Package org.apache.fop.pdf

Class PDFObject

java.lang.Object
org.apache.fop.pdf.PDFObject
All Implemented Interfaces:
PDFWritable
Direct Known Subclasses:
AbstractPDFStream, PDFAction, PDFAnnotList, PDFArray, PDFCharProcs, PDFCIDFont, PDFCIDSystemInfo, PDFDestination, PDFDictionary, PDFEncryptionJCE, PDFFunction, PDFGState, PDFICCBasedColorSpace, PDFInfo, PDFLink, PDFName, PDFNumber, PDFNumsArray, PDFOutline, PDFOutputIntent, PDFPages, PDFPathPaint, PDFShading, PDFText
public abstract class PDFObject extends Object implements PDFWritable
generic PDF object. A PDF Document is essentially a collection of these objects. A PDF Object has a number and a generation (although the generation will always be 0 in new documents).

  • Field Details

    • log

      protected static final org.apache.commons.logging.Log log
      logger for all PDFObjects (and descendants)

  • Constructor Details

    • PDFObject

      public PDFObject()
      Default constructor.

    • PDFObject

      public PDFObject(PDFObject parent)
      Constructor for direct objects.
      Parameters:
      parent - the containing PDFObject instance

  • Method Details

    • getObjectNumber

      public PDFObjectNumber getObjectNumber()
      Returns the object's number.
      Returns:
      the PDF Object number

    • hasObjectNumber

      public boolean hasObjectNumber()
      Indicates whether this PDFObject has already been assigned an object number.
      Returns:
      True if it has an object number

    • setObjectNumber

      public void setObjectNumber(PDFDocument document)
      Sets the object number

    • setObjectNumber

      public void setObjectNumber(PDFObjectNumber objectNumber)

    • setObjectNumber

      public void setObjectNumber(int objectNumber)

    • getGeneration

      public int getGeneration()
      Returns this object's generation.
      Returns:
      the PDF Object generation

    • getDocument

      public final PDFDocument getDocument()
      Returns the parent PDFDocument if assigned.
      Returns:
      the parent PDFDocument (May be null if the parent PDFDocument has not been assigned)

    • getDocumentSafely

      public final PDFDocument getDocumentSafely()
      Returns the parent PDFDocument, but unlike getDocument() it throws an informative Exception if the parent document is unavailable instead of having a NullPointerException somewhere without a message.
      Returns:
      the parent PDFDocument

    • setDocument

      public void setDocument(PDFDocument doc)
      Sets the parent PDFDocument.
      Parameters:
      doc - the PDFDocument.

    • getParent

      public PDFObject getParent()
      Returns this objects's parent. The parent is null if it is a "direct object".
      Returns:
      the parent or null if there's no parent (or it hasn't been set)

    • setParent

      public void setParent(PDFObject parent)
      Sets the direct parent object.
      Parameters:
      parent - the direct parent

    • getObjectID

      public String getObjectID()
      Returns the PDF representation of the Object ID.
      Returns:
      the Object ID

    • referencePDF

      public String referencePDF()
      Returns the PDF representation of a reference to this object.
      Returns:
      the reference string

    • makeReference

      public PDFReference makeReference()
      Creates and returns a reference to this object.
      Returns:
      the object reference

    • output

      public int output(OutputStream stream) throws IOException
      Write the PDF represention of this object
      Parameters:
      stream - the stream to write the PDF to
      Returns:
      the number of bytes written
      Throws:
      IOException - if there is an error writing to the stream

    • outputInline

      public void outputInline(OutputStream out, StringBuilder textBuffer) throws IOException
      Writes a "direct object" (inline object) representation to the stream. A text buffer is given for optimized encoding of text content.

      IMPORTANT: If you need to write out binary output, call PDFDocument.flushTextBuffer(StringBuilder, OutputStream) before writing any content to the OutputStream!

      Specified by:
      outputInline in interface PDFWritable
      Parameters:
      out - the OutputStream (for binary content)
      textBuffer - the text buffer for text content
      Throws:
      IOException - if an I/O error occurs

    • toPDF

      protected byte[] toPDF()
      Encodes the object as a byte array for output to a PDF file.
      Returns:
      PDF string

    • toPDFString

      protected String toPDFString()
      This method returns a String representation of the PDF object. The result is normally converted/encoded to a byte array by toPDF(). Only use this method to implement the serialization if the object can be fully represented as text. If the PDF representation of the object contains binary content use toPDF() or output(OutputStream) instead. This applies to any object potentially containing a string object because string object are encrypted and therefore need to be binary.
      Returns:
      String the String representation

    • encode

      public static final byte[] encode(String text)
      Converts text to a byte array for writing to a PDF file.
      Parameters:
      text - text to convert/encode
      Returns:
      byte[] the resulting byte array

    • encodeText

      protected byte[] encodeText(String text)
      Encodes a Text String (3.8.1 in PDF 1.4 specs)
      Parameters:
      text - the text to encode
      Returns:
      byte[] the encoded text

    • encodeString

      protected byte[] encodeString(String string)
      Encodes a String (3.2.3 in PDF 1.4 specs)
      Parameters:
      string - the string to encode
      Returns:
      byte[] the encoded string

    • encodeBinaryToHexString

      protected void encodeBinaryToHexString(byte[] data, OutputStream out) throws IOException
      Encodes binary data as hexadecimal string object.
      Parameters:
      data - the binary data
      out - the OutputStream to write the encoded object to
      Throws:
      IOException - if an I/O error occurs

    • formatObject

      protected void formatObject(Object obj, OutputStream out, StringBuilder textBuffer) throws IOException
      Formats an object for serialization to PDF.

      IMPORTANT: If you need to write out binary output, call PDFDocument.flushTextBuffer(StringBuilder, OutputStream) before writing any content to the OutputStream!

      Parameters:
      obj - the object
      out - the OutputStream to write to
      textBuffer - a text buffer for text output
      Throws:
      IOException - If an I/O error occurs

    • contentEquals

      protected boolean contentEquals(PDFObject o)
      Check if the other PDFObject has the same content as the current object.

      Note: This function has a contract which is less binding than Object.equals(Object). Whereas equals would require all values to be identical, this method is not required to check everything. In the case of PDFObjects, this means that the overriding function does not have to check for getObjectID().

      Parameters:
      o - object to compare to.
      Returns:
      true if the other object has the same content.

    • getChildren

      public void getChildren(Set<PDFObject> children)