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6 | Copyright CiviCRM LLC (c) 2004-2019 |
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8 | This file is a part of CiviCRM. |
10 | CiviCRM is free software; you can copy, modify, and distribute it |
11 | under the terms of the GNU Affero General Public License |
12 | Version 3, 19 November 2007 and the CiviCRM Licensing Exception. |
14 | CiviCRM is distributed in the hope that it will be useful, but |
15 | WITHOUT ANY WARRANTY; without even the implied warranty of |
16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
17 | See the GNU Affero General Public License for more details. |
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20 | License and the CiviCRM Licensing Exception along |
21 | with this program; if not, contact CiviCRM LLC |
22 | at info[AT]civicrm[DOT]org. If you have questions about the |
23 | GNU Affero General Public License or the licensing of CiviCRM, |
24 | see the CiviCRM license FAQ at http://civicrm.org/licensing |
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31 * @copyright CiviCRM LLC (c) 2004-2019
35 * Static utility functions for working with colors
37 class CRM_Utils_Color
{
40 * Determine the appropriate text color for a given background.
44 * @param string $hexcolor
45 * @param string $black
46 * @param string $white
49 public static function getContrast($hexcolor, $black = 'black', $white = 'white') {
50 list($r, $g, $b) = self
::getRgb($hexcolor);
51 $yiq = (($r * 299) +
($g * 587) +
($b * 114)) / 1000;
52 return ($yiq >= 128) ?
$black : $white;
56 * Convert hex color to decimal
58 * @param string $hexcolor
62 public static function getRgb($hexcolor) {
63 $hexcolor = trim($hexcolor, ' #');
64 if (strlen($hexcolor) === 3) {
65 $hexcolor = $hexcolor[0] . $hexcolor[0] . $hexcolor[1] . $hexcolor[1] . $hexcolor[2] . $hexcolor[2];
68 hexdec(substr($hexcolor, 0, 2)),
69 hexdec(substr($hexcolor, 2, 2)),
70 hexdec(substr($hexcolor, 4, 2)),
75 * Calculate a highlight color from a base color
80 public static function getHighlight($hexcolor) {
81 $rgb = CRM_Utils_Color
::getRgb($hexcolor);
82 $avg = array_sum($rgb) / 3;
83 foreach ($rgb as &$v) {
85 // For very bright values, lower the brightness
89 // Bump up brightness on a nonlinear curve - darker colors get more of a boost
90 $v = min(255, intval((-.0035 * ($v - 242) ** 2) +
260));
93 return '#' . implode(array_map('dechex', $rgb));