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/**
* ownCloud
*
* @author John Molakvoæ
* @copyright 2016 John Molakvoæ <fremulon@protonmail.com>
* @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:
*
* $('#albumart').imageplaceholder('The Album Title', 'Album Title');
*
* Resulting in:
*
* <div id="albumart" style="background-color: hsl(123, 90%, 65%); ... ">A</div>
*
*/
/*
* Alternatively, you can use the prototype function to convert your string to hsl colors:
*
* "a6741a86aded5611a8e46ce16f2ad646".toHsl()
*
* Will return the hsl parameters within an array:
*
* [290, 60, 68]
*
*/
(function ($) {
String.prototype.toHsl = function() {
var hash = this.toLowerCase().replace(/[^0-9a-f]+/g, '');
// Already a md5 hash?
if( !hash.match(/^[0-9a-f]{32}$/g) ) {
hash = md5(hash);
}
function rgbToHsl(r, g, b) {
r /= 255; g /= 255; b /= 255;
var max = Math.max(r, g, b), min = Math.min(r, g, b);
var h, s, l = (max + min) / 2;
if(max === min) {
h = s = 0; // achromatic
} else {
var d = max - min;
s = l > 0.5 ? d / (2 - max - min) : d / (max + min);
switch(max) {
case r: h = (g - b) / d + (g < b ? 6 : 0); break;
case g: h = (b - r) / d + 2; break;
case b: h = (r - g) / d + 4; break;
}
h /= 6;
}
return [h, s, l];
}
// Init vars
var result = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0];
var rgb = [0, 0, 0];
var sat = 70;
var lum = 68;
var modulo = 16;
// Splitting evenly the string
for(var i in hash) {
result[i%modulo] = result[i%modulo] + parseInt(hash.charAt(i), 16).toString();
}
// Converting our data into a usable rgb format
// Start at 1 because 16%3=1 but 15%3=0 and makes the repartition even
for(var count=1;count<modulo;count++) {
rgb[count%3] += parseInt(result[count]);
}
// Reduce values bigger than rgb requirements
rgb[0] = rgb[0]%255;
rgb[1] = rgb[1]%255;
rgb[2] = rgb[2]%255;
var hsl = rgbToHsl(rgb[0], rgb[1], rgb[2]);
// Classic formulla to check the brigtness for our eye
// If too bright, lower the sat
var bright = Math.sqrt( 0.299 * Math.pow(rgb[0], 2) + 0.587 * Math.pow(rgb[1], 2) + 0.114 * Math.pow(rgb[2], 2) );
if (bright >= 200) {
sat = 60;
}
return [parseInt(hsl[0] * 360), sat, lum];
};
$.fn.imageplaceholder = function(seed, text, size) {
text = text || seed;
// Compute the hash
var hsl = seed.toHsl();
this.css('background-color', 'hsl('+hsl[0]+', '+hsl[1]+'%, '+hsl[2]+'%)');
// Placeholders are square
var height = this.height() || size || 32;
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());
}
};
$.fn.clearimageplaceholder = function() {
this.css('background-color', '');
this.css('color', '');
this.css('font-weight', '');
this.css('text-align', '');
this.css('line-height', '');
this.css('font-size', '');
};
}(jQuery));
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