Function parseOsc11BackgroundColor

src/core/themeDetection.ts:44–65

(sequence: string)

/** Parse common OSC 11 background-color responses into RGB. */
export function parseOsc11BackgroundColor(sequence: string): RgbColor | null {
  const rgbMatch =
    /\x1b\]11;rgb:([0-9a-f]{2,4})\/([0-9a-f]{2,4})\/([0-9a-f]{2,4})(?:\x07|\x1b\\)/i.exec(sequence);
  if (rgbMatch) {
    const red = parseHexChannel(rgbMatch[1]!);
    const green = parseHexChannel(rgbMatch[2]!);
    const blue = parseHexChannel(rgbMatch[3]!);
    return red === null || green === null || blue === null ? null : { red, green, blue };
  }

  const hexMatch = /\x1b\]11;#([0-9a-f]{6})(?:\x07|\x1b\\)/i.exec(sequence);
  if (!hexMatch) {
    return null;
  }

  const [, hex] = hexMatch;
  return {
    red: Number.parseInt(hex!.slice(0, 2), 16),
    green: Number.parseInt(hex!.slice(2, 4), 16),
    blue: Number.parseInt(hex!.slice(4, 6), 16),
  };
}

/** Classify a background color using relative luminance. */
export function themeModeForBackgroundColor({ red, green, blue }: RgbColor): TerminalThemeMode {