com.itextpdf.text.pdf.PdfObject Maven / Gradle / Ivy
/*
* $Id: 2ab8bf5772c22c32b24335809056f6a2fc61d25c $
*
* This file is part of the iText (R) project.
* Copyright (c) 1998-2016 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
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* Section 5 of the GNU Affero General Public License.
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* a covered work must retain the producer line in every PDF that is created
* or manipulated using iText.
*
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package com.itextpdf.text.pdf;
import com.itextpdf.text.pdf.internal.PdfIsoKeys;
import java.io.IOException;
import java.io.OutputStream;
import java.io.Serializable;
/**
* PdfObject is the abstract superclass of all PDF objects.
*
* PDF supports seven basic types of objects: Booleans, numbers, strings, names,
* arrays, dictionaries and streams. In addition, PDF provides a null object.
* Objects may be labeled so that they can be referred to by other objects.
* All these basic PDF objects are described in the 'Portable Document Format
* Reference Manual version 1.3' Chapter 4 (pages 37-54).
*
* @see PdfNull
* @see PdfBoolean
* @see PdfNumber
* @see PdfString
* @see PdfName
* @see PdfArray
* @see PdfDictionary
* @see PdfStream
* @see PdfIndirectReference
*/
public abstract class PdfObject implements Serializable {
// CONSTANTS
/** A possible type of PdfObject */
public static final int BOOLEAN = 1;
/** A possible type of PdfObject */
public static final int NUMBER = 2;
/** A possible type of PdfObject */
public static final int STRING = 3;
/** A possible type of PdfObject */
public static final int NAME = 4;
/** A possible type of PdfObject */
public static final int ARRAY = 5;
/** A possible type of PdfObject */
public static final int DICTIONARY = 6;
/** A possible type of PdfObject */
public static final int STREAM = 7;
/** A possible type of PdfObject */
public static final int NULL = 8;
/** A possible type of PdfObject */
public static final int INDIRECT = 10;
/** An empty string used for the PdfNull-object and for an empty PdfString-object. */
public static final String NOTHING = "";
/**
* This is the default encoding to be used for converting Strings into
* bytes and vice versa. The default encoding is PdfDocEncoding.
*/
public static final String TEXT_PDFDOCENCODING = "PDF";
/** This is the encoding to be used to output text in Unicode. */
public static final String TEXT_UNICODE = "UnicodeBig";
// CLASS VARIABLES
/** The content of this PdfObject */
protected byte[] bytes;
/** The type of this PdfObject */
protected int type;
/** Holds the indirect reference. */
protected PRIndirectReference indRef;
// CONSTRUCTORS
/**
* Constructs a PdfObject of a certain type
* without any content.
*
* @param type type of the new PdfObject
*/
protected PdfObject(int type) {
this.type = type;
}
/**
* Constructs a PdfObject of a certain type
* with a certain content.
*
* @param type type of the new PdfObject
* @param content content of the new PdfObject as a
* String.
*/
protected PdfObject(int type, String content) {
this.type = type;
bytes = PdfEncodings.convertToBytes(content, null);
}
/**
* Constructs a PdfObject of a certain type
* with a certain content.
*
* @param type type of the new PdfObject
* @param bytes content of the new PdfObject as an array of
* byte.
*/
protected PdfObject(int type, byte[] bytes) {
this.bytes = bytes;
this.type = type;
}
// methods dealing with the content of this object
/**
* Writes the PDF representation of this PdfObject as an
* array of bytes to the writer.
*
* @param writer for backwards compatibility
* @param os The OutputStream to write the bytes to.
* @throws IOException
*/
public void toPdf(PdfWriter writer, OutputStream os) throws IOException {
if (bytes != null) {
PdfWriter.checkPdfIsoConformance(writer, PdfIsoKeys.PDFISOKEY_OBJECT, this);
os.write(bytes);
}
}
/**
* Returns the String-representation of this
* PdfObject.
*
* @return a String
*/
public String toString() {
if (bytes == null)
return super.toString();
return PdfEncodings.convertToString(bytes, null);
}
/**
* Gets the presentation of this object in a byte array
*
* @return a byte array
*/
public byte[] getBytes() {
return bytes;
}
/**
* Whether this object can be contained in an object stream.
*
* PdfObjects of type STREAM OR INDIRECT can not be contained in an
* object stream.
*
* @return true if this object can be in an object stream.
* Otherwise false
*/
public boolean canBeInObjStm() {
switch (type) {
case NULL:
case BOOLEAN:
case NUMBER:
case STRING:
case NAME:
case ARRAY:
case DICTIONARY:
return true;
case STREAM:
case INDIRECT:
default:
return false;
}
}
/**
* Returns the length of the actual content of the PdfObject.
*
* In some cases, namely for PdfString and PdfStream,
* this method differs from the method pdfLength because pdfLength
* returns the length of the PDF representation of the object, not of the actual content
* as does the method length.
*
* Remark: the actual content of an object is in some cases identical to its representation.
* The following statement is always true: length() >= pdfLength().
*
* @return The length as int
*/
public int length() {
return toString().length();
}
/**
* Changes the content of this PdfObject.
*
* @param content the new content of this PdfObject
*/
protected void setContent(String content) {
bytes = PdfEncodings.convertToBytes(content, null);
}
// methods dealing with the type of this object
/**
* Returns the type of this PdfObject.
*
* May be either of:
* - NULL: A PdfNull
* - BOOLEAN: A PdfBoolean
* - NUMBER: A PdfNumber
* - STRING: A PdfString
* - NAME: A PdfName
* - ARRAY: A PdfArray
* - DICTIONARY: A PdfDictionary
* - STREAM: A PdfStream
* - INDIRECT: >PdfIndirectObject
*
* @return The type
*/
public int type() {
return type;
}
/**
* Checks if this PdfObject is of the type
* PdfNull.
*
* @return true or false
*/
public boolean isNull() {
return (type == NULL);
}
/**
* Checks if this PdfObject is of the type
* PdfBoolean.
*
* @return true or false
*/
public boolean isBoolean() {
return (type == BOOLEAN);
}
/**
* Checks if this PdfObject is of the type
* PdfNumber.
*
* @return true or false
*/
public boolean isNumber() {
return (type == NUMBER);
}
/**
* Checks if this PdfObject is of the type
* PdfString.
*
* @return true or false
*/
public boolean isString() {
return (type == STRING);
}
/**
* Checks if this PdfObject is of the type
* PdfName.
*
* @return true or false
*/
public boolean isName() {
return (type == NAME);
}
/**
* Checks if this PdfObject is of the type
* PdfArray.
*
* @return true or false
*/
public boolean isArray() {
return (type == ARRAY);
}
/**
* Checks if this PdfObject is of the type
* PdfDictionary.
*
* @return true or false
*/
public boolean isDictionary() {
return (type == DICTIONARY);
}
/**
* Checks if this PdfObject is of the type
* PdfStream.
*
* @return true or false
*/
public boolean isStream() {
return (type == STREAM);
}
/**
* Checks if this PdfObject is of the type
* PdfIndirectObject.
*
* @return true if this is an indirect object,
* otherwise false
*/
public boolean isIndirect() {
return (type == INDIRECT);
}
/**
* Get the indirect reference
*
* @return A PdfIndirectReference
*/
public PRIndirectReference getIndRef() {
return indRef;
}
/**
* Set the indirect reference
*
* @param indRef New value as a PdfIndirectReference
*/
public void setIndRef(PRIndirectReference indRef) {
this.indRef = indRef;
}
}