lib/sidebars/concerns/positionable_list.rb


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# frozen_string_literal: true

# This module handles elements in a list. All elements
# must have a different class
module Sidebars
  module Concerns
    module PositionableList
      def add_element(list, element)
        list << element
      end

      def insert_element_before(list, before_element, new_element)
        index = index_of(list, before_element)

        if index
          list.insert(index, new_element)
        else
          list.unshift(new_element)
        end
      end

      def insert_element_after(list, after_element, new_element)
        index = index_of(list, after_element)

        if index
          list.insert(index + 1, new_element)
        else
          add_element(list, new_element)
        end
      end

      private

      def index_of(list, element)
        list.index { |e| e.is_a?(element) }
      end
    end
  end
end