Module: Vedeu::Esc

Extended by:
Esc
Included in:
Esc
Defined in:
lib/vedeu/output/esc.rb

Overview

Provides escape sequence strings for setting the cursor position and various display related functions.

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.actions ⇒ Hash<Symbol => String>

Returns:

  • (Hash<Symbol => String>) 


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# File 'lib/vedeu/output/esc.rb', line 78

def actions
  {
    hide_cursor:   "\e[?25l",
    show_cursor:   "\e[?25h",
    bg_reset:      "\e[49m",
    blink:         "\e[5m",
    blink_off:     "\e[25m",
    bold:          "\e[1m",
    bold_off:      "\e[22m",
    border_on:     "\e(0",
    border_off:    "\e(B",
    dim:           "\e[2m",
    fg_reset:      "\e[39m",
    negative:      "\e[7m",
    positive:      "\e[27m",
    reset:         "\e[0m",
    underline:     "\e[4m",
    underline_off: "\e[24m",
  }
end

.background_codes ⇒ Hash<Symbol => Fixnum>

Produces the background named colour escape sequence hash from the foreground escape sequence hash.

Returns:

  • (Hash<Symbol => Fixnum>) 


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# File 'lib/vedeu/output/esc.rb', line 57

def background_codes
  Vedeu::Esc.codes.inject({}) { |h, (k, v)| h.merge!(k => v + 10) }
end

.border ⇒ String

Return the escape sequence to render a border character.

Yield Returns:

  • (void) —

    The border character to wrap with border on and off escape sequences.

Returns:

  • (String) 


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# File 'lib/vedeu/output/esc.rb', line 137

def border
  return '' unless block_given?

  [border_on, yield, border_off].join
end

.clear ⇒ String (private)

Returns:

  • (String) 


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# File 'lib/vedeu/output/esc.rb', line 146

def clear
  [colour_reset, "\e[2J"].join
end

.clear_last_line ⇒ String (private)

Returns:

  • (String) 


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# File 'lib/vedeu/output/esc.rb', line 156

def clear_last_line
  Vedeu::Position.new((Vedeu::Terminal.height - 1), 1).to_s { clear_line }
end

.clear_line ⇒ String (private)

Returns:

  • (String) 


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# File 'lib/vedeu/output/esc.rb', line 151

def clear_line
  [colour_reset, "\e[2K"].join
end

.codes ⇒ Hash<Symbol => Fixnum> Also known as: foreground_codes

Produces the foreground named colour escape sequence hash. The background escape sequences are also generated from this by adding 10 to the values. This hash gives rise to methods you can call directly on ‘Esc` to produce the desired colours:

Examples:

Esc.red                     # => "\e[31m"

Esc.red { 'some text' }     # => "\e[31msome text\e[39m"

Esc.on_blue                 # => "\e[44m"

Esc.on_blue { 'some text' } # => "\e[44msome text\e[49m"

# Valid names:
:black, :red, :green, :yellow, :blue, :magenta, :cyan, :light_grey,
:default, :dark_grey, :light_red, :light_green, :light_yellow,
:light_blue, :light_magenta, :light_cyan, :white

Returns:

  • (Hash<Symbol => Fixnum>) 


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# File 'lib/vedeu/output/esc.rb', line 30

def codes
  {
    black:         30,
    red:           31,
    green:         32,
    yellow:        33,
    blue:          34,
    magenta:       35,
    cyan:          36,
    light_grey:    37,
    default:       39,
    dark_grey:     90,
    light_red:     91,
    light_green:   92,
    light_yellow:  93,
    light_blue:    94,
    light_magenta: 95,
    light_cyan:    96,
    white:         97,
  }
end

.colour_reset ⇒ String (private)

Returns:

  • (String) 


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# File 'lib/vedeu/output/esc.rb', line 161

def colour_reset
  [fg_reset, bg_reset].join
end

.escape(stream = '') ⇒ String

Return the stream with the escape sequences escaped so that they can be printed to the terminal instead of being interpreted by the terminal which will render them. This way we can see what escape sequences are being sent along with the content.

Parameters:

  • stream (String) (defaults to: '')

Returns:

  • (String) 


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# File 'lib/vedeu/output/esc.rb', line 110

def escape(stream = '')
  return stream if stream.nil? || stream.empty?

  stream.gsub(/\e/, '\\e')
end

.key ⇒ String

Dynamically creates methods for each terminal named colour. When a block is given, then the colour is reset to ‘default’ once the block is called.

Returns:

  • (String) 


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# File 'lib/vedeu/output/esc.rb', line 65

foreground_codes.each do |key, code|
  define_method(key) do |&blk|
    "\e[#{code}m" + (blk ? blk.call + "\e[39m" : '')
  end
end

.normal ⇒ String (private)

Returns:

  • (String) 


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# File 'lib/vedeu/output/esc.rb', line 166

def normal
  [underline_off, bold_off, positive].join
end

.screen_exit ⇒ String (private)

Returns:

  • (String) 


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# File 'lib/vedeu/output/esc.rb', line 176

def screen_exit
  [show_cursor, colour_reset, reset].join
end

.screen_init ⇒ String (private)

Returns:

  • (String) 


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# File 'lib/vedeu/output/esc.rb', line 171

def screen_init
  [reset, clear, hide_cursor].join
end

.string(value = '') ⇒ String

Return the escape sequence string from the list of recognised sequence ‘commands’, or an empty string if the ‘command’ cannot be found.

Parameters:

  • value (String|Symbol) (defaults to: '')

Returns:

  • (String) 


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# File 'lib/vedeu/output/esc.rb', line 121

def string(value = '')
  name = value.to_sym

  return '' if name.empty?

  send(name)

rescue NoMethodError
  ''
end

Instance Method Details

#actions ⇒ Hash<Symbol => String>

Returns:

  • (Hash<Symbol => String>) 


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# File 'lib/vedeu/output/esc.rb', line 78

def actions
  {
    hide_cursor:   "\e[?25l",
    show_cursor:   "\e[?25h",
    bg_reset:      "\e[49m",
    blink:         "\e[5m",
    blink_off:     "\e[25m",
    bold:          "\e[1m",
    bold_off:      "\e[22m",
    border_on:     "\e(0",
    border_off:    "\e(B",
    dim:           "\e[2m",
    fg_reset:      "\e[39m",
    negative:      "\e[7m",
    positive:      "\e[27m",
    reset:         "\e[0m",
    underline:     "\e[4m",
    underline_off: "\e[24m",
  }
end

#background_codes ⇒ Hash<Symbol => Fixnum>

Produces the background named colour escape sequence hash from the foreground escape sequence hash.

Returns:

  • (Hash<Symbol => Fixnum>) 


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# File 'lib/vedeu/output/esc.rb', line 57

def background_codes
  Vedeu::Esc.codes.inject({}) { |h, (k, v)| h.merge!(k => v + 10) }
end

#border ⇒ String

Return the escape sequence to render a border character.

Yield Returns:

  • (void) —

    The border character to wrap with border on and off escape sequences.

Returns:

  • (String) 


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# File 'lib/vedeu/output/esc.rb', line 137

def border
  return '' unless block_given?

  [border_on, yield, border_off].join
end

#clear ⇒ String (private)

Returns:

  • (String) 


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# File 'lib/vedeu/output/esc.rb', line 146

def clear
  [colour_reset, "\e[2J"].join
end

#clear_last_line ⇒ String (private)

Returns:

  • (String) 


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# File 'lib/vedeu/output/esc.rb', line 156

def clear_last_line
  Vedeu::Position.new((Vedeu::Terminal.height - 1), 1).to_s { clear_line }
end

#clear_line ⇒ String (private)

Returns:

  • (String) 


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# File 'lib/vedeu/output/esc.rb', line 151

def clear_line
  [colour_reset, "\e[2K"].join
end

#codes ⇒ Hash<Symbol => Fixnum> Also known as: foreground_codes

Produces the foreground named colour escape sequence hash. The background escape sequences are also generated from this by adding 10 to the values. This hash gives rise to methods you can call directly on ‘Esc` to produce the desired colours:

Examples:

Esc.red                     # => "\e[31m"

Esc.red { 'some text' }     # => "\e[31msome text\e[39m"

Esc.on_blue                 # => "\e[44m"

Esc.on_blue { 'some text' } # => "\e[44msome text\e[49m"

# Valid names:
:black, :red, :green, :yellow, :blue, :magenta, :cyan, :light_grey,
:default, :dark_grey, :light_red, :light_green, :light_yellow,
:light_blue, :light_magenta, :light_cyan, :white

Returns:

  • (Hash<Symbol => Fixnum>) 


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# File 'lib/vedeu/output/esc.rb', line 30

def codes
  {
    black:         30,
    red:           31,
    green:         32,
    yellow:        33,
    blue:          34,
    magenta:       35,
    cyan:          36,
    light_grey:    37,
    default:       39,
    dark_grey:     90,
    light_red:     91,
    light_green:   92,
    light_yellow:  93,
    light_blue:    94,
    light_magenta: 95,
    light_cyan:    96,
    white:         97,
  }
end

#colour_reset ⇒ String (private)

Returns:

  • (String) 


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# File 'lib/vedeu/output/esc.rb', line 161

def colour_reset
  [fg_reset, bg_reset].join
end

#escape(stream = '') ⇒ String

Return the stream with the escape sequences escaped so that they can be printed to the terminal instead of being interpreted by the terminal which will render them. This way we can see what escape sequences are being sent along with the content.

Parameters:

  • stream (String) (defaults to: '')

Returns:

  • (String) 


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# File 'lib/vedeu/output/esc.rb', line 110

def escape(stream = '')
  return stream if stream.nil? || stream.empty?

  stream.gsub(/\e/, '\\e')
end

#key ⇒ String

Dynamically creates methods for each terminal named colour. When a block is given, then the colour is reset to ‘default’ once the block is called.

Returns:

  • (String) 


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# File 'lib/vedeu/output/esc.rb', line 65

foreground_codes.each do |key, code|
  define_method(key) do |&blk|
    "\e[#{code}m" + (blk ? blk.call + "\e[39m" : '')
  end
end

#normal ⇒ String (private)

Returns:

  • (String) 


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# File 'lib/vedeu/output/esc.rb', line 166

def normal
  [underline_off, bold_off, positive].join
end

#screen_exit ⇒ String (private)

Returns:

  • (String) 


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# File 'lib/vedeu/output/esc.rb', line 176

def screen_exit
  [show_cursor, colour_reset, reset].join
end

#screen_init ⇒ String (private)

Returns:

  • (String) 


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# File 'lib/vedeu/output/esc.rb', line 171

def screen_init
  [reset, clear, hide_cursor].join
end

#string(value = '') ⇒ String

Return the escape sequence string from the list of recognised sequence ‘commands’, or an empty string if the ‘command’ cannot be found.

Parameters:

  • value (String|Symbol) (defaults to: '')

Returns:

  • (String) 


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# File 'lib/vedeu/output/esc.rb', line 121

def string(value = '')
  name = value.to_sym

  return '' if name.empty?

  send(name)

rescue NoMethodError
  ''
end