helper->user->getInitials($user['name'] ?: $user['username']); $rgb = $this->getBackgroundColor($user['name'] ?: $user['username']); return sprintf( '

', $rgb[0], $rgb[1], $rgb[2], $this->helper->text->e($user['name'] ?: $user['username']), $initials ); } /** * Determine if the provider is active * * @access public * @param array $user * @return boolean */ public function isActive(array $user) { return true; } /** * Get background color based on a string * * @param string $str * @return array */ public function getBackgroundColor($str) { $hsl = $this->getHSL($str); return $this->getRGB($hsl[0], $hsl[1], $hsl[2]); } /** * Convert HSL to RGB * * @access protected * @param integer $hue Hue ∈ [0, 360) * @param integer $saturation Saturation ∈ [0, 1] * @param integer $lightness Lightness ∈ [0, 1] * @return array */ protected function getRGB($hue, $saturation, $lightness) { $hue /= 360; $q = $lightness < 0.5 ? $lightness * (1 + $saturation) : $lightness + $saturation - $lightness * $saturation; $p = 2 * $lightness - $q; return array_map(function ($color) use ($q, $p) { if ($color < 0) { $color++; } if ($color > 1) { $color--; } if ($color < 1/6) { $color = $p + ($q - $p) * 6 * $color; } else if ($color < 0.5) { $color = $q; } else if ($color < 2/3) { $color = $p + ($q - $p) * 6 * (2/3 - $color); } else { $color = $p; } return round($color * 255); }, array($hue + 1/3, $hue, $hue - 1/3)); } /** * Returns the hash in [h, s, l]. * Note that H ∈ [0, 360); S ∈ [0, 1]; L ∈ [0, 1]; * * @access protected * @param string $str * @return int[] */ protected function getHSL($str) { $hash = $this->hash($str); $hue = $hash % 359; $hash = intval($hash / 360); $saturation = $this->saturation[$hash % count($this->saturation)]; $hash = intval($hash / count($this->saturation)); $lightness = $this->lightness[$hash % count($this->lightness)]; return array($hue, $saturation, $lightness); } /** * BKDR Hash (modified version) * * @access protected * @param string $str * @return integer */ protected function hash($str) { $seed = 131; $seed2 = 137; $hash = 0; // Make hash more sensitive for short string like 'a', 'b', 'c' $str .= 'x'; $max = intval(9007199254740991 / $seed2); for ($i = 0, $ilen = mb_strlen($str, 'UTF-8'); $i < $ilen; $i++) { if ($hash > $max) { $hash = intval($hash / $seed2); } $hash = $hash * $seed + $this->getCharCode(mb_substr($str, $i, 1, 'UTF-8')); } return $hash; } /** * Backport of Javascript function charCodeAt() * * @access protected * @param string $c * @return integer */ protected function getCharCode($c) { list(, $ord) = unpack('N', mb_convert_encoding($c, 'UCS-4BE', 'UTF-8')); return $ord; } }