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Diffstat (limited to 'apps/theming/lib/util.php')
| -rw-r--r-- | apps/theming/lib/util.php | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/apps/theming/lib/util.php b/apps/theming/lib/util.php new file mode 100644 index 00000000000..8ff5ae89b14 --- /dev/null +++ b/apps/theming/lib/util.php @@ -0,0 +1,57 @@ +<?php +/** + * @copyright Copyright (c) 2016 Julius Härtl <jus@bitgrid.net> + * + * @license GNU AGPL version 3 or any later version + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License as + * published by the Free Software Foundation, either version 3 of the + * License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + */ + +namespace OCA\Theming; + +class Util { + + /** + * @param string $color rgb color value + * @return bool + */ + public static function invertTextColor($color) { + $l = self::calculateLuminance($color); + if($l>0.5) { + return true; + } else { + return false; + } + } + + /** + * @param string $color rgb color value + * @return float + */ + public static function calculateLuminance($color) { + $hex = preg_replace("/[^0-9A-Fa-f]/", '', $color); + if (strlen($hex) === 3) { + $hex = $hex{0} . $hex{0} . $hex{1} . $hex{1} . $hex{2} . $hex{2}; + } + if (strlen($hex) !== 6) { + return 0; + } + $r = hexdec(substr($hex, 0, 2)); + $g = hexdec(substr($hex, 2, 2)); + $b = hexdec(substr($hex, 4, 2)); + return (0.299 * $r + 0.587 * $g + 0.114 * $b)/255; + } + +} |