122

Ok with this.. 

$(window).scroll(function()
{
    $('.slides_layover').removeClass('showing_layover');
    $('#slides_effect').show();
});

I can tell when someone is scrolling from what I understand. So with that I am trying to figure out how to catch when someone has stopped. From the above example you can see I am removing a class from a set of elements while the scrolling is occurring. However, I want to put that class back on when the user stops scrolling.

The reason for this is I am intent on having a layover show while the page is scrolling to give the page a special effect I am attempting to work on. But the one class I am trying to remove while scrolling conflicts with that effect as its a transparency effect to some nature.

Brian Tompsett - 汤莱恩
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chris
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    possible duplicate of [fire event after scrollling scrollbars or mousewheel javascript](http://stackoverflow.com/questions/8931605/fire-event-after-scrollling-scrollbars-or-mousewheel-javascript) – Rob W Feb 04 '12 at 21:11
  • Awesome, not exactly duplicate but definitively up the alley of what I was looking for and helped me in the end solve my issue. Thank you. – chris Feb 04 '12 at 22:05

13 Answers13

267
$(window).scroll(function() {
    clearTimeout($.data(this, 'scrollTimer'));
    $.data(this, 'scrollTimer', setTimeout(function() {
        // do something
        console.log("Haven't scrolled in 250ms!");
    }, 250));
});

Update

I wrote an extension to enhance jQuery's default on-event-handler. It attaches an event handler function for one or more events to the selected elements and calls the handler function if the event was not triggered for a given interval. This is useful if you want to fire a callback only after a delay, like the resize event, or such.

It is important to check the github-repo for updates!

https://github.com/yckart/jquery.unevent.js

;(function ($) {
    var on = $.fn.on, timer;
    $.fn.on = function () {
        var args = Array.apply(null, arguments);
        var last = args[args.length - 1];

        if (isNaN(last) || (last === 1 && args.pop())) return on.apply(this, args);

        var delay = args.pop();
        var fn = args.pop();

        args.push(function () {
            var self = this, params = arguments;
            clearTimeout(timer);
            timer = setTimeout(function () {
                fn.apply(self, params);
            }, delay);
        });

        return on.apply(this, args);
    };
}(this.jQuery || this.Zepto));

Use it like any other on or bind-event handler, except that you can pass an extra parameter as a last:

$(window).on('scroll', function(e) {
    console.log(e.type + '-event was 250ms not triggered');
}, 250);

http://yckart.github.com/jquery.unevent.js/

(this demo uses resize instead of scroll, but who cares?!)

yckart
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  • It's still not 100% accurate: sometimes user stops and resumes scrolling even after 250 ms – Arman Bimatov Jan 13 '14 at 23:52
  • This code works great, but it broke jquery ui's autocomplete widget totally. – kkazakov Feb 04 '15 at 07:16
  • @ArmanBimatov then it will be considered as the user keeps scrolling, which sounds good, no? – godblessstrawberry May 25 '16 at 15:32
  • This timeout only fires when scroll events stops and NOT when the user stops scrolling. The user can lift their finger from the mouse and scrolling can continue for a few seconds depending on the speed of their scrolling. This solution will not give you an indication when the user has stopped scrolling. – Johann Jun 30 '17 at 11:47
  • @yckart thanks for your work. but a thing... setTimouts breaks context binding. so inside handler function there is no access to the context... I couldn't find any workaround for that. Can you edit it to support that? – Manoochehr Dadashi Oct 23 '17 at 17:38
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    @abzarak this abstract helper isn't perfect, in no case! I haven't updated the github-repo recently, for reasons — this was an terrible idea. Just use a "throttle" or "debounce" wrapper function instead. I should note that somewhere else too! :) – yckart Oct 25 '17 at 10:16
54

Using jQuery throttle / debounce

jQuery debounce is a nice one for problems like this. jsFidlle

$(window).scroll($.debounce( 250, true, function(){
    $('#scrollMsg').html('SCROLLING!');
}));
$(window).scroll($.debounce( 250, function(){
    $('#scrollMsg').html('DONE!');
}));

The second parameter is the "at_begin" flag. Here I've shown how to execute code both at "scroll start" and "scroll finish".

Using Lodash

As suggested by Barry P, jsFiddle, underscore or lodash also have a debounce, each with slightly different apis.

$(window).scroll(_.debounce(function(){
    $('#scrollMsg').html('SCROLLING!');
}, 150, { 'leading': true, 'trailing': false }));

$(window).scroll(_.debounce(function(){
    $('#scrollMsg').html('STOPPED!');
}, 150));
Sinetheta
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  • Is it possible to utilise a normal scroll function at the same time? $(window).scroll(function(){ ... }); – danVnest May 16 '13 at 10:46
  • Of course, jQuery will bind as many handlers to an event as you'd like. – Sinetheta May 16 '13 at 21:26
  • Thanks for updating this @BarryP Jsfiddle also provides lo-dash so you can avoid the external link http://jsfiddle.net/qjggnyhf/ – Sinetheta Sep 14 '14 at 01:19
  • FYI, I was having issues where rapid scrolls were not reverting back. It seemed that you needed to add a few milliseconds to the "STOPPED" debounce, else it causes a race condition where, sometime, the STOPPED triggers before the STARTED, and you end up with the item stuck as if you are still scrolling. I made mine 150 and 160, respectively, and it seemed to do the trick. – CodeChimp May 24 '16 at 22:04
  • Thanks @CodeChimp that's neat, but I'd worried about handling edge cases by fixing them 15 out of 16 times ;) Maybe a single handler with all of the logic inside would be safest. Check the `leading` and `trailing` yourself, then be sure that there can be no confusion. – Sinetheta May 24 '16 at 22:15
  • @Sinetheta, you are absolutely right. One method to rule them all would not only be cleaner, but it seems safer. – CodeChimp May 24 '16 at 22:21
  • ➕100 if it was possible. – Chris Marisic Jul 28 '16 at 21:33
10

Rob W suggected I check out another post here on stack that was essentially a similar post to my original one. Which reading through that I found a link to a site:

http://james.padolsey.com/javascript/special-scroll-events-for-jquery/

This actually ended up helping solve my problem very nicely after a little tweaking for my own needs, but over all helped get a lot of the guff out of the way and saved me about 4 hours of figuring it out on my own.

Seeing as this post seems to have some merit, I figured I would come back and provide the code found originally on the link mentioned, just in case the author ever decided to go a different direction with the site and ended up taking down the link.

(function(){

    var special = jQuery.event.special,
        uid1 = 'D' + (+new Date()),
        uid2 = 'D' + (+new Date() + 1);

    special.scrollstart = {
        setup: function() {

            var timer,
                handler =  function(evt) {

                    var _self = this,
                        _args = arguments;

                    if (timer) {
                        clearTimeout(timer);
                    } else {
                        evt.type = 'scrollstart';
                        jQuery.event.handle.apply(_self, _args);
                    }

                    timer = setTimeout( function(){
                        timer = null;
                    }, special.scrollstop.latency);

                };

            jQuery(this).bind('scroll', handler).data(uid1, handler);

        },
        teardown: function(){
            jQuery(this).unbind( 'scroll', jQuery(this).data(uid1) );
        }
    };

    special.scrollstop = {
        latency: 300,
        setup: function() {

            var timer,
                    handler = function(evt) {

                    var _self = this,
                        _args = arguments;

                    if (timer) {
                        clearTimeout(timer);
                    }

                    timer = setTimeout( function(){

                        timer = null;
                        evt.type = 'scrollstop';
                        jQuery.event.handle.apply(_self, _args);

                    }, special.scrollstop.latency);

                };

            jQuery(this).bind('scroll', handler).data(uid2, handler);

        },
        teardown: function() {
            jQuery(this).unbind( 'scroll', jQuery(this).data(uid2) );
        }
    };

})();
chris
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5

I agreed with some of the comments above that listening for a timeout wasn't accurate enough as that will trigger when you stop moving the scroll bar for long enough instead of when you stop scrolling. I think a better solution is to listen for the user letting go of the mouse (mouseup) as soon as they start scrolling:

$(window).scroll(function(){
    $('#scrollMsg').html('SCROLLING!');
    var stopListener = $(window).mouseup(function(){ // listen to mouse up
        $('#scrollMsg').html('STOPPED SCROLLING!');
        stopListner(); // Stop listening to mouse up after heard for the first time 
    });
});

and an example of it working can be seen in this JSFiddle

Theo
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    This seems great, but if you are scrolling by 2-finger gesture on a trackpad, or a scrollwheel, then the mouseup isn't fired. This is probably the most common way to scroll too, which makes it problematic. – Adam Mar 20 '14 at 21:15
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    Good point. But potentially there are a couple of fixes for that. Using jquery's 'mousewheel' event or keeping track on if mousedown first, and using a timeout approach as suggested by others. But I think using a combination of other answers for mouse wheel events and this answer for scroll bar dragging will give the most accurate results – Theo Mar 21 '14 at 09:29
5

ES6 style with checking scrolling start also.

function onScrollHandler(params: {
  onStart: () => void,
  onStop: () => void,
  timeout: number
}) {
  const {onStart, onStop, timeout = 200} = params
  let timer = null

  return (event) => {
    if (timer) {
      clearTimeout(timer)
    } else {
      onStart && onStart(event)
    }
    timer = setTimeout(() => {
      timer = null
      onStop && onStop(event)
    }, timeout)
  }
}

Usage:

yourScrollableElement.addEventListener('scroll', onScrollHandler({
  onStart: (event) => {
    console.log('Scrolling has started')
  },
  onStop: (event) => {
    console.log('Scrolling has stopped')
  },
  timeout: 123 // Remove to use default value
}))
Ilya Iksent
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3
function scrolled() {
    //do by scroll start
    $(this).off('scroll')[0].setTimeout(function(){
        //do by scroll end
        $(this).on('scroll',scrolled);
    }, 500)
}
$(window).on('scroll',scrolled);

very small Version with start and end ability

Dieter Bender
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3

You could set an interval that runs every 500 ms or so, along the lines of the following:

var curOffset, oldOffset;
oldOffset = $(window).scrollTop();
var $el = $('.slides_layover'); // cache jquery ref
setInterval(function() {
  curOffset = $(window).scrollTop();
  if(curOffset != oldOffset) {
    // they're scrolling, remove your class here if it exists
    if($el.hasClass('showing_layover')) $el.removeClass('showing_layover');
  } else {
    // they've stopped, add the class if it doesn't exist
    if(!$el.hasClass('showing_layover')) $el.addClass('showing_layover');
  }
  oldOffset = curOffset;
}, 500);

I haven't tested this code, but the principle should work.

justinbach
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2

This detects the scroll stop after 1 milisecond (or change it) using a global timer:

var scrollTimer;

$(window).on("scroll",function(){
    clearTimeout(scrollTimer);
    //Do  what you want whilst scrolling
    scrollTimer=setTimeout(function(){afterScroll()},1);
})

function afterScroll(){
    //I catched scroll stop.
}
Ali Sheikhpour
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1

Ok this is something that I've used before. Basically you look a hold a ref to the last scrollTop(). Once your timeout clears, you check the current scrollTop() and if they are the same, you are done scrolling.

$(window).scroll((e) ->
  clearTimeout(scrollTimer)
  $('header').addClass('hidden')

  scrollTimer = setTimeout((() ->
    if $(this).scrollTop() is currentScrollTop
      $('header').removeClass('hidden') 
  ), animationDuration)

  currentScrollTop = $(this).scrollTop()
)
matrangam
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0

please check the jquery mobile scrollstop event

$(document).on("scrollstop",function(){
  alert("Stopped scrolling!");
});
Barett
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Irshad Pathan
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0

For those Who Still Need This Here Is The Solution

  $(function(){
      var t;
      document.addEventListener('scroll',function(e){
          clearTimeout(t);
          checkScroll();
      });
      
      function checkScroll(){
          t = setTimeout(function(){
             alert('Done Scrolling');
          },500); /* You can increase or reduse timer */
      }
  });
smacaz
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0

This should work:

var Timer;
$('.Scroll_Table_Div').on("scroll",function() 
{
    // do somethings

    clearTimeout(Timer);
    Timer = setTimeout(function()
    {
        console.log('scrolling is stop');
    },50);
});
Mohamad Hamouday
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0

Here is how you can handle this:

    var scrollStop = function (callback) {
        if (!callback || typeof callback !== 'function') return;
        var isScrolling;
        window.addEventListener('scroll', function (event) {
            window.clearTimeout(isScrolling);
            isScrolling = setTimeout(function() {
                callback();
            }, 66);
        }, false);
    };
    scrollStop(function () {
        console.log('Scrolling has stopped.');
    });
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
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</html>
Mohammad Ghonchesefidi
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