64 lines
1.4 KiB
Ruby
64 lines
1.4 KiB
Ruby
# 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
|