app/helpers/numbered_pagination_helper.rb

   1 module NumberedPaginationHelper
   2   def element_versions_pagination(top_version, active_version: top_version + 1, window_half_size: 50, step_size: 50, &)
   3     lists = []
   4
   5     if top_version <= 5
   6       lists << tag.ul(:class => "pagination pagination-sm mt-1") do
   7         (1..top_version).each do |v|
   8           concat element_versions_pagination_item(v, **yield(v), :active => v == active_version)
   9         end
  10       end
  11     else
  12       start_list_versions = 1..(active_version < 3 ? active_version + 1 : 1)
  13       end_list_versions = (active_version > top_version - 2 ? active_version - 1 : top_version)..top_version
  14
  15       middle_list_version_sentinels = [start_list_versions.last, end_list_versions.first]
  16       middle_list_version_steps = Range.new(*middle_list_version_sentinels).filter { |v| (v % step_size).zero? }
  17       middle_list_version_window = Range.new([active_version - window_half_size, start_list_versions.last].max,
  18                                              [active_version + window_half_size, end_list_versions.first].min).to_a
  19       middle_list_versions_with_sentinels = (middle_list_version_sentinels | middle_list_version_steps | middle_list_version_window).sort
  20       middle_list_versions_with_gaps = middle_list_versions_with_sentinels.each_cons(2).flat_map do |previous_version, v|
  21         v == previous_version + 1 ? [v] : [:gap, v]
  22       end[...-1]
  23       middle_list_versions = middle_list_versions_with_gaps
  24
  25       lists << tag.ul(:id => "versions-navigation-list-start",
  26                       :class => "pagination pagination-sm mt-1") do
  27         start_list_versions.each do |v|
  28           concat element_versions_pagination_item(v, **yield(v), :active => v == active_version,
  29                                                                  :edge => [false, v == start_list_versions.last],
  30                                                                  :edge_border => true)
  31         end
  32       end
  33       lists << tag.ul(:id => "versions-navigation-list-middle",
  34                       :class => [
  35                         "pagination pagination-sm",
  36                         "overflow-x-scroll pb-3", # horizontal scrollbar with reserved space below
  37                         "pt-1 px-1 mx-n1", # space reserved for focus outlines
  38                         "position-relative" # required for centering when clicking "Version #n"
  39                       ]) do
  40         middle_list_versions.each_with_index do |v, i|
  41           edge = [i.zero?, i == middle_list_versions.length - 1]
  42           if v == :gap
  43             concat element_versions_pagination_item("...", :edge => edge)
  44           else
  45             concat element_versions_pagination_item(v, **yield(v), :active => v == active_version, :edge => edge)
  46           end
  47         end
  48       end
  49       lists << tag.ul(:id => "versions-navigation-list-end",
  50                       :class => "pagination pagination-sm mt-1") do
  51         end_list_versions.each do |v|
  52           concat element_versions_pagination_item(v, **yield(v), :active => v == active_version,
  53                                                                  :edge => [v == end_list_versions.first, false],
  54                                                                  :edge_border => true)
  55         end
  56       end
  57     end
  58
  59     tag.div safe_join(lists), :class => "d-flex align-items-start"
  60   end
  61
  62   private
  63
  64   def element_versions_pagination_item(body, href: nil, title: nil, active: false, edge: [false, false], edge_border: false)
  65     link_class = ["page-link", { "rounded-start-0" => edge.first,
  66                                  "border-start-0" => edge.first && !edge_border,
  67                                  "rounded-end-0" => edge.last,
  68                                  "border-end-0" => edge.last && !edge_border }]
  69     link = if href
  70              link_to body, href, :class => link_class, :title => title
  71            else
  72              tag.span body, :class => link_class
  73            end
  74     tag.li link, :id => ("versions-navigation-active-page-item" if active),
  75                  :class => ["page-item", { "disabled" => !href, "active" => active }]
  76   end
  77 end