require 'io/console'
module CLI
module UI
module Prompt
class InteractiveOptions
DONE = "Done"
CHECKBOX_ICON = { false => "☐", true => "☑" }
# Prompts the user with options
# Uses an interactive session to allow the user to pick an answer
# Can use arrows, y/n, numbers (1/2), and vim bindings to control
#
# https://user-images.githubusercontent.com/3074765/33797984-0ebb5e64-dcdf-11e7-9e7e-7204f279cece.gif
#
# ==== Example Usage:
#
# Ask an interactive question
# CLI::UI::Prompt::InteractiveOptions.call(%w(rails go python))
#
def self.call(options, multiple: false)
list = new(options, multiple: multiple)
selected = list.call
if multiple
selected.map { |s| options[s - 1] }
else
options[selected - 1]
end
end
# Initializes a new +InteractiveOptions+
# Usually called from +self.call+
#
# ==== Example Usage:
#
# CLI::UI::Prompt::InteractiveOptions.new(%w(rails go python))
#
def initialize(options, multiple: false)
@options = options
@active = 1
@marker = '>'
@answer = nil
@state = :root
@multiple = multiple
# 0-indexed array representing if selected
# @options[0] is selected if @chosen[0]
@chosen = Array.new(@options.size) { false } if multiple
@redraw = true
end
# Calls the +InteractiveOptions+ and asks the question
# Usually used from +self.call+
#
def call
CLI::UI.raw { print(ANSI.hide_cursor) }
while @answer.nil?
render_options
process_input_until_redraw_required
reset_position
end
clear_output
@answer
ensure
CLI::UI.raw do
print(ANSI.show_cursor)
end
end
private
def reset_position
# This will put us back at the beginning of the options
# When we redraw the options, they will be overwritten
CLI::UI.raw do
num_lines.times { print(ANSI.previous_line) }
end
end
def clear_output
CLI::UI.raw do
# Write over all lines with whitespace
num_lines.times { puts(' ' * CLI::UI::Terminal.width) }
end
reset_position
end
def num_lines
options = presented_options.map(&:first)
# @options will be an array of questions but each option can be multi-line
# so to get the # of lines, you need to join then split
# empty_option_count is needed since empty option titles are omitted
# from the line count when reject(&:empty?) is called
empty_option_count = options.count(&:empty?)
joined_options = options.join("\n")
joined_options.split("\n").reject(&:empty?).size + empty_option_count
end
ESC = "\e"
def up
min_pos = @multiple ? 0 : 1
@active = @active - 1 >= min_pos ? @active - 1 : @options.length
@redraw = true
end
def down
min_pos = @multiple ? 0 : 1
@active = @active + 1 <= @options.length ? @active + 1 : min_pos
@redraw = true
end
# n is 1-indexed selection
# n == 0 if "Done" was selected in @multiple mode
def select_n(n)
if @multiple
if n == 0
@answer = []
@chosen.each_with_index do |selected, i|
@answer << i + 1 if selected
end
else
@active = n
@chosen[n - 1] = !@chosen[n - 1]
end
elsif n == 0
# Ignore pressing "0" when not in multiple mode
else
@active = n
@answer = n
end
@redraw = true
end
def select_bool(char)
return unless (@options - %w(yes no)).empty?
opt = @options.detect { |o| o.start_with?(char) }
@active = @options.index(opt) + 1
@answer = @options.index(opt) + 1
@redraw = true
end
def select_current
select_n(@active)
end
def process_input_until_redraw_required
@redraw = false
wait_for_user_input until @redraw
end
# rubocop:disable Style/WhenThen,Layout/SpaceBeforeSemicolon
def wait_for_user_input
char = read_char
case @state
when :root
case char
when :timeout ; raise Interrupt # Timeout, use interrupt to simulate
when ESC ; @state = :esc
when 'k' ; up
when 'j' ; down
when '0' ; select_n(char.to_i)
when ('1'..@options.size.to_s) ; select_n(char.to_i)
when 'y', 'n' ; select_bool(char)
when " ", "\r", "\n" ; select_current # <enter>
when "\u0003" ; raise Interrupt # Ctrl-c
end
when :esc
case char
when :timeout ; raise Interrupt # Timeout, use interrupt to simulate
when '[' ; @state = :esc_bracket
else ; raise Interrupt # unhandled escape sequence.
end
when :esc_bracket
@state = :root
case char
when :timeout ; raise Interrupt # Timeout, use interrupt to simulate
when 'A' ; up
when 'B' ; down
else ; raise Interrupt # unhandled escape sequence.
end
end
end
# rubocop:enable Style/WhenThen,Layout/SpaceBeforeSemicolon
def read_char
raw_tty! do
getc = $stdin.getc
getc ? getc.chr : :timeout
end
rescue IOError
"\e"
end
def raw_tty!
if ENV['TEST'] || !$stdin.tty?
yield
else
$stdin.raw { yield }
end
end
def presented_options(recalculate: false)
return @presented_options unless recalculate
@presented_options = @options.zip(1..Float::INFINITY)
@presented_options.unshift([DONE, 0]) if @multiple
while num_lines > max_options
# try to keep the selection centered in the window:
if distance_from_selection_to_end > distance_from_start_to_selection
# selection is closer to top than bottom, so trim a row from the bottom
ensure_last_item_is_continuation_marker
@presented_options.delete_at(-2)
else
# selection is closer to bottom than top, so trim a row from the top
ensure_first_item_is_continuation_marker
@presented_options.delete_at(1)
end
end
@presented_options
end
def distance_from_selection_to_end
last_visible_option_number = @presented_options[-1].last || @presented_options[-2].last
last_visible_option_number - @active
end
def distance_from_start_to_selection
first_visible_option_number = @presented_options[0].last || @presented_options[1].last
@active - first_visible_option_number
end
def ensure_last_item_is_continuation_marker
@presented_options.push(["...", nil]) if @presented_options.last.last
end
def ensure_first_item_is_continuation_marker
@presented_options.unshift(["...", nil]) if @presented_options.first.last
end
def max_options
@max_options ||= CLI::UI::Terminal.height - 2 # Keeps a one line question visible
end
def render_options
max_num_length = (@options.size + 1).to_s.length
presented_options(recalculate: true).each do |choice, num|
is_chosen = @multiple && num && @chosen[num - 1]
padding = ' ' * (max_num_length - num.to_s.length)
message = " #{num}#{num ? '.' : ' '}#{padding}"
format = "%s"
# If multiple, bold only selected. If not multiple, bold everything
format = "{{bold:#{format}}}" if !@multiple || is_chosen
format = "{{cyan:#{format}}}" if @multiple && is_chosen && num != @active
format = " #{format}"
message += sprintf(format, CHECKBOX_ICON[is_chosen]) if @multiple && num && num > 0
message += choice.split("\n").map { |l| sprintf(format, l) }.join("\n")
if num == @active
message = message.split("\n").map.with_index do |l, idx|
idx == 0 ? "{{blue:> #{l.strip}}}" : "{{blue:>#{l.strip}}}"
end.join("\n")
end
CLI::UI.with_frame_color(:blue) do
puts CLI::UI.fmt(message) + CLI::UI::ANSI.clear_to_end_of_line
end
end
end
end
end
end
end