Module: Origami::Object

Included in:
Array, Boolean, Dictionary, Name, Number, Reference, Stream, String
Defined in:
lib/origami/object.rb,
lib/origami/obfuscation.rb

Overview

Parent module representing a PDF Object. PDF specification declares a set of primitive object types :

  • Null

  • Boolean

  • Integer

  • Real

  • Name

  • String

  • Array

  • Dictionary

  • Stream

Constant Summary collapse

TOKENS =

:nodoc:

%w{ obj endobj }
@@regexp_obj = 
Regexp.new(WHITESPACES + "(\\d+)" + WHITESPACES + "(\\d+)" + WHITESPACES + TOKENS.first + WHITESPACES)
@@regexp_endobj = 
Regexp.new(WHITESPACES + TOKENS.last + WHITESPACES)

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#file_offset ⇒ Object

Returns the value of attribute file_offset.



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# File 'lib/origami/object.rb', line 262

def file_offset
  @file_offset
end

#generation ⇒ Object

Returns the value of attribute generation.



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# File 'lib/origami/object.rb', line 262

def generation
  @generation
end

#no ⇒ Object

Returns the value of attribute no.



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# File 'lib/origami/object.rb', line 262

def no
  @no
end

#objstm_offset ⇒ Object

Returns the value of attribute objstm_offset.



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# File 'lib/origami/object.rb', line 262

def objstm_offset
  @objstm_offset
end

#parent ⇒ Object

Returns the value of attribute parent.



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# File 'lib/origami/object.rb', line 263

def parent
  @parent
end

Class Method Details

.parse(stream) ⇒ Object

:nodoc:



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# File 'lib/origami/object.rb', line 451

def parse(stream) #:nodoc:
  offset = stream.pos

  #
  # End of body ?
  #
  return nil if stream.match?(/xref/) or stream.match?(/trailer/) or stream.match?(/startxref/)
 
  if stream.scan(@@regexp_obj).nil?
    raise InvalidObjectError, 
      "Object shall begin with '%d %d obj' statement"
  end
    
  no = stream[2].to_i
  gen = stream[4].to_i

  type = typeof(stream) 
  if type.nil?
    raise InvalidObjectError, 
      "Cannot determine object (no:#{no},gen:#{gen}) type"
  end
    
  begin
    newObj = type.parse(stream)
  rescue Exception => e
    raise InvalidObjectError, 
      "Failed to parse object (no:#{no},gen:#{gen})\n\t -> [#{e.class}] #{e.message}"
  end

  newObj.set_indirect(true)
  newObj.no = no
  newObj.generation = gen
  newObj.file_offset = offset
    
  if stream.skip(@@regexp_endobj).nil?
    raise UnterminatedObjectError.new("Object shall end with 'endobj' statement", newObj)
  end
    
  newObj
end

.skip_until_next_obj(stream) ⇒ Object

:nodoc:



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# File 'lib/origami/object.rb', line 492

def skip_until_next_obj(stream) #:nodoc:
  stream.pos += 1 until stream.match?(@@regexp_obj) or 
    stream.match?(/xref/) or stream.match?(/trailer/) or stream.match?(/startxref/) or
    stream.eos?
  
  not stream.eos?
end

.typeof(stream, noref = false) ⇒ Object

:nodoc:



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# File 'lib/origami/object.rb', line 424

def typeof(stream, noref = false) #:nodoc:
  stream.skip(REGEXP_WHITESPACES)

  case stream.peek(1)
    when '/' then return Name
    when '<'
      return (stream.peek(2) == '<<') ? Stream : HexaString
    when '(' then return ByteString
    when '[' then return Origami::Array
    when 'n' then 
      return Null if stream.peek(4) == 'null'
    when 't' then
      return Boolean if stream.peek(4) == 'true'
    when 'f' then 
      return Boolean if stream.peek(5) == 'false'
  else
    if not noref and stream.check(Reference::REGEXP_TOKEN) then return Reference
    elsif stream.check(Real::REGEXP_TOKEN) then return Real
    elsif stream.check(Integer::REGEXP_TOKEN) then return Integer
    else
      nil
    end
  end
  
  nil
end

Instance Method Details

#<=>(obj) ⇒ Object

Compare two objects from their respective numbers.



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# File 'lib/origami/object.rb', line 307

def <=>(obj)
  [@no, @generation] <=> [obj.no, obj.generation]
end

#copy ⇒ Object

Deep copy of an object.



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# File 'lib/origami/object.rb', line 321

def copy
  Marshal.load(Marshal.dump(self))
end

#indirect_parent ⇒ Object

Returns the indirect object which contains this object. If the current object is already indirect, returns self.



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# File 'lib/origami/object.rb', line 377

def indirect_parent 
  obj = self
  obj = obj.parent until obj.is_indirect?
    
  obj
end

#initialize(*cons) ⇒ Object

Creates a new PDF Object.



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# File 'lib/origami/object.rb', line 268

def initialize(*cons)
  @indirect = false
  @no, @generation = 0, 0
  
  super(*cons) unless cons.empty?
end

#is_indirect? ⇒ Boolean

Returns whether the objects is indirect, which means that it is not embedded into another object.

Returns:



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# File 'lib/origami/object.rb', line 314

def is_indirect?
  @indirect
end

#pdf ⇒ Object

Returns the PDF which the object belongs to.



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# File 'lib/origami/object.rb', line 408

def pdf
  if self.is_indirect? then @pdf
  else
    @parent.pdf if @parent
  end
end

#pdf_version_required ⇒ Object

:nodoc:



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# File 'lib/origami/object.rb', line 502

def pdf_version_required #:nodoc:
  [ 1.0, 0 ]
end

#post_build ⇒ Object

Generic method called just after the object is finalized. At this time, any indirect object has its own number and generation identifier.



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# File 'lib/origami/object.rb', line 300

def post_build
  self
end

#pre_build ⇒ Object

Generic method called just before the object is finalized. At this time, no number nor generation allocation has yet been done.



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# File 'lib/origami/object.rb', line 292

def pre_build
  self
end

#reference ⇒ Object

Returns an indirect reference to this object, or a Null object is this object is not indirect.



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# File 'lib/origami/object.rb', line 328

def reference
  unless self.is_indirect?
    raise InvalidObjectError, "Cannot reference a direct object"
  end

  ref = Reference.new(@no, @generation)
  ref.parent = self

  ref
end

#set_indirect(dir) ⇒ Object

Sets whether the object is indirect or not. Indirect objects are allocated numbers at build time.



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# File 'lib/origami/object.rb', line 279

def set_indirect(dir)
  unless dir == true or dir == false
    raise TypeError, "The argument must be boolean"
  end
  
  @indirect = dir
  self
end

#set_pdf(pdf) ⇒ Object 



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# File 'lib/origami/object.rb', line 415

def set_pdf(pdf)
  if self.is_indirect? then @pdf = pdf
  else
    raise InvalidObjectError, "You cannot set the PDF parent of a direct object"
  end
end

#size ⇒ Object

Returns the size of this object once converted to PDF code.



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# File 'lib/origami/object.rb', line 401

def size
  to_s.size
end

#solve ⇒ Object

Returns self.



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# File 'lib/origami/object.rb', line 394

def solve
  self
end

#to_o ⇒ Object

Returns self.



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# File 'lib/origami/object.rb', line 387

def to_o
  self
end

#to_s(data) ⇒ Object Also known as: output, to_obfuscated_str

Outputs this object into PDF code.

data

The object data.



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# File 'lib/origami/object.rb', line 518

def to_s(data)
  
  content = ""
  content << "#{no} #{generation} obj" << EOL if self.is_indirect?
  content << data
  content << EOL << "endobj" << EOL if self.is_indirect?
  
  content
end

#type ⇒ Object Also known as: real_type

Returns the symbol type of this Object.



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# File 'lib/origami/object.rb', line 509

def type
  self.class.to_s.split("::").last.to_sym
end

#xrefs ⇒ Object

Returns an array of references pointing to the current object.



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# File 'lib/origami/object.rb', line 342

def xrefs
  unless self.is_indirect?
    raise InvalidObjectError, "Cannot find xrefs to a direct object"
  end

  if self.pdf.nil?
    raise InvalidObjectError, "Not attached to any PDF"
  end

  xref_cache = Hash.new([])
  @pdf.root_objects.each do |obj|
    case obj
      when Dictionary,Array then
        xref_cache.update(obj.xref_cache) do |ref, cache1, cache2|
          cache1.concat(cache2)
        end

      when Stream then
        obj.dictionary.xref_cache.each do |ref, cache|
          cache.map!{obj}
        end

        xref_cache.update(obj.dictionary.xref_cache) do |ref, cache1, cache2|
          cache1.concat(cache2)
        end
    end
  end

  xref_cache[self.reference]
end