Class: Dvl::Color::Generator

Inherits:
Object
  • Object
show all
Defined in:
lib/dvl/color/generator.rb

Constant Summary collapse

DARK_BACKGROUND_CUTOFF = 
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Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(background_color) ⇒ Generator

Returns a new instance of Generator.

Parameters:

  • background_color (Chroma::Color or String) 


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# File 'lib/dvl/color/generator.rb', line 12

def initialize(background_color)
  self.background_color = background_color

  unless background_color.is_a?(Chroma::Color)
    self.background_color = Chroma.paint(background_color)
  end

  self.input_background, self.input_background_focus, self.input_color = generate_input_colors
  self.dropdown_background, self.dropdown_color = generate_dropdown_colors
end

Instance Attribute Details

#background_color ⇒ Object

Returns the value of attribute background_color.



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# File 'lib/dvl/color/generator.rb', line 4

def background_color
  @background_color
end

#dropdown_background ⇒ Object

Returns the value of attribute dropdown_background.



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# File 'lib/dvl/color/generator.rb', line 4

def dropdown_background
  @dropdown_background
end

#dropdown_color ⇒ Object

Returns the value of attribute dropdown_color.



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# File 'lib/dvl/color/generator.rb', line 4

def dropdown_color
  @dropdown_color
end

#input_background ⇒ Object

Returns the value of attribute input_background.



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# File 'lib/dvl/color/generator.rb', line 4

def input_background
  @input_background
end

#input_background_focus ⇒ Object

Returns the value of attribute input_background_focus.



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# File 'lib/dvl/color/generator.rb', line 4

def input_background_focus
  @input_background_focus
end

#input_color ⇒ Object

Returns the value of attribute input_color.



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# File 'lib/dvl/color/generator.rb', line 4

def input_color
  @input_color
end

Instance Method Details

#base_color ⇒ Object 



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# File 'lib/dvl/color/generator.rb', line 84

def base_color
  @base_color ||= begin
    text = background_color.dup

    # If the background is dark, we lighten it.
    # If the background is light, we darken it.
    amt = if background_color.brightness < DARK_BACKGROUND_CUTOFF # Dark
            1
          else
            -1
          end

    target = target_contrast_ratio

    while contrast(background_color, text) < target
      new_text = text.lighten(amt)

      # prevent infinite loop
      break if text == new_text

      text = new_text
    end

    # If the background is a conservative color, use a conservative
    # (desaturated) text color.

    if conservative_background_dark? || conservative_background_light?
      hsl = text.hsl
      hsl.s = hsl.s * 0.15
      text = Chroma.paint(hsl)
    end

    text
  end
end

#black ⇒ Object 



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# File 'lib/dvl/color/generator.rb', line 195

def black
  Chroma.paint('#000')
end

#conservative_background_dark? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/dvl/color/generator.rb', line 66

def conservative_background_dark?
  background_color.brightness < 52
end

#conservative_background_light? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/dvl/color/generator.rb', line 70

def conservative_background_light?
  background_color.brightness > 229
end

#error_bubble_background ⇒ Object 



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# File 'lib/dvl/color/generator.rb', line 171

def error_bubble_background
  if error_color.brightness > 200
    white
  else
    error_color
  end
end

#error_bubble_color ⇒ Object 



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# File 'lib/dvl/color/generator.rb', line 179

def error_bubble_color
  if error_bubble_background == white
    background_color
  else
    white
  end
end

#error_color ⇒ Object 



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# File 'lib/dvl/color/generator.rb', line 120

def error_color
  @error_color ||= begin
    error = background_color.dup

    # Spin the color wheel until we land on "red"
    amt = if error.hsl.h > 180
            15
          else
            -15
          end

    while !red?(error)
      error = error.spin(amt)
    end

    # White
    if background_color == white
      error = Chroma.paint('d95b76')
    # Black
    elsif background_color == black
      error = Chroma.paint('d95b76')
    # Grayscale
    elsif error.hsl.s == 0
      error = error.saturate(100)
    # Otherwise, ensure saturation is at least 0.4, or else it's not really red...
    elsif error.hsl.s < 0.4
      hsl = error.hsl
      hsl.s = 0.4
      error = Chroma.paint(hsl)
    elsif conservative_background_light?
      hsl = error.hsl
      hsl.l = hsl.l - 0.4
      error = Chroma.paint(hsl)
    end

    amt = if background_color.brightness < 100
            2
          else
            -2
          end

    while contrast(error, background_color) < 2.5
      new_error = error.lighten(amt)
      break if error == new_error
      error = new_error
    end

    error
  end
end

#generate_dropdown_colors ⇒ Object 



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# File 'lib/dvl/color/generator.rb', line 187

def generate_dropdown_colors
  if background_color.brightness < DARK_BACKGROUND_CUTOFF
    [base_color, background_color]
  else
    [background_color, base_color]
  end
end

#target_contrast_ratio ⇒ Object 



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# File 'lib/dvl/color/generator.rb', line 74

def target_contrast_ratio
  if conservative_background_dark?
    13
  elsif conservative_background_light?
    10
  else
    7
  end
end

#to_debug_s ⇒ Object 



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# File 'lib/dvl/color/generator.rb', line 46

def to_debug_s
  str = []

  to_h.each do |k, v|
    str << "#{k}: #{v}"
  end

  str << "Background brightness: #{background_color.brightness}"

  str << "Ratio: #{contrast(background_color, base_color).round(2)}"
  str << "Error Ratio: #{contrast(background_color, error_color).round(2)}"
  str << "Error Bubble Ratio: #{contrast(error_bubble_background, error_bubble_color).round(2)}"
  str << "Input ratio: #{contrast(input_background, input_color).round(2)}"
  str << "Error satur: #{error_color.hsl.s.round(2)}"
  str << "Conservative light: #{conservative_background_light?}"
  str << "Conservative dark: #{conservative_background_dark?}"

  str.join("<br>")
end

#to_h ⇒ Object 



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# File 'lib/dvl/color/generator.rb', line 23

def to_h
  {
    backgroundColor: background_color.to_hex,
    baseColor: base_color.to_hex,
    errorColor: error_color.to_hex,
    errorBubbleBackground: error_bubble_background.to_hex,
    errorBubbleColor: error_bubble_color.to_hex,
    inputBackground: input_background.to_hex,
    inputBackgroundFocus: input_background_focus.to_hex,
    inputColor: input_color.to_hex,
    dropdownBackground: dropdown_background.to_hex,
    dropdownColor: dropdown_color.to_hex
  }
end

#to_scss ⇒ Object 



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# File 'lib/dvl/color/generator.rb', line 38

def to_scss
  ''.tap do |str|
    to_h.each do |k, v|
      str << "$#{k}:#{v};"
    end
  end
end

#white ⇒ Object 



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# File 'lib/dvl/color/generator.rb', line 199

def white
  Chroma.paint('#fff')
end