Develop Reference

Disabling Mousewheel JS horizontal scroll under certain screen size

I'm using .mousewheel to translate my downwards scroll into horizontal scroll on desktop, however for mobile I want to disable this behavior. I have tried the following:
if ( $(window).width() > 480) {
$('html, body, *').mousewheel(function(e, delta) {
this.scrollLeft -= (delta * -0.5);
e.preventDefault();
});
}
else {
$("html, body, *").bind("mousewheel", function() {
return false;
});
}
But no success, the horizontal scrolling works fine but the body content is still locked in place on mobile.

To get the viewport width:
var viewportWidth = Math.max(document.documentElement.clientWidth, window.innerWidth || 0)
Then you can just make a small change to your if statement:
if (viewportWidth > 480) { ... }
Full code example
This includes a little "fix-up" with the way that the scroll translation was happening - I couldn't get the previous way to work.
var viewportWidth = Math.max(document.documentElement.clientWidth, window.innerWidth || 0);
if (viewportWidth > 480) {
$('body').mousewheel(function(e) {
$(this).scrollLeft($(this).scrollLeft() - e.deltaY);
e.preventDefault();
});
} else {
$("body").on("mousewheel", function() { return false; });
}

Adjust div height dynamically based on scroll

I know there's a pretty simple way of doing this, but I can't seem to find anything in my searches.
I've found lots of examples of getting to a certain scroll location on the page and then animating a div to a different size, however I want to adjust a div's max height depending on the scroll location. Initially i'd like the div max-height to be about 150px, and then as you scroll from around 200px down the page to 400px down the page, I want the max-height of the div to decrease to 75px. Then obviously as you scroll back up, it gets larger.
I can't provide an example of what I've tried already, as I'm yet to attempt it as I have no idea on where to start.
Note: The size should gradually adjust with the scroll position.

I'm not sure if I understood your problem, but when I did I came out with this :D
$(window).scroll(function(){
var scrollTop = $(window).scrollTop();
if(scrollTop < 200){
maxHeight = 150;
}else if(scrollTop > 400){
maxHeight = 75;
}else{
maxHeight = 150 - 75 * (((scrollTop-200) * 100)/200)/100;
}
$('#thediv').stop().animate({'max-height': maxHeight+"px"}, 500);
})
Here you have a sample : https://jsfiddle.net/keccs4na/

You could try this:
$(window).on('scroll', function() {
var scrollTop = $(window).scrollTop();
if (scrollTop >= 200 && scrollTop <= 400) {
$('#divID').stop().animate({height: "75px"}, 250);
} else {
$('#divID').stop().animate({height: "150px"}, 250);
}
});
Note: You'll want to use CSS to initially set the height to 150px.

Try this.
$(window).on('scroll', function () {
var v = $(window).scrollTop();
if (v > 200) {
$('#id-of-div').css({"height": "75px","max-height":"75px"});
}
else {
$('#id-of-div').css({"height": "150px","max-height":"150px"});
}
});
EDIT:
$(window).on('scroll', function () {
var v = $(window).scrollTop();
if (v > 200) {
$('#id-of-div').animate({"height": "75px","max-height":"75px"},500);
}
else {
$('#id-of-div').animate({"height": "150px","max-height":"150px"},500);
}
});

Fix div position between two heights

I have a div that I want to keep position: fixed when scrolling between two points.
For example, it should remain fixed only between the height of it's container div
I've done the following:
$window.scroll(function(e) {
pos = $('.container-element').height();
if ($window.scrollTop() > pos) {
$(scroll-element).css({
position: 'relative',
});
} else {
$(scroll-element).css({
position: 'fixed',
});
}
});
However, this doesn't stop the scroll-element from becoming relative on reaching the end of the container-element. What should I do to achieve the intended behavior?
EDIT:
JSFiddle: http://jsfiddle.net/09760d60/

I think You should remove fixed position when $(window).scrollTop() > containerHeight-childHeight
$(document).ready(function(){
$(window).scroll(function(e) {
containerHeight = $('.container-element').height();
childHeight = $(".scroll-element").height();
if ($(window).scrollTop() > containerHeight-childHeight) {
$('.scroll-element').removeClass('fixed');
} else {
$('.scroll-element').addClass('fixed');
}
});
});
Please check updated fiddle
http://jsfiddle.net/PrashantShirke/1u991v1j/

You should check the top and bottom bounds of your container, and compare it with the top and bottom bounds of your scroll element :
$(document).ready(function(){
$(window).scroll(function(e) {
containerTop = $('.container-element').offset().top;
containerBottom = $('.container-element').height()+$('.container-element').offset().top;
scrollEl = $('.scroll-element').height();
if ($(window).scrollTop() >= containerTop && $(window).scrollTop()+scrollEl <= containerBottom) {
$('.scroll-element').css({
"top":$(window).scrollTop()+"px"
});
}
});
});
Exemple
$(window).scrollTop() < containerTop: scroll element is at top of content
$(window).scrollTop()+scrollEl > containerBottom: bottom of scroll element is at bottom of content
If scroll element has to move, adjust its top property while being absolutelly positioned by CSS.

I think it would be more robust to check the bottoms of the container and window, not the heights of the container and child.
$(document).ready(function(){
var $window = $(window);
var $container = $('.container-element');
var $scroll = $('.scroll-element');
var containerBox = $container[0].getBoundingClientRect();
$window.scroll(function(e) {
var scrollBottom = $window.scrollTop() + $window.height();
var canSeeContainerBottom = scrollBottom > containerBox.bottom;
$scroll.css('position', canSeeContainerBottom ? 'relative' : 'fixed');
});
});
http://jsfiddle.net/bryandowning/09760d60/14/

JQuery window scroll top and bottom

I am able to load my ajax when scrolling all the way to the bottom, i am trying to figure out how i can modify the piece of code below so that it works only when the window is scrolled to the top ?
$(window).scroll(function () {
if ($(document).height() <= $(window).scrollTop() + $(window).height()) {
//this works here for scrolling bottom
}
else if ($(document).height() >= $(window).scrollTop() + $(window).height()){
//i tried checking for greater than the window scroll but that didn't owrk
}
});

When the scrollTop() returns the vertical position of the scroll bar 0 it means the scroll bar is in top position.
$(window).scroll(function () {
if ($(window).scrollTop() == 0){
alert("Up");
}
});
Or you can update your code as follows,
$(window).scroll(function () {
if ($(window).scrollTop() + $(window).height() < $(document).height()){
alert("Up");
//i tried checking for greater than the window scroll but that didn't work
}
});

Check this or perhaps you should check if height of document and window object to make sure they're not null.
$(window).scroll(function () {
if ($(document).height() <= Number($(window).scrollTop() + $(window).height())) {
//this works here for scrolling bottom
}
// only greater i think, not equa
else if ($(document).height() > Number($(window).scrollTop() + $(window).height())){
}
});

Jquery follow scroll

I have a sort of sidebar on my website, which has to scroll down together with the user so that it is always in the view.
The code I'm using now is actually working fine however there is one problem. On smaller screens the sidebar scrolls before your at the sidebar thus making it impossible to see it all even if you scroll.
So what I want is the sidebar to scroll with the bottom instead of it being pushed down with the top so that when you reach the end of the sidebar it starts to scroll.
This is the code that I'm currently using.
var documentHeight = 0;
var topPadding = 10;
$(function() {
var offset = $("#mainright").offset();
documentHeight = $(document).height();
$(window).scroll(function() {
var sideBarHeight = $("#mainright").height();
if ($(window).scrollTop() > offset.top) {
var newPosition = ($(window).scrollTop() - offset.top) + topPadding;
var maxPosition = documentHeight - (sideBarHeight);
if (newPosition > maxPosition) {
newPosition = maxPosition;
}
$("#mainright").stop().animate({
marginTop: newPosition
});
} else {
$("#mainright").stop().animate({
marginTop: 0
});
};
});
});

I guess the "best practice" for accomplishing a task like this is to use dynamically changing css position from absolute to fixed and vice versa. A basic example could look like:
$(function(){
var $box = $('.box'),
offset = $box.offset(),
doc_h = $(document).height();
$(window).scroll(function(){
if($(window).scrollTop() > offset.top) {
if(!$box.hasClass('fix'))
$box.toggleClass('normal fix');
}
else{
if(!$box.hasClass('normal'))
$box.toggleClass('normal fix');
}
});
});​
Example in action: http://www.jsfiddle.net/YjC6y/14/

$(function() {
var top = 50;
$(window).scroll(function() {
$('#box').stop().animate({ top: $(window).scrollTop() + top}, 1000);
});
});
Try the example : http://jsbin.com/omiyi3

I think you can instead make the sidebar responsive by throwing your function into one of these:
if (responsive_viewport >= 768) {}
This makes it so that the function will only load if the viewport is bigger than or equal to 768px.