Class: EmbedXMP::ImageFile

Inherits:
Object
  • Object
show all
Defined in:
lib/embed_xmp/image_file.rb

Overview

Basic image file representation.

Direct Known Subclasses

JFIF, PNG, RIFF, SVG

Instance Method Summary collapse

Constructor Details

#initialize(input_image) ⇒ ImageFile

Returns a new instance of ImageFile.



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# File 'lib/embed_xmp/image_file.rb', line 11

def initialize(input_image)
  @image_data = read_io_or_string(input_image)
end

Instance Method Details

#insert_into_file(offset, data) ⇒ Object

Insert a chunk of data at file_offset from the start of file_data.



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# File 'lib/embed_xmp/image_file.rb', line 29

def insert_into_file(offset, data)
  @image_data = @image_data[0..offset - 1] + data + @image_data[offset..-1]
end

#read_io_or_string(thing) ⇒ Object

Read from a readable IO object or a String (file path or a thing).



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# File 'lib/embed_xmp/image_file.rb', line 16

def read_io_or_string(thing)
  if thing.respond_to?(:encoding)
    return IO.binread(thing) if File.exist?(thing)

    return thing
  elsif thing.respond_to?(:read)
    return IO.binread(thing)
  end

  raise 'FileNotAnIOorString'
end

#write(output_file, data: nil) ⇒ Object

Write image to file (or return if argument is nil).



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# File 'lib/embed_xmp/image_file.rb', line 34

def write(output_file, data: nil)
  data = @image_data if data.nil?
  return data if output_file.nil?

  written_bytes = 0
  File.open(output_file, 'wb') do |file|
    written_bytes = file.write(data)
  end

  written_bytes > 0 && written_bytes == data.b.length
end