http://www.hiromimatsumoto.com/assets/scripts/vlt-helpers.js

1/***********************************************
2 * VLThemes
3 ***********************************************/
4
5'use strict';
6
7/**
8 * Initialize main helper object
9 */
10var VLTJS = {
11	window: jQuery(window),
12	document: jQuery(document),
13	html: jQuery('html'),
14	body: jQuery('body'),
15	is_safari: /^((?!chrome|android).)*safari/i.test(navigator.userAgent),
16	is_firefox: navigator.userAgent.toLowerCase().indexOf('firefox') > -1,
17	is_chrome: /Chrome/.test(navigator.userAgent) && /Google Inc/.test(navigator.vendor),
18	is_ie10: navigator.appVersion.indexOf('MSIE 10') !== -1,
19	transitionEnd: 'transitionend webkitTransitionEnd oTransitionEnd otransitionend MSTransitionEnd',
20	animIteration: 'animationiteration webkitAnimationIteration oAnimationIteration MSAnimationIteration',
21	animationEnd: 'animationend webkitAnimationEnd'
22};
23
24/**
25 * Detects whether user is viewing site from a mobile device
26 */
27VLTJS.isMobile = {
28	Android: function () {
29		return navigator.userAgent.match(/Android/i);
30	},
31	BlackBerry: function () {
32		return navigator.userAgent.match(/BlackBerry/i);
33	},
34	iOS: function () {
35		return navigator.userAgent.match(/iPhone|iPad|iPod/i);
36	},
37	Opera: function () {
38		return navigator.userAgent.match(/Opera Mini/i);
39	},
40	Windows: function () {
41		return navigator.userAgent.match(/IEMobile/i);
42	},
43	any: function () {
44		return (VLTJS.isMobile.Android() || VLTJS.isMobile.BlackBerry() || VLTJS.isMobile.iOS() || VLTJS.isMobile.Opera() || VLTJS.isMobile.Windows());
45	}
46};
47
48/**
49 * Debounce resize
50 */
51var resizeArr = [];
52var resizeTimeout;
53VLTJS.window.on('load resize orientationchange', function(e) {
54	if (resizeArr.length) {
55		clearTimeout(resizeTimeout);
56		resizeTimeout = setTimeout(function() {
57			for (var i = 0; i < resizeArr.length; i++) {
58				resizeArr[i](e);
59			}
60		}, 250);
61	}
62});
63
64VLTJS.debounceResize = function(callback) {
65	if (typeof callback === 'function') {
66		resizeArr.push(callback);
67	} else {
68		window.dispatchEvent(new Event('resize'));
69	}
70}
71
72VLTJS.addLedingZero = function (number) {
73	return ('0' + number).slice(-2);
74}
75
76/**
77 * Throttle scroll
78 */
79var throttleArr = [];
80var didScroll;
81var delta = 5;
82var lastScrollTop = 0;
83
84VLTJS.window.on('load resize scroll orientationchange', function() {
85	if (throttleArr.length) {
86		didScroll = true;
87	}
88});
89
90function hasScrolled() {
91
92	var scrollTop = VLTJS.window.scrollTop(),
93		windowHeight = VLTJS.window.height(),
94		documentHeight = VLTJS.document.height(),
95		scrollState = '';
96
97	// Make sure they scroll more than delta
98	if (Math.abs(lastScrollTop - scrollTop) <= delta) {
99		return;
100	}
101
102	if (scrollTop > lastScrollTop) {
103		scrollState = 'down';
104	} else if (scrollTop < lastScrollTop) {
105		scrollState = 'up';
106	} else {
107		scrollState = 'none';
108	}
109
110	if (scrollTop === 0) {
111		scrollState = 'start';
112	} else if (scrollTop >= documentHeight - windowHeight) {
113		scrollState = 'end';
114	}
115
116	for (var i in throttleArr) {
117		if (typeof throttleArr[i] === 'function') {
118			throttleArr[i](scrollState, scrollTop, lastScrollTop, VLTJS.window);
119		}
120	}
121
122	lastScrollTop = scrollTop;
123}
124
125setInterval(function() {
126	if (didScroll) {
127		didScroll = false;
128		window.requestAnimationFrame(hasScrolled);
129	}
130}, 250);
131
132VLTJS.throttleScroll = function(callback) {
133	if (typeof callback === 'function') {
134		throttleArr.push(callback);
135	}
136}
137
138/**
139 * VAR polyfill
140 */
141if (typeof cssVars !== 'undefined') {
142	cssVars({
143		onlyVars: true,
144	});
145}