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How to make an element disappear after scrolling?

I have a custom icon element that is only displayed when its specific row in the table is hovered over, but when I scroll down without moving my mouse it doesn't update the hover and maintains the button on the screen and over my table's header. How can I make sure this doesn't happen?
export const StyleTr = styled.tr`
z-index: ${({ theme }) => theme.zIndex.userMenu};
&:hover {
background-color: ${({ theme, isData }) =>
isData ? theme.colors.primary.lighter : theme.colors.white};
div {
visibility: visible;
}
svg[icon] {
display: initial;
}
}
`;

I was just working on something similar to this for a web scraper recently.
Something like this should work:
function checkIfIconInViewport() {
// define current viewport (maximum browser compatability use both calls)
const viewportHeight =
window.innerHeight || document.documentElement.clientHeight;
//Get our Icon
let icon = document.getElementById('icon');
let iPos = icon.getBoundingClientRect();
//Show if any part of icon is visible:
if (viewportHeight - iPos.top > 0 && iPos.bottom > 0) {
icon.style.visibility = visibile;
}
else { icon.style.visibility = hidden; }
//Show only if all of icon is visible:
if (iPos.bottom > 0 && iPos.top >= 0) {
{
icon.style.visibility = visibile;
}
else { icon.style.visibility = hidden; }
//Add && iPos.bottom <= viewportHeight to the if check above for very large elements.
{
//Run function everytime that the window is scrolled.
document.addEventListener('scroll', checkIfIconInViewport);
Basically, every time a scroll event happens, we just check to see if the top & bottom of our element (the icon in your case) are within the bounds of the viewport.
Negative values, or values greater than the viewport's height mean that the respective portion of the element is outside the viewport's boundary.
Hopefully this helps! If you are dealing with a large quantity of objects, it may make sense to bundle the objects you are tracking together into an array and check each of them in a single function call to avoid saving function definitions for each individual object.
Edit: I just realized that I misunderstood your issue a bit. I think you can get by with just the bottom part of the code, and when a scroll event happens, set the icon's visibility to hidden. Assuming you want to hide it whenever the user scrolls?

Have you tried getting the scroll position of the DOM, then disabling (removing) the element once a certain scroll position is reached?

Add class onscroll combined with onepage-scroll.js plug-in

I'm currently using the onepage-scroll.js (https://github.com/peachananr/onepage-scroll) plug-in on my website to scroll through the homepage. When scrolling past the first "slide" I would also like to add a class (sticky) to my header to change some CSS. I've tried the code below, but I can't seem to get it working and I'm kinda in the dark here on how to make this solution work.
var header = $("header");
$("#sliders").scroll(function() {
var scroll = $('#sliders').scrollTop();
console.log(scroll);
if (scroll >= 50) {
header.addClass("sticky");
} else {
header.removeClass("sticky");
}
});

Try to make it on document ready.
Down only my example worked code on onepage-scroll.js
$(document).ready(function(){
$(".main").onepage_scroll({
sectionContainer: ".sectionscroll",
responsiveFallback: 600,
loop: true,
afterMove:function (index){
if ((index == 2)||(index == 3)){
$('#main').addClass('darktheme');
}else{
$('#main').removeClass('darktheme');
}
}
});
//$(".main").moveTo(2);
$(".btn-list-bottom").click(function(){$(".main").moveTo(4)});
});
All you section must have the same class.

On scroll, logo color changes, but scrolling back up it stays the same

Im creating a fixed header where on load, the logo is flat white. On scroll, it changes to the full color logo.
However, when scrolling back to the top, it stays the same colored logo instead of going back to white.
Here's the code (and a pen)
$(function() {
$(window).scroll(function() {
var navlogo = $('.nav-logo-before');
var scroll = $(window).scrollTop();
if (scroll >= 1) {
navlogo.removeClass('.nav-logo-before').addClass('nav-logo-after');
} else {
navlogo.removeClass('.nav-logo-after').addClass('nav-logo-before');
}
});
});
http://codepen.io/bradpaulp/pen/gmXOjG

There's a couple of things here:
1) You start with a .nav-logo-before class but when the logo becomes black you remove that class and then try to get the same element using a class selector that doesn't exist anymore
2) removeClass('.nav-logo-before') is different than removeClass('nev-logo-before), notice the "." in the first selector.
3) You get the element using the $('.selector')in every scroll event, this can be a performance issue, it's better to cache them on page load and then use the element stored in memory
4) It's not a good practice to listen to scroll events as this can be too performance demanding, it's usually better to use the requestAnimationFrame and then check if the scroll position has changed. Using the scroll event it could happen that you scroll up really fast and the scroll event doesn't happen at 0, so your logo won't change. With requestAnimationFrame this can't happen
$(function() {
var navlogo = $('.nav-logo');
var $window = $(window);
var oldScroll = 0;
function loop() {
var scroll = $window.scrollTop();
if (oldScroll != scroll) {
oldScroll = scroll;
if (scroll >= 1) {
navlogo.removeClass('nav-logo-before').addClass('nav-logo-after');
} else {
navlogo.removeClass('nav-logo-after').addClass('nav-logo-before');
}
}
requestAnimationFrame(loop);
}
requestAnimationFrame(loop);
});
body {
background-color: rgba(0,0,0,.2);
}
.space {
padding: 300px;
}
.nav-logo-before {
content: url(https://image.ibb.co/kYANyv/logo_test_before.png)
}
.nav-logo-after {
content: url(https://image.ibb.co/jYzFJv/logo_test_after.png)
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div>
<img class="nav-logo nav-logo-before">
</div>
<div class="space">
</div>

Dont need to add the dot . in front of the class name in removeClass and addClass:
Use this:
navlogo.removeClass('nav-logo-before')
Secondly, you are removing the class that you are using to get the element in the first place.
I have an updated codepen, see if this suits your needs: http://codepen.io/anon/pen/ZeaYRO

You are removing the class nav-logo-before, so the second time the function runs, it can't find any element with nav-logo-before.
Just give a second class to your navlogo element and use that on line 3.
Like this:
var navlogo = $('.second-class');
working example:
http://codepen.io/anon/pen/ryYajx

You are getting the navlogo variable using
var navlogo = $('.nav-logo-before');
but then you change the class to be 'nav-logo-after', so next time the function gets called you won't be able to select the logo using jquery as it won't have the '.nav-logo-before'class anymore.
You could add an id to the logo and use that to select it, for example.
Apart from that, removeClass('.nav-logo-before') should be removeClass('nav-logo-before') without the dot before the class name.

The problem is that you removes nav-logo-before and then you want to select element with such class but it doesn't exist.
I've rafactored you code to avert it.
Another problem is that you uses dot in removeClass('.before') while it should be removeClass('before') - without dot
$(function() {
var navlogo = $('.nav-logo');
$(window).scroll(function() {
var scroll = $(window).scrollTop();
if (scroll >= 1) {
navlogo.removeClass('before').addClass('after');
} else {
navlogo.removeClass('after').addClass('before');
}
});
});
body {
background-color: rgba(0,0,0,.2);
}
.space {
padding: 300px;
}
.before {
content: url(https://image.ibb.co/kYANyv/logo_test_before.png)
}
.after {
content: url(https://image.ibb.co/jYzFJv/logo_test_after.png)
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div>
<img class="nav-logo before">
</div>
<div class="space">
</div>

two column equal height layout using bootstrap

I have two column layout, left side only one image column and right side content etc. right now both are same height if rotate screen then it is not equal height but i refresh page(rotate screen) then both column do have equal height. i am trying to equal height without refresh page at rotate screen.
$(function(){
$balancer = function() {
$('.main-box').each(function(){
if($('.cola',this).height()>$('.colb',this).height()){
$('.colb',this).height($('.cola',this).height())
} else {
$('.cola',this).height($('.colb',this).height())
}
});
}
$balancer();
$(window).load($balancer());
$(window).resize($balancer());
});
html
<div class="main-box">
<div class="cola"></div>
<div class="colb"></div>
</div>

You can hook into the DeviceOrientation change event.
window.addEventListener("deviceorientation", function (e) {
//DO stuff here.
}, false);
Which should trigger when you go from horizontal to vertical and back again.

your jquery selector seems wrong.
$('.main-box').each....
You need to select the inner divs not the wrapper.
$('.main-box > div').each....
if( $(this).height() > $(this).siblings().height() ) {
$(this).siblings().height( $(this).height() );
} else {
$(this).height( $(this).siblings().height() )
}

Possible duplicate of : How can I make Bootstrap columns all the same height?
And there is another link which can help you: http://getbootstrap.com.vn/examples/equal-height-columns/

element css follows jquery declaration, not stylesheet

I have this initially in my .css stylesheet:
#media only screen and (min-width: 901px){
#main_panel {
width: 750px;
}
}
#media only screen and (min-width: 300px) and (max-width: 900px), handheld {
#main_panel {
width: 500px;
}
}
And then after some user interaction, this jQuery command changes this CSS-value:
$("#collapse").click(function() {
if ((($(window).width()) >= 600) && ($(window).width() <= 900)) {
$("#main_panel").animate({width: "500px"}, 'slow');
}
});
When I resize the window to more than 901px, it still follows the recent declaration by the jQuery and not the CSS-declaration in the stylesheet for 901px.
How to prioritize CSS-declaration when resizing the window?
Or how do you handle this better?
Please don't make me rely to $(window).resize() event forever :) That disregards the CSS.

** EDIT **
If you want to give priority to the CSS and still be able to animate it, what you probably need is this:
http://jsfiddle.net/2Fe22/1/
1) create a "normal" panel class and style it
.panel {width:750px;height:400px}
2) create a collapsed class and style it
.collapsed {width:500px}
3) create a function to read the collapsed and normal widths from the css:
function getClassWidth(aClass) {
return parseInt($("<div />").addClass(aClass).css('width'));
}
4) handle the click by first animating and then (at the end of the animation) add or remove the "collapsed" class to the panel and removing inline styles left by the animation:
var collapsed=false;
$("#collapse").click(function() {
collapsed=!collapsed;
if(collapsed) {
$("#main_panel").animate({width: (getClassWidth('collapsed'))+"px"}, 'slow',afterAnimation);
} else {
$("#main_panel").animate({width: (getClassWidth('panel'))+"px"}, 'slow',afterAnimation);
}
});
function afterAnimation() {
if(collapsed) $("#main_panel").addClass( "collapsed" ).removeAttr("style");
else $("#main_panel").removeClass( "collapsed" ).removeAttr("style");
}
You do this, so if the user resizes the window and the css changes your screen updates correctly.
** OLD POST (for reference) **
If you set sizes with JQuery you may go on setting them this way:
var collapsed=false;
$( window ).resize(calculateNewSizes); // When resized
calculateNewSizes(); // At startup
function calculateNewSizes() {
if(collapsed) {
// if screen width < xxx set elemt width to yyy, etc.. collapsed version
} else {
// if screen width < xxx set elemt width to yyy, etc..
}
}
// This toggles the collapsed state if user clicks on an element
$("#collapse").click(function() {
collapsed=!collapsed;
calculateNewSizes(); // or do the animation here
});
This script should be called as fast as possible after the beginning of all the elements to be resized to avoid a FOUC.
<div class="to be resized">
<script>
//do the $( window ).resize(...) here
</script>
... all other stuff </div>.
Warning, this code is UNTESTED. It is just to show an idea.

Since you are using jQuery Animate, the element style will directly receive width value.
Like this:
<el id="mainpanel" style="width: 500px">
This will always override any css on the element unless you use !IMPORTANT:
width: 100px !IMPORTANT;
http://codepen.io/rafaelcastrocouto/pen/suEHn (DEMO)
Notice that you should avoid that since you won't be able to change this if you need.