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# frozen_string_literal: true
require 'pdf/core/utils'
module PDF
module Core
# PDF indirect objects
#
# @api private
class Reference
# Object identifier
# @return [Integer]
attr_accessor :identifier
# Object generation
# @return [Integer]
attr_accessor :gen
# Object data
# @return [any]
attr_accessor :data
# Offset of the serialized object in the document
# @return [Integer]
attr_accessor :offset
# Object stream
# @return [Stream]
attr_accessor :stream
# In PDF only dict object can have a stream attached. This exception
# indicates someone tried to add a stream to another kind of object.
class CannotAttachStream < StandardError
# @param message [String] Error message
def initialize(message = 'Cannot attach stream to a non-dictionary object')
super
end
end
# @param id [Integer] Object identifier
# @param data [any] Object data
def initialize(id, data)
@identifier = id
@gen = 0
@data = data
@stream = Stream.new
end
# Serialized PDF object
#
# @return [String]
def object
output = +"#{@identifier} #{gen} obj\n"
if @stream.empty?
output << PDF::Core.pdf_object(data) << "\n"
else
output << PDF::Core.pdf_object(data.merge(@stream.data)) <<
"\n" << @stream.object
end
output << "endobj\n"
end
# Appends data to object stream
#
# @param io [String] data
# @return [io]
# @raise [CannotAttachStream] if object is not a dict
def <<(io)
unless @data.is_a?(::Hash)
raise CannotAttachStream
end
(@stream ||= Stream.new) << io
end
# Object reference in PDF format
#
# @return [String]
def to_s
"#{@identifier} #{gen} R"
end
# Creates a deep copy of this ref.
#
# @param share [Array<Symbol>] a list of dictionary entries to share
# between the old ref and the new
# @return [Reference]
def deep_copy(share = [])
r = dup
case r.data
when ::Hash
# Copy each entry not in +share+.
(r.data.keys - share).each do |k|
r.data[k] = Utils.deep_clone(r.data[k])
end
when PDF::Core::NameTree::Node
r.data = r.data.deep_copy
else
r.data = Utils.deep_clone(r.data)
end
r.stream = Utils.deep_clone(r.stream)
r
end
# Replaces the data and stream with that of other_ref.
#
# @param other_ref [Reference]
# @return [void]
def replace(other_ref)
@data = other_ref.data
@stream = other_ref.stream
end
end
end
end
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