https://www.amen.nl/cache/1_1125zyk3afxh2.2b64eb4f5960.js

1/**
2 * @author		Peter Slagter
3 * @author		Ryan Fioravanti
4 * @source		http://code.google.com/mobile/articles/fast_buttons.html
5 */
6
7window.PbLib = window.PbLib || {};
8PbLib.UI = PbLib.UI || {};
9PbLib.UI.clickbuster = PbLib.UI.clickbuster || {};
10
11/** Construct the FastButton with a reference to the element and click handler. */
12PbLib.UI.FastTap = function(element, handler) {
13	this.element = element;
14	this.handler = handler;
15
16	element.addEventListener('touchstart', this, false);
17	element.addEventListener('click', this, false);
18};
19
20PbLib.UI.FastTap.prototype.handleEvent = function(event) {
21	switch (event.type) {
22		case 'touchstart':
23			this.onTouchStart(event);
24			break;
25		case 'touchmove':
26			this.onTouchMove(event);
27			break;
28		case 'touchend':
29			this.onClick(event);
30			break;
31		case 'click':
32			this.onClick(event);
33			break;
34	}
35};
36
37/**
38 * Save a reference to the touchstart coordinate and start listening to touchmove and touchend events.
39 * Calling stopPropagation guarantees that other behaviors don't get a chance to handle the same click event.
40 */
41
42PbLib.UI.FastTap.prototype.onTouchStart = function(event) {
43	event.stopPropagation();
44
45	this.element.addEventListener('touchend', this, false);
46	document.body.addEventListener('touchmove', this, false);
47
48	this.startX = event.touches[0].clientX;
49	this.startY = event.touches[0].clientY;
50};
51
52/** When a touchmove event is invoked, check if the user has dragged past the threshold of 10px. */
53PbLib.UI.FastTap.prototype.onTouchMove = function(event) {
54	if (Math.abs(event.touches[0].clientX - this.startX) > 10 ||
55			Math.abs(event.touches[0].clientY - this.startY) > 10) {
56		this.reset();
57	}
58};
59
60/** Invoke the actual click handler and prevent ghost clicks if this was a touchend event. */
61PbLib.UI.FastTap.prototype.onClick = function(event) {
62	event.stopPropagation();
63	this.reset();
64	this.handler(event);
65
66	if (event.type == 'touchend') {
67		PbLib.UI.clickbuster.preventGhostClick(this.startX, this.startY);
68	}
69};
70
71PbLib.UI.FastTap.prototype.reset = function() {
72	this.element.removeEventListener('touchend', this, false);
73	document.body.removeEventListener('touchmove', this, false);
74};
75
76PbLib.UI.FastTap.prototype.removeHandler = function() {
77	this.element.removeEventListener('touchstart', this, false);
78	this.element.removeEventListener('click', this, false);
79};
80
81/** Call preventGhostClick to bust all click events that happen within 25px of the provided x, y coordinates in the next 2.5s. */
82PbLib.UI.clickbuster.preventGhostClick = function(x, y) {
83	PbLib.UI.clickbuster.coordinates.push(x, y);
84	window.setTimeout(PbLib.UI.clickbuster.pop, 2500);
85};
86
87PbLib.UI.clickbuster.pop = function () {
88	PbLib.UI.clickbuster.coordinates.splice(0, 2);
89};
90
91/**
92 * If we catch a click event inside the given radius and time threshold then we call stopPropagation and preventDefault.
93 * Calling preventDefault will stop links from being activated.
94 */
95
96PbLib.UI.clickbuster.onClick = function(event) {
97	for (var i = 0; i < PbLib.UI.clickbuster.coordinates.length; i += 2) {
98		var x = PbLib.UI.clickbuster.coordinates[i];
99		var y = PbLib.UI.clickbuster.coordinates[i + 1];
100		if (Math.abs(event.clientX - x) < 25 && Math.abs(event.clientY - y) < 25) {
101			event.stopPropagation();
102			event.preventDefault();
103		}
104	}
105};
106
107if (document.addEventListener) {
108	document.addEventListener('click', PbLib.UI.clickbuster.onClick, true);
109}
110
111PbLib.UI.clickbuster.coordinates = [];