Develop Reference

Scroll event not working on chrome and not precise in firefox

I tried to build a custom scroll for my website but it's not perfect and I don't know how to improve it. It should scroll from one position to another specific position but there is a difference of pixels that become bigger every scroll events. It also seems to not work on chrome.
here is a link to the html file :http://infographie.inraci.be/blc/blc.html
here is the code :
$(window).bind('mousewheel DOMMouseScroll', function(event){
var hauteur5 = $(window).height();
var scroll5 = $(window).scrollTop();
if (event.originalEvent.wheelDelta > 0 || event.originalEvent.detail < 0) {
$(window).scrollTo(scroll5-hauteur5/4,1,function(){
})
} else {
$(window).scrollTo(scroll5+hauteur5/4,1,function(){
})
}
});

If you want check this snippet: https://stackoverflow.com/a/38572744/3605379
There I check the week speed with a timeout. Play with it so you can get the timing right.

Page noscroll keeping scrollTop position in sticky footer layout

I can't handle such a mind-breaker:
It's common approach to hide page scroll when a tall popup shows. But when you set overflow: hidden to html and body elements, the content automatically returns to it's top (scrollTop: 0). It's no problem to keep scrollTop position, and reset it on popup's disappearing. But if you use transparent mask, user will see unnecessary jump from current scroll position to the top. How to escape this?
In the current Chrome and Firefox, I can set overflow: hidden only to html element to reach what I want, but it's not working on mobile devices.
Maybe someone can propose a good cross-browser solution.

I don't think this should be happening. I would look at the popup code to see if it's the culprit sending the page to the top and using subpar css to position the popup element.
In any case, here's code that ought to counter the behavior you're encountering. Since I cannot reproduce the problem, I cannot test my proposed fix. I think you'll find though that your pop up will be scrolled away out of view.
function keepScroll(){
var x = $('body').scrollLeft() + $(document.documentElement).scrollLeft();
var y = $('body').scrollTop() + $(document.documentElement).scrollTop();
$('html').css({
'overflow':'hidden'
});
$('body').css({
'overflow':'hidden'
});
$(window).scrollTop(y).scrollLeft(x);
}

The sicky footer layout has html and body height equal to '100%'. And when you set overflow:hidden it crops all the content and returns it to the top position.
To avoid this, you should set html and body height to 'auto' if scroll exists (you should check it to keep sticky footer behavior)
function keepScroll(){
var scrollHeight = $('body')[0].scrollHeight > $('html')[0].scrollHeight ? $('body')[0].scrollHeight : $('html')[0].scrollHeight,
keepCSS = scrollHeight > $(window).height() ? {'overflow':'hidden','height':'auto'} : {'overflow':'hidden'};
$('html, body').css(keepCSS);
}
See the fiddle, for live demo
Edit 1
This solution is still not working on mobile (overflow: hidden doesn't disable scrolling on iPad, the position 'fixed' fix for body throw the content to the top), so the issue is open
Edit 2
Find a fix, for mobiles. Maybe it isn't so clean, but works.
var scrollKeeper = (function() {
var scrollHeight = $('body')[0].scrollHeight > $('html')[0].scrollHeight ? $('body')[0].scrollHeight : $('html')[0].scrollHeight,
keepCSS = scrollHeight > $(window).height() ? {'overflow':'hidden','height':'auto'} : {'overflow':'hidden'},
scrollTop = 0;
return {
keep : function() {
scrollTop = $(window).scrollTop();
$('body').css({'position': 'fixed', 'width':'100%', 'top': -scrollTop + 'px'});
$('html, body').css(keepCSS);
},
release : function() {
$('html, body').removeAttr('style').scrollTop(scrollTop);
}
}
})();
Tip: Of course in the real development you should use css classes to avoid removeAttr(style) etc.
Tested on iPhone and Ipad (iOS 8+).
The fiddle http://jsfiddle.net/m1eav032/5/

Infinite Scroll Effect with javascript

anyone have a clue how to make a sroll effect like this?
http://www.eurekasoft.com
I know the content is repeated at the end to create the illusion but i would like to know how to achieve the seemingly never end scroll.
Thanks!

It appears that site is using Skrollr: http://prinzhorn.github.io/skrollr/
Scroll all the way down for links to the Github and more examples.
Deep down, it is using the function window.scrollTo() to set the scroll position, and probably setting DOM around that area so that it looks the same as where it was scrolled from.
https://github.com/Prinzhorn/skrollr/blob/master/src/skrollr.js#L617

This works for me :)
here is the example: http://www.cancerbero.mx (only enable in Chrome and Safari)
// #loop is the div ID where repetition begins
$(document).ready(function(){
$(window).scroll(function(){
var scroll = $(window).scrollTop();
var limit = $('#loop').position().top;
if(scroll >= limit){
window.scrollTo(0,1); // 1 to avoid conflicts
}
if(scroll == 0){
window.scrollTo(0,limit);
}
});
});

Preventing elastic scrolling on OS X Chrome and Safari

I'm looking for a way to prevent the elastic scrolling that occurs on OS X in both Chrome and Safari.
If you don't understand what I mean, it's when you scroll up while the page is at the top, or down when the page is at the bottom, and it shows a gray background behind the page.
There is a css solution for single page apps where you just add overflow:hidden to the html or body
However, I need to be able to scroll.
I've come up with a solution using Javascript (JQuery), but it's only for scrolling passed the top, and only works for chrome. Also, it's a bit buggy in Safari.
$(window).on('scroll', function(e){
scrollAmount = $(this).scrollTop();
if(scrollAmount < 1){
$(this).scrollTop(1);
}
});
So that's just checking of the user scrolls below 1 meaning they try to scroll up passed where the page ends. I tried 0 but that didn't work.
I haven't been able to find a way to check if the user scrolls passed the bottom of the page.
So any thoughts?
Edit:
$(window).on('scroll', function(e){
scrollAmount = $(this).scrollTop();
if(scrollAmount < 1){
$(this).scrollTop(1);
}
if(scrollAmount > $(document).height() - $(window).height()){
$(this).scrollTop($(window).height());
}
});
Now I've added a check for if we scroll passed the bottom of the page. This method is not working though, it's bouncing around very ungracefully.

When you quickly scroll up to the top, the elastic browser causes the scroll top to become negative. Using the st <= 0, will make sure no action is taken when this happens.
$(window).on('scroll',function(){
var dh = $(document).height(),
wh = $(window).height(),
st = $(window).scrollTop();
if (st <= 0) {
$(this).scrollTop(0);
} else if (st + wh >= dh) {
$(this).scrollTop(dh);
}
});

You can now use overscroll-behavior:
html, body {
overscroll-behavior: none;
}

While I dislike the methodology, you can use jQuery to get the document height (and thus the bottom of the page for the scroll distance using $(document).height();)
Another method would be to wrap the entire page with a <div id="preventScroll"></div> wrapper, with the property overflow: scroll; height: 100%; width: 100%;
That would be a separate scrolling device and prevent your whole issue.

Keeping sidebar in viewport, problem with scrolling

I've got a solution for keeping a sidebar in the viewport as you scroll up and down the page. Problem comes in when the sidebar is longer than the content area, and you keep scrolling you get this jittering effect as the sidebar keeps pushing the footer down.
I've got an example of this setup in jsFiddle: http://jsfiddle.net/U9F7w/2/ (full screen: http://jsfiddle.net/U9F7w/2/embedded/result/ )
My question is, is there a way to make the sidebar stop once it touches the bottom/footer area?
I've read some solutions about setting the sidebar to absolute, unfortunately it's an existing site and changing the position didn't work and messed with a lot of the existing page elements.
Here's the jQuery/js I'm working with:
// set the offset
var sidebarOffset = $(".sidebar").offset();
var sidebarPadding = 15;
// when the window scrolls, keep sidebar in view
$(window).scroll(function() {
if ($(window).scrollTop() > sidebarOffset.top) {
$(".sidebar").stop().animate({marginTop: $(window).scrollTop() - sidebarOffset.top + sidebarPadding });
}
else {
$(".sidebar").stop().animate({marginTop: 0});
};
});
edit
One thing I thought about was (not sure if this is possible) to detect if the bottom of one div was lower than the bottom of another, stop the scrolling. Is there a way to detect if the bottom of one div is lower than the other?

Check if the sidebar's height is greater then that of the content:
var ct = $(".content");
var sb = $(".sidebar");
var sbOffsetTop = sb.offset().top;
var sbPadding = 15;
$(window).scroll(function() {
if (sb.height() < ct.height()) {
if ($(window).scrollTop() > sbOffsetTop) {
sb.stop().animate({top: $(window).scrollTop() - sbOffsetTop + sbPadding });
}
else {
sb.stop().animate({top: 0});
};
};
});
See demo fiddle with large content and demo fiddle with large sidebar.
And I don't know why exactly, I would use top in conjunction with position: relative, but marginTop works also fine.