Class: Sass::Script::Value::Color

Inherits:
Base
  • Object
show all
Defined in:
/Users/ceppstei/Projects/sass-lang/.sass/lib/sass/script/value/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 Attribute Summary (collapse)

Attributes inherited from Base

#options, #source_range, #value

Class Method Summary (collapse)

Instance Method Summary (collapse)

Methods inherited from Base

#==, #_perform, #assert_int!, #eql?, #neq, #null?, #separator, #single_eq, #to_a, #to_bool, #to_h, #to_i, #unary_div, #unary_minus, #unary_not, #unary_plus

Constructor Details

- (Color) initialize(attrs) - (Color) initialize(rgba, [representation])

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

RGB values are clipped within 0 and 255. Saturation and lightness values are clipped within 0 and 100. The alpha value is clipped within 0 and 1.

Overloads:

  • - (Color) initialize(attrs)

    The attributes are specified as a hash. This hash must contain either :hue, :saturation, and :lightness keys, or :red, :green, and :blue keys. It cannot contain both HSL and RGB keys. It may also optionally contain an :alpha key, and a :representation key indicating the original representation of the color that the user wrote in their stylesheet.

    Parameters:

    • attrs ({Symbol => Numeric}) —

      A hash of color attributes to values

    Raises:

    • (ArgumentError) —

      if not enough attributes are specified, or both RGB and HSL attributes are specified

  • - (Color) initialize(rgba, [representation])

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

    Parameters:

    • rgba (Array<Numeric>) —

      A three- or four-element array of the red, green, blue, and optionally alpha values (respectively) of the color

    • representation (String) —

      The original representation of the color that the user wrote in their stylesheet.

    Raises:

    • (ArgumentError) —

      if not enough attributes are specified

Raises:



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# File '/Users/ceppstei/Projects/sass-lang/.sass/lib/sass/script/value/color.rb', line 229

def initialize(attrs, representation = nil, 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| Sass::Util.round(c)}
    @attrs = {:red => red, :green => green, :blue => blue}
    @attrs[:alpha] = attrs[3] ? attrs[3].to_f : 1
    @representation = representation
  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
    @representation = @attrs.delete(:representation)
  end

  [:red, :green, :blue].each do |k|
    next if @attrs[k].nil?
    @attrs[k] = Sass::Util.restrict(Sass::Util.round(@attrs[k]), 0..255)
  end

  [:saturation, :lightness].each do |k|
    next if @attrs[k].nil?
    @attrs[k] = Sass::Util.restrict(@attrs[k], 0..100)
  end

  @attrs[:alpha] = Sass::Util.restrict(@attrs[:alpha], 0..1)
end

Instance Attribute Details

- (String) representation (readonly)

The user’s original representation of the color.

Returns:



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# File '/Users/ceppstei/Projects/sass-lang/.sass/lib/sass/script/value/color.rb', line 196

def representation
  @representation
end

Class Method Details

+ (Color) from_hex(hex_string, alpha = nil)

Create a new color from a valid CSS hex string.

The leading hash is optional.

Returns:



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# File '/Users/ceppstei/Projects/sass-lang/.sass/lib/sass/script/value/color.rb', line 279

def self.from_hex(hex_string, alpha = nil)
  unless hex_string =~ /^#?([0-9a-f]{2})([0-9a-f]{2})([0-9a-f]{2})$/i ||
         hex_string =~ /^#?([0-9a-f])([0-9a-f])([0-9a-f])$/i
    raise ArgumentError.new("#{hex_string.inspect} is not a valid hex color.")
  end
  red   = $1.ljust(2, $1).to_i(16)
  green = $2.ljust(2, $2).to_i(16)
  blue  = $3.ljust(2, $3).to_i(16)

  hex_string = "##{hex_string}" unless hex_string[0] == ?#
  attrs = {:red => red, :green => green, :blue => blue, :representation => hex_string}
  attrs[:alpha] = alpha if alpha
  new(attrs)
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 '/Users/ceppstei/Projects/sass-lang/.sass/lib/sass/script/value/color.rb', line 346

def alpha
  @attrs[:alpha].to_f
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 '/Users/ceppstei/Projects/sass-lang/.sass/lib/sass/script/value/color.rb', line 354

def alpha?
  alpha < 1
end

- (Fixnum) blue

The blue component of the color.

Returns:

  • (Fixnum) 


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# File '/Users/ceppstei/Projects/sass-lang/.sass/lib/sass/script/value/color.rb', line 313

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.
Sass::Script::Value::Color
Divides each of this color’s RGB color channels by the other color’s.
Sass::Script::Value
See Base#div.

Parameters:

  • other (Value) —

    The right-hand side of the operator

Returns:

  • (Color) —

    The resulting color

Raises:



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# File '/Users/ceppstei/Projects/sass-lang/.sass/lib/sass/script/value/color.rb', line 528

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

- (Bool) eq(other)

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

Parameters:

  • other (Value) —

    The right-hand side of the operator

Returns:

  • (Bool) —

    True if this value is the same as the other, false otherwise



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# File '/Users/ceppstei/Projects/sass-lang/.sass/lib/sass/script/value/color.rb', line 397

def eq(other)
  Sass::Script::Value::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 '/Users/ceppstei/Projects/sass-lang/.sass/lib/sass/script/value/color.rb', line 305

def green
  hsl_to_rgb!
  @attrs[:green]
end

- hash 



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# File '/Users/ceppstei/Projects/sass-lang/.sass/lib/sass/script/value/color.rb', line 402

def hash
  [rgb, alpha].hash
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 '/Users/ceppstei/Projects/sass-lang/.sass/lib/sass/script/value/color.rb', line 378

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

- (Array<Fixnum>) hsla

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

Returns:

  • (Array<Fixnum>) —

    A frozen four-element array of the hue, saturation, lightness, and alpha values (respectively) of the color



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# File '/Users/ceppstei/Projects/sass-lang/.sass/lib/sass/script/value/color.rb', line 386

def hsla
  [hue, saturation, lightness, alpha].freeze
end

- (Numeric) hue

The hue component of the color.

Returns:

  • (Numeric) 


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# File '/Users/ceppstei/Projects/sass-lang/.sass/lib/sass/script/value/color.rb', line 321

def hue
  rgb_to_hsl!
  @attrs[:hue]
end

- (String) inspect

Returns a string representation of the color.

Returns:



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# File '/Users/ceppstei/Projects/sass-lang/.sass/lib/sass/script/value/color.rb', line 574

def inspect
  alpha? ? rgba_str : hex_str
end

- (Numeric) lightness

The lightness component of the color.

Returns:

  • (Numeric) 


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# File '/Users/ceppstei/Projects/sass-lang/.sass/lib/sass/script/value/color.rb', line 337

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.
Sass::Script::Value::Color
Subtracts each of the other color’s RGB color channels from this color’s.
Sass::Script::Value
See Base#minus.

Parameters:

  • other (Value) —

    The right-hand side of the operator

Returns:

  • (Color) —

    The resulting color

Raises:



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# File '/Users/ceppstei/Projects/sass-lang/.sass/lib/sass/script/value/color.rb', line 485

def minus(other)
  if other.is_a?(Sass::Script::Value::Number) || other.is_a?(Sass::Script::Value::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.
Sass::Script::Value::Color
Takes each of this color’s RGB color channels modulo the other color’s.

Parameters:

  • other (Number, Color) —

    The right-hand side of the operator

Returns:

  • (Color) —

    The resulting color

Raises:



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# File '/Users/ceppstei/Projects/sass-lang/.sass/lib/sass/script/value/color.rb', line 549

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

- (String?) name

Returns the color’s name, if it has one.

Returns:



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# File '/Users/ceppstei/Projects/sass-lang/.sass/lib/sass/script/value/color.rb', line 581

def name
  COLOR_NAMES_REVERSE[rgba]
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.
Sass::Script::Value::Color
Adds each of the RGB color channels together.
Sass::Script::Value
See Base#plus.

Parameters:

  • other (Value) —

    The right-hand side of the operator

Returns:

  • (Color) —

    The resulting color

Raises:



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# File '/Users/ceppstei/Projects/sass-lang/.sass/lib/sass/script/value/color.rb', line 462

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

- (Fixnum) red

The red component of the color.

Returns:

  • (Fixnum) 


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# File '/Users/ceppstei/Projects/sass-lang/.sass/lib/sass/script/value/color.rb', line 297

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 '/Users/ceppstei/Projects/sass-lang/.sass/lib/sass/script/value/color.rb', line 362

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

- (Array<Fixnum>) rgba

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

Returns:

  • (Array<Fixnum>) —

    A frozen four-element array of the red, green, blue, and alpha values (respectively) of the color



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# File '/Users/ceppstei/Projects/sass-lang/.sass/lib/sass/script/value/color.rb', line 370

def rgba
  [red, green, blue, alpha].freeze
end

- (Numeric) saturation

The saturation component of the color.

Returns:

  • (Numeric) 


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# File '/Users/ceppstei/Projects/sass-lang/.sass/lib/sass/script/value/color.rb', line 329

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.
Sass::Script::Value::Color
Multiplies each of the RGB color channels together.

Parameters:

  • other (Number, Color) —

    The right-hand side of the operator

Returns:

  • (Color) —

    The resulting color

Raises:



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# File '/Users/ceppstei/Projects/sass-lang/.sass/lib/sass/script/value/color.rb', line 505

def times(other)
  if other.is_a?(Sass::Script::Value::Number) || other.is_a?(Sass::Script::Value::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 '/Users/ceppstei/Projects/sass-lang/.sass/lib/sass/script/value/color.rb', line 563

def to_s(opts = {})
  return smallest if options[:style] == :compressed
  return representation if representation
  return name if name
  alpha? ? rgba_str : 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:

  • attrs ({Symbol => Numeric}) —

    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 '/Users/ceppstei/Projects/sass-lang/.sass/lib/sass/script/value/color.rb', line 425

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, nil, :allow_both_rgb_and_hsl)
end