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<?php |
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/** |
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* @copyright Copyright (c) 2016 Julius Härtl <[email protected]> |
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* |
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* @license GNU AGPL version 3 or any later version |
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* |
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* This program is free software: you can redistribute it and/or modify |
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* it under the terms of the GNU Affero General Public License as |
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* published by the Free Software Foundation, either version 3 of the |
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* License, or (at your option) any later version. |
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* |
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* This program is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU Affero General Public License for more details. |
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* |
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* You should have received a copy of the GNU Affero General Public License |
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* along with this program. If not, see <http://www.gnu.org/licenses/>. |
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* |
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*/ |
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namespace OCA\Theming; |
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class Util { |
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/** |
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* @param string $color rgb color value |
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* @return bool |
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*/ |
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public static function invertTextColor($color) { |
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$l = self::calculateLuminance($color); |
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if($l>0.5) { |
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return true; |
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} else { |
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return false; |
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} |
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} |
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/** |
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* @param string $color rgb color value |
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* @return float |
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*/ |
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public static function calculateLuminance($color) { |
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$hex = preg_replace("/[^0-9A-Fa-f]/", '', $color); |
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if (strlen($hex) === 3) { |
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$hex = $hex{0} . $hex{0} . $hex{1} . $hex{1} . $hex{2} . $hex{2}; |
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} |
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if (strlen($hex) !== 6) { |
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return 0; |
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} |
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$r = hexdec(substr($hex, 0, 2)); |
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$g = hexdec(substr($hex, 2, 2)); |
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$b = hexdec(substr($hex, 4, 2)); |
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return (0.299 * $r + 0.587 * $g + 0.114 * $b)/255; |
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} |
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} |
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