itextpdf-master/xtra/src/main/java/com/itextpdf/text/pdf/pdfcleanup/PdfCleanUpContext.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.
 * These activities include: offering paid services to customers as an ASP,
 * serving PDFs on the fly in a web application, shipping iText with a closed
 * source product.
 *
 * For more information, please contact iText Software Corp. at this
 * address: sales@itextpdf.com
 */
package com.itextpdf.text.pdf.pdfcleanup;

import com.itextpdf.text.pdf.*;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Stack;

/**
 * Stores parameters related to specific context which is either page or xobject
 * (in other words: which is the object having contents stream)
 */
class PdfCleanUpContext {

    private PdfDictionary resources;
    private PdfContentByte canvas;

    /**
     * PdfContentStreamProcessor is able to process only Device* color spaces,
     * so I had to add this workaround.
     */
    private Stack<List<PdfObject>> strokeColorOperands;

    public PdfCleanUpContext() {
        List<PdfObject> initialStrokeColor = new ArrayList<PdfObject>(Arrays.asList(PdfName.DEVICEGRAY, new PdfLiteral("CS")));
        strokeColorOperands = new Stack<List<PdfObject>>();
        strokeColorOperands.push(initialStrokeColor);
    }

    public PdfCleanUpContext(PdfDictionary resources, PdfContentByte canvas) {
        this();
        this.resources = resources;
        this.canvas = canvas;
    }

    public PdfDictionary getResources() {
        return resources;
    }

    public void setResources(PdfDictionary resources) {
        this.resources = resources;
    }

    public PdfContentByte getCanvas() {
        return canvas;
    }

    public void setCanvas(PdfContentByte canvas) {
        this.canvas = canvas;
    }

    public void pushStrokeColor(List<PdfObject> strokeColorOperands) {
        this.strokeColorOperands.push(new ArrayList<PdfObject>(strokeColorOperands));
    }

    public List<PdfObject> peekStrokeColor() {
        if (strokeColorOperands.size() == 0) {
            return null;
        } else {
            return strokeColorOperands.peek();
        }
    }

    public List<PdfObject> popStrokeColor() {
        return strokeColorOperands.pop();
    }
}
