Develop Reference

Header disappearing on scroll

I'm trying to make my header disappear when scrolling down and only re-appear when scrolling up. I can't get it to work:
http://jsfiddle.net/mxj562qt/
Any ideas where I'm going wrong?
HTML:
<div id="header" class="custom-header">
This is your menu.
</div>
<main>
This is your body.
</main>
<footer>
This is your footer.
</footer>
Javascript:
// Hide Header on on scroll down
var didScroll;
var lastScrollTop = 0;
var delta = 5;
var navbarHeight = $("#header").outerHeight();
$(window).scroll(function(event){
didScroll = true;
});
setInterval(function() {
if (didScroll) {
hasScrolled();
didScroll = false;
}
}, 250);
function hasScrolled() {
var st = $(this).scrollTop();
// Make sure they scroll more than delta
if(Math.abs(lastScrollTop - st) <= delta)
return;
// If they scrolled down and are past the navbar, add class .nav-up.
// This is necessary so you never see what is "behind" the navbar.
if (st > lastScrollTop && st > navbarHeight){
// Scroll Down
$("#header").addClass('nav-up');
} else {
// Scroll Up
if(st + $(window).height() < $(document).height()) {
$("#header").removeClass('nav-up');
}
}
lastScrollTop = st;
}
CSS:
body {
padding-top: 40px;
}
#header {
background: #f5b335;
height: 50px;
position: fixed;
top: 0;
transition: top 0.2s ease-in-out;
width: 100%;
}
.nav-up {
top: -50px;
}
main {
height: 2000px;
}
footer { background: #ddd;}
* { color: transparent}
It would appear that the CSS class doesn't get added but I'm not sure why. Am I referencing the Div in the wrong way?

So, I can see that the issue stems from this bit of code ...
// Scroll Up
if(st + $(window).height() < $(document).height()) {
$("#header").removeClass('nav-up');
}
In my tests, the doc height was always > than the st + window height.
I did this ...
// Scroll Up
console.log('doc height: ', $(document).height());
console.log('st+window height: ', st + $(window).height());
if(st + $(window).height() < $(document).height()) {
$("#header").removeClass('nav-up');
}
// results from scrolling up + down
// doc height: 2058
// st+window height: 313
// doc height: 2058
// st+window height: 280
// doc height: 2058
// st+window height 1614
// doc height: 2058
// st+window height: 1580
Changing the aforementioned JS to this seems to get you where you need to be.
$("#header").removeClass('nav-up');
Then your CSS needed some work ...
I noticed that your top element wasn't applying due to the CSS selector priority.
.nav-up {
top: -50px !important;
}
The result: scrolling down, the nav bar hides, scrolling up, the navbar shows.
I forked your code below;
http://jsfiddle.net/itsbjk/aw6qb2mr/16/

The problem here is with your CSS. You have specified position:fixed; in your code and that bit of CSS overrides all the JS you are writing. Fixed will force your header to be visible no matter what you are doing. Instead, you could try this in your CSS:
body {
padding-top: 40px;
}
#header {
background: #f5b335;
height: 50px;
position: absolute;
top: 0;
transition: top 0.2s ease-in-out;
width: 100%;
}
.nav-up {
top: -50px;
}
main {
height: 2000px;
}
footer { background: #ddd;}
* { color: transparent}
The absolute property should make it disappear on scrolling. And also, your referencing of the <div> tag isn't wrong!

Stop fixed element scrolling at certain point

I have fixed sidebar which should scroll along with main content and stop at certain point when I scroll down. And vise versa when I scroll up.
I wrote script which determines window height, scrollY position, position where sidebar should 'stop'. I stop sidebar by adding css 'bottom' property. But I have 2 problems with this approach:
When sidebar is close to 'pagination' where it should stop, it suddenly jumps down. When I scroll up it suddenly jumps up.
When I scroll page, sidebar moves all the time
Here's my code. HTML:
<div class="container">
<aside></aside>
<div class="content">
<div class="pagination"></div>
</div>
<footer></footer>
</div>
CSS:
aside {
display: flex;
position: fixed;
background-color: #fff;
border-radius: 4px;
transition: 0s;
transition: margin .2s, bottom .05s;
background: orange;
height: 350px;
width: 200px;
}
.content {
display: flex;
align-items: flex-end;
height: 1000px;
width: 100%;
background: green;
}
.pagination {
height: 100px;
width: 100%;
background: blue;
}
footer {
height: 500px;
width: 100%;
background: red;
}
JS:
let board = $('.pagination')[0].offsetTop;
let filterPanel = $('aside');
if (board <= window.innerHeight) {
filterPanel.css('position', 'static');
filterPanel.css('padding-right', '0');
}
$(document).on('scroll', function () {
let filterPanelBottom = filterPanel.offset().top + filterPanel.outerHeight(true);
let bottomDiff = board - filterPanelBottom;
if(filterPanel.css('position') != 'static') {
if (window.scrollY + window.innerHeight - (bottomDiff*2.6) >= board)
filterPanel.css('bottom', window.scrollY + window.innerHeight - board);
else
filterPanel.css('bottom', '');
}
});
Here's live demo on codepen
Side bar is marked with orange background and block where it should stop is marked with blue. Than you for your help in advance.

I solved my problem with solution described here
var windw = this;
let board = $('.pagination').offset().top;
let asideHeight = $('aside').outerHeight(true);
let coords = board - asideHeight;
console.log(coords)
$.fn.followTo = function ( pos ) {
var $this = this,
$window = $(windw);
$window.scroll(function(e){
if ($window.scrollTop() > pos) {
$this.css({
position: 'absolute',
top: pos
});
} else {
$this.css({
position: 'fixed',
top: 0
});
}
});
};
$('aside').followTo(coords);
And calculated coordinates as endpoint offset top - sidebar height. You can see solution in my codepen

animated loads in wrong spot

I have a div that animates up and down which works fine. The issue I'm getting is that every time the page loads the div starts at the very top of the page and then jumps down to where it needs to be after the animation starts.
<body id="body">
<div id="square"></div>
</body>
#body {
background: #000;
}
#square {
background-color: #fff;
margin: 0 auto;
position: relative;
width: 100px;
height: 100px;
}
var box = document.getElementById('square');
TOP = (window.innerHeight - box.offsetHeight)/2;
box.style.top = TOP;
var down = setInterval(animateDown, 15);
var up;
function animateDown()
{
TOP += 3;
box.style.top = TOP + 'px';
if(TOP > 900){
clearInterval(down);
up = setInterval(animateUp, 15);
}
}
function animateUp()
{
TOP -= 3;
box.style.top = TOP + 'px';
if(TOP <= (window.innerHeight - box.offsetHeight)/2){
clearInterval(up);
down = setInterval(animateDown, 15);
}
}
Here is a link to the jsfiddle as well >> https://jsfiddle.net/xgilmore/pLbgvc3L/
thanks in advance

This is sort of a work around, but you can start the box off as hidden, and then once you start animating, set it visible. https://jsfiddle.net/pLbgvc3L/1/
function animateDown()
{
box.style.visibility = 'visible';
#square {
background-color: #fff;
//margin: 0 auto;
position: relative;
width: 100px;
height: 100px;
top: 20%;
visibility: hidden;
}
Oh sorry, I actually know what is going on, it just took a second look to figure it out. top: 20% doesn't do anything because percentages only work if the parent element (body) has an explicit height. Like so https://jsfiddle.net/pLbgvc3L/2/

How do you create 3 adjustable divs?

What I want:
| A | | B | | C |
^ ^
When you move the handles left and right A, B, and C resize accordingly
| A | | B | | C |
What I have is the || between B and C sliding, but not resizing B and all I get on the other one is the resize cursor. Basically C is a curtain and covers A and B. I did get min size working for C.
| A | C |
I broke somebody else's perfectly good code to get this far:
var isResizing = false,
who='',
lastDownX = 0;
$(function () {
var container = $('#container'),
left = $('#left'),
right = $('#right'),
middle = $('#middle'),
hand2 = $('#hand2'),
handle = $('#handle');
handle.on('mousedown', function (e) {
isResizing = true;
who=e.target.id;
lastDownX = e.clientX;
});
$(document).on('mousemove', function (e) {
var temp, min;
// we don't want to do anything if we aren't resizing.
if (!isResizing)
return;
min=container.width() * 0.1;
temp = container.width() - (e.clientX - container.offset().left);
if (temp < min)
temp = min;
if (who == 'handle')
right.css('width', temp);
if (who == 'hand2')
left.css('width', temp);
}).on('mouseup', function (e) {
// stop resizing
isResizing = false;
});
});
body, html {
width: 100%;
height: 100%;
margin: 0;
padding: 0;
}
#container {
width: 100%;
height: 100%;
/* Disable selection so it doesn't get annoying when dragging. */
-webkit-touch-callout: none;
-webkit-user-select: none;
-khtml-user-select: none;
-moz-user-select: moz-none;
-ms-user-select: none;
user-select: none;
}
#container #left {
width: 40%;
height: 100%;
float: left;
background: red;
}
#container #middle {
margin-left: 40%;
height: 100%;
background: green;
}
#container #right {
position: absolute;
right: 0;
top: 0;
bottom: 0;
width: 200px;
background: rgba(0, 0, 255, 0.90);
}
#container #handle {
position: absolute;
left: -4px;
top: 0;
bottom: 0;
width: 80px;
cursor: w-resize;
}
#container #hand2 {
position: absolute;
left: 39%;
top: 0;
bottom: 0;
width: 80px;
cursor: w-resize;
}
<div id="container">
<!-- Left side -->
<div id="left"> This is the left side's content!</div>
<!-- middle -->
<div id="middle">
<div id="hand2"></div> This is the middle content!
</div>
<!-- Right side -->
<div id="right">
<!-- Actual resize handle -->
<div id="handle"></div> This is the right side's content!
</div>
</div>
Been playing with it here: https://jsfiddle.net/ju9zb1he/5/

I was looking for a solution that required less extensive CSS. It does have one minor bug(FIXED), but hopefully this should get you started. Here is a DEMO.
Also I aimed to use DOM Traversal methods like .next() and .prev() that way it wouldn't be so attribute dependent, and would be easily reusable if you needed a feature like this multiple times on a page.
Edit - Further Explanation
The idea here is onClick of a .handle we want to gather the total width (var tWidth) of the .prev() and .next() divs relative to the .handle in the DOM. We can then use the start mouse position (var sPos) to substract the amount of pixels we've moved our mouse (e.pageX). Doing so gives us the correct width that the .prev() div should have on mousemove. To get the width of the .next() div we need only to subtract the width of the .prev() div from the total width (var tWidth) that we stored onClick of the .handle. Hope this helps! Let me know if you have any further questions, however I will likely be unavailable till tomorrow.
HTML
<div class="container">
<div id="left"></div>
<div id="l-handle" class="handle"></div>
<div id="middle"></div>
<div id="r-handle" class="handle"></div>
<div id="right"></div>
</div>
CSS
#left, #middle, #right {
display: inline-block;
background: #e5e5e5;
min-height: 200px;
margin: 0px;
}
#l-handle, #r-handle {
display: inline-block;
background: #000;
width: 2px;
min-height: 200px;
cursor: col-resize;
margin: 0px;
}
jQuery
var isDragging = false,
cWidth = $('.container').width(),
sPos,
handle,
tWidth;
$('#left, #middle, #right').width((cWidth / 3) - 7); // Set the initial width of content sections
$('.handle').on('mousedown', function(e){
isDragging = true;
sPos = e.pageX;
handle = $(this);
tWidth = handle.prev().width() + handle.next().width();
});
$(window).on('mouseup', function(e){
isDragging = false;
});
$('.container').on('mousemove', function(e){
if(isDragging){ // Added an additional condition here below
var cPos = sPos - e.pageX;
handle.prev().width((tWidth / 2) - cPos); // This was part of the bug...
handle.next().width(tWidth - handle.prev().width());
// Added an update to sPos here below
}
});
Edit
The bug was caused by 2 things.
1) On mousemove we were dividing the total width by two, instead of an updated mouse offset.
2) The sPos was not updating on mousemove, and stayed a static number based off of the click location.
Resolution
Update the sPos on mousemove that way the mouse offset is accurately based off of the previous mousemove position, rather than the click position. When this is done we can then subtract the .next() div's width from the total width. Then we subtract our current mouse position from the remaining width. The fiddle has been updated as well.
$('.container').on('mousemove', function(e){
var cPos = sPos - e.pageX;
if(isDragging && ((tWidth - handle.next().width()) - cPos) <= tWidth){
handle.prev().width((tWidth - handle.next().width()) - cPos);
handle.next().width(tWidth - handle.prev().width());
sPos = e.pageX;
}
});
Edit
Added an additional condition on mousemove to prevent the drag from exceeding the total width (var tWidth).

Can you please explain what you're trying to accomplish?
I don't believe you need to use position: absolute. The premise of absolute positioning is to override the margin and padding imposed on an element by its parent.
You don't need to do this, all elements have relative positioning by default which makes them push eachother around and don't allow overlapping.
I'm probably missing something, but I think this is what you want with nothing but some very basic CSS: http://jsfiddle.net/3bdoazpk/
<div class='first'>
asdf
</div><div class='second'>
dasdf
</div><div class='third'>
sadf
</div>
body {
margin: 0;
}
div {
display: inline-block;
height: 100%;
}
.first, .third {
width: 40%;
}
.first {
background-color: red;
}
.second {
background-color: blue;
width: 20%;
}
.third {
background-color: green;
}

Making a sticky header work

I've got the following code for a sticky header, but I can't get the scroll to work and it's not a smooth transition. The #top-nav-wrapper barely scrolls when the fixed header below is activated:
<script>
$(document).scroll( function() {
var value = $(this).scrollTop();
if ( value > 48 ) {
$(".header").css("position", "fixed");
$("body").css("padding-top", "90px");
} else {
$(".header").css("position", "relative");
$("body").css("padding-top", "0");
}
});
</script>
The 48 value is the height of the #top-nav-wrapper, plus it has a box-shadow.
The .header class with the search bar is what should remain.
The basic html:
<div class="headerWrapper">
<div id="top-nav-wrapper"></div>
<div class="header"></div>
</div>
The CSS:
body {
background: #EEE;
}
#top-nav-wrapper {
width: 100%;
position: relative;
box-shadow: 0px 1px 1px 0px #B8B8B8;
z-index: 2001;
background: #EEE;
}
.header {
position: relative;
left: 0;
top: 0;
width: 100%;
min-height: 90px;
z-index: 2000;
background: #EEE;
height: 90px;
box-shadow: 0px 1px 2px #C4C4C4;
}
* I tried the following suggestion, but it's the same effect as before:
<script>
$(window).scroll( function() {
var value = $(this).scrollTop();
var $body = $('body');
var docked = $body.hasClass('docked');
if ( value > 48 ) {
if( !docked ) {
$body.addClass('docked');
}
} else {
if( docked ) {
$body.removeClass('docked');
}
}
});
</script>
Any ideas appreciated.
Update - I've changed the script to the following and placed it in the head - this resolves the top nav not scrolling dynamically and I added a placeholder div after the header and before the content with the same size height as the fixed header to keep the content where it should be (because the fixed header changes the natural flow), but there's still the lag/jump when the fixed header kicks in.
Placeholder CSS:
.headerPlaceholder {
height: 90px;
width: 100%;
display: none;
}
Solution to top nav not scrolling all the way after 48px scroll height was set:
<script>
$(document).ready(function () {
var div = $('.header');
var div2 = $('.headerPlaceholder');
var start = $(div).offset().top;
$.event.add(window, "scroll", function () {
var p = $(window).scrollTop();
$(div).css('position', ((p) > start) ? 'fixed' : 'static');
$(div).css('top', ((p) > start) ? '0px' : '');
$(div2).css('display', ((p) > start) ? 'block' : 'none');
});
});
</script>
To make it a smooth transition, there might need to be a slight delay and fadein/out effect, if anyone could help with that?

You can try
$(window).scroll( function() {
var value = $(this).scrollTop();
var $body = $('body');
var docked = $body.hasClass('docked');
if ( value > 48 ) {
if( !docked ) {
$body.addClass('docked');
}
} else {
if( docked ) {
$body.removeClass('docked');
}
}
});
CSS
.docked {
padding-top: 90px;
}
.docked .header {
position: fixed;
z-index: 2005;
}
You can be more efficient if there is an overall container you can target instead of body.