Touch move getting stuck Ignored attempt to cancel a touchmove
I'm messing around with touch events on a touch slider and I keep getting the following error:
Ignored attempt to cancel a touchmove event with cancelable=false, for example because scrolling is in progress and cannot be interrupted.
I'm not sure what is causing this problem, I am new to working with touch events and can't seem to fix this problem.
Here is the code handling the touch event:
Slider.prototype.isSwipe = function(threshold) {
return Math.abs(deltaX) > Math.max(threshold, Math.abs(deltaY));
}
Slider.prototype.touchStart = function(e) {
if (this._isSliding) return false;
touchMoving = true;
deltaX = deltaY = 0;
if (e.originalEvent.touches.length === 1) {
startX = e.originalEvent.touches[0].pageX;
startY = e.originalEvent.touches[0].pageY;
this._$slider.on('touchmove touchcancel', this.touchMove.bind(this)).one('touchend', this.touchEnd.bind(this));
isFlick = true;
window.setTimeout(function() {
isFlick = false;
}, flickTimeout);
}
}
Slider.prototype.touchMove = function(e) {
deltaX = startX - e.originalEvent.touches[0].pageX;
deltaY = startY - e.originalEvent.touches[0].pageY;
if(this.isSwipe(swipeThreshold)) {
e.preventDefault();
e.stopPropagation();
swiping = true;
}
if(swiping) {
this.slide(deltaX / this._sliderWidth, true)
}
}
Slider.prototype.touchEnd = function(e) {
var threshold = isFlick ? swipeThreshold : this._sliderWidth / 2;
if (this.isSwipe(threshold)) {
deltaX < 0 ? this.prev() : this.next();
}
else {
this.slide(0, !deltaX);
}
swiping = false;
this._$slider.off('touchmove', this.touchMove).one(transitionend, $.proxy(function() {
this.slide(0, true);
touchMoving = false;
}, this));
}
You can find the actual slider here at this pen.
If you swipe through fast enough it will throw the error and sometimes get stuck in the middle of a swipe. Still can't wrap my head around why it is not working. Any help/insight would be greatly appreciated. Not sure what I am doing wrong.
Solution 1:
The event must be cancelable
. Adding an if
statement solves this issue.
if (e.cancelable) {
e.preventDefault();
}
In your code you should put it here:
if (this.isSwipe(swipeThreshold) && e.cancelable) {
e.preventDefault();
e.stopPropagation();
swiping = true;
}
Solution 2:
I had this problem and all I had to do is return true
from touchend and the warning went away.
Solution 3:
I know this is an old post but I had a lot of issues trying to solve this and I finally did so I wanted to share.
My issue was that I was adding an event listener within the ontouchstart and removing it in the ontouchend functions - something like this
function onTouchStart() {
window.addEventListener("touchmove", handleTouchMove, {
passive: false
});
}
function onTouchEnd() {
window.removeEventListener("touchmove", handleTouchMove, {
passive: true
});
}
function handleTouchMove(e) {
e.preventDefault();
}
For some reason adding it removing it like this was causing this issue of the event randomly not being cancelable. So to solve this I kept the listener active and toggled a boolean on whether or not it should prevent the event - something like this:
let stopScrolling = false;
window.addEventListener("touchmove", handleTouchMove, {
passive: false
});
function handleTouchMove(e) {
if (!stopScrolling) {
return;
}
e.preventDefault();
}
function onTouchStart() {
stopScrolling = true;
}
function onTouchEnd() {
stopScrolling = false;
}
I was actually using React so my solution involved setting state, but I've simplified it for a more generic solution. Hopefully this helps someone!
Solution 4:
Calling preventDefault
on touchmove
while you're actively scrolling is not working in Chrome. To prevent performance issues, you cannot interrupt a scroll.
Try to call preventDefault()
from touchstart
and everything should be ok.
Solution 5:
Please remove e.preventDefault()
, because event.cancelable
of touchmove is false
.
So you can't call this method.