问题
How to detect a long touch pressure with javascript for android and iphone? native javascript or jquery...
I want something that sound like :
<input type=\'button\' onLongTouch=\'myFunc();\' />
回答1:
The problem with using Touch End to detect the long touch is it won't work if you want the event to fire after a certain period of time. It is better to use a timer on touch start and clear the event timer on touch end. The following pattern can be used:
var onlongtouch;
var timer;
var touchduration = 500; //length of time we want the user to touch before we do something
touchstart() {
timer = setTimeout(onlongtouch, touchduration);
}
touchend() {
//stops short touches from firing the event
if (timer)
clearTimeout(timer); // clearTimeout, not cleartimeout..
}
onlongtouch = function() { //do something };
回答2:
Here is an extended version of Joshua answer, as his code works well till user doesn't perform multitouch (you can tap screen with two fingers and function will be triggered two times, 4 fingers - 4 times). After some additional test scenarios I even triggered possibility to touch very freequently and receive function executing after each tap.
I added variable named 'lockTimer' which should lock any additional touchstarts before user trigger 'touchend'.
var onlongtouch;
var timer, lockTimer;
var touchduration = 800; //length of time we want the user to touch before we do something
function touchstart(e) {
e.preventDefault();
if(lockTimer){
return;
}
timer = setTimeout(onlongtouch, touchduration);
lockTimer = true;
}
function touchend() {
//stops short touches from firing the event
if (timer){
clearTimeout(timer); // clearTimeout, not cleartimeout..
lockTimer = false;
}
}
onlongtouch = function() {
document.getElementById('ping').innerText+='ping\n';
};
document.addEventListener("DOMContentLoaded", function(event) {
window.addEventListener("touchstart", touchstart, false);
window.addEventListener("touchend", touchend, false);
});<div id="ping"></div>回答3:
I've done it this way in my Android app:
registered events listeners:
var touchStartTimeStamp = 0; var touchEndTimeStamp = 0; window.addEventListener('touchstart', onTouchStart,false); window.addEventListener('touchend', onTouchEnd,false);added functions:
var timer; function onTouchStart(e) { touchStartTimeStamp = e.timeStamp; } function onTouchEnd(e) { touchEndTimeStamp = e.timeStamp; console.log(touchEndTimeStamp - touchStartTimeStamp);// in miliseconds }checked time difference and did my stuff
I hope this will help.
回答4:
Right here: http://m14i.wordpress.com/2009/10/25/javascript-touch-and-gesture-events-iphone-and-android/
Use touchstart and touchend to detect long touch given a time
回答5:
For cross platform developers:
Mouseup/down seemed to work okay on android - but not all devices ie (samsung tab4). Did not work at all on iOS.
Further research its seems that this is due to the element having selection and the native magnification interupts the listener.
This event listener enables a thumbnail image to be opened in a bootstrap modal, if the user holds the image for 500ms.
It uses a responsive image class therefore showing a larger version of the image. This piece of code has been fully tested upon (iPad/Tab4/TabA/Galaxy4):
var pressTimer;
$(".thumbnail").on('touchend', function (e) {
clearTimeout(pressTimer);
}).on('touchstart', function (e) {
var target = $(e.currentTarget);
var imagePath = target.find('img').attr('src');
var title = target.find('.myCaption:visible').first().text();
$('#dds-modal-title').text(title);
$('#dds-modal-img').attr('src', imagePath);
// Set timeout
pressTimer = window.setTimeout(function () {
$('#dds-modal').modal('show');
}, 500)
});
回答6:
We can calculate the time difference when the touch started and when the touch end. If the calculated time difference exceed the touch duration then we use a function name taphold.
var touchduration = 300;
var timerInterval;
function timer(interval) {
interval--;
if (interval >= 0) {
timerInterval = setTimeout(function() {
timer(interval);
});
} else {
taphold();
}
}
function touchstart() {
timer(touchduration);
}
function touchend() {
clearTimeout(timerInterval);
}
function taphold(){
alert("taphold");
}
document.getElementById("xyz").addEventListener('touchstart',touchstart);
document.getElementById("xyz").addEventListener('touchend',touchend);
回答7:
Long tap event that working in all browser
(function (a) {
function n(b) { a.each("touchstart touchmove touchend touchcancel".split(/ /), function (d, e) { b.addEventListener(e, function () { a(b).trigger(e) }, false) }); return a(b) } function j(b) { function d() { a(e).data(h, true); b.type = f; jQuery.event.handle.apply(e, o) } if (!a(this).data(g)) { var e = this, o = arguments; a(this).data(h, false).data(g, setTimeout(d, a(this).data(i) || a.longclick.duration)) } } function k() { a(this).data(g, clearTimeout(a(this).data(g)) || null) } function l(b) {
if (a(this).data(h)) return b.stopImmediatePropagation() ||
false
} var p = a.fn.click; a.fn.click = function (b, d) { if (!d) return p.apply(this, arguments); return a(this).data(i, b || null).bind(f, d) }; a.fn.longclick = function () { var b = [].splice.call(arguments, 0), d = b.pop(); b = b.pop(); var e = a(this).data(i, b || null); return d ? e.click(b, d) : e.trigger(f) }; a.longclick = { duration: 500 }; a.event.special.longclick = {
setup: function () {
/iphone|ipad|ipod/i.test(navigator.userAgent) ? n(this).bind(q, j).bind([r, s, t].join(" "), k).bind(m, l).css({ WebkitUserSelect: "none" }) : a(this).bind(u, j).bind([v,
w, x, y].join(" "), k).bind(m, l)
}, teardown: function () { a(this).unbind(c) }
}; var f = "longclick", c = "." + f, u = "mousedown" + c, m = "click" + c, v = "mousemove" + c, w = "mouseup" + c, x = "mouseout" + c, y = "contextmenu" + c, q = "touchstart" + c, r = "touchend" + c, s = "touchmove" + c, t = "touchcancel" + c, i = "duration" + c, g = "timer" + c, h = "fired" + c
})(jQuery);
Bind longclick event with time interval
$('element').longclick(250, longClickHandler);
below function fire on Long Tap on touch device
function longClickHandler() {
alter('Long tap Fired');
}
来源：https://stackoverflow.com/questions/6139225/how-to-detect-a-long-touch-pressure-with-javascript-for-android-and-iphone