Class: ZBar::Processor

Inherits:
Object
  • Object
show all
Defined in:
lib/zbar/processor.rb

Instance Method Summary collapse

Constructor Details

#initialize(config = nil) ⇒ Processor

Create a new processor. Accepts a hash of configurations



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# File 'lib/zbar/processor.rb', line 5

def initialize(config = nil)
  # This function used to accept an integer refering to the number of threads
  if config.kind_of?(Integer)
    config = { :threads => config }
  end
  
  config ||= {}
  
  @processor = FFI::AutoPointer.new(
    ZBar.zbar_processor_create(config[:threads] || 0),
    ZBar.method(:zbar_processor_destroy)
    )
  
  if ZBar.zbar_processor_init(@processor, nil, 0) > 0
    ZBar._zbar_error_spew(@processor, 0)
    raise "error!"
  end
  
  config.each { |key,value|
    if key == :threads
      # do nothing; we handled this above
    else
      setter = "#{key}=".to_sym
      if respond_to?(setter)
        send(setter, value)
      else
        raise ArgumentError, "unsupported configuration option: #{key}"
      end
    end
  }
end

Instance Method Details

#process(image) ⇒ Object

Attempt to recognize barcodes in this image. Raises an exception if ZBar signals an error, otherwise returns an array of ZBar::Symbol objects.

Raises:

  • (ArgumentError) 


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# File 'lib/zbar/processor.rb', line 94

def process(image)
  raise ArgumentError, "process() operates only on ZBar::Image objects" unless image.kind_of?(ZBar::Image)
  image = image.instance_variable_get(:@img)
  
  if ZBar.zbar_process_image(@processor, image) != 0
    raise ArgumentError, "processing failed"
  end
  
  out = []
  
  sym = ZBar.zbar_image_first_symbol(image)
  until sym.null?
    out << Symbol.new(sym)
    sym = ZBar.zbar_symbol_next(sym)
  end
  
  out
end

#symbologies=(symbologies) ⇒ Object

Indicates that this processor should only search for the indicated symbologies. Accepts an array of the following symbologies, specified as a string or symbol:

  • qrcode

  • upca

  • upce

  • ean13

  • ean8

  • i25

  • scanner

  • isbn13

  • isbn10

  • code39

  • pdf417

  • code128



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# File 'lib/zbar/processor.rb', line 51

def symbologies=(symbologies)
  self.zbar_config = ["disable"] + symbologies.map { |sym| "#{sym}.enable" }
  true
end

#symbology=(symbology) ⇒ Object

Indicates that this processor should only search for the indicated symbology. See #symbologies= for details.



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# File 'lib/zbar/processor.rb', line 58

def symbology=(symbology)
  self.symbologies = [symbology]
end

#zbar_config=(config_value) ⇒ Object

Configures this processor using the specified configuration string. See zbar_parse_config (zbar/config.c) for supported values.



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# File 'lib/zbar/processor.rb', line 64

def zbar_config=(config_value)
  case config_value
  when String
    symbology = FFI::MemoryPointer.new :int
    config_t = FFI::MemoryPointer.new :int
    value = FFI::MemoryPointer.new :int
  
    if ZBar.zbar_parse_config(config_value, symbology, config_t, value) == 0
      # parsed successfully
      if ZBar.zbar_processor_set_config(@processor, symbology.read_int, config_t.read_int, value.read_int) == 0
        true
      else
        raise ArgumentError, "config string #{config_value.inspect} parsed but could not be set"
      end
    else
      raise ArgumentError, "config string #{config_value.inspect} was not recognized"
    end
    
  when Enumerable
    config_value.each { |value|
      self.zbar_config = value
    }
    
  else
    raise ArgumentError, "unsupported config value"
  end
end