Class: HexaPDF::Writer

Inherits:
Object
  • Object
show all
Defined in:
lib/hexapdf/writer.rb

Overview

Writes the contents of a PDF document to an IO stream.

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(document, io) ⇒ Writer

Creates a new writer object for the given HexaPDF document that gets written to the IO object.



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# File 'lib/hexapdf/writer.rb', line 59

def initialize(document, io)
  @document = document
  @io = io

  @io.binmode
  @io.seek(0, IO::SEEK_SET) # TODO: incremental update!

  @serializer = Serializer.new
  @serializer.encrypter = @document.encrypted? ? @document.security_handler : nil
  @rev_size = 0
end

Class Method Details

.write(document, io, incremental: false) ⇒ Object

Writes the document to the IO object. If incremental is true and the document was created from an existing PDF file, the changes are appended to a full copy of the source document.



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# File 'lib/hexapdf/writer.rb', line 49

def self.write(document, io, incremental: false)
  if incremental && document.revisions.parser
    new(document, io).write_incremental
  else
    new(document, io).write
  end
end

Instance Method Details

#write ⇒ Object

Writes the document to the IO object.



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# File 'lib/hexapdf/writer.rb', line 72

def write
  write_file_header

  pos = nil
  @document.trailer.info[:Producer] = "HexaPDF version #{HexaPDF::VERSION}"
  @document.revisions.each do |rev|
    pos = write_revision(rev, pos)
  end
end

#write_incremental ⇒ Object

Writes the complete source document and one revision containing all changes to the IO.

For this method to work the document must have been created from an existing file.



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# File 'lib/hexapdf/writer.rb', line 85

def write_incremental
  @document.revisions.parser.io.seek(0, IO::SEEK_SET)
  IO.copy_stream(@document.revisions.parser.io, @io)

  @rev_size = @document.revisions.current.next_free_oid

  revision = Revision.new(@document.revisions.current.trailer)
  @document.revisions.each do |rev|
    rev.each_modified_object {|obj| revision.send(:add_without_check, obj) }
  end
  write_revision(revision, @document.revisions.parser.startxref_offset)
end