sane-ffi/lib/sane/device.rb
2011-06-01 14:07:08 +02:00

109 lines
2.2 KiB
Ruby

class Sane
class Device
def initialize(options)
@name = options[:name]
@vendor = options[:vendor]
@model = options[:model]
@type = options[:type]
@handle = nil
end
def closed?
@handle.nil?
end
def open?
!closed?
end
def open
ensure_closed!
@handle = Sane.instance.send(:open, @name)
if block_given?
begin
yield(self)
ensure
close
end
end
end
def close
ensure_open!
Sane.instance.send(:close, @handle)
@handle = nil
end
def start
ensure_open!
Sane.instance.start(@handle)
end
def read
ensure_open!
Sane.instance.send(:read, @handle)
end
def option_count
ensure_open!
Sane.instance.send(:get_option, @handle, 0)
end
def parameters
ensure_open!
Sane.instance.send(:get_parameters, @handle)
end
def [](option)
ensure_open!
Sane.instance.send(:get_option, @handle, option_lookup(option))
end
def []=(option, value)
ensure_open!
Sane.instance.send(:set_option, @handle, option_lookup(option), value)
end
def option_descriptors
option_count.times.map { |i| Sane.instance.send(:get_option_descriptor, @handle, i) }
end
def option_names
option_descriptors.map { |option| option[:name] }
end
def option_values
option_count.times.map do |i|
begin
self[i]
rescue Error
nil # we can't get values of some options, ignore them
end
end
end
def options
{}.tap { |hash| option_count.times { |i| hash[option_names[i]] = option_values[i] } }
end
def option_lookup(option_name)
return option_name if (0..option_count).include?(option_name)
option_descriptors.index { |option| option[:name] == option_name.to_s } or raise ArgumentError, "Option not found: #{option_name}"
end
def describe(option)
option_descriptors[option_lookup(option)]
end
private
def ensure_closed!
raise "Device is already open" if open?
end
def ensure_open!
raise "Device is closed" if closed?
end
end
end