Class: Vedeu::Colours::Translator Private

Inherits:
Object
  • Object
show all
Defined in:
lib/vedeu/colours/translator.rb

Overview

This class is part of a private API. You should avoid using this class if possible, as it may be removed or be changed in the future.

TODO:

More documentation required (create a fancy chart!)

Convert a CSS/HTML colour string into a terminal escape sequence.

If provided with an empty value or a string it cannot convert, it will return an empty string.

When provided with a named colour, uses the terminal’s value for that colour. If a theme is being used with the terminal, which overrides the defaults, then the theme’s colour will be used. The recognised names are:

:black, :red, :green, :yellow, :blue, :magenta, :cyan, :white, :default.

When a number between 0 and 255 is provided, Vedeu will use the terminal colour corresponding with that colour.

Finally, when provided a CSS/HTML colour string e.g. ‘#ff0000’, Vedeu will translate that to the 8-bit escape sequence or when you have a capable terminal and the ‘TERM=xterm-truecolor` environment variable set, a 24-bit representation.

Direct Known Subclasses

Background, Foreground

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(colour = '') ⇒ Vedeu::Colours::Translator

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Return a new instance of Vedeu::Colours::Translator.

Parameters:

  • colour (Fixnum|String|Symbol) (defaults to: '') 


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# File 'lib/vedeu/colours/translator.rb', line 53

def initialize(colour = '')
  @colour = colour || ''
end

Instance Attribute Details

#colour ⇒ String (readonly) Also known as: value

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns:

  • (String) 


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# File 'lib/vedeu/colours/translator.rb', line 35

def colour
  @colour
end

Class Method Details

.coerce(value) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Produces new objects of the correct class from the value, ignores objects Colours::that have already been coerced.

Parameters:

  • value (Object|NilClass)

Returns:

  • (Object) 


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# File 'lib/vedeu/colours/translator.rb', line 43

def self.coerce(value)
  return value if value.is_a?(self)

  new(value)
end

Instance Method Details

#blue ⇒ Fixnum (private)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Takes the blue component of #css_to_rgb and converts to the correct value for setting the terminal blue value.

Returns:

  • (Fixnum) 


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# File 'lib/vedeu/colours/translator.rb', line 252

def blue
  (css_to_rgb[2] / 51) * 1
end

#css_to_numbered ⇒ Fixnum (private)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns:

  • (Fixnum) 


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# File 'lib/vedeu/colours/translator.rb', line 222

def css_to_numbered
  if rgb?
    [16, red, green, blue].inject(:+)

  elsif numbered?
    colour

  end
end

#css_to_rgb ⇒ Array (private)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns a collection of converted HTML/CSS octets as their decimal equivalents.

Examples:

colour = '#aadd55'
css_to_rgb # => [170, 221, 85]

Returns:

  • (Array) 


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# File 'lib/vedeu/colours/translator.rb', line 213

def css_to_rgb
  [
    colour[1..2].to_i(16),
    colour[3..4].to_i(16),
    colour[5..6].to_i(16),
  ]
end

#empty? ⇒ Boolean

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns:

  • (Boolean) 


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# File 'lib/vedeu/colours/translator.rb', line 58

def empty?
  colour.nil? || colour.to_s.empty?
end

#eql?(other) ⇒ Boolean Also known as: ==

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

An object is equal when its values are the same.

Parameters:

Returns:

  • (Boolean) 


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# File 'lib/vedeu/colours/translator.rb', line 66

def eql?(other)
  self.class == other.class && colour == other.colour
end

#escape_sequence ⇒ String Also known as: to_s, to_str

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns:

  • (String)

See Also:



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# File 'lib/vedeu/colours/translator.rb', line 73

def escape_sequence
  if empty?
    ''

  elsif registered?(colour)
    retrieve(colour)

  elsif rgb?
    rgb

  elsif numbered?
    numbered

  elsif named?
    named

  else
    ''

  end
end

#green ⇒ Fixnum (private)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Takes the green component of #css_to_rgb and converts to the correct value for setting the terminal green value.

Returns:

  • (Fixnum) 


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# File 'lib/vedeu/colours/translator.rb', line 244

def green
  (css_to_rgb[1] / 51) * 6
end

#named ⇒ String (private)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Note:

Valid names can be found at EscapeSequences::Esc#codes

Returns an escape sequence for a named background colour.

Returns:

  • (String) 


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# File 'lib/vedeu/colours/translator.rb', line 147

def named
  "\e[#{named_codes}m".freeze
end

#named? ⇒ Boolean (private)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns:

  • (Boolean) 


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# File 'lib/vedeu/colours/translator.rb', line 136

def named?
  colour.is_a?(Symbol) && valid_name?
end

#not_implemented ⇒ Vedeu::Error::NotImplemented (private) Also known as: named_codes, numbered_prefix, repository, rgb_prefix

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns:

Raises:



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# File 'lib/vedeu/colours/translator.rb', line 259

def not_implemented
  fail Vedeu::Error::NotImplemented, 'Subclasses implement this.'.freeze
end

#numbered ⇒ String (private)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns an escape sequence.

Returns:

  • (String) 


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# File 'lib/vedeu/colours/translator.rb', line 170

def numbered
  "#{numbered_prefix}#{css_to_numbered}m".freeze
end

#numbered? ⇒ Boolean (private)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns a boolean indicating whether the colour provided is a terminal numbered colour.

Returns:

  • (Boolean) 


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# File 'lib/vedeu/colours/translator.rb', line 163

def numbered?
  colour.is_a?(Fixnum) && valid_range?
end

#red ⇒ Fixnum (private)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Takes the red component of #css_to_rgb and converts to the correct value for setting the terminal red value.

Returns:

  • (Fixnum) 


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# File 'lib/vedeu/colours/translator.rb', line 236

def red
  (css_to_rgb[0] / 51) * 36
end

#register(colour, escape_sequence) ⇒ String (private)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Registers a HTML/CSS colour code and escape sequence to reduce processing.

Parameters:

  • colour (String) —

    A HTML/CSS colour code.

  • escape_sequence (String) —

    The HTML/CSS colour code as an escape sequence.

Returns:

  • (String) 


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# File 'lib/vedeu/colours/translator.rb', line 122

def register(colour, escape_sequence)
  repository.register(colour, escape_sequence)
end

#registered?(colour) ⇒ Boolean (private)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns a boolean indicating the HTML/CSS colour code has been registered.

Parameters:

  • colour (String)

Returns:

  • (Boolean) 


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# File 'lib/vedeu/colours/translator.rb', line 131

def registered?(colour)
  repository.registered?(colour)
end

#retrieve(colour) ⇒ String (private)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Retrieves the escape sequence for the HTML/CSS colour code.

Parameters:

  • colour (String)

Returns:

  • (String) 


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# File 'lib/vedeu/colours/translator.rb', line 111

def retrieve(colour)
  repository.retrieve(colour)
end

#rgb ⇒ String (private)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns an escape sequence.

Returns:

  • (String) 


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# File 'lib/vedeu/colours/translator.rb', line 187

def rgb
  if Vedeu::Configuration.colour_mode == 16_777_216
    register(colour, format(rgb_prefix, *css_to_rgb))

  else
    numbered

  end
end

#rgb? ⇒ Boolean (private)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns a boolean indicated whether the colour is a valid HTML/CSS colour.

Returns:

  • (Boolean) 


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# File 'lib/vedeu/colours/translator.rb', line 178

def rgb?
  return true if colour =~ /^#([A-Fa-f0-9]{6})$/.freeze

  false
end

#to_html(_options = {}) ⇒ String

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Parameters:

  • _options (Hash) (defaults to: {}) —

    Ignored.

Returns:

  • (String) 


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# File 'lib/vedeu/colours/translator.rb', line 99

def to_html(_options = {})
  return colour if rgb?

  ''
end

#valid_name? ⇒ Boolean (private)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns a boolean indicating whether the colour provided is a valid named colour.

Returns:

  • (Boolean) 


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# File 'lib/vedeu/colours/translator.rb', line 155

def valid_name?
  Vedeu::EscapeSequences::Esc.codes.keys.include?(colour)
end

#valid_range? ⇒ Boolean (private)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns a boolean indicating whether the numbered colour is within the range of valid terminal numbered colours.

Returns:

  • (Boolean) 


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# File 'lib/vedeu/colours/translator.rb', line 201

def valid_range?
  colour >= 0 && colour <= 255
end