Detect if user is scrolling
JavascriptJavascript Problem Overview
How can I detect in javascript if the user is scrolling?
Javascript Solutions
Solution 1 - Javascript
this works:
window.onscroll = function (e) {
// called when the window is scrolled.
}
edit:
you said this is a function in a TimeInterval..
Try doing it like so:
userHasScrolled = false;
window.onscroll = function (e)
{
userHasScrolled = true;
}
then inside your Interval insert this:
if(userHasScrolled)
{
//do your code here
userHasScrolled = false;
}
Solution 2 - Javascript
You just said javascript in your tags, so @Wampie Driessen post could helps you.
I want also to contribute, so you can use the following when using jQuery if you need it.
//Firefox
$('#elem').bind('DOMMouseScroll', function(e){
if(e.detail > 0) {
//scroll down
console.log('Down');
}else {
//scroll up
console.log('Up');
}
//prevent page fom scrolling
return false;
});
//IE, Opera, Safari
$('#elem').bind('mousewheel', function(e){
if(e.wheelDelta< 0) {
//scroll down
console.log('Down');
}else {
//scroll up
console.log('Up');
}
//prevent page fom scrolling
return false;
});
Another example:
$(function(){
var _top = $(window).scrollTop();
var _direction;
$(window).scroll(function(){
var _cur_top = $(window).scrollTop();
if(_top < _cur_top)
{
_direction = 'down';
}
else
{
_direction = 'up';
}
_top = _cur_top;
console.log(_direction);
});
});
Solution 3 - Javascript
window.addEventListener("scroll",function(){
window.lastScrollTime = new Date().getTime()
});
function is_scrolling() {
return window.lastScrollTime && new Date().getTime() < window.lastScrollTime + 500
}
Change the 500 to the number of milliseconds after the last scroll event at which you consider the user to be "no longer scrolling".
(addEventListener
is better than onScroll
because the former can coexist nicely with any other code that uses onScroll
.)
Solution 4 - Javascript
If you want detect when user scroll over certain div, you can do something like this:
window.onscroll = function() {
var distanceScrolled = document.documentElement.scrollTop;
console.log('Scrolled: ' + distanceScrolled);
}
For example, if your div appear after scroll until the position 112:
window.onscroll = function() {
var distanceScrolled = document.documentElement.scrollTop;
if (distanceScrolled > 112) {
do something...
}
}
But as you can see you don't need a div, just the offset distance you want something to happen.
Solution 5 - Javascript
Use an interval to check
You can setup an interval to keep checking if the user has scrolled then do something accordingly.
Borrowing from the great John Resig in his article.
Example:
let didScroll = false;
window.onscroll = () => didScroll = true;
setInterval(() => {
if ( didScroll ) {
didScroll = false;
console.log('Someone scrolled me!')
}
}, 250);