itextpdf-master/itext/src/main/java/com/itextpdf/text/Element.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.
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 * 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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 * address: sales@itextpdf.com
 */
package com.itextpdf.text;

import java.util.List;

/**
 * Interface for a text element.
 * <P>
 * Remark: I looked at the interface javax.swing.text.Element, but I decided to
 * write my own text-classes for two reasons:
 * <OL>
 * <LI>The javax.swing.text-classes may be very generic, I think they are
 * overkill: they are to heavy for what they have to do.
 * <LI>A lot of people using iText (formerly known as rugPdf), still use
 * JDK1.1.x. I try to keep the Java2 requirements limited to the Collection
 * classes (I think they're really great). However, if I use the
 * javax.swing.text classes, it will become very difficult to downgrade rugPdf.
 * </OL>
 *
 * @see Anchor
 * @see Chapter
 * @see Chunk
 * @see Header
 * @see Image
 * @see Jpeg
 * @see List
 * @see ListItem
 * @see Meta
 * @see Paragraph
 * @see Phrase
 * @see Rectangle
 * @see Section
 */

public interface Element {

	// static membervariables (meta information)

	/** This is a possible type of <CODE>Element</CODE>. */
	public static final int HEADER = 0;

	/** This is a possible type of <CODE>Element</CODE>. */
	public static final int TITLE = 1;

	/** This is a possible type of <CODE>Element</CODE>. */
	public static final int SUBJECT = 2;

	/** This is a possible type of <CODE>Element</CODE>. */
	public static final int KEYWORDS = 3;

	/** This is a possible type of <CODE>Element </CODE>. */
	public static final int AUTHOR = 4;

	/** This is a possible type of <CODE>Element </CODE>. */
	public static final int PRODUCER = 5;

	/** This is a possible type of <CODE>Element </CODE>. */
	public static final int CREATIONDATE = 6;

	/** This is a possible type of <CODE>Element </CODE>. */
	public static final int CREATOR = 7;

    /** This is a possible type of <CODE>Element </CODE>. */
    public static final int LANGUAGE = 8;

	// static membervariables (content)

	/** This is a possible type of <CODE>Element</CODE>. */
	public static final int CHUNK = 10;

	/** This is a possible type of <CODE>Element</CODE>. */
	public static final int PHRASE = 11;

	/** This is a possible type of <CODE>Element</CODE>. */
	public static final int PARAGRAPH = 12;

	/** This is a possible type of <CODE>Element</CODE> */
	public static final int SECTION = 13;

	/** This is a possible type of <CODE>Element</CODE> */
	public static final int LIST = 14;

	/** This is a possible type of <CODE>Element</CODE> */
	public static final int LISTITEM = 15;

	/** This is a possible type of <CODE>Element</CODE> */
	public static final int CHAPTER = 16;

	/** This is a possible type of <CODE>Element</CODE> */
	public static final int ANCHOR = 17;

	// static membervariables (tables)

	/** This is a possible type of <CODE>Element</CODE>. */
	public static final int PTABLE = 23;

	// static membervariables (annotations)

	/** This is a possible type of <CODE>Element</CODE>. */
	public static final int ANNOTATION = 29;

	// static membervariables (geometric figures)

	/** This is a possible type of <CODE>Element</CODE>. */
	public static final int RECTANGLE = 30;

	/** This is a possible type of <CODE>Element</CODE>. */
	public static final int JPEG = 32;

	/** This is a possible type of <CODE>Element</CODE>. */
	public static final int JPEG2000 = 33;

	/** This is a possible type of <CODE>Element</CODE>. */
	public static final int IMGRAW = 34;

	/** This is a possible type of <CODE>Element</CODE>. */
	public static final int IMGTEMPLATE = 35;

	/**
	 * This is a possible type of <CODE>Element</CODE>.
	 * @since	2.1.5
	 */
	public static final int JBIG2 = 36;

    /** This is a possible type of <CODE>Element</CODE>. */
	public static final int DIV = 37;

	/** This is a possible type of <CODE>Element</CODE>. */
	public static final int BODY = 38;

	/** This is a possible type of <CODE>Element</CODE>. */
	public static final int MARKED = 50;

	/** This is a possible type of <CODE>Element</CODE>.
	 * @since 2.1.2
	 */
	public static final int YMARK = 55;

	/**
	 * This is an element thats not an element.
	 * @see WritableDirectElement
	 */
	public static final int WRITABLE_DIRECT = 666;

	// static membervariables (alignment)

	/**
	 * A possible value for paragraph alignment. This specifies that the text is
	 * aligned to the left indent and extra whitespace should be placed on the
	 * right.
	 */
	public static final int ALIGN_UNDEFINED = -1;

	/**
	 * A possible value for paragraph alignment. This specifies that the text is
	 * aligned to the left indent and extra whitespace should be placed on the
	 * right.
	 */
	public static final int ALIGN_LEFT = 0;

	/**
	 * A possible value for paragraph alignment. This specifies that the text is
	 * aligned to the center and extra whitespace should be placed equally on
	 * the left and right.
	 */
	public static final int ALIGN_CENTER = 1;

	/**
	 * A possible value for paragraph alignment. This specifies that the text is
	 * aligned to the right indent and extra whitespace should be placed on the
	 * left.
	 */
	public static final int ALIGN_RIGHT = 2;

	/**
	 * A possible value for paragraph alignment. This specifies that extra
	 * whitespace should be spread out through the rows of the paragraph with
	 * the text lined up with the left and right indent except on the last line
	 * which should be aligned to the left.
	 */
	public static final int ALIGN_JUSTIFIED = 3;

	/**
	 * A possible value for vertical alignment.
	 */

	public static final int ALIGN_TOP = 4;

	/**
	 * A possible value for vertical alignment.
	 */

	public static final int ALIGN_MIDDLE = 5;

	/**
	 * A possible value for vertical alignment.
	 */

	public static final int ALIGN_BOTTOM = 6;

	/**
	 * A possible value for vertical alignment.
	 */
	public static final int ALIGN_BASELINE = 7;

	/**
	 * Does the same as ALIGN_JUSTIFIED but the last line is also spread out.
	 */
	public static final int ALIGN_JUSTIFIED_ALL = 8;

	// static member variables for CCITT compression

	/**
	 * Pure two-dimensional encoding (Group 4)
	 */
	public static final int CCITTG4 = 0x100;

	/**
	 * Pure one-dimensional encoding (Group 3, 1-D)
	 */
	public static final int CCITTG3_1D = 0x101;

	/**
	 * Mixed one- and two-dimensional encoding (Group 3, 2-D)
	 */
	public static final int CCITTG3_2D = 0x102;

	/**
	 * A flag indicating whether 1-bits are to be interpreted as black pixels
	 * and 0-bits as white pixels,
	 */
	public static final int CCITT_BLACKIS1 = 1;

	/**
	 * A flag indicating whether the filter expects extra 0-bits before each
	 * encoded line so that the line begins on a byte boundary.
	 */
	public static final int CCITT_ENCODEDBYTEALIGN = 2;

	/**
	 * A flag indicating whether end-of-line bit patterns are required to be
	 * present in the encoding.
	 */
	public static final int CCITT_ENDOFLINE = 4;

	/**
	 * A flag indicating whether the filter expects the encoded data to be
	 * terminated by an end-of-block pattern, overriding the Rows parameter. The
	 * use of this flag will set the key /EndOfBlock to false.
	 */
	public static final int CCITT_ENDOFBLOCK = 8;

	// methods

	/**
	 * Processes the element by adding it (or the different parts) to an <CODE>
	 * ElementListener</CODE>.
	 *
	 * @param listener
	 *            an <CODE>ElementListener</CODE>
	 * @return <CODE>true</CODE> if the element was processed successfully
	 */

	public boolean process(ElementListener listener);

	/**
	 * Gets the type of the text element.
	 *
	 * @return a type
	 */

	public int type();

	/**
	 * Checks if this element is a content object.
	 * If not, it's a metadata object.
	 * @since	iText 2.0.8
	 * @return	true if this is a 'content' element; false if this is a 'metadata' element
	 */

	public boolean isContent();

	/**
	 * Checks if this element is nestable.
	 * @since	iText 2.0.8
	 * @return	true if this element can be nested inside other elements.
	 */

	public boolean isNestable();

	/**
	 * Gets all the chunks in this element.
	 *
	 * @return an <CODE>ArrayList</CODE>
	 */

	public List<Chunk> getChunks();

	/**
	 * Gets the content of the text element.
	 *
	 * @return a type
	 */

	public String toString();
}
