Class: PDF::Core::Stream

Inherits:
Object
  • Object
show all
Defined in:
lib/pdf/core/stream.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(io = nil) ⇒ Stream

Returns a new instance of Stream.



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# File 'lib/pdf/core/stream.rb', line 14

def initialize(io = nil)
  @filtered_stream = ''
  @stream = io
  @filters = FilterList.new
end

Instance Attribute Details

#filters ⇒ Object (readonly)

Returns the value of attribute filters.



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# File 'lib/pdf/core/stream.rb', line 12

def filters
  @filters
end

Instance Method Details

#<<(io) ⇒ Object 



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# File 'lib/pdf/core/stream.rb', line 20

def <<(io)
  (@stream ||= +'') << io
  @filtered_stream = nil
  self
end

#compress! ⇒ Object 



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# File 'lib/pdf/core/stream.rb', line 26

def compress!
  unless @filters.names.include? :FlateDecode
    @filtered_stream = nil
    @filters << :FlateDecode
  end
end

#compressed? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/pdf/core/stream.rb', line 33

def compressed?
  @filters.names.include? :FlateDecode
end

#data ⇒ Object 



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# File 'lib/pdf/core/stream.rb', line 71

def data
  if @stream
    filter_names = @filters.names
    filter_params = @filters.decode_params

    d = {
      Length: filtered_stream.length
    }
    if filter_names.any?
      d[:Filter] = filter_names
    end
    if filter_params.any? { |f| !f.nil? }
      d[:DecodeParms] = filter_params
    end

    d
  else
    {}
  end
end

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/pdf/core/stream.rb', line 37

def empty?
  @stream.nil?
end

#filtered_stream ⇒ Object 



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# File 'lib/pdf/core/stream.rb', line 41

def filtered_stream
  if @stream
    if @filtered_stream.nil?
      @filtered_stream = @stream.dup

      @filters.each do |(filter_name, params)|
        filter = PDF::Core::Filters.const_get(filter_name)
        if filter
          @filtered_stream = filter.encode @filtered_stream, params
        end
      end
    end

    @filtered_stream
    # XXX Fillter stream
  end
end

#inspect ⇒ Object 



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# File 'lib/pdf/core/stream.rb', line 92

def inspect
  format(
    '#<%<class>s:0x%<object_id>014x '\
      '@stream=%<stream>s, @filters=%<filters>s>',
    class: self.class.name,
    object_id: object_id,
    stream: @stream.inspect,
    filters: @filters.inspect
  )
end

#length ⇒ Object 



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# File 'lib/pdf/core/stream.rb', line 59

def length
  @stream.length
end

#object ⇒ Object 



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# File 'lib/pdf/core/stream.rb', line 63

def object
  if filtered_stream
    "stream\n#{filtered_stream}\nendstream\n"
  else
    ''
  end
end