class ColorHex

class ColorHex extends ColorBase {
    
    /**
     * The Hex triplet of the color.
     *
     * @var int
     */
    private $color;
    
    /**
     * Create a new Hex from a string.
     *
     * @param string $color
     *   The string hex value (i.e. "FFFFFF").
     * @param string $opacity
     *   The opacity value.
     *
     * @throws Exception
     */
    public function __construct($color, $opacity) {
        $color = trim(strtolower($color));
        if (substr($color, 0, 1) === '#') {
            $color = substr($color, 1);
        }
        if (strlen($color) === 3) {
            $color = str_repeat($color[0], 2) . str_repeat($color[1], 2) . str_repeat($color[2], 2);
        }
        if (!preg_match('/[0-9A-F]{6}/i', $color)) {
            // @throws exception.
        }
        $this->color = hexdec($color);
        $this->setOpacity(floatval($opacity));
        return $this;
    }
    
    /**
     * A string representation of this color in the current format.
     *
     * @param bool $opacity
     *   Whether or not to display the opacity.
     *
     * @return string
     *   The color in format: #RRGGBB.
     */
    public function toString($opacity = TRUE) {
        $rgb = $this->toRgb();
        $hex = '#';
        $hex .= str_pad(dechex($rgb->getRed()), 2, "0", STR_PAD_LEFT);
        $hex .= str_pad(dechex($rgb->getGreen()), 2, "0", STR_PAD_LEFT);
        $hex .= str_pad(dechex($rgb->getBlue()), 2, "0", STR_PAD_LEFT);
        if ($opacity) {
            $hex .= ' ' . $this->getOpacity();
        }
        return strtolower($hex);
    }
    
    /**
     * {@inheritdoc}
     */
    public function toHex() {
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function toRgb() {
        $red = ($this->color & 0xff0000) >> 16;
        $green = ($this->color & 0xff00) >> 8;
        $blue = $this->color & 0xff;
        $opacity = $this->getOpacity();
        return new ColorRGB($red, $green, $blue, $opacity);
    }
    
    /**
     * {@inheritdoc}
     */
    public function toHsl() {
        return $this->toRGB()
            ->toHsl();
    }

}