Waypoint.js: Add class when N distance to top - javascript

I dont know if it is easy or not, but i just cant figure out something with Waypoint.js
I need to add a class to #stickytop when user reach, for ex, 100px of scroll
Any idea how to do this?
offset is not working for me.
Thanks in advance

This is not really the use case for jQuery waypoints. It's designed for testing how far specific elements are from the top of the screen, not how far a user has scrolled.
However you can easily do what you want with jQuery:
$(document).on('scroll', function () {
// if the scroll distance is greater than 100px
if ($(window).scrollTop() > 100) {
// do something
$('#stickytop').addClass('myClass');
}
});
Or vanilla JavaScript:
document.addEventListener('scroll', function () {
if (window.scrollY > 100) {
var el = document.getElementById('#stickytop');
el.className = el.className + " myClass";
}
})

Related

jQuery Navbar transition on scroll. How to adjust specific point of transition

In a site I'm building I'm trying to make the navbar change color when I scroll. However, I don't want it to change colors as soon as I start scrolling. I want it at a specified point (once I scroll past my jumbotron).
So far, I've only been able to make it work by scrolling from the top. I'm not quite skilled enough to figure out how to do it past a specific point on my page. I would greatly appreciate some guidance on this.
jQuery script
$(function () {
$(document).scroll(function () {
var $nav = $(".fixed-top");
$nav.toggleClass('scrolled', $(this).scrollTop() > $nav.height());
});
});
Thanks for any help or guidance!
There are a lot of ways you can do it.
one way could be done with pure javascript.
change changeColorValue that represents the scroll bar value according to your needs.
Here is my suggestion:
LIVE DEMO
JavaScript:
var changeColorValue = 50;
window.addEventListener("scroll", scrollAnim);
function scrollAnim () {
var val = getScrollVal();
if(val > changeColorValue)
{
document.getElementById('mynav').style.backgroundColor = 'red';
}
else
{
document.getElementById('mynav').style.backgroundColor = '#333';
}
}
function getScrollVal()
{
var val = $(document).scrollTop();
return val;
}

Add class to element if y-position bigger as another element

I want to add a class to an element as soon as the users' scroll-position has "hit" a special - other - element.
I try to use that code therefore
var hands = $(".sw_3--breit");
$(window).scroll(function() {
var scroll = $(window).scrollTop();
// The next line is the one I am asking for help
if (scroll >= window.innerHeight)
{
hands.addClass("fixed");
} else {
hands.removeClass("fixed");
}
});
Which works nice by adding the class after the scroll is bigger then the users display-height I guess. But I want to add - and afterwards also remove - a class when then user has "hit" another element.
What I am asking for is something - very roughly and stupid I know - like:
var other_elements_position = $(".other_element"().position;
if (scroll >= other_elements_position)
How can I achieve that? And I already do use jquery for other things, so using jquery there would make sense I guess.
Thanks!
For people that got the same problem as I do have, this worked for me:
var hands = $(".sw_3--breit");
var hands_original = $(".sw_8").position();
var hands_off = $("#target_agentur").position();
var hands_corrected = (hands_original.top + 680) // here I add a small delay to the trigger of the "animation"
$(window).scroll(function () {
var scroll = $(window).scrollTop();
if (scroll >= hands_corrected && scroll <= hands_off.top) // I doublecheck against 2 heights
{
hands.addClass("fixed");
} else {
hands.removeClass("fixed");
}
});

jquery toggle class on scroll

I'm using bootstrap as my css framework. I want to be able to toggle a class on that navbar once the user has scrolled past the big header image at the top of the website.
EDIT:
I went full derp... so I drank some more coffee and figured this out. Now if it's the best way to do it, not sure but here is what I have, and it works..
$(window).scroll(function() {
if ($(".navbar").offset().top + $(".navbar").outerHeight(true) > $('.landing-header').outerHeight(true)) {
$(".navbar").addClass("darker-bg");
} else {
$(".navbar").removeClass("darker-bg");
}
});
#SetSailMedia also answered it so I went with their answer, which was cleaner than my imo
A better way to measure is to compare $(this).scrollTop during $(window).scroll() event.
$(window).scroll( function( e ){
if( $(this).scrollTop() > $('.landing-header').offset().top ){
$(".navbar").addClass("darker-bg");
} else {
$(".navbar").removeClass("darker-bg");
}
});
Forgive me, first post of this answer kept your original .offset().bottom property, which does not exist. I've updated to .offset().top. If you wanted to measure against bottom of the element, replace that line with:
if( $(document).scrollTop() > ($('.landing-header').offset().top + $('.landing-header').outerHeight()) ){
You can toggle class when scroll somewhere with something like this:
$(window).scroll(function() {
var scroll = $(window).scrollTop();
if (scroll >= 1) {
$(".header").addClass("change");
} else {
$(".header").removeClass("change");
}
});
Here is jsfiddle.

Pure js add and remove (toggle) class after scrolling x amount?

I don't want to use jQuery for this.
It's really simple, I just want to add a class after scrolling past a certain amount of pixels (lets say 10px) and remove it if we ever go back to the top 10 pixels.
My best attempt was:
var scrollpos = window.pageYOffset;
var header = document.getElementById("header");
function add_class_on_scroll() {
header.classList.add("fade-in");
}
function remove_class_on_scroll() {
header.classList.remove("fade-in");
}
window.addEventListener('scroll', function(){
if(scrollpos > 10){
add_class_on_scroll();
}
else {
remove_class_on_scroll();
}
console.log(scrollpos);
});
But console shows a number that continues to grow regardless of scrolling up or down. And the class fade-in never gets added, though console shows we past 10.
You forgot to change the offset value in the scroll handler.
//use window.scrollY
var scrollpos = window.scrollY;
var header = document.getElementById("header");
function add_class_on_scroll() {
header.classList.add("fade-in");
}
function remove_class_on_scroll() {
header.classList.remove("fade-in");
}
window.addEventListener('scroll', function(){
//Here you forgot to update the value
scrollpos = window.scrollY;
if(scrollpos > 10){
add_class_on_scroll();
}
else {
remove_class_on_scroll();
}
console.log(scrollpos);
});
Now you code works properly
Explanation
There is no documentation for that, like you asked for. This is just an issue in the logic workflow.
When you say that scrollpos = window.scrollY your page is at an top-offset of 0, so your variable stores that value.
When the page scrolls, your scroll listener will fires. When yout listener checks for the scrollpos value, the value is still 0, of course.
But if, at every scroll handler, you update the scrollpos value, now you can have a dynamic value.
Another option is you to create a getter, like
var scrollpos = function(){return window.scrollY};
This way you can dynamically check what that method will return for you at every offset.
if(scrollpos() > 10)
See? Hope that helped. (:
One simple way to achieve what you want (one line of code inside the scroll event):
window.addEventListener('scroll', function(e) {
document.getElementById('header').classList[e.pageY > 10 ? 'add' : 'remove']('fade-in');
});
#header {
height: 600px;
}
.fade-in {
background-color: orange;
}
<div id='header'></div>
just use the method toggle in classList
header.classList.toggle('fade-in')

How do I add a class to the body using jQuery, scrollTop, and toggleClass

I have a question concerning jQuery's scrollTop functionality, and it's ability to toggle a class based on the amount of vertical scroll.
What I am trying to accomplish is on any page with a "section.banner" class, that after you scroll past the banner a class is applied to the body tag. This will allow me to change the fill colors of several SVGs that are in the site's header, as well as a fixed positioned side nav that is for pagination.
I am terrible at javascript, and have been stuck searching and trying to get this for hours. any help will be greatly appreciated. Here's the code that I'm working with now (CodeKit is telling me it is wrong, which I am not surprised). The value of 200 is just a placeholder and will be calculated by the height of a fluid image. Full disclosure, I have no idea if the brackets and parenthesis are correct.
// Header/Fixed Pagination Banner Scroll Recoloriing (toggle class)
// Check If '.banner' Exists
if( $('section.banner').length > 0) {
$('body').scrollTop(function)()
{
if $(window).scrollTop >= 200 {
$('body').toggleClass('downtown');
return false;
}
}
}
Try something like this :
if( $('section.banner').length > 0) {
$(window).scroll(function() {
{
if ($(window).scrollTop() >= $('section.banner').scrollTop()) {
$('body').toggleClass('downtown');
return false;
}
});
}
UPDATE
There was little mistake in my code : http://jsfiddle.net/t2yp15hq/
var top = $('section.banner').position().top;
if($('section.banner').length > 0) {
$(window).scroll(function() {
if ($(this).scrollTop() >= top) {
$('body').addClass('downtown');
}
else
{
$('body').removeClass('downtown');
}
});
}
It does not work with toogleClass, the background is flashing.
UPDATE
http://codepen.io/anon/pen/wBWzXy
The solution is to recalculate the top when the window is resized :
$(window).resize(function(){
top = $('section.story-intro').offset().top - 90;
});

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