Class: Sass::Script::Color

Inherits:
Literal show all
Extends:
Sass::Util
Defined in:
/var/www/sass-pages/.sass/lib/sass/script/color.rb

Overview

A SassScript object representing a CSS color.

A color may be represented internally as RGBA, HSLA, or both. It’s originally represented as whatever its input is; if it’s created with RGB values, it’s represented as RGBA, and if it’s created with HSL values, it’s represented as HSLA. Once a property is accessed that requires the other representation – for example, #red for an HSL color – that component is calculated and cached.

The alpha channel of a color is independent of its RGB or HSL representation. It’s always stored, as 1 if nothing else is specified. If only the alpha channel is modified using #with, the cached RGB and HSL values are retained.

Constant Summary

Instance Method Summary

Methods inherited from Literal

#==, #_perform, #assert_int!, #children, #comma, #deep_copy, #neq, #options, #single_eq, #space, #to_a, #to_bool, #to_i, #unary_div, #unary_minus, #unary_not, #unary_plus

Methods inherited from Node

#_perform, #children, #dasherize, #deep_copy, #opts, #perform

Constructor Details

- initialize(attrs) - initialize(rgba)

Constructs an RGB or HSL color object, optionally with an alpha channel.

The RGB values must be between 0 and 255. The saturation and lightness values must be between 0 and 100. The alpha value must be between 0 and 1.

Overloads:

  • - initialize(attrs)

    The attributes are specified as a hash. This hash must contain either :hue, :saturation, and :value keys, or :red, :green, and :blue keys. It cannot contain both HSL and RGB keys. It may also optionally contain an :alpha key.

    Parameters:

    • ({Symbol => Numeric}) attrs — A hash of color attributes to values

    Raises:

    • (ArgumentError) — if not enough attributes are specified, or both RGB and HSL attributes are specified
  • - initialize(rgba)

    The attributes are specified as an array. This overload only supports RGB or RGBA colors.

    Parameters:

    • (Array<Numeric>) rgba — A three- or four-element array of the red, green, blue, and optionally alpha values (respectively) of the color

    Raises:

    • (ArgumentError) — if not enough attributes are specified

Raises:



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# File '/var/www/sass-pages/.sass/lib/sass/script/color.rb', line 71

def initialize(attrs, allow_both_rgb_and_hsl = false)
  super(nil)

  if attrs.is_a?(Array)
    unless (3..4).include?(attrs.size)
      raise ArgumentError.new("Color.new(array) expects a three- or four-element array")
    end

    red, green, blue = attrs[0...3].map {|c| c.to_i}
    @attrs = {:red => red, :green => green, :blue => blue}
    @attrs[:alpha] = attrs[3] ? attrs[3].to_f : 1
  else
    attrs = attrs.reject {|k, v| v.nil?}
    hsl = [:hue, :saturation, :lightness] & attrs.keys
    rgb = [:red, :green, :blue] & attrs.keys
    if !allow_both_rgb_and_hsl && !hsl.empty? && !rgb.empty?
      raise ArgumentError.new("Color.new(hash) may not have both HSL and RGB keys specified")
    elsif hsl.empty? && rgb.empty?
      raise ArgumentError.new("Color.new(hash) must have either HSL or RGB keys specified")
    elsif !hsl.empty? && hsl.size != 3
      raise ArgumentError.new("Color.new(hash) must have all three HSL values specified")
    elsif !rgb.empty? && rgb.size != 3
      raise ArgumentError.new("Color.new(hash) must have all three RGB values specified")
    end

    @attrs = attrs
    @attrs[:hue] %= 360 if @attrs[:hue]
    @attrs[:alpha] ||= 1
  end

  [:red, :green, :blue].each do |k|
    next if @attrs[k].nil?
    @attrs[k] = @attrs[k].to_i
    Sass::Util.check_range("#{k.to_s.capitalize} value", 0..255, @attrs[k])
  end

  [:saturation, :lightness].each do |k|
    next if @attrs[k].nil?
    value = Number.new(@attrs[k], ['%']) # Get correct unit for error messages
    @attrs[k] = Sass::Util.check_range("#{k.to_s.capitalize}", 0..100, value, '%')
  end

  @attrs[:alpha] = Sass::Util.check_range("Alpha channel", 0..1, @attrs[:alpha])
end

Instance Method Details

- (Fixnum) alpha

The alpha channel (opacity) of the color. This is 1 unless otherwise defined.

Returns:

  • (Fixnum) 


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# File '/var/www/sass-pages/.sass/lib/sass/script/color.rb', line 168

def alpha
  @attrs[:alpha]
end

- (Boolean) alpha?

Returns whether this color object is translucent; that is, whether the alpha channel is non-1.

Returns:

  • (Boolean) 


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# File '/var/www/sass-pages/.sass/lib/sass/script/color.rb', line 176

def alpha?
  alpha < 1
end

- (Fixnum) blue

The blue component of the color.

Returns:

  • (Fixnum) 


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# File '/var/www/sass-pages/.sass/lib/sass/script/color.rb', line 135

def blue
  hsl_to_rgb!
  @attrs[:blue]
end

- (Color) div(other)

The SassScript / operation. Its functionality depends on the type of its argument:

Number
Divides each of the RGB color channels by the number.
Color
Divides each of this color’s RGB color channels by the other color’s.
Literal
See Literal#div.

Parameters:

  • (Literal) other — The right-hand side of the operator

Returns:

  • (Color) — The resulting color

Raises:



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# File '/var/www/sass-pages/.sass/lib/sass/script/color.rb', line 330

def div(other)
  if other.is_a?(Sass::Script::Number) || other.is_a?(Sass::Script::Color)
    piecewise(other, :/)
  else
    super
  end
end

- (Bool) eq(other)

The SassScript == operation. Note that this returns a Sass::Script::Bool object, not a Ruby boolean.

Parameters:

  • (Literal) other — The right-hand side of the operator

Returns:

  • (Bool) — True if this literal is the same as the other, false otherwise 


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# File '/var/www/sass-pages/.sass/lib/sass/script/color.rb', line 203

def eq(other)
  Sass::Script::Bool.new(
    other.is_a?(Color) && rgb == other.rgb && alpha == other.alpha)
end

- (Fixnum) green

The green component of the color.

Returns:

  • (Fixnum) 


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# File '/var/www/sass-pages/.sass/lib/sass/script/color.rb', line 127

def green
  hsl_to_rgb!
  @attrs[:green]
end

- (Array<Fixnum>) hsl

Returns the hue, saturation, and lightness components of the color.

Returns:

  • (Array<Fixnum>) — A frozen three-element array of the hue, saturation, and lightness values (respectively) of the color 


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# File '/var/www/sass-pages/.sass/lib/sass/script/color.rb', line 192

def hsl
  [hue, saturation, lightness].freeze
end

- (Numeric) hue

The hue component of the color.

Returns:

  • (Numeric) 


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# File '/var/www/sass-pages/.sass/lib/sass/script/color.rb', line 143

def hue
  rgb_to_hsl!
  @attrs[:hue]
end

- (String) inspect

Returns a string representation of the color.

Returns:



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# File '/var/www/sass-pages/.sass/lib/sass/script/color.rb', line 374

def inspect
  alpha? ? rgba_str : hex_str
end

- (Numeric) lightness

The lightness component of the color.

Returns:

  • (Numeric) 


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# File '/var/www/sass-pages/.sass/lib/sass/script/color.rb', line 159

def lightness
  rgb_to_hsl!
  @attrs[:lightness]
end

- (Color) minus(other)

The SassScript - operation. Its functionality depends on the type of its argument:

Number
Subtracts the number from each of the RGB color channels.
Color
Subtracts each of the other color’s RGB color channels from this color’s.
Literal
See Literal#minus.

Parameters:

  • (Literal) other — The right-hand side of the operator

Returns:

  • (Color) — The resulting color

Raises:



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# File '/var/www/sass-pages/.sass/lib/sass/script/color.rb', line 287

def minus(other)
  if other.is_a?(Sass::Script::Number) || other.is_a?(Sass::Script::Color)
    piecewise(other, :-)
  else
    super
  end
end

- (Color) mod(other)

The SassScript % operation. Its functionality depends on the type of its argument:

Number
Takes each of the RGB color channels module the number.
Color
Takes each of this color’s RGB color channels modulo the other color’s.

Parameters:

  • (Number, Color) other — The right-hand side of the operator

Returns:

  • (Color) — The resulting color

Raises:



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# File '/var/www/sass-pages/.sass/lib/sass/script/color.rb', line 350

def mod(other)
  if other.is_a?(Sass::Script::Number) || other.is_a?(Sass::Script::Color)
    piecewise(other, :%)
  else
    raise NoMethodError.new(nil, :mod)
  end
end

- (Color) plus(other)

The SassScript + operation. Its functionality depends on the type of its argument:

Number
Adds the number to each of the RGB color channels.
Color
Adds each of the RGB color channels together.
Literal
See Literal#plus.

Parameters:

  • (Literal) other — The right-hand side of the operator

Returns:

  • (Color) — The resulting color

Raises:



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# File '/var/www/sass-pages/.sass/lib/sass/script/color.rb', line 264

def plus(other)
  if other.is_a?(Sass::Script::Number) || other.is_a?(Sass::Script::Color)
    piecewise(other, :+)
  else
    super
  end
end

- (Fixnum) red

The red component of the color.

Returns:

  • (Fixnum) 


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# File '/var/www/sass-pages/.sass/lib/sass/script/color.rb', line 119

def red
  hsl_to_rgb!
  @attrs[:red]
end

- (Array<Fixnum>) rgb

Returns the red, green, and blue components of the color.

Returns:

  • (Array<Fixnum>) — A frozen three-element array of the red, green, and blue values (respectively) of the color 


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# File '/var/www/sass-pages/.sass/lib/sass/script/color.rb', line 184

def rgb
  [red, green, blue].freeze
end

- (Numeric) saturation

The saturation component of the color.

Returns:

  • (Numeric) 


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# File '/var/www/sass-pages/.sass/lib/sass/script/color.rb', line 151

def saturation
  rgb_to_hsl!
  @attrs[:saturation]
end

- (Color) times(other)

The SassScript * operation. Its functionality depends on the type of its argument:

Number
Multiplies the number by each of the RGB color channels.
Color
Multiplies each of the RGB color channels together.

Parameters:

  • (Number, Color) other — The right-hand side of the operator

Returns:

  • (Color) — The resulting color

Raises:



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# File '/var/www/sass-pages/.sass/lib/sass/script/color.rb', line 307

def times(other)
  if other.is_a?(Sass::Script::Number) || other.is_a?(Sass::Script::Color)
    piecewise(other, :*)
  else
    raise NoMethodError.new(nil, :times)
  end
end

- (String) to_s(opts = {}) Also known as: to_sass

Returns a string representation of the color. This is usually the color’s hex value, but if the color has a name that’s used instead.

Returns:

  • (String) — The string representation 


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# File '/var/www/sass-pages/.sass/lib/sass/script/color.rb', line 363

def to_s(opts = {})
  return rgba_str if alpha?
  return smallest if options[:style] == :compressed
  return HTML4_COLORS_REVERSE[rgb] if HTML4_COLORS_REVERSE[rgb]
  hex_str
end

- (Color) with(attrs)

Returns a copy of this color with one or more channels changed. RGB or HSL colors may be changed, but not both at once.

For example:

Color.new([10, 20, 30]).with(:blue => 40)
  #=> rgb(10, 40, 30)
Color.new([126, 126, 126]).with(:red => 0, :green => 255)
  #=> rgb(0, 255, 126)
Color.new([255, 0, 127]).with(:saturation => 60)
  #=> rgb(204, 51, 127)
Color.new([1, 2, 3]).with(:alpha => 0.4)
  #=> rgba(1, 2, 3, 0.4)

Parameters:

  • ({Symbol => Numeric}) attrs — A map of channel names (:red, :green, :blue, :hue, :saturation, :lightness, or :alpha) to values

Returns:

  • (Color) — The new Color object

Raises:

  • (ArgumentError) — if both RGB and HSL keys are specified 


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# File '/var/www/sass-pages/.sass/lib/sass/script/color.rb', line 227

def with(attrs)
  attrs = attrs.reject {|k, v| v.nil?}
  hsl = !([:hue, :saturation, :lightness] & attrs.keys).empty?
  rgb = !([:red, :green, :blue] & attrs.keys).empty?
  if hsl && rgb
    raise ArgumentError.new("Cannot specify HSL and RGB values for a color at the same time")
  end

  if hsl
    [:hue, :saturation, :lightness].each {|k| attrs[k] ||= send(k)}
  elsif rgb
    [:red, :green, :blue].each {|k| attrs[k] ||= send(k)}
  else
    # If we're just changing the alpha channel,
    # keep all the HSL/RGB stuff we've calculated
    attrs = @attrs.merge(attrs)
  end
  attrs[:alpha] ||= alpha

  Color.new(attrs, :allow_both_rgb_and_hsl)
end