Class AbstractPDFStream

java.lang.Object
org.apache.fop.pdf.PDFObject
org.apache.fop.pdf.AbstractPDFStream
All Implemented Interfaces:
CompressedObject, PDFWritable
Direct Known Subclasses:
AbstractPDFFontStream, PDFStream, PDFXObject
public abstract class AbstractPDFStream extends PDFObject
This is an abstract base class for PDF streams.

  • Field Details

    • dictionary

      private final PDFDictionary dictionary

    • filters

      private PDFFilterList filters
      The filters that should be applied

    • encodeOnTheFly

      private boolean encodeOnTheFly

    • refLength

      private PDFNumber refLength

  • Constructor Details

    • AbstractPDFStream

      protected AbstractPDFStream()

    • AbstractPDFStream

      protected AbstractPDFStream(PDFDictionary dictionary)

    • AbstractPDFStream

      protected AbstractPDFStream(boolean encodeOnTheFly)

    • AbstractPDFStream

      protected AbstractPDFStream(PDFDictionary dictionary, boolean encodeOnTheFly)

  • Method Details

    • getDictionary

      protected final PDFDictionary getDictionary()

    • get

      public Object get(String key)

    • put

      public void put(String key, Object value)
      Puts the given object in the dictionary associated to this stream.
      Parameters:
      key - the key in the dictionary
      value - the value to store

    • setupFilterList

      protected void setupFilterList()
      Sets up the default filters for this stream if they haven't been set from outside.

    • getDefaultFilterName

      protected String getDefaultFilterName()
      Returns the name of a suitable filter for this PDF object.
      Returns:
      the default filter
      See Also:

    • getFilterList

      public PDFFilterList getFilterList()
      Returns the associated filter list.
      Returns:
      the filter list

    • getSizeHint

      protected abstract int getSizeHint() throws IOException
      Returns a value that hints at the size of the encoded stream. This is used to optimize buffer allocation so fewer buffer reallocations are necessary.
      Returns:
      an estimated size (0 if no hint can be given)
      Throws:
      IOException - in case of an I/O problem

    • outputRawStreamData

      protected abstract void outputRawStreamData(OutputStream out) throws IOException
      Sends the raw stream data to the target OutputStream.
      Parameters:
      out - OutputStream to write to
      Throws:
      IOException - In case of an I/O problem

    • outputStreamData

      protected int outputStreamData(StreamCache encodedStream, OutputStream out) throws IOException
      Output just the stream data enclosed by stream/endstream markers
      Parameters:
      encodedStream - already encoded/filtered stream to write
      out - OutputStream to write to
      Returns:
      int number of bytes written
      Throws:
      IOException - in case of an I/O problem

    • encodeStream

      protected StreamCache encodeStream() throws IOException
      Encodes the raw data stream for output to a PDF file.
      Returns:
      the encoded stream
      Throws:
      IOException - in case of an I/O problem

    • encodeAndWriteStream

      protected int encodeAndWriteStream(OutputStream out, PDFNumber refLength) throws IOException
      Encodes and writes a stream directly to an OutputStream. The length of the stream, in this case, is set on a PDFNumber object that has to be prepared beforehand.
      Parameters:
      out - OutputStream to write to
      refLength - PDFNumber object to receive the stream length
      Returns:
      number of bytes written (header and trailer included)
      Throws:
      IOException - in case of an I/O problem

    • output

      public int output(OutputStream stream) throws IOException
      Overload the base object method so we don't have to copy byte arrays around so much Write the PDF represention of this object
      Specified by:
      output in interface CompressedObject
      Overrides:
      output in class PDFObject
      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

    • setDocument

      public void setDocument(PDFDocument doc)
      Description copied from class: PDFObject
      Sets the parent PDFDocument.
      Overrides:
      setDocument in class PDFObject
      Parameters:
      doc - the PDFDocument.

    • populateStreamDict

      protected void populateStreamDict(Object lengthEntry)
      Populates the dictionary with all necessary entries for the stream. Override this method if you need additional entries.
      Parameters:
      lengthEntry - value for the /Length entry

    • prepareImplicitFilters

      protected void prepareImplicitFilters()
      Prepares implicit filters (such as the DCTFilter for JPEG images). You must make sure that the appropriate filters are in the filter list at the right places.

    • multipleFiltersAllowed

      protected boolean multipleFiltersAllowed()
      Whether multiple filters can be applied.
      Returns:
      true if multiple filters allowed

    • getChildren

      public void getChildren(Set<PDFObject> children)
      Overrides:
      getChildren in class PDFObject

    • registerChildren

      public void registerChildren()

    • supportsObjectStream

      public boolean supportsObjectStream()
      Overrides:
      supportsObjectStream in class PDFObject