Class: Ansi::Selector::Impl

Inherits:
Object
  • Object
show all
Defined in:
lib/ansi/selector/impl.rb

Direct Known Subclasses

MultiImpl, SingleImpl

Constant Summary collapse

POSITION_SCRIPT_PATH = 
File.expand_path(File.join(File.dirname(__FILE__), "..", "..", "..", "position.sh"))
CODES = 
{
  standout_mode: `tput rev`,
  exit_standout_mode: `tput rmso`,
  cursor_up: `tput cuu1`,
  cursor_down: `tput cud1`,
  carriage_return_key: `tput cr`
}

Instance Method Summary collapse

Constructor Details

#initialize(options, formatter, preselected) ⇒ Impl

Returns a new instance of Impl.



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# File 'lib/ansi/selector/impl.rb', line 16

def initialize(options, formatter, preselected)
  @options = options
  @formatter = formatter
  @highlighted_line_index = 0
  @cursor_line_index = 0
  @columns = terminal_columns

  # Converts options to column-aligned strings.
  formatted = @options.map(&@formatter).map(&method(:Array)).map { |line| line.map(&:to_s).map(&method(:strip_ansi_colors)) }
  @formatted ||= formatted.map do |f|
    f.map.with_index do |part, column|
      width = formatted.map { |fm| fm[column] }.compact.map(&:size).max
      part.ljust(width)
    end.join('  ')
  end

  Signal.trap('SIGWINCH', proc do
    columns = terminal_columns
    if columns < @columns && !all_options_fit?(columns)
      # When a buffer gets narrower, the text that doesn't fit into the screen anymore
      # starts jumping around in a way that makes it hard to predict. In such case we
      # clear everything and re-print options at the beginning of the buffer to
      # simplify things.
      tty.print(`printf '\e[2J'`)
      tty.print(`tput cup 0 0`)
    else
      print_line(0)
    end

    @columns = columns
    print_options
  end)
end

Instance Method Details

#all_options_fit?(columns) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/ansi/selector/impl.rb', line 50

def all_options_fit?(columns)
  option_indices.map(&method(:final_text_for_line)).map(&:size).all? { |size| size < columns }
end

#select ⇒ Object 



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# File 'lib/ansi/selector/impl.rb', line 64

def select
  print_options
  answer = ask_to_choose
  # We need to reprint here in order to render the lines that are behind the buffer.
  range(@highlighted_line_index, @options.size - 1).each(&method(:print_line))
  go_to_line(@options.size)

  answer
ensure
  tty.close
end

#terminal_columns ⇒ Fixnum

Returns:

  • (Fixnum) 


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# File 'lib/ansi/selector/impl.rb', line 55

def terminal_columns
  `tput cols`.to_i
end

#terminal_lines ⇒ Fixnum

Returns:

  • (Fixnum) 


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# File 'lib/ansi/selector/impl.rb', line 60

def terminal_lines
  `tput lines`.to_i
end