Class: Studio::ThemeResolver

Inherits:
Object
  • Object
show all
Defined in:
lib/studio/theme_resolver.rb

Constant Summary collapse

ROLES = 
%i[primary dark light success warning danger accent].freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(colors = {}) ⇒ ThemeResolver

colors: hash of role => hex string (e.g. { primary: "#8E82FE", dark: "#1A1535", ... })



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# File 'lib/studio/theme_resolver.rb', line 8

def initialize(colors = {})
  @colors = colors.symbolize_keys
end

Instance Attribute Details

#colors ⇒ Object (readonly)

Returns the value of attribute colors.



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# File 'lib/studio/theme_resolver.rb', line 5

def colors
  @colors
end

Instance Method Details

#contrast_ink(base, direction:, start:, target:, against:) ⇒ Object

Bounded, clamped search: raise the blend amount from start until the ink clears target contrast against every background in against. Clamps at 1.0 (pure white/black), so a pathological base degrades to the best achievable ink instead of looping.



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# File 'lib/studio/theme_resolver.rb', line 102

def contrast_ink(base, direction:, start:, target:, against:)
  amount = start
  loop do
    ink = direction == :lighten ? ColorScale.lighten(base, amount) : ColorScale.darken(base, amount)
    return ink if against.all? { |bg| ColorScale.contrast_ratio(ink, bg) >= target } || amount >= 1.0

    amount = [amount + 0.02, 1.0].min
  end
end

#dark_mode_vars ⇒ Object 



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# File 'lib/studio/theme_resolver.rb', line 30

def dark_mode_vars
  dark_base   = colors[:dark] || "#1A1535"
  primary     = colors[:primary] || "#8E82FE"
  border_rgb  = ColorScale.lighten(dark_base, 0.30)
  danger      = colors[:danger] || "#EF4444"

  {
    "--color-page"           => dark_base,
    "--color-surface"        => ColorScale.lighten(dark_base, 0.15),
    "--color-surface-alt"    => ColorScale.darken(dark_base, 0.14),
    "--color-inset"          => ColorScale.darken(dark_base, 0.43),
    "--color-text"           => "#ffffff",
    "--color-text-body"      => "#e2e8f0",
    # Derived by a bounded contrast search, not hardcoded: fixed slate
    # grays fail WCAG on themes whose dark base lifts the surface (a
    # hardcoded #64748b measured 2.14:1 on a navy surface), and any FIXED
    # blend amount is tuned to particular hexes — the operator can pick an
    # arbitrary base in the theme editor. contrast_ink walks the blend up
    # until the ink clears its target on every emitted dark surface
    # (clamped at pure white for pathological bases). Note the blend
    # DESATURATES toward gray; only strongly-tinted bases keep a cast.
    "--color-text-secondary" => contrast_ink(dark_base, direction: :lighten, start: 0.70, target: 4.5,
                                             against: dark_surfaces(dark_base)),
    "--color-text-muted"     => contrast_ink(dark_base, direction: :lighten, start: 0.55, target: 3.0,
                                             against: dark_surfaces(dark_base)),
    "--color-border"         => ColorScale.with_opacity(border_rgb, 0.2),
    "--color-border-strong"  => ColorScale.with_opacity(border_rgb, 0.4),
    "--color-shadow"         => "transparent",
    "--color-cta"            => primary,
    "--color-cta-hover"      => ColorScale.darken(primary, 0.30),
    "--color-success"        => colors[:success] || "#4BAF50",
    "--color-warning"        => colors[:warning] || "#FF7C47",
    "--color-danger"         => danger,
    # THE DANGER *INK*, which is not the danger *colour*. --color-danger is a
    # brand fill (button backgrounds, borders) and is free to be vivid;
    # --color-danger-ink is the same red used as TEXT, where it must clear
    # WCAG AA 4.5:1 on every surface it can land on.
    #
    # No STATIC red clears AA on BOTH themes — measured: text-red-300 is
    # 1.92:1 light / 5.81 dark, text-red-400 2.77 / 4.03, #EF4444 3.76 / 2.96,
    # text-red-600 4.77 / 2.34. So it is DERIVED per theme by the same bounded
    # search that already produces --color-text-secondary and --color-text-muted.
    #
    # start: 0.0 is deliberate — the search tries the operator's actual danger
    # colour FIRST and blends only as far as AA demands, so a theme whose red
    # already passes keeps its exact brand hex.
    "--color-danger-ink"     => contrast_ink(danger, direction: :lighten, start: 0.0, target: 4.5,
                                             against: dark_surfaces(dark_base)),
    "--color-accent"         => colors[:accent] || "#F72585"
  }
end

#dark_surfaces(dark_base) ⇒ Object

Every dark-mode background a text var can sit on (page, surface, surface-alt, inset) — the ink must clear its target on ALL of them.



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# File 'lib/studio/theme_resolver.rb', line 84

def dark_surfaces(dark_base)
  [ dark_base,
    ColorScale.lighten(dark_base, 0.15),
    ColorScale.darken(dark_base, 0.14),
    ColorScale.darken(dark_base, 0.43) ]
end

#light_mode_vars ⇒ Object 



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# File 'lib/studio/theme_resolver.rb', line 132

def light_mode_vars
  light_base = colors[:light] || "#f8fafc"
  primary    = colors[:primary] || "#8E82FE"
  danger     = colors[:danger] || "#EF4444"

  {
    "--color-page"           => light_base,
    "--color-surface"        => "#ffffff",
    "--color-surface-alt"    => ColorScale.darken(light_base, 0.03),
    "--color-inset"          => ColorScale.darken(light_base, 0.08),
    "--color-text"           => "#0f172a",
    "--color-text-body"      => "#334155",
    # Same bounded search as dark mode: the old fixed grays measured as
    # low as 2.05:1 (muted on --color-inset) — below the very defect this
    # derivation exists to prevent. Ink darkens away from the light base.
    "--color-text-secondary" => contrast_ink(light_base, direction: :darken, start: 0.55, target: 4.5,
                                             against: light_surfaces(light_base)),
    "--color-text-muted"     => contrast_ink(light_base, direction: :darken, start: 0.40, target: 3.0,
                                             against: light_surfaces(light_base)),
    "--color-border"         => ColorScale.darken(light_base, 0.08),
    "--color-border-strong"  => ColorScale.darken(light_base, 0.15),
    "--color-shadow"         => "rgba(0,0,0,0.05)",
    "--color-cta"            => primary,
    "--color-cta-hover"      => ColorScale.darken(primary, 0.30),
    "--color-success"        => colors[:success] || "#4BAF50",
    "--color-warning"        => colors[:warning] || "#FF7C47",
    "--color-danger"         => danger,
    # THE DANGER *INK*, which is not the danger *colour*. --color-danger is a
    # brand fill (button backgrounds, borders) and is free to be vivid;
    # --color-danger-ink is the same red used as TEXT, where it must clear
    # WCAG AA 4.5:1 on every surface it can land on.
    #
    # No STATIC red clears AA on BOTH themes — measured: text-red-300 is
    # 1.92:1 light / 5.81 dark, text-red-400 2.77 / 4.03, #EF4444 3.76 / 2.96,
    # text-red-600 4.77 / 2.34. So it is DERIVED per theme by the same bounded
    # search that already produces --color-text-secondary and --color-text-muted.
    #
    # start: 0.0 is deliberate — the search tries the operator's actual danger
    # colour FIRST and blends only as far as AA demands, so a theme whose red
    # already passes keeps its exact brand hex.
    "--color-danger-ink"     => contrast_ink(danger, direction: :darken, start: 0.0, target: 4.5,
                                             against: light_surfaces(light_base)),
    "--color-accent"         => colors[:accent] || "#F72585"
  }
end

#light_surfaces(light_base) ⇒ Object 



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# File 'lib/studio/theme_resolver.rb', line 91

def light_surfaces(light_base)
  [ light_base,
    "#ffffff",
    ColorScale.darken(light_base, 0.03),
    ColorScale.darken(light_base, 0.08) ]
end

#primary_palette_vars ⇒ Object

Generate --color-primary-Studio::ThemeResolver.50.50..900 + RGB variants for Tailwind opacity support



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# File 'lib/studio/theme_resolver.rb', line 113

def primary_palette_vars
  primary = colors[:primary] || "#8E82FE"
  scale = ColorScale.generate(primary)
  vars = {}

  scale.each do |shade, hex|
    vars["--color-primary-#{shade}"] = hex
    r, g, b = ColorScale.hex_to_rgb(hex)
    vars["--color-primary-#{shade}-rgb"] = "#{r} #{g} #{b}"
  end

  # DEFAULT aliases
  r, g, b = ColorScale.hex_to_rgb(primary)
  vars["--color-primary"] = primary
  vars["--color-primary-rgb"] = "#{r} #{g} #{b}"

  vars
end

#to_css ⇒ Object 



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# File 'lib/studio/theme_resolver.rb', line 12

def to_css
  dark_vars  = dark_mode_vars.map { |k, v| "  #{k}: #{v};" }.join("\n")
  light_vars = light_mode_vars.map { |k, v| "  #{k}: #{v};" }.join("\n")
  palette_vars = primary_palette_vars.map { |k, v| "  #{k}: #{v};" }.join("\n")

  <<~CSS
    :root, .dark {
    #{dark_vars}
    #{palette_vars}
    }

    html:not(.dark) {
    #{light_vars}
    #{palette_vars}
    }
  CSS
end