		this.structParent = sp.intValue();
		PdfIndirectReference pg = dict.getAsIndirectObject(PdfName.PG);
		if (pg == null)
			pg = structElem.getAsIndirectObject(PdfName.PG);
		this.pageref = pg.getNumber();
	}
	
	/**
	 * Returns the structure element.
	 * @return a StructElem dictionary
	 */
	public PdfDictionary getStructElem() {
		return structElem;
	}
	
	/**
	 * Returns the structure element's reference.
	 * @return an indirect reference to a StructElem dictionary
	 */
	public PdfIndirectReference getRef() {
		return ref;
	}
	
	/**
	 * Returns the object referred to by the OBJR dictionary.
	 * Note that this method returns a dictionary which means
	 * that in case the object is a stream, only the stream
	 * dictionary will be returned.
	 * @return the object referred to by OBJR as a dictionary
	 */
	public PdfDictionary getObjAsDict() {
		if (obj.isDictionary())
			return (PdfDictionary)obj;
		return null;
	}
	
	/**
	 * Returns the reference to the object.
	 * @return	an object reference
	 */
	public PdfIndirectReference getObjRef() {
		return objref;
	}
	
	/**
	 * Checks if a StructParent corresponds with the StructParent stored in the object.
	 * @return  1 in case the StructParent matches,
	 *         -1 in case there's no match.
	 */
	public int checkStructParent(int pg, int sp) {
		if (pg == pageref && sp == structParent)
			return 1;
		return -1;
	}
	
	/**
	 * Creates a String representation of the object.
	 * @see java.lang.Object#toString()
	 */
	public String toString() {
		return "StructParent " + structParent + " of object " + obj + " on page with reference " + pageref;
	}
}
