class TTY::Prompt::BlockPaginator

Public Instance Methods

paginate(list, active, per_page = nil, &block) click to toggle source

Paginate list of choices based on current active choice. Move entire pages.

@api public

# File lib/tty/prompt/block_paginator.rb, line 11
def paginate(list, active, per_page = nil, &block)
  default_size = (list.size <= DEFAULT_PAGE_SIZE ? list.size : DEFAULT_PAGE_SIZE)
  @per_page = @per_page || per_page || default_size

  check_page_size!

  # Don't paginate short lists
  if list.size <= @per_page
    @start_index = 0
    @end_index = list.size - 1
    if block
      return list.each_with_index(&block)
    else
      return list.each_with_index.to_enum
    end
  end

  unless active.nil? # User may input index out of range
    @last_index = active
  end
  page  = (@last_index / @per_page.to_f).ceil
  pages = (list.size / @per_page.to_f).ceil
  if page == 0
    @start_index = 0
    @end_index = @start_index + @per_page - 1
  elsif page > 0 && page < pages
    @start_index = (page - 1) * @per_page
    @end_index = @start_index + @per_page - 1
  elsif page == pages
    @start_index = (page - 1) * @per_page
    @end_index = list.size - 1
  else
    @end_index = list.size - 1
    @start_index = @end_index - @per_page + 1
  end

  sliced_list = list[@start_index..@end_index]
  page_range = (@start_index..@end_index)

  return sliced_list.zip(page_range).to_enum unless block_given?

  sliced_list.each_with_index do |item, index|
    block[item, @start_index + index]
  end
end