Develop Reference

How do I stop the moving of a button while clicking another?

The following code contains 2 buttons and their respective drop-down contents.
When I click the first button, the other moves by itself. How do I stop this from happening?
var coll = document.getElementsByClassName("button");
var i;
for (i = 0; i < coll.length; i++) {
coll[i].addEventListener("click", function() {
this.classList.toggle("active");
var content = this.nextElementSibling;
if (content.style.display === "block")
content.style.display = "none";
else
content.style.display = "block";
});
}
.content {
display: none;
}
<button type="button" class="button" style="position: static; left: 100;">For Copper Rollers</button>
<div class="content" style=" width: 48%; background-color: lightblue; padding: 10px; border-radius: 10px; margin-right: 5px; ">
</div>
<button class="button" type="button" style="position: static; left: 175px; ">For Rubber Rollers</button>
<div class="content" style="margin-left:50%; float: left; width: 48%; background-color: lightblue; padding: 10px; border-radius: 10px;">
</div>

If you assign position:absolute you can do some rudimentary calculations in Javascript to determine the position the content should appear at. Is this more or less the desired effect?
document.querySelectorAll('button').forEach(( bttn, index )=>bttn.addEventListener('click',function(e){
this.classList.toggle("active");
// get the bounding box for the button so we can
// get a suitable height offset for content
let bb=this.getBoundingClientRect();
// find the content and toggle display state
let div=this.nextElementSibling;
div.style.display=div.style.display=='block' ? 'none' : 'block';
// find the current style properties for the content
let style=getComputedStyle( div );
let bbd=div.getBoundingClientRect();
// calculate x / y positions for content
let x=( Math.ceil( bbd.width ) + parseInt( style.paddingLeft ) - parseInt( style.marginLeft ) ) * index;
let y=Math.ceil( bb.height ) + Math.ceil( bb.bottom );
// apply those positions to the content
div.style.top=`${y}px`;
div.style.left=`${x}px`;
// identify content by parent
div.textContent=this.textContent.replace('For ','');
}));
body{
width:100%;
height:100vh;
}
button.button{
padding:0.25rem;
}
/*
assign the absolute position
to the content divs but let
javascript calculate x/y positions.
*/
.content {
position:absolute;
display: none;
width: calc( 50% - 3rem );
background-color:lightblue;
padding:1rem;
border-radius:10px;
border:1px solid grey;
float:none;
clear:none;
margin:0 0.25rem;
}
.content:first-of-type{
background:pink;
}
.active{
color:green
}
<!--
let css do the styling and positioning as `inline` styles
make updating a pain in the proverbial
-->
<button type="button" class="button">For Copper Rollers</button>
<div class="content"></div>
<button class="button" type="button">For Rubber Rollers</button>
<div class="content"></div>

I would go with making the dropdown content have a position: asolute (css), that way it won't affect any other elements on the page.
PS: make sure to keep accessibility in mind when making dropdowns, your current snippet unfortunately isn't.

Sliding animation when hiding/showing a div

I have two divs, top and bottom. Both divs have dynamic height, the top div will show or hide depending on a variable.
I would like to add in a sliding animation to the top div when showing or hiding, but the bottom div should stick with the top div and slide with it too.
var hide = true;
var trigger = document.getElementById("trigger");
var topdiv = document.getElementById("topdiv");
trigger.addEventListener('click', function() {
if (hide) {
topdiv.classList.add('hide');
} else {
topdiv.classList.remove('hide');
}
hide = !hide;
});
div {
position: relative;
display: block;
width: 100%;
padding: 10px;
}
.top {
background: #999;
}
.body {
background: #555;
}
.hide {
display: none !important;
}
<div id="topdiv" class="top hide">
<p>Top</p>
</div>
<div class="body">
<p>Body</p>
<button id="trigger">
Trigger
</button>
</div>
I tried adding transform animations, but the effect is only applied to the top div while the bottom div remains unanimated.
#keyframes topDivAnimate {
from {
transform: translateY(-100%);
}
to {
transform:translateY(0%);
}
}
Help is much appreciated.

I would use CSS transition rather than animation. I've found it easiest to do by animating the lower div rather than the upper one, and changing its position so that it covers the top one (or, of course, not). See demonstration below, I've made as minimal changes as I could to the CSS and JS:
var cover = true;
var trigger = document.getElementById("trigger");
var bottomdiv = document.getElementsByClassName("body")[0];
trigger.addEventListener('click', function() {
if (cover) {
bottomdiv.classList.add('cover');
} else {
bottomdiv.classList.remove('cover');
}
cover = !cover;
});
div {
position: relative;
display: block;
width: 100%;
padding: 10px;
}
.top {
background: #999;
}
.body {
background: #555;
transform: translateY(0%);
transition: transform 0.5s;
}
.cover {
transform: translateY(-100%);
}
<div id="topdiv" class="top hide">
<p>Top</p>
</div>
<div class="body">
<p>Body</p>
<button id="trigger">
Trigger
</button>
</div>

Are you looking something like this? Then please try this:
var trigger = document.getElementById("trigger");
var topdiv = document.getElementById("topdiv");
trigger.addEventListener('click', function() {
if ($('#topdiv').css('display') == 'none') {
$(topdiv).slideDown();
} else {
$(topdiv).slideUp();
}
});
div {
position: relative;
display: block;
width: 100%;
padding: 10px;
}
.top {
display: none;
background: #999;
}
.body {
background: #555;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div id="topdiv" class="top hide">
<p>Top</p>
</div>
<div class="body">
<p>Body</p>
<button id="trigger">
Trigger
</button>
</div>

Try this code and see if that's the effect you wanted. It uses the Animate.css library so you'll need to link that in your <head></head>
function animateCSS(element, animationName, callback) {
const node = document.querySelector(element)
node.classList.add('animated', animationName)
function handleAnimationEnd() {
node.classList.remove('animated', animationName)
node.removeEventListener('animationend', handleAnimationEnd)
if (typeof callback === 'function') callback()
}
node.addEventListener('animationend', handleAnimationEnd)
}
var hide = false;
var trigger = document.getElementById("trigger");
var topdiv = document.getElementById("topdiv");
trigger.addEventListener('click', function() {
if (!hide) {
topdiv.classList.remove('hide');
animateCSS('.body', 'slideInDown');
animateCSS('#topdiv', 'slideInDown');
} else {
animateCSS('#topdiv', 'slideOutUp', function() {
topdiv.classList.add('hide');
})
animateCSS('.body', 'slideOutUp');
}
hide = !hide;
});
Working Codepen demo of my solution
Here's some more explanation on how to use the Animate.css library.

js vertical slider with arrows

The thing is that I need to make a vertical images slider,so that when i press arrow down/arrow up every image changes it's position (the highest one goes bottom,the previous take it's place)
what it should look like:
what i have got so far:
$(function(){
var $vsliderboxes = $('#vsliderboxes'),
$vslidernav = $('#vslidernav'),
boxHeight = $vsliderboxes.height(),
current_index = 0;
function clickslide(){
clearInterval(intervalTimer);
clearTimeout(timeoutTimer);
timeoutTimer = setTimeout(function () {
intervalTimer = window.setInterval(autoslide, 2000);
}, 2500);
var index = $(this).index();
current_index = index;
$vsliderboxes.children().stop().animate({
top : (boxHeight * index * -1)
}, 500);
}
function autoslide(){
current_index++;
if (current_index >= $vsliderboxes.children().children().length) {
current_index = 0;
}
$vslidernav.find('a').eq(current_index).trigger('click');
}
$vslidernav.find('a').click(clickslide);
var intervalTimer = window.setInterval(autoslide, 2000),
timeoutTimer = null;
});
#vslidernav ul {
list-style: none;
padding: 0;
}
#vslidernav ul a {
padding: 0;
cursor: pointer;
height: 50px;
}
#vslidernav ul a:active {
color: #9C9A99;
}
#vslidernav ul a li {
height: 50px;
}
#vslidernav ul .active li {
}
.#vslidernav ul a:active {
background: transparent;
color: #9C9A99;
}
.vslider {
display: inline-block;
}
#vslidernav {
float: left;
width: 100px;
z-index: 1;
height: 250px;
}
#vsliderboxes {
position : relative;
overflow : hidden;
}
#vsliderboxes div {
height: 250px;
width: 900px;
}
#vsliderboxs-inner {
position : relative;
width : 900px;
height : 250px;
}
<div class="vslider">
<div id="vslidernav">
<ul>
<a id="1">
<li><img src="img/arrtop.gif"></li>
</a>
<a id="2">
<li><img src="img/arrdown.gif"></li>
</a>
<a id="3">
<li></li>
</a>
</ul>
</div>
<div id="vsliderboxes">
<div id="vsliderboxs-inner">
<div id="box1" class="active"><img src="img/slide1.gif"></div>
<div id="box2" class="inactive"><img src="img/slide2.gif"></div>
<div id="box3" class="inactive"><img src="img/slide3.gif"></div>
</div>
</div>
</div>
thanks for any advice

I think, that it isn't possible to solve this issue like you try to.
Because, when you work with the "top" property, you can't take one image from the top and append it to the other end because appending the image, will move the other images to another place --> the top property wouldn't be correct any more.
I think the contributed sliders (e.g. http://www.jssor.com/demos/vertical-slider.slider) work with the transform CSS property.
transform: translate3d()
Try to research about this property.
Roko C. Buljan answered on this page: loop carousel jquery
He uses a scrollTop loop for your problem.
I've also written a simple slider some time ago. I have now implemented the Roku C. Buljan method. Feel free to look at my code on Bitbucket.
https://bitbucket.org/d-stone/jqueryslider
An excerpt may help you:
value = prev_or_next == 'next' ? self.globals.slide_height : 0;
last = $('#container').find('> div:last');
first = $('#container').find('> div:first');
if(prev_or_next == 'prev') { // click on "next"-button
first.before(last); // put last element before first
settings.elements.inner.scrollTop(self.globals.slide_height); // set the scrollTop to 1 slide-height
}
// animation itself:
$('#container').stop().animate({scrollTop: value}, {
duration: settings.slide_speed,
done: function() {
if(prev_or_next == 'next') {
// put first item after last
last.after(first);
}
}
});
I'd advise you to validate your HTML (W3C Validator). There are some errors inside.
Invalid HTML can be the reason for some CSS and Javascript Errors.

jQuery - Change background colour on scroll

I want to transition the background colour of a fixed header element on scroll. So as a user scrolls down a full page block website, the header subtly changes to complement the block colours. I have almost achieved this on a Pen, however I can't quite work out how to measure how much has been scrolled as a flag for when to change.
Some extra info: The scroll amount to change at is 400px. The background colours are stored and fetched in an array. For reference my jQuery code is below:
$(document).ready(function(){
var bgArray = ["#252525","#333333","#454545","#777777"];
var scrollHeight = 400;
var scrolled = $(window).scrollTop(); //What is this measuring?
$(window).scroll(function() { //Can these conditions be neatened into one function?
if(scrolled < scrollHeight) {
$('header').css('background', bgArray[0]);
}
if(scrolled > scrollHeight) { // i.e more than 400px
$('header').css('background', bgArray[1]);
}
// and so on (800, 1200...)
})
})
Please refer to the Pen for full code. Any suggestions are greatly appreciated!

Updated Solution (2019)
To set a background for the header based on the current block in view below the header while scrolling:
because header has fixed position, we can get the amount by which window has scrolled by using $header.offset().top,
(index of the current block in view) is the ratio of (the amount by which window has scrolled) to the (height of each block),
now adjusting for the height of the header, the index of the current block in view is Math.floor(($header.offset().top + headerHeight) / sectionHeight).
See simplified demo below:
$(function() {
var $header = $('header'),
$window = $(window),
bgArray = ["#252525", "red", "blue", "green"],
headerHeight = 50,
sectionHeight = 400;
$window.scroll(function() {
$header.css('background', bgArray[Math.floor(($header.offset().top + headerHeight)
/ sectionHeight)]);
});
});
:root {
--header: 50px; /* header height */
--block: 400px; /* block height */
}
* {
box-sizing: border-box; /* include padding in width / height calculations */
}
body {
margin: 0; /* reset default margin of body */
}
header {
height: var(--header); /* sets height of header */
position: fixed;
top: 0;
left: 0;
width: 100%;
color: #FFF;
padding: 12px 0;
background: #252525; /* initial background */
transition: background 1s ease;
}
.container {
margin: 0 auto;
}
.wrap>div {
height: var(--block); /* sets height of each block */
text-align: center;
}
p {
margin: 0; /* reset margin of p */
}
.block-1 {
background: #27AACC;
color: #FFF;
}
.block-2 {
background: #668E99;
color: #FFF;
}
.block-3 {
background: #4AFFC1;
color: #444;
}
.block-4 {
background: #FF8F8A;
color: #FFF;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<header>
<div class="container">
Website Title.
</div>
</header>
<div class="wrap">
<div class="block-1">
<div class="container">
<p>This pen was made to solve a problem on a project...</p>
</div>
</div>
<div class="block-2">
<div class="container">
<p>...I needed a sticky header with thr right bg colour.</p>
</div>
</div>
<div class="block-3">
<div class="container">
<p>But this conflicted with the footer, which was the same colour...</p>
</div>
</div>
<div class="block-4">
<div class="container">
<p>So the solution was to subtley change the header's bg on scroll</p>
</div>
</div>
</div>
Original Solution
Check the top of each block with respect to how much the window has been scrolled (scrollTop) using $(window).scrollTop() > $('.block-1').offset().top. So now we can use this to change color on entering the block - see demo below:
$(document).ready(function() {
var $header = $('header'),
$window = $(window),
bgArray = ["#252525", "#333333", "#454545", "#777777"],
headerHeight = $header.outerHeight();
$window.scroll(function() {
for (var i = 1; i < 5; i++) {
if ($window.scrollTop() + headerHeight > $('.block-' + i).offset().top) {
$header.css('background', bgArray[i - 1]);
}
}
});
});
#import url('https://fonts.googleapis.com/css?family=Roboto:300,400,700');
body {
font-family: 'Roboto', sans-serif;
font-size: 30px;
font-weight: 300;
margin-top: 0;
}
header {
width: 100%;
height: 50px;
line-height: 50px;
position: fixed;
font-size: 24px;
font-weight: 700;
color: #FFF;
padding: 12px 0;
margin: 0;
background: #252525;
transition: background 1s ease;
}
.wrap {
padding-top: 74px;
margin: 0;
}
.container {
width: 960px;
margin: 0 auto;
overflow: hidden;
}
.block-1,
.block-2,
.block-3,
.block-4 {
height: 400px;
text-align: center;
}
p {
margin-top: 185px;
}
.block-1 {
background: #27AACC;
color: #FFF;
}
.block-2 {
background: #668E99;
color: #FFF;
}
.block-3 {
background: #4AFFC1;
color: #444;
}
.block-4 {
background: #FF8F8A;
color: #FFF;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<header>
<div class="container">
Website Title.
</div>
</header>
<div class="wrap">
<div class="block-1">
<div class="container">
<p>This pen was made to solve a problem on a project...</p>
</div>
</div>
<div class="block-2">
<div class="container">
<p>...I needed a sticky header with thr right bg colour.</p>
</div>
</div>
<div class="block-3">
<div class="container">
<p>But this conflicted with the footer, which was the same colour...</p>
</div>
</div>
<div class="block-4">
<div class="container">
<p>So the solution was to subtley change the header's bg on scroll</p>
</div>
</div>
</div>
Note that this solution needlessly loops through the sections on each scroll update called by the browser - and I don't like the look of it.

you are using scrolled as a fixed variable you should use it directly in your condition
this will make it dynamic for all elements inside wrap div
$(document).ready(function(){
var bgArray = ["#252525","#333333","#454545","#777777"];
$(window).scroll(function() {
for(var i = 1; i < bgArray.length; i++) {
if ($(window).scrollTop() > $('.wrap div:nth-child(' + i + ')').offset().top) {
$('header').css('background', bgArray[i-1]);
}
}
});
})

Try Like this:
$(document).ready(function(){
var bgArray = ["#252525","#333333","#454545","#777777"];
var scrollHeight = 400;
$(window).scroll(function() {
var scrolled = $(window).scrollTop();
var index=Number((scrolled/scrollHeight).toFixed());
if(bgArray[index]!=undefined)
$('header').css('background', bgArray[index]);
});
})
This is current scroll, so it should be inside: $(window).scrollTop()

Change navigation font color based on background

My problem is this. I have a fixed left navigation bar and I have to change the list font color based on the background of the section under it. The code is like this fiddle. So if the section is black and is below a link, the text is not seen. I have to change each list based on the background of a section under it so that it can be readable.
html
<div class="content">
<div id="left_side">
<div id="static_menu" class="">
<div id="main_navigation" class="">
<ul class="menu mainLeft" id="mymenu">
<li>Nav list 1</li>
<li>Nav list 2</li>
<li>Nav list 3</li>
<li>Nav list 4</li>
<li>Nav list 5</li>
</ul>
</div>
</div>
</div>
<div id="wrapper">
<div class="section" id="section1">section1</div>
<div class="section" id="section2">section2</div>
<div class="section" id="section3">section3</div>
<div class="section" id="section4">section4</div>
<div class="section" id="section5">section5</div>
</div>
</div>
css
.content{
position:relative;
}
#left_side
{
position:fixed;
left: 20px;
right: 20px;
z-index:999;
}
.mainLeft
{
list-style-type:none;
margin-left:0px;
padding-left:0px;
}
.mainLeft li
{
padding:5px 0;
}
.mainLeft li a
{
color:#000;
margin-bottom:5px;
}
#wrapper
{
position:relative;
}
.section
{
width: 100%;
text-align:center;
padding:150px 0;
border:1px solid #666;
}
#section1
{
background: #fff;
}
#section2
{
background: #000;
color:#fff;
}
#section3
{
background: #fff;
}
#section4
{
background: #000;
color:#fff;
}
#section5
{
background: #fff;
}
Fiddel

To do what you asked for you can do this with jquery:
working fiddle
var _li, _sections;
$(function() {
_li = $("#mymenu").find("li");
_sections = $("#wrapper").find(".section");
$(window).on('scroll', liBgs);
});
function liBgs() {
for (var i = 0; i < _li.length ; i++) {
var _litop = _li.eq(i).offset().top;
for (var j = 0; j < _sections.length; j++) {
var $s = _sections.eq(j),
_sectop = $s.offset().top,
_secbottom = $s.offset().top+$s.height()-20;
if (_litop > _sectop && _litop > _secbottom) {
var _color = rgb2hex($s.css('background-color'));
_li.eq(i).find('a').css('color', (_color=="#ffffff") ? "#000000" : "#ffffff");
}
}
}
}
function rgb2hex(rgb) {
rgb = rgb.match(/^rgb\((\d+),\s*(\d+),\s*(\d+)\)$/);
function hex(x) {
return ("0" + parseInt(x).toString(16)).slice(-2);
}
return "#" + hex(rgb[1]) + hex(rgb[2]) + hex(rgb[3]);
}
NOTE: rgb2hex() function was taken from this question: How to get hex color value rather than RGB value?
What this code does:
I'm basically comparing positions of the menu li's to the sections, checking under what
section each li is over everytime you scroll.. I'm not sure this is very efficient, but for something small scale it's ok.. if anyone knows how to make this even more efficient I'll be happy to learn.

Used jquery to do this. Found a reference here
HTML:
Added a extra attribute of color
<div class="section" id="section1" data-color="#333">section1</div>
JS:
$(window).on('scroll', function() {
var scrollTop = $(this).scrollTop();
$('.section').each(function() {
var topDistance = $(this).offset().top;
if ( (topDistance) < scrollTop ) {
$('#mymenu a').css('color',$(this).attr('data-color'));
}
});
});
DEMO

Can't you just give it a neutral colour to the fixed div and make it wrap around its content rather than have to resort to client scripts to dynamically change the colour? I have sanitized a bit the fixed element to make it look a bit more appealing...padding, margins, etc.
#left_side
{
position:fixed;
left: 20px;
top:10px;
z-index:999;
background-color:#eee;
padding:10px;
}
JS Fiddler Example

Something like this would work:
$(window).scroll(function() {
/* get current scroll-position within window */
var scroll = $(window).scrollTop();
$('.mainLeft li').each(function() {
/* get position of navigation-element (distance from top minus half of it's height, so that it changes color while it's half over black and half over white background) */
var elementPositionTop = parseFloat($(this).offset().top) + (parseFloat($(this).height() / 2));
/* change color for each background-change */
if (elementPositionTop >= 320 && elementPositionTop <= 640 || elementPositionTop >= 960 && elementPositionTop <= 1280) {
$(this).addClass('whiteText');
} else {
$(this).removeClass('whiteText');
}
});
});
Here's the additional CSS:
.mainLeft li.whiteText a {
color: #fff;
}
.section {
height: 18px;
overflow: hidden;
}
I gave the .section divs a fixed height because the JS I used works with fixed pixel values, and not all browsers interpret the height of elements the same if they're not defined...
Here's a fiddle: http://jsfiddle.net/Niffler/z34cG/

Updated.. see this fiddle
Do u Mean like this
$(document).scroll(function(){
var top=$(document).scrollTop()-322;
console.log(top)
if(top<0)
{
$('.mainLeft li a').css('color','black')
$('#li1 a').css('color',$('#section1').css('color'))
//$('#li1 a').css('color',"red")
}
if(top>0 && top<322)
{
$('.mainLeft li a').css('color','black')
$('#li2 a').css('color',$('#section2').css('color'))
//$('#li1 a').css('color',"red")
}
if(top>322 && top<644)
{
$('.mainLeft li a').css('color','black')
$('#li3 a').css('color',$('#section3').css('color'))
//$('#li1 a').css('color',"red")
}
if(top>644 && top<966)
{
$('.mainLeft li a').css('color','black')
$('#li4 a').css('color',$('#section4').css('color'))
//$('#li1 a').css('color',"red")
}
if(top>966 && top<1288)
{
$('.mainLeft li a').css('color','black')
$('#li5 a').css('color',$('#section5').css('color'))
//$('#li1 a').css('color',"red")
}
});