/*
* $Id: PdfObject.java 4784 2011-03-15 08:33:00Z blowagie $
*
* This file is part of the iText (R) project.
* Copyright (c) 1998-2011 1T3XT BVBA
* 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 1T3XT,
* 1T3XT 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: [email protected]
*/
package com.itextpdf.text.pdf;
import java.io.IOException;
import java.io.OutputStream;
/**
* <CODE>PdfObject</CODE> is the abstract superclass of all PDF objects.
* <P>
* 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.<BR>
* 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 {
// CONSTANTS
/** A possible type of <CODE>PdfObject</CODE> */
public static final int BOOLEAN = 1;
/** A possible type of <CODE>PdfObject</CODE> */
public static final int NUMBER = 2;
/** A possible type of <CODE>PdfObject</CODE> */
public static final int STRING = 3;
/** A possible type of <CODE>PdfObject</CODE> */
public static final int NAME = 4;
/** A possible type of <CODE>PdfObject</CODE> */
public static final int ARRAY = 5;
/** A possible type of <CODE>PdfObject</CODE> */
public static final int DICTIONARY = 6;
/** A possible type of <CODE>PdfObject</CODE> */
public static final int STREAM = 7;
/** A possible type of <CODE>PdfObject</CODE> */
public static final int NULL = 8;
/** A possible type of <CODE>PdfObject</CODE> */
public static final int INDIRECT = 10;
/** An empty string used for the <CODE>PdfNull</CODE>-object and for an empty <CODE>PdfString</CODE>-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 <CODE>PdfObject</CODE> */
protected byte[] bytes;
/** The type of this <CODE>PdfObject</CODE> */
protected int type;
/** Holds the indirect reference. */
protected PRIndirectReference indRef;
// CONSTRUCTORS
/**
* Constructs a <CODE>PdfObject</CODE> of a certain <VAR>type</VAR>
* without any <VAR>content</VAR>.
*
* @param type type of the new <CODE>PdfObject</CODE>
*/
protected PdfObject(int type) {
this.type = type;
}
/**
* Constructs a <CODE>PdfObject</CODE> of a certain <VAR>type</VAR>
* with a certain <VAR>content</VAR>.
*
* @param type type of the new <CODE>PdfObject</CODE>
* @param content content of the new <CODE>PdfObject</CODE> as a
* <CODE>String</CODE>.
*/
protected PdfObject(int type, String content) {
this.type = type;
bytes = PdfEncodings.convertToBytes(content, null);
}
/**
* Constructs a <CODE>PdfObject</CODE> of a certain <VAR>type</VAR>
* with a certain <VAR>content</VAR>.
*
* @param type type of the new <CODE>PdfObject</CODE>
* @param bytes content of the new <CODE>PdfObject</CODE> as an array of
* <CODE>byte</CODE>.
*/
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 <CODE>PdfObject</CODE> as an
* array of <CODE>byte</CODE>s to the writer.
*
* @param writer for backwards compatibility
* @param os The <CODE>OutputStream</CODE> to write the bytes to.
* @throws IOException
*/
public void toPdf(PdfWriter writer, OutputStream os) throws IOException {
if (bytes != null)
os.write(bytes);
}
/**
* Returns the <CODE>String</CODE>-representation of this
* <CODE>PdfObject</CODE>.
*
* @return a <CODE>String</CODE>
*/
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 <CODE>true</CODE> if this object can be in an object stream.
* Otherwise <CODE>false</CODE>
*/
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 PDF representation of the <CODE>PdfObject</CODE>.
* <P>
* In some cases, namely for <CODE>PdfString</CODE> and <CODE>PdfStream</CODE>,
* this method differs from the method <CODE>length</CODE> because <CODE>length</CODE>
* returns the length of the actual content of the <CODE>PdfObject</CODE>.</P>
* <P>
* Remark: the actual content of an object is in most cases identical to its representation.
* The following statement is always true: length() >= pdfLength().</P>
*
* @return a length
*/
// public int pdfLength() {
// return toPdf(null).length;
// }
/**
* Returns the length of the actual content of the <CODE>PdfObject</CODE>.
* <P>
* In some cases, namely for <CODE>PdfString</CODE> and <CODE>PdfStream</CODE>,
* this method differs from the method <CODE>pdfLength</CODE> because <CODE>pdfLength</CODE>
* returns the length of the PDF representation of the object, not of the actual content
* as does the method <CODE>length</CODE>.</P>
* <P>
* Remark: the actual content of an object is in some cases identical to its representation.
* The following statement is always true: length() >= pdfLength().</P>
*
* @return The length as <CODE>int</CODE>
*/
public int length() {
return toString().length();
}
/**
* Changes the content of this <CODE>PdfObject</CODE>.
*
* @param content the new content of this <CODE>PdfObject</CODE>
*/
protected void setContent(String content) {
bytes = PdfEncodings.convertToBytes(content, null);
}
// methods dealing with the type of this object
/**
* Returns the type of this <CODE>PdfObject</CODE>.
*
* May be either of:
* - <VAR>NULL</VAR>: A <CODE>PdfNull</CODE>
* - <VAR>BOOLEAN</VAR>: A <CODE>PdfBoolean</CODE>
* - <VAR>NUMBER</VAR>: A <CODE>PdfNumber</CODE>
* - <VAR>STRING</VAR>: A <CODE>PdfString</CODE>
* - <VAR>NAME</VAR>: A <CODE>PdfName</CODE>
* - <VAR>ARRAY</VAR>: A <CODE>PdfArray</CODE>
* - <VAR>DICTIONARY</VAR>: A <CODE>PdfDictionary</CODE>
* - <VAR>STREAM</VAR>: A <CODE>PdfStream</CODE>
* - <VAR>INDIRECT</VAR>: ><CODE>PdfIndirectObject</CODE>
*
* @return The type
*/
public int type() {
return type;
}
/**
* Checks if this <CODE>PdfObject</CODE> is of the type
* <CODE>PdfNull</CODE>.
*
* @return <CODE>true</CODE> or <CODE>false</CODE>
*/
public boolean isNull() {
return (type == NULL);
}
/**
* Checks if this <CODE>PdfObject</CODE> is of the type
* <CODE>PdfBoolean</CODE>.
*
* @return <CODE>true</CODE> or <CODE>false</CODE>
*/
public boolean isBoolean() {
return (type == BOOLEAN);
}
/**
* Checks if this <CODE>PdfObject</CODE> is of the type
* <CODE>PdfNumber</CODE>.
*
* @return <CODE>true</CODE> or <CODE>false</CODE>
*/
public boolean isNumber() {
return (type == NUMBER);
}
/**
* Checks if this <CODE>PdfObject</CODE> is of the type
* <CODE>PdfString</CODE>.
*
* @return <CODE>true</CODE> or <CODE>false</CODE>
*/
public boolean isString() {
return (type == STRING);
}
/**
* Checks if this <CODE>PdfObject</CODE> is of the type
* <CODE>PdfName</CODE>.
*
* @return <CODE>true</CODE> or <CODE>false</CODE>
*/
public boolean isName() {
return (type == NAME);
}
/**
* Checks if this <CODE>PdfObject</CODE> is of the type
* <CODE>PdfArray</CODE>.
*
* @return <CODE>true</CODE> or <CODE>false</CODE>
*/
public boolean isArray() {
return (type == ARRAY);
}
/**
* Checks if this <CODE>PdfObject</CODE> is of the type
* <CODE>PdfDictionary</CODE>.
*
* @return <CODE>true</CODE> or <CODE>false</CODE>
*/
public boolean isDictionary() {
return (type == DICTIONARY);
}
/**
* Checks if this <CODE>PdfObject</CODE> is of the type
* <CODE>PdfStream</CODE>.
*
* @return <CODE>true</CODE> or <CODE>false</CODE>
*/
public boolean isStream() {
return (type == STREAM);
}
/**
* Checks if this <CODE>PdfObject</CODE> is of the type
* <CODE>PdfIndirectObject</CODE>.
*
* @return <CODE>true</CODE> if this is an indirect object,
* otherwise <CODE>false</CODE>
*/
public boolean isIndirect() {
return (type == INDIRECT);
}
/**
* Get the indirect reference
*
* @return A <CODE>PdfIndirectReference</CODE>
*/
public PRIndirectReference getIndRef() {
return indRef;
}
/**
* Set the indirect reference
*
* @param indRef New value as a <CODE>PdfIndirectReference</CODE>
*/
public void setIndRef(PRIndirectReference indRef) {
this.indRef = indRef;
}
}
|