Hello there I've been trying to find a fix for the many scroll events firing on one scroll. This is the only thing close to working for me so far. I want to smoothscroll between two divs (#boxes and #header) I want to use the scroll bar to trigger this smooth scroll and not a button. Any suggestions on how to only take one scroll event? I also used solutions based from prev stackoverflow questions. I used my own locator instead of offsets because thats also unreliable
$(window).scroll(function () {
if (timer) {
window.clearTimeout(timer);
}
timer = window.setTimeout(function () {
if (locator == 0) {
id = $("#boxes");
locator = 1;
} else if (locator = 1) {
id = $("#header");
locator = 0;
}
// target element
var $id = $(id);
if ($id.length === 0) {
return;
}
// top position relative to the document
var pos = $id.offset().top;
// animated top scrolling
$('html, body').animate({scrollTop: pos}, 1500, function () {
$('html, body').clearQueue();
$('html, body').stop();
});
}, 2);
});
So, to be clear, you want any minor scroll event to scroll between one item and the other? Note that when a user scrolls, there is a "momentum" that the browser implements, and you'll be battling with that.
Regardless: You don't need to wrap this in a setTimeout. Right now, your javascript is creating a new setTimeout function that is being fired every 2ms. Scroll events occur with every pixel of movement in the scroll, so if you scroll 100px, you're going to be firing 100 times every 2ms. (That's 50,000 times).
Instead, have a a variable (isScrolling) track the state, so, if you're in the middle of scrolling, the function won't fire.
var isScrolling = false;
var locator = 0;
$(window).scroll(function () {
if (isScrolling) return false;
if (locator == 0) {
id = $("#boxes");
locator = 1;
} else if (locator = 1) {
id = $("#header");
locator = 0;
}
// target element
var $id = $(id);
if ($id.length === 0) {
return;
}
// top position relative to the document
var pos = $id.offset().top;
// animated top scrolling
isScrolling = true;
$('html, body').animate({scrollTop: pos}, 1500, function () {
$('html, body').clearQueue();
$('html, body').stop();
isScrolling = false;
});
});
Here's a JSbin: http://jsbin.com/jugefup/edit?html,css,js,output
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.
I'd like to set something up on my site where when you scroll within 15% of the bottom of the page an element flyouts from the side... I'm not sure how to get started here... should I add a listener for a scroll function or something?
I'm trying to recreate the effect at the bottom of this page: http://www.nytimes.com/2011/01/25/world/europe/25moscow.html?_r=1
update
I have this code....
console.log(document.body.scrollTop); //shows 0
console.log(document.body.scrollHeight * 0.85); //shows 1038.7
if (document.body.scrollTop > document.body.scrollHeight * 0.85) {
console.log();
$('#flyout').animate({
right: '0'
},
5000,
function() {
});
}
the console.log() values aren't changing when I scroll to the bottom of the page. The page is twice as long as my viewport.
[Working Demo]
$(document).ready(function () {
var ROOT = (function () {
var html = document.documentElement;
var htmlScrollTop = html.scrollTop++;
var root = html.scrollTop == htmlScrollTop + 1 ? html : document.body;
html.scrollTop = htmlScrollTop;
return root;
})();
// may be recalculated on resize
var limit = (document.body.scrollHeight - $(window).height()) * 0.85;
var visible = false;
var last = +new Date;
$(window).scroll(function () {
if (+new Date - last > 30) { // more than 30 ms elapsed
if (visible && ROOT.scrollTop < limit) {
setTimeout(function () { hide(); visible = false; }, 1);
} else if (!visible && ROOT.scrollTop > limit) {
setTimeout(function () { show(); visible = true; }, 1);
}
last = +new Date;
}
});
});
I know this is an old topic, but the above code that received the check mark was also triggering the $(window).scroll() event listener too many times.
I guess twitter had this same issue at one point. John Resig blogged about it here: http://ejohn.org/blog/learning-from-twitter/
$(document).ready(function(){
var ROOT = (function () {
var html = document.documentElement;
var htmlScrollTop = html.scrollTop++;
var root = html.scrollTop == htmlScrollTop + 1 ? html : document.body;
html.scrollTop = htmlScrollTop;
return root;
})();
// may be recalculated on resize
var limit = (document.body.scrollHeight - $(window).height()) * 0.85;
var visible = false;
var last = +new Date;
var didScroll = false;
$(window).scroll(function(){
didScroll = true;
})
setInterval(function(){
if(didScroll){
didScroll = false;
if (visible && ROOT.scrollTop < limit) {
hideCredit();
visible = false;
} else if (!visible && ROOT.scrollTop > limit) {
showCredit();
visible = true;
}
}
}, 30);
function hideCredit(){
console.log('The hideCredit function has been called.');
}
function showCredit(){
console.log('The showCredit function has been called.');
}
});
So the difference between the two blocks of code is when and how the timer is called. In this code the timer is called off the bat. So every 30 millaseconds, it checks to see if the page has been scrolled. if it's been scrolled, then it checks to see if we've passed the point on the page where we want to show the hidden content. Then, if that checks true, the actual function then gets called to show the content. (In my case I've just got a console.log print out in there right now.
This seems to be better to me than the other solution because the final function only gets called once per iteration. With the other solution, the final function was being called between 4 and 5 times. That's got to be saving resources. But maybe I'm missing something.
bad idea to capture the scroll event, best to use a timer and every few milliseconds check the scroll position and if in the range you need then execute the necessary code for what you need
Update: in the past few years the best practice is to subscribe to the event and use a throttle avoiding excessive processing https://lodash.com/docs#throttle
Something like this should work:
$(window).scroll(function() {
if (document.body.scrollTop > document.body.scrollHeight * 0.85) {
// flyout
}
});
document.body.scrollTop may not work equally well on all browsers (it actually depends on browser and doctype); so we need to abstract that in a function.
Also, we need to flyout only one time. So we can unbind the event handler after having flyed out.
And we don't want the flyout effect to slow down scrolling, so we will run our flytout function out of the event loop (by using setTimeout()).
Here is the final code:
// we bind the scroll event, with the 'flyout' namespace
// so we can unbind easily
$(window).bind('scroll.flyout', (function() {
// this function is defined only once
// it is private to our event handler
function getScrollTop() {
// if one of these values evaluates to false, this picks the other
return (document.documentElement.scrollTop||document.body.scrollTop);
}
// this is the actual event handler
// it has the getScrollTop() in its scope
return function() {
if (getScrollTop() > (document.body.scrollHeight-$(window).height()) * 0.85) {
// flyout
// out of the event loop
setTimeout(function() {
alert('flyout!');
}, 1);
// unbind the event handler
// so that it's not call anymore
$(this).unbind('scroll.flyout');
}
};
})());
So in the end, only getScrollTop() > document.body.scrollHeight * 0.85 is executed at each scroll event, which is acceptable.
The flyout effect is ran only one time, and after the event has returned, so it won't affect scrolling.
Is it possible to implement "long press" in JavaScript (or jQuery)? How?
(source: androinica.com)
HTML
Long press
JavaScript
$("a").mouseup(function(){
// Clear timeout
return false;
}).mousedown(function(){
// Set timeout
return false;
});
There is no 'jQuery' magic, just JavaScript timers.
var pressTimer;
$("a").mouseup(function(){
clearTimeout(pressTimer);
// Clear timeout
return false;
}).mousedown(function(){
// Set timeout
pressTimer = window.setTimeout(function() { ... Your Code ...},1000);
return false;
});
Based on Maycow Moura's answer, I wrote this. It also ensures that the user didn't do a right click, which would trigger a long press and works on mobile devices. DEMO
var node = document.getElementsByTagName("p")[0];
var longpress = false;
var presstimer = null;
var longtarget = null;
var cancel = function(e) {
if (presstimer !== null) {
clearTimeout(presstimer);
presstimer = null;
}
this.classList.remove("longpress");
};
var click = function(e) {
if (presstimer !== null) {
clearTimeout(presstimer);
presstimer = null;
}
this.classList.remove("longpress");
if (longpress) {
return false;
}
alert("press");
};
var start = function(e) {
console.log(e);
if (e.type === "click" && e.button !== 0) {
return;
}
longpress = false;
this.classList.add("longpress");
if (presstimer === null) {
presstimer = setTimeout(function() {
alert("long click");
longpress = true;
}, 1000);
}
return false;
};
node.addEventListener("mousedown", start);
node.addEventListener("touchstart", start);
node.addEventListener("click", click);
node.addEventListener("mouseout", cancel);
node.addEventListener("touchend", cancel);
node.addEventListener("touchleave", cancel);
node.addEventListener("touchcancel", cancel);
You should also include some indicator using CSS animations:
p {
background: red;
padding: 100px;
}
.longpress {
-webkit-animation: 1s longpress;
animation: 1s longpress;
}
#-webkit-keyframes longpress {
0%, 20% { background: red; }
100% { background: yellow; }
}
#keyframes longpress {
0%, 20% { background: red; }
100% { background: yellow; }
}
You can use taphold event of jQuery mobile API.
jQuery("a").on("taphold", function( event ) { ... } )
I created long-press-event (0.5k pure JS) to solve this, it adds a long-press event to the DOM.
Listen for a long-press on any element:
// the event bubbles, so you can listen at the root level
document.addEventListener('long-press', function(e) {
console.log(e.target);
});
Listen for a long-press on a specific element:
// get the element
var el = document.getElementById('idOfElement');
// add a long-press event listener
el.addEventListener('long-press', function(e) {
// stop the event from bubbling up
e.preventDefault()
console.log(e.target);
});
Works in IE9+, Chrome, Firefox, Safari & hybrid mobile apps (Cordova & Ionic on iOS/Android)
Demo
While it does look simple enough to implement on your own with a timeout and a couple of mouse event handlers, it gets a bit more complicated when you consider cases like click-drag-release, supporting both press and long-press on the same element, and working with touch devices like the iPad. I ended up using the longclick jQuery plugin (Github), which takes care of that stuff for me. If you only need to support touchscreen devices like mobile phones, you might also try the jQuery Mobile taphold event.
For modern, mobile browsers:
document.addEventListener('contextmenu', callback);
https://developer.mozilla.org/en-US/docs/Web/Events/contextmenu
jQuery plugin. Just put $(expression).longClick(function() { <your code here> });. Second parameter is hold duration; default timeout is 500 ms.
(function($) {
$.fn.longClick = function(callback, timeout) {
var timer;
timeout = timeout || 500;
$(this).mousedown(function() {
timer = setTimeout(function() { callback(); }, timeout);
return false;
});
$(document).mouseup(function() {
clearTimeout(timer);
return false;
});
};
})(jQuery);
$(document).ready(function () {
var longpress = false;
$("button").on('click', function () {
(longpress) ? alert("Long Press") : alert("Short Press");
});
var startTime, endTime;
$("button").on('mousedown', function () {
startTime = new Date().getTime();
});
$("button").on('mouseup', function () {
endTime = new Date().getTime();
longpress = (endTime - startTime < 500) ? false : true;
});
});
DEMO
For cross platform developers (Note All answers given so far will not work on iOS):
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)
});
The Diodeus's answer is awesome, but it prevent you to add a onClick function, it'll never run hold function if you put an onclick. And the Razzak's answer is almost perfect, but it run hold function only on mouseup, and generally, the function runs even if user keep holding.
So, I joined both, and made this:
$(element).on('click', function () {
if(longpress) { // if detect hold, stop onclick function
return false;
};
});
$(element).on('mousedown', function () {
longpress = false; //longpress is false initially
pressTimer = window.setTimeout(function(){
// your code here
longpress = true; //if run hold function, longpress is true
},1000)
});
$(element).on('mouseup', function () {
clearTimeout(pressTimer); //clear time on mouseup
});
You could set the timeout for that element on mouse down and clear it on mouse up:
$("a").mousedown(function() {
// set timeout for this element
var timeout = window.setTimeout(function() { /* … */ }, 1234);
$(this).mouseup(function() {
// clear timeout for this element
window.clearTimeout(timeout);
// reset mouse up event handler
$(this).unbind("mouseup");
return false;
});
return false;
});
With this each element gets its own timeout.
This worked for me:
const a = document.querySelector('a');
a.oncontextmenu = function() {
console.log('south north');
};
https://developer.mozilla.org/docs/Web/API/GlobalEventHandlers/oncontextmenu
You can use jquery-mobile's taphold. Include the jquery-mobile.js and the following code will work fine
$(document).on("pagecreate","#pagename",function(){
$("p").on("taphold",function(){
$(this).hide(); //your code
});
});
Most elegant and clean is a jQuery plugin:
https://github.com/untill/jquery.longclick/,
also available as packacke:
https://www.npmjs.com/package/jquery.longclick.
In short, you use it like so:
$( 'button').mayTriggerLongClicks().on( 'longClick', function() { your code here } );
The advantage of this plugin is that, in contrast to some of the other answers here, click events are still possible. Note also that a long click occurs, just like a long tap on a device, before mouseup. So, that's a feature.
I needed something for longpress keyboard events, so I wrote this.
var longpressKeys = [13];
var longpressTimeout = 1500;
var longpressActive = false;
var longpressFunc = null;
document.addEventListener('keydown', function(e) {
if (longpressFunc == null && longpressKeys.indexOf(e.keyCode) > -1) {
longpressFunc = setTimeout(function() {
console.log('longpress triggered');
longpressActive = true;
}, longpressTimeout);
// any key not defined as a longpress
} else if (longpressKeys.indexOf(e.keyCode) == -1) {
console.log('shortpress triggered');
}
});
document.addEventListener('keyup', function(e) {
clearTimeout(longpressFunc);
longpressFunc = null;
// longpress key triggered as a shortpress
if (!longpressActive && longpressKeys.indexOf(e.keyCode) > -1) {
console.log('shortpress triggered');
}
longpressActive = false;
});
In vanila JS if need to detect long-click after click released:
document.addEventListener("mousedown", longClickHandler, true);
document.addEventListener("mouseup", longClickHandler, true);
let startClick = 0;
function longClickHandler(e){
if(e.type == "mousedown"){
startClick = e.timeStamp;
}
else if(e.type == "mouseup" && startClick > 0){
if(e.timeStamp - startClick > 500){ // 0.5 secound
console.log("Long click !!!");
}
}
}
May need to use timer if need to check long-click while clicking. But for most case after release click is enought.
For me it's work with that code (with jQuery):
var int = null,
fired = false;
var longclickFilm = function($t) {
$body.css('background', 'red');
},
clickFilm = function($t) {
$t = $t.clone(false, false);
var $to = $('footer > div:first');
$to.find('.empty').remove();
$t.appendTo($to);
},
touchStartFilm = function(event) {
event.preventDefault();
fired = false;
int = setTimeout(function($t) {
longclickFilm($t);
fired = true;
}, 2000, $(this)); // 2 sec for long click ?
return false;
},
touchEndFilm = function(event) {
event.preventDefault();
clearTimeout(int);
if (fired) return false;
else clickFilm($(this));
return false;
};
$('ul#thelist .thumbBox')
.live('mousedown touchstart', touchStartFilm)
.live('mouseup touchend touchcancel', touchEndFilm);
You can check the time to identify Click or Long Press [jQuery]
function AddButtonEventListener() {
try {
var mousedowntime;
var presstime;
$("button[id$='" + buttonID + "']").mousedown(function() {
var d = new Date();
mousedowntime = d.getTime();
});
$("button[id$='" + buttonID + "']").mouseup(function() {
var d = new Date();
presstime = d.getTime() - mousedowntime;
if (presstime > 999/*You can decide the time*/) {
//Do_Action_Long_Press_Event();
}
else {
//Do_Action_Click_Event();
}
});
}
catch (err) {
alert(err.message);
}
}
You can use jquery Touch events. (see here)
let holdBtn = $('#holdBtn')
let holdDuration = 1000
let holdTimer
holdBtn.on('touchend', function () {
// finish hold
});
holdBtn.on('touchstart', function () {
// start hold
holdTimer = setTimeout(function() {
//action after certain time of hold
}, holdDuration );
});
like this?
target.addEeventListener("touchstart", function(){
// your code ...
}, false);