https://www.lequotidien.com.tn/media/plg_system_sl_scrolltotop/js/scrolltotop_mt.js

1/**
2 * @copyright	Copyright (c) 2013 Skyline Software (http://extstore.com). All rights reserved.
3 * @license		GNU General Public License version 2 or later; see LICENSE.txt
4 */
5
6var Skyline_ScrollToTop	= new Class({
7	Implements: [Options],
8
9	options: {
10		'id':			'scrollToTop',
11		'className':	'scrollToTop',
12		'image':		'',
13		'text':			'^ Scroll to Top',
14		'title':		'Scroll to Top',
15		'transition':	Fx.Transitions.linear,
16		'duration':		500
17	},
18
19	initialize:	function(options) {
20		this.setOptions(options);
21
22		// Create scroll FX
23		this.scrollFx	= new Fx.Scroll(window, {
24			transition:	this.options.transition,
25			duration:	this.options.duration
26		});
27
28		// Create 'Scroll to Top' link and insert it to body
29		this.scrollLink	= new Element('a', {
30			'id':		this.options.id,
31			'html':		this.options.text,
32			'title':	this.options.title,
33			'class':	this.options.className,
34			'styles': {
35				'visibility': 	'hidden',
36				'opacity':		0
37			},
38			'events': {
39				// Scroll to top on click
40				click: function() {
41					this.scrollFx.toTop();
42				}.bind(this)
43			}
44		}).inject(document.id(document.body));
45
46		if (this.options.image != '') {
47			new Element('img', {
48				'src':	this.options.image,
49				'alt':	this.options.title
50			}).inject(this.scrollLink, 'top');
51		}
52
53		// Show/Hide 'Scroll to Top' link
54		if (window.getScrollTop() != 0) {
55			this.scrollLink.fade(1);
56		}
57
58		window.addEvent('scroll', function() {
59			var flag = this.scrollLink.getStyle('visibility') == 'visible';
60
61			if (window.getScrollTop() != 0 && !flag) {
62				this.scrollLink.fade(1);
63			} else if (window.getScrollTop() == 0 && flag) {
64				this.scrollLink.fade(0);
65			}
66		}.bind(this));
67	}
68});