server/core/js/placeholder.js
Roeland Jago Douma 2fc458479e [Avatars] Calculate 'sane' hue precissions
We used to get the numeric value of the entrire md5 string which is a
128bit integer. We would then devide this by the maxval of a 128bit int.

There is no need for such huge computations. As we just require a value
between 0 and 255. Thus using two 16 bit values is more than enough to
get the precision we need. By just taking the MSB we get nearly
identical results.
2015-12-24 10:50:12 +01:00

77 lines
2.2 KiB
JavaScript

/**
* ownCloud
*
* @author Morris Jobke
* @copyright 2013 Morris Jobke <morris.jobke@gmail.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
* License as published by the Free Software Foundation; either
* version 3 of the License, or any later version.
*
* This library 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 library. If not, see <http://www.gnu.org/licenses/>.
*
*/
/*
* Adds a background color to the element called on and adds the first character
* of the passed in string. This string is also the seed for the generation of
* the background color.
*
* You have following HTML:
*
* <div id="albumart"></div>
*
* And call this from Javascript:
*
* $('#albumart').imageplaceholder('The Album Title');
*
* Which will result in:
*
* <div id="albumart" style="background-color: hsl(123, 90%, 65%); ... ">T</div>
*
* You may also call it like this, to have a different background, than the seed:
*
* $('#albumart').imageplaceholder('The Album Title', 'Album Title');
*
* Resulting in:
*
* <div id="albumart" style="background-color: hsl(123, 90%, 65%); ... ">A</div>
*
*/
(function ($) {
$.fn.imageplaceholder = function(seed, text, size) {
// set optional argument "text" to value of "seed" if undefined
text = text || seed;
var hash = md5(seed).substring(0, 4),
maxRange = parseInt('ffff', 16),
hue = parseInt(hash, 16) / maxRange * 256,
height = this.height() || size || 32;
this.css('background-color', 'hsl(' + hue + ', 90%, 65%)');
// Placeholders are square
this.height(height);
this.width(height);
// CSS rules
this.css('color', '#fff');
this.css('font-weight', 'normal');
this.css('text-align', 'center');
// calculate the height
this.css('line-height', height + 'px');
this.css('font-size', (height * 0.55) + 'px');
if(seed !== null && seed.length) {
this.html(text[0].toUpperCase());
}
};
}(jQuery));