https://tyrone-power.com/js/styleswitcher.js

1// Styles Switcher
2jQuery(document).ready(function(){
3
4	// Show Colors Panel
5	jQuery('#show-panel').click(function(){
6		if(jQuery(this).hasClass('show-panel')) {
7			jQuery('.colors-switcher').css({'right': 0});
8			jQuery('#show-panel').removeClass('show-panel');
9			jQuery('#show-panel').addClass('hide-panel');
10		}else if(jQuery(this).hasClass('hide-panel')) {
11			jQuery('.colors-switcher').css({'right': '-100px'});
12			jQuery('#show-panel').removeClass('hide-panel');
13			jQuery('#show-panel').addClass('show-panel');
14		}
15	});
16	
17});
18
19function setActiveStyleSheet(title) {
20  var i, a, main;
21  for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
22    if(a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute("title")) {
23      a.disabled = true;
24      if(a.getAttribute("title") == title) a.disabled = false;
25    }
26  }
27}
28
29function getActiveStyleSheet() {
30  var i, a;
31  for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
32    if(a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute("title") && !a.disabled) return a.getAttribute("title");
33  }
34  return null;
35}
36
37function getPreferredStyleSheet() {
38  var i, a;
39  for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
40    if(a.getAttribute("rel").indexOf("style") != -1
41       && a.getAttribute("rel").indexOf("alt") == -1
42       && a.getAttribute("title")
43       ) return a.getAttribute("title");
44  }
45  return null;
46}
47
48function createCookie(name,value,days) {
49  if (days) {
50    var date = new Date();
51    date.setTime(date.getTime()+(days*24*60*60*1000));
52    var expires = "; expires="+date.toGMTString();
53  }
54  else expires = "";
55  document.cookie = name+"="+value+expires+"; path=/";
56}
57
58function readCookie(name) {
59  var nameEQ = name + "=";
60  var ca = document.cookie.split(';');
61  for(var i=0;i < ca.length;i++) {
62    var c = ca[i];
63    while (c.charAt(0)==' ') c = c.substring(1,c.length);
64    if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
65  }
66  return null;
67}
68
69window.onload = function(e) {
70  var cookie = readCookie("style");
71  var title = cookie ? cookie : getPreferredStyleSheet();
72  setActiveStyleSheet(title);
73}
74
75window.onunload = function(e) {
76  var title = getActiveStyleSheet();
77  createCookie("style", title, 365);
78}
79
80var cookie = readCookie("style");
81var title = cookie ? cookie : getPreferredStyleSheet();
82setActiveStyleSheet(title);
83