Module: FileData::TagEnumerator

Included in:
Ifd, OrdinalIfd
Defined in:
lib/file_data/formats/exif/ifd.rb

Overview

Contains the ability to enumerate through the exif tags in an ifd

Constant Summary collapse

TAG_RECORD_SIZE = 
12

Instance Method Summary collapse

Instance Method Details

#read_num_tags ⇒ Object 



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# File 'lib/file_data/formats/exif/ifd.rb', line 16

def read_num_tags
  stream.read_value(2)
end

#tags_enum ⇒ Object 



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# File 'lib/file_data/formats/exif/ifd.rb', line 6

def tags_enum
  Enumerator.new do |e|
    read_num_tags.times do
      tag_start_pos = stream.pos
      e.yield stream.read_value(2)
      stream.seek(tag_start_pos + TAG_RECORD_SIZE)
    end
  end.lazy
end

#tags_size(num_tags) ⇒ Object 



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# File 'lib/file_data/formats/exif/ifd.rb', line 20

def tags_size(num_tags)
  num_tags * TAG_RECORD_SIZE
end