itextpdf-master/itext/src/main/java/com/itextpdf/text/pdf/PdfPageEvent.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;
import com.itextpdf.text.Document;
import com.itextpdf.text.Paragraph;
import com.itextpdf.text.Rectangle;

/**
 * Allows a class to catch several document events.
 *<p>
 * Note: do not use Document.add() inside a page event.
 *
 * @author  Paulo Soares
 */

public interface PdfPageEvent {
    
/**
 * Called when the document is opened.
 *
 * @param writer the <CODE>PdfWriter</CODE> for this document
 * @param document the document
 */
    public void onOpenDocument(PdfWriter writer, Document document);
    
/**
 * Called when a page is initialized.
 * <P>
 * Note that if even if a page is not written this method is still
 * called. It is preferable to use <CODE>onEndPage</CODE> to avoid
 * infinite loops.
 * </P>
 * <P>
 * Note that this method isn't called for the first page. You should apply modifications for the first
 * page either before opening the document or by using the onOpenDocument() method.
 * </P>
 *
 * @param writer the <CODE>PdfWriter</CODE> for this document
 * @param document the document
 */
    public void onStartPage(PdfWriter writer, Document document);
    
/**
 * Called when a page is finished, just before being written to the document.
 *
 * @param writer the <CODE>PdfWriter</CODE> for this document
 * @param document the document
 */
    public void onEndPage(PdfWriter writer, Document document);
    
/**
 * Called when the document is closed.
 * <P>
 * Note that this method is called with the page number equal
 * to the last page plus one.
 *
 * @param writer the <CODE>PdfWriter</CODE> for this document
 * @param document the document
 */
    public void onCloseDocument(PdfWriter writer, Document document);
    
/**
 * Called when a Paragraph is written.
 * <P>
 * <CODE>paragraphPosition</CODE> will hold the height at which the
 * paragraph will be written to. This is useful to insert bookmarks with
 * more control.
 *
 * @param writer the <CODE>PdfWriter</CODE> for this document
 * @param document the document
 * @param paragraphPosition the position the paragraph will be written to
 */
    public void onParagraph(PdfWriter writer, Document document, float paragraphPosition);
    
/**
 * Called when a Paragraph is written.
 * <P>
 * <CODE>paragraphPosition</CODE> will hold the height of the end of the paragraph.
 *
 * @param writer the <CODE>PdfWriter</CODE> for this document
 * @param document the document
 * @param paragraphPosition the position of the end of the paragraph
 */
    public void onParagraphEnd(PdfWriter writer,Document document,float paragraphPosition);
    
/**
 * Called when a Chapter is written.
 * <P>
 * <CODE>position</CODE> will hold the height at which the
 * chapter will be written to.
 *
 * @param writer            the <CODE>PdfWriter</CODE> for this document
 * @param document          the document
 * @param paragraphPosition the position the chapter will be written to
 * @param title             the title of the Chapter
 */
    public void onChapter(PdfWriter writer,Document document,float paragraphPosition, Paragraph title);
    
/**
 * Called when the end of a Chapter is reached.
 * <P>
 * <CODE>position</CODE> will hold the height of the end of the chapter.
 *
 * @param writer            the <CODE>PdfWriter</CODE> for this document
 * @param document          the document
 * @param paragraphPosition the position the chapter will be written to
 */
    public void onChapterEnd(PdfWriter writer,Document document,float paragraphPosition);
    
/**
 * Called when a Section is written.
 * <P>
 * <CODE>position</CODE> will hold the height at which the
 * section will be written to.
 *
 * @param writer            the <CODE>PdfWriter</CODE> for this document
 * @param document          the document
 * @param paragraphPosition the position the section will be written to
 * @param depth				the number depth of the section
 * @param title             the title of the section
 */
    public void onSection(PdfWriter writer,Document document,float paragraphPosition, int depth, Paragraph title);
    
/**
 * Called when the end of a Section is reached.
 * <P>
 * <CODE>position</CODE> will hold the height of the section end.
 *
 * @param writer            the <CODE>PdfWriter</CODE> for this document
 * @param document          the document
 * @param paragraphPosition the position the section will be written to
 */
    public void onSectionEnd(PdfWriter writer,Document document,float paragraphPosition);
    
/**
 * Called when a <CODE>Chunk</CODE> with a generic tag is written.
 * <P>
 * It is useful to pinpoint the <CODE>Chunk</CODE> location to generate
 * bookmarks, for example.
 *
 * @param writer the <CODE>PdfWriter</CODE> for this document
 * @param document the document
 * @param rect the <CODE>Rectangle</CODE> containing the <CODE>Chunk</CODE>
 * @param text the text of the tag
 */
    public void onGenericTag(PdfWriter writer, Document document, Rectangle rect, String text);
}
