class DBus::Data::Variant

A generic type.

Implementation note: @value is a {Data::Base}.

Attributes

member_type[R]

@return [Type]

Public Class Methods

alignment() click to toggle source

    # File lib/dbus/data.rb
717 def self.alignment
718   1
719 end

from_items(value, mode:, member_type:) click to toggle source

@param member_type [Type]

    # File lib/dbus/data.rb
726 def self.from_items(value, mode:, member_type:)
727   return value if mode == :plain
728 
729   new(value, member_type: member_type)
730 end

from_typed(value, type:) click to toggle source

@param value [::Object] @param type [Type] @return [Variant]

    # File lib/dbus/data.rb
735 def self.from_typed(value, type:)
736   assert_type_matches_class(type)
737 
738   # nil: decide on type of value
739   new(value, member_type: nil)
740 end

guess_type(value) click to toggle source

Determine the type of value @param value [::Object] @return [Type] @api private See also {PacketMarshaller.make_variant}

    # File lib/dbus/data.rb
763 def self.guess_type(value)
764   sct, = PacketMarshaller.make_variant(value)
765   DBus.type(sct)
766 end

new(value, member_type:) click to toggle source

@param member_type [SingleCompleteType,Type,nil]

Calls superclass method DBus::Data::Base::new

    # File lib/dbus/data.rb
769 def initialize(value, member_type:)
770   member_type = Type::Factory.make_type(member_type) if member_type
771   # TODO: validate that the given *member_type* matches *value*
772   case value
773   when Data::Variant
774     # Copy the contained value instead of boxing it more
775     # TODO: except perhaps for round-tripping in exact mode?
776     @member_type = value.member_type
777     value = value.exact_value
778   when Data::Base
779     @member_type = member_type || value.type
780     raise ArgumentError, "Variant type #{@member_type} does not match value type #{value.type}" \
781       unless @member_type == value.type
782   else
783     @member_type = member_type || self.class.guess_type(value)
784     value = Data.make_typed(@member_type, value)
785   end
786   super(value)
787 end

type() click to toggle source

@return [Type]

    # File lib/dbus/data.rb
743 def self.type
744   # memoize
745   @type ||= Type.new(type_code).freeze
746 end

type_code() click to toggle source

    # File lib/dbus/data.rb
713 def self.type_code
714   "v"
715 end

Public Instance Methods

[](index) click to toggle source

Internal helpers to keep the {DBus.variant} method working. Formerly it returned just a pair of [DBus.type(string_type), value] so let’s provide [0], [1], .first, .last

    # File lib/dbus/data.rb
792 def [](index)
793   case index
794   when 0
795     member_type
796   when 1
797     value
798   else
799     raise ArgumentError, "DBus.variant can only be indexed with 0 or 1, seen #{index.inspect}"
800   end
801 end

first() click to toggle source

@see []

    # File lib/dbus/data.rb
804 def first
805   self[0]
806 end

last() click to toggle source

@see []

    # File lib/dbus/data.rb
809 def last
810   self[1]
811 end

type() click to toggle source

Note that for Variants type.to_s==“v”, for the specific see {Variant#member_type} @return [Type] the exact type of this value

    # File lib/dbus/data.rb
751 def type
752   self.class.type
753 end

value() click to toggle source

    # File lib/dbus/data.rb
721 def value
722   @value.value
723 end