39 lines
1.0 KiB
JavaScript
39 lines
1.0 KiB
JavaScript
/*
|
|
* This file is part of the Kimai time-tracking app.
|
|
*
|
|
* For the full copyright and license information, please view the LICENSE
|
|
* file that was distributed with this source code.
|
|
*/
|
|
|
|
/*!
|
|
* [KIMAI] KimaiColor: handle colors
|
|
*/
|
|
|
|
export default class KimaiColor {
|
|
|
|
/**
|
|
* @param {string} hexcolor
|
|
* @return {string}
|
|
*/
|
|
static calculateContrastColor(hexcolor)
|
|
{
|
|
if (hexcolor.slice(0, 1) === '#') {
|
|
hexcolor = hexcolor.slice(1);
|
|
}
|
|
|
|
if (hexcolor.length === 3) {
|
|
hexcolor = hexcolor.split('').map(function (hex) { return hex + hex; }).join('');
|
|
}
|
|
|
|
const r = parseInt(hexcolor.substring(0,2),16);
|
|
const g = parseInt(hexcolor.substring(2,4),16);
|
|
const b = parseInt(hexcolor.substring(4,6),16);
|
|
|
|
// https://gomakethings.com/dynamically-changing-the-text-color-based-on-background-color-contrast-with-vanilla-js/
|
|
const yiq = ((r * 299) + (g * 587) + (b * 114)) / 1000;
|
|
|
|
return (yiq >= 128) ? '#000000' : '#ffffff';
|
|
}
|
|
|
|
}
|