Module: Prawn::Stamp

Included in:
Document
Defined in:
lib/prawn/stamp.rb

Instance Method Summary collapse

Instance Method Details

#create_stamp(user_defined_name = "", &block) ⇒ Object

Raises:



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# File 'lib/prawn/stamp.rb', line 45

def create_stamp(user_defined_name="", &block)
  raise Prawn::Errors::InvalidName if user_defined_name.empty?

  if stamp_dictionary_registry[user_defined_name]
    raise Prawn::Errors::NameTaken
  end

  # BBox origin is the lower left margin of the page, so we need
  # it to be the full dimension of the page, or else things that
  # should appear near the top or right margin are invisible
  stamp_dictionary = ref!(:Type    => :XObject,
                          :Subtype => :Form,
                          :BBox => [0, 0, page_dimensions[2], page_dimensions[3]])

  stamp_dictionary_name = "Stamp#{next_stamp_dictionary_id}"

  stamp_dictionary_registry[user_defined_name] = 
    { :stamp_dictionary_name => stamp_dictionary_name, 
      :stamp_dictionary      => stamp_dictionary}

  
  @active_stamp_stream = ""
  @active_stamp_dictionary = stamp_dictionary

  yield if block_given?

  stamp_dictionary.data[:Length] = @active_stamp_stream.length + 1
  stamp_dictionary << @active_stamp_stream

  @active_stamp_stream = nil
  @active_stamp_dictionary = nil
end

#stamp(user_defined_name) ⇒ Object

Raises:



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# File 'lib/prawn/stamp.rb', line 13

def stamp(user_defined_name)
  raise Prawn::Errors::InvalidName if user_defined_name.empty?
  unless stamp_dictionary_registry[user_defined_name]
    raise Prawn::Errors::UndefinedObjectName
  end
  
  dict = stamp_dictionary_registry[user_defined_name]

  stamp_dictionary_name = dict[:stamp_dictionary_name]
  stamp_dictionary = dict[:stamp_dictionary]

  add_content "/#{stamp_dictionary_name} Do"
  
  page_xobjects.merge!(stamp_dictionary_name => stamp_dictionary)
end

#stamp_at(user_defined_name, point) ⇒ Object 



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# File 'lib/prawn/stamp.rb', line 29

def stamp_at(user_defined_name, point)
  # Save the graphics state
  add_content "q"

  # Translate the user space
  x,y = point
  translate_position = "1 0 0 1 %.3f %.3f cm" % [x, y]
  add_content translate_position
  
  # Draw the stamp in the now translated user space
  stamp(user_defined_name)
  
  # Restore the graphics state to remove the translation
  add_content "Q"
end