Develop Reference

vertical scroll two tables at the same time

I have two tables that must scroll together:
$('.vscroll').on('scroll', function (e) {
divTable1.scrollTop = e.scrollTop;
divTable2.scrollTop = e.scrollTop;
There's a little lag issue though. Table1 scrolls milliseconds before Table2.
I know scrollTop fires the scroll event, but is there a way to delay the scrolling of Table1 until Table2's scrollTop is also set?

Try using a setTimeout to trigger the scrolls, and then return false to cancel the original scrollevent:
var ignoreEvent = false;
$(".vscroll").on('scroll', function (e) {
if (!ignoreEvent) {
setTimeout(function() {
ignoreEvent = true;
table1.scrollTop = e.scrollTop;
table2.scrolLTop = e.scrollTop;
}, 100);
}
ignoreEvent = false;
return false; // cancels the original scroll event.
}

I'm using divs instead of tables but you get the idea
$("div").on("scroll",function(){
$("div:not(this)").scrollTop($(this).scrollTop());
});
DEMO

How to stop window.scroll() after specific event?

I want to make the sticky-nav to act similar(scroll is off when the menu is expanded) to this website's nav(http://amandagerhardsen.com/#cloudbusting/4) when expanded.
How do I do it?
var Boxlayout = (function () {
var $el = $('#sticky-nav'),
$sections = $el.children('section'),
// work panels
$workPanelsContainer = $('#bl-panel-work-items'),
// close work panel trigger
$closeWorkItem = $workPanelsContainer.find('nav > span.hidemenu'),
transEndEventNames = {
'WebkitTransition': 'webkitTransitionEnd',
'MozTransition': 'transitionend',
'OTransition': 'oTransitionEnd',
'msTransition': 'MSTransitionEnd',
'transition': 'transitionend'
},
// transition end event name
transEndEventName = transEndEventNames[Modernizr.prefixed('transition')],
// support css transitions
supportTransitions = Modernizr.csstransitions;
function init() {
initEvents();
}
function initEvents() {
$sections.each(function () {
var $section = $(this);
// expand the clicked section and scale down the others
$section.on('click', function () {
if (!$section.data('open')) {
$section.data('open', true).addClass('bl-expand bl-expand-top');
$el.addClass('bl-expand-item');
}
}).find('span.hidemenu').on('click', function () {
// close the expanded section and scale up the others
$section.data('open', false).removeClass('bl-expand').on(transEndEventName, function (event) {
if (!$(event.target).is('section')) return false;
$(this).off(transEndEventName).removeClass('bl-expand-top');
});
if (!supportTransitions) {
$section.removeClass('bl-expand-top');
}
$el.removeClass('bl-expand-item');
return false;
});
});
// clicking on a work item: the current section scales down and the respective work panel slides up
$workItems.on('click', function (event) {
// scale down main section
$sectionWork.addClass('bl-scale-down');
// show panel for this work item
$workPanelsContainer.addClass('bl-panel-items-show');
var $panel = $workPanelsContainer.find("[data-panel='" + $(this).data('panel') + "']");
currentWorkPanel = $panel.index();
$panel.addClass('bl-show-work');
return false;
});
// navigating the work items: current work panel scales down and the next work panel slides up
$nextWorkItem.on('click', function (event) {
if (isAnimating) {
return false;
}
isAnimating = true;
var $currentPanel = $workPanels.eq(currentWorkPanel);
currentWorkPanel = currentWorkPanel < totalWorkPanels - 1 ? currentWorkPanel + 1 : 0;
var $nextPanel = $workPanels.eq(currentWorkPanel);
$currentPanel.removeClass('bl-show-work').addClass('bl-hide-current-work').on(transEndEventName, function (event) {
if (!$(event.target).is('div')) return false;
$(this).off(transEndEventName).removeClass('bl-hide-current-work');
isAnimating = false;
});
if (!supportTransitions) {
$currentPanel.removeClass('bl-hide-current-work');
isAnimating = false;
}
$nextPanel.addClass('bl-show-work');
return false;
});
// clicking the work panels close button: the current work panel slides down and the section scales up again
$closeWorkItem.on('click', function (event) {
// scale up main section
$sectionWork.removeClass('bl-scale-down');
$workPanelsContainer.removeClass('bl-panel-items-show');
$workPanels.eq(currentWorkPanel).removeClass('bl-show-work');
return false;
});
}
return {
init: init
};
})();

Here is a fiddle: http://jsfiddle.net/77P2e/
Be careful to unlock scrolling again when done, or this could be very annoying for the user!
Setup code
var $window = $(window), previousScrollTop = 0, scrollLock = false;
$window.scroll(function(event) {
if(scrollLock) {
$window.scrollTop(previousScrollTop);
}
previousScrollTop = $window.scrollTop();
});
To lock scroll position:
scrollLock = true;
And to unlock again...
scrollLock = false;
As an example use, you could lock the window scroll position when the mouse enters the navigation area, and unlock it again when the mouse leaves:
$("nav")
.mouseenter(function(){ scrollLock = true; })
.mouseleave(function(){ scrollLock = false; });

In my opinion the accepted answer is not what should be achieved, as the window.scroll() function will be still running (endlessly), even if the 'event' has occured.
The window.scroll() function is an event handler. So use on() to bind the event and off() to unbind it (after the 'event' has occured).
$(window).on('scroll', function() { // bind event handler
var offset = $(window).scrollTop();
console.log("page Y-Offset: ", offset); // just to see it working
if(offset >= 100) $(window).off('scroll'); // unbind the event handler when the condition is met
});

The Javascript solution is a little janky for me, on mobile. It's like it scrolls a little bit and then snaps back into place.
However, I figured out a way to do it much more cleanly, without any jank, just by changing CSS's overflow property on the part you don't want to scroll. Here's the code in d3 but the concept should be pretty clear:
var body = d3.select('body');
var preventScroll = function () {
body.style('overflow', 'hidden');
},
allowScroll = function () {
body.style('overflow', 'scroll');
};
d3.select('#sticky-nav')
.on('touchmove', preventScroll)
.on('touchstart', preventScroll)
.on('touchend', allowScroll)
.on('touchcancel', allowScroll);

As I was using jquery animation,
if ($(window).scrollTop() >= $('.btn').offset().top + $('.btn').outerHeight() - window.innerHeight)
{
$(".tab").stop();
}
I did this and it worked.
.btn is the button. That .tab div would stop if it scrolls to that position.

If you're using jquery animation you can try using the stop() function on the animated object.

Setting a jScrollPane to autoscroll left and right, but pause on click?

Fiddle: http://jsfiddle.net/RJShm/
I have a jScrollPane that currently scroll from left, to right, then back left, and stops. What I'd like is for this to continually scroll from left to right, the right to left, then repeat. I have this fairly close to working by using pane.bind('jsp-scroll-x'..., but I can't seem to get it to scroll back to the right after one cycle. Current code for that:
pane.bind('jsp-scroll-x', function (event, pos_x, at_left, at_right) {
if (at_right)
{
api.scrollToX(0);
$(this).unbind(event);
}
});
I would also like for this to stop autoscrolling when anything in the pane is clicked (scroll bar, arrows, content, anything), and it would preferably restart after a few seconds of no clicks.
So, in short, how do I:
Make the jScrollPane scroll left/right automatically
Stop autoscrolling when clicked
Restart autoscrolling after a few seconds of no clicks inside the pane
Thanks
EDIT: jScrollPane Settings, and api for your convenience.

I have updated the handler for toggling the infinite scroll and also implemented click handler to pause the scroll and resume after a timeout (5 seconds). See draft code below and check the DEMO: http://jsfiddle.net/p6jLt/
var defaultSettings = {
showArrows: true,
animateScroll: true,
animateDuration: 5000
},
pauseSettings = {
showArrows: true,
animateScroll: false
};
var pane = $('.scroll-pane').jScrollPane(defaultSettings);
var api = pane.data('jsp');
var isFirst = true,
posX = 0,
isLeft = false,
timer;
pane.bind('jsp-scroll-x', scrollFx)
.mousedown(function () {
//lets make sure the below is
//executed only once after automatic croll
if (posX != -1) {
$(this).unbind('jsp-scroll-x');
api.scrollToX(posX);
api.reinitialise(pauseSettings); //no animation
posX = -1;
}
}).mouseup(function () {
clearTimeout(timer); //clear any previous timer
timer = setTimeout(function () {
isFirst = true;
posX = 0; //reset the killer switch
api.reinitialise(defaultSettings); //animateed scroll
pane.bind('jsp-scroll-x', scrollFx); //rebind
api.scrollToX(isLeft ? 0 : api.getContentWidth()); //resume scroll
}, 5000);
});
var scroll = api.scrollToX(api.getContentWidth());
function scrollFx(event, pos_x, at_left, at_right) {
if (posX == -1) { //kill scroll
$(this).unbind(event);
return false;
}
if (at_right) {
api.scrollToX(0);
isLeft = true; //used for restart
} else if (at_left && !isFirst) {
api.scrollToX(api.getContentWidth());
isLeft = false; //used for restart
}
isFirst = false;
posX = pos_x;
}
Issues: The plugin is little buggy with scroll sometimes, but it doesn't break the infinite scroll. You may find the little hicks on scroll, but it works for the most part. Test it out thoroughly and see how it goes.

Cancel scrolling after user interaction

My webpage animates scrolling when users click on links to the same page. I want to cancel this animation as soon as the user tries to scroll (otherwise the user and the browser are fighting for control) – no matter whether with the mouse wheel, the keyboard or the scrollbar (or any other way – are there other ways of scrolling?). I managed to cancel the animation after the mouse wheel or keyboard are used, how do I get this working with the scrollbar?
Here is how my code looks for the keyboard:
$(document.documentElement).keydown( function (event) {
if(event.keyCode == 38 || 40) stopScroll();
});
function stopScroll() {
$("html, body").stop(true, false);
}
I also tried a more elegant way of doing this by using scroll(), the problem is that scroll() catches everything including the animated and automated scrolling. I could not think of any way to let it catch all scrolling except the animated scrolling.

you need animation marker, something like this
$("html, body").stop(true, false).prop('animatedMark',0.0).animate({scrollTop : top, animatedMark: '+=1.0'})
Here is the code, the code was mix of GWT and javascript so moved it to js, not fully tested, please try it
var lastAnimatedMark=0.0;
function scrollToThis(top){
// Select/ stop any previous animation / reset the mark to 0
// and finally animate the scroll and the mark
$("html, body").stop(true, false).prop('animatedMark',0.0).
animate({scrollTop : top, animatedMark: '+=1.0'}
,10000,function(){
//We finished , nothing just clear the data
lastAnimatedMark=0.0;
$("html, body").prop('animatedMark',0.0);
});
}
//Gets the animatedMark value
function animatedMark() {
var x=$("html, body").prop('animatedMark');
if (x==undefined){
$("html, body").prop('animatedMark', 0.0);
}
x=$("html, body").prop('animatedMark');
return x;
};
//Kills the animation
function stopBodyAnimation() {
lastAnimatedMark=0;
$("html, body").stop(true, false);
}
//This should be hooked to window scroll event
function scrolled(){
//get current mark
var currentAnimatedMark=animatedMark();
//mark must be more than zero (jQuery animation is on) & but
//because last=current , this is user interaction.
if (currentAnimatedMark>0 && (lastAnimatedMark==currentAnimatedMark)) {
//During Animation but the marks are the same !
stopBodyAnimation();
return;
}
lastAnimatedMark=currentAnimatedMark;
}
Here is the blog about it
http://alaamurad.com/blog/#!canceling-jquery-animation-after-user-interaction
Enjoy!

Here's a jquery function that should do the trick:
function polite_scroll_to(val, duration, callback) {
/* scrolls body to a value, without fighting the user if they
try to scroll in the middle of the animation. */
var auto_scroll = false;
function stop_scroll() {
if (!auto_scroll) {
$("html, body").stop(true, false);
}
};
$(window).on('scroll', stop_scroll);
$("html, body").animate({
scrollTop: val
}, {
duration: duration,
step: function() {
auto_scroll = true;
$(window).one('scroll', function() {
auto_scroll = false;
});
},
complete: function() {
callback && callback();
},
always: function() {
$(window).off('scroll', stop_scroll);
}
});
};

It's not very elegant, but you could use a flag of some kind to detect what type of scrolling you're dealing with (animated or 'manual') and always kill it when it's animated. Here's an untested example:
var animatedScroll = false;
// you probably have a method looking something like this:
function animatedScrollTo(top) {
// set flag to true
animatedScroll = true;
$('html').animate({
scrollTop : top
}, 'slow', function() {
// reset flag after animation is completed
animatedScroll = false;
});
}
function stopScroll() {
if (animatedScroll) {
$("html, body").stop(true, false);
}
}

Event when user stops scrolling

I'd like to do some fancy jQuery stuff when the user scrolls the page. But I have no idea how to tackle this problem, since there is only the scroll() method.
Any ideas?

You can make the scroll() have a time-out that gets overwritten each times the user scrolls. That way, when he stops after a certain amount of milliseconds your script is run, but if he scrolls in the meantime the counter will start over again and the script will wait until he is done scrolling again.
Update:
Because this question got some action again I figured I might as well update it with a jQuery extension that adds a scrollEnd event
// extension:
$.fn.scrollEnd = function(callback, timeout) {
$(this).on('scroll', function(){
var $this = $(this);
if ($this.data('scrollTimeout')) {
clearTimeout($this.data('scrollTimeout'));
}
$this.data('scrollTimeout', setTimeout(callback,timeout));
});
};
// how to call it (with a 1000ms timeout):
$(window).scrollEnd(function(){
alert('stopped scrolling');
}, 1000);
<script src="https://code.jquery.com/jquery-3.5.1.min.js" integrity="sha256-9/aliU8dGd2tb6OSsuzixeV4y/faTqgFtohetphbbj0=" crossorigin="anonymous"></script>
<div style="height: 200vh">
Long div
</div>

Here is a simple example using setTimeout to fire a function when the user stops scrolling:
(function() {
var timer;
$(window).bind('scroll',function () {
clearTimeout(timer);
timer = setTimeout( refresh , 150 );
});
var refresh = function () {
// do stuff
console.log('Stopped Scrolling');
};
})();
The timer is cleared while the scroll event is firing. Once scrolling stops, the refresh function is fired.
Or as a plugin:
$.fn.afterwards = function (event, callback, timeout) {
var self = $(this), delay = timeout || 16;
self.each(function () {
var $t = $(this);
$t.on(event, function(){
if ($t.data(event+'-timeout')) {
clearTimeout($t.data(event+'-timeout'));
}
$t.data(event + '-timeout', setTimeout(function () { callback.apply($t); },delay));
})
});
return this;
};
To fire callback after 100ms of the last scroll event on a div (with namespace):
$('div.mydiv').afterwards('scroll.mynamespace', function(e) {
// do stuff when stops scrolling
$(this).addClass('stopped');
}, 100
);
I use this for scroll and resize.

Here is another more generic solution based on the same ideas mentioned:
var delayedExec = function(after, fn) {
var timer;
return function() {
timer && clearTimeout(timer);
timer = setTimeout(fn, after);
};
};
var scrollStopper = delayedExec(500, function() {
console.log('stopped it');
});
document.getElementById('box').addEventListener('scroll', scrollStopper);

I had the need to implement onScrollEnd event discussed hear as well.
The idea of using timer works for me.
I implement this using JavaScript Module Pattern:
var WindowCustomEventsModule = (function(){
var _scrollEndTimeout = 30;
var _delayedExec = function(callback){
var timer;
return function(){
timer && clearTimeout(timer);
timer = setTimeout(callback, _scrollEndTimeout);
}
};
var onScrollEnd = function(callback) {
window.addEventListener('scroll', _delayedExec(callback), false);
};
return {
onScrollEnd: onScrollEnd
}
})();
// usage example
WindowCustomEventsModule.onScrollEnd(function(){
//
// do stuff
//
});
Hope this will help / inspire someone

Why so complicated? As the documentation points out, this http://jsfiddle.net/x3s7F/9/ works!
$('.frame').scroll(function() {
$('.back').hide().fadeIn(100);
}
http://api.jquery.com/scroll/.
Note: The scroll event on Windows Chrome is differently to all others. You need to scroll fast to get the same as result as in e.g. FF. Look at https://liebdich.biz/back.min.js the "X" function.
Some findings from my how many ms a scroll event test:
Safari, Mac FF, Mac Chrome: ~16ms an event.
Windows FF: ~19ms an event.
Windows Chrome: up to ~130ms an event, when scrolling slow.
Internet Explorer: up to ~110ms an event.
http://jsfiddle.net/TRNCFRMCN/1Lygop32/4/.

There is no such event as 'scrollEnd'. I recommend that you check the value returned by scroll() every once in a while (say, 200ms) using setInterval, and record the delta between the current and the previous value. If the delta becomes zero, you can use it as your event.

There are scrollstart and scrollstop functions that are part of jquery mobile.
Example using scrollstop:
$(document).on("scrollstop",function(){
alert("Stopped scrolling!");
});
Hope this helps someone.

The scrollEnd event is coming. It's currently experimental and is only supported by Firefox. See the Mozilla documentation here - https://developer.mozilla.org/en-US/docs/Web/API/Document/scrollend_event
Once it's supported by more browsers, you can use it like this...
document.onscrollend = (event) => {
console.log('Document scrollend event fired!');
};

I pulled some code out of a quick piece I cobbled together that does this as an example (note that scroll.chain is an object containing two arrays start and end that are containers for the callback functions). Also note that I am using jQuery and underscore here.
$('body').on('scroll', scrollCall);
scrollBind('end', callbackFunction);
scrollBind('start', callbackFunction);
var scrollCall = function(e) {
if (scroll.last === false || (Date.now() - scroll.last) <= 500) {
scroll.last = Date.now();
if (scroll.timeout !== false) {
window.clearTimeout(scroll.timeout);
} else {
_(scroll.chain.start).each(function(f){
f.call(window, {type: 'start'}, e.event);
});
}
scroll.timeout = window.setTimeout(self.scrollCall, 550, {callback: true, event: e});
return;
}
if (e.callback !== undefined) {
_(scroll.chain.end).each(function(f){
f.call(window, {type: 'end'}, e.event);
});
scroll.last = false;
scroll.timeout = false;
}
};
var scrollBind = function(type, func) {
type = type.toLowerCase();
if (_(scroll.chain).has(type)) {
if (_(scroll.chain[type]).indexOf(func) === -1) {
scroll.chain[type].push(func);
return true;
}
return false;
}
return false;
}