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# frozen_string_literal: true
# This module handles element positions in a list.
module Sidebars
module Concerns
module PositionableList
def add_element(list, element)
return unless element
list << element
end
def insert_element_before(list, before_element, new_element)
return unless 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)
return unless new_element
index = index_of(list, after_element)
if index
list.insert(index + 1, new_element)
else
add_element(list, new_element)
end
end
def replace_element(list, element_to_replace, new_element)
return unless new_element
index = index_of(list, element_to_replace)
return unless index
list[index] = new_element
end
def remove_element(list, element_to_remove)
index = index_of(list, element_to_remove)
return unless index
list.slice!(index)
end
private
# Classes including this method will have to define
# the way to identify elements through this method
def index_of(list, element)
raise NotImplementedError
end
end
end
end
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