module Gtn::HashedColours

Public Class Methods

colour_tag (contents)

This function generates the CSS for a colour tag Params

contents

The contents of the tag

Returns

String

The CSS for the tag

Example

HashedColours.colour_tag("test") => "--color-primary: #f799ff; --color-darker: #f571ff; --color-dimmed: #f686ff;"

# File _plugins/colour-tags.rb, line 20
def self.colour_tag(contents)
  d = (Digest::SHA256.hexdigest contents).to_i(16)

  hue = ((d >> 4) % 360).abs
  lightnessOffset = 75
  lightness = lightnessOffset + (hash & 0xf)

  # randomly make yellow tags bright
  lightness += (100 - lightness) * 0.75 if (hue > 70) && (hue < 96) && ((d & 0x100) == 0x100)

  primary = Hsluv.hsluv_to_hex(hue, 100, lightness)
  darker = Hsluv.hsluv_to_hex(hue, 100, lightness * 0.9)
  dimmed = Hsluv.hsluv_to_hex(hue, 100, lightness * 0.95)

  "--color-primary: #{primary}; --color-darker: #{darker}; --color-dimmed: #{dimmed};"
end