Develop Reference

JS slider flickering on transform: translate

I have a Vue component that is an image slider, and I use transform: translateX to cycle through the images. I based my work off of Luis Velasquez's tutorial here: https://dev.to/luvejo/how-to-build-a-carousel-from-scratch-using-vue-js-4ki0
(needed to make a couple of adjustments, but it follows it pretty closely)
All works fairly well, except I get a strange flicker after the sliding animation completes, and I cannot figure out why.
In my component I have:
<button
:class="btnClass"
#click="prev"
#keyup.enter="prev"
#keyup.space="prev"/>
<button
:class="btnClass"
#click="next"
#keyup.enter="next"
#keyup.space="next" />
<div class="slider-wrap">
<div class="slider-cards">
<div ref="slidewrap"
v-hammer:swipe.horizontal="handleSwipe"
class="cards"
>
<div class="inner" :style="innerStyles" ref="inner">
<SliderCard v-for="(item, index) in slides"
:key="`${item.id}-${index}`"
:item="item"
/>
</div>
</div>
</div>
</div>
The navigation of those is handled via the following methods (just including the "next" navigation one to spare some redundancy here:
next () {
// translate the inner div left, push first element to last index, and slide
// inner div back to original position
if (this.transitioning) {
return;
}
this.transitioning = true;
const elementToMoveToEnd = this.slides[2];
this.moveLeft();
this.afterTransition(() => {
this.resetTranslate();
this.slides.splice(0, 1);
this.slides.push(elementToMoveToEnd);
this.transitioning = false;
});
},
resetTranslate() {
/// NOTE: this.navigationStep is just a static px value set up elsewhere in my component, based on screenwidth -- it just sets how much the slider should translate based on the card widths.
this.innerStyles = {
transition: 'none',
transform: `translateX(-${this.navigationStep})`
};
},
moveLeft() {
this.innerStyles = {
transform: `translateX(-${this.navigationStep})
translateX(-${this.navigationStep})`
};
},
afterTransition (callback) {
const listener = () => {
// fire the callback (reorganizing slides, resetting the translation),
// and remove listener immediately after
callback();
this.$refs.inner.removeEventListener('transitionend', listener);
};
this.$refs.inner.addEventListener('transitionend', listener);
},
In my CSS, I control the translation animation via:
.inner {
transition: transform 0.2s linear;
white-space: nowrap;
-webkit-transform-style: preserve-3d;
}
(the preserve-3d was a desperate attempt to fix the flickering).
My slides move, but there is a flash immediately after they move -- I suspect it has something to do with competing translations/transitions in the moveLeft and resetTranslation methods, but I've messed with those, and nothing has improved the flashing. If anyone has any ideas, I'd really appreciate it!

How to make autosliding carousel thumbnail change background image when active

my question has 3 parts. Any assistance with any part of this JS problem would be greatly appreciated. I am attempting to learn and comprehend JS by trial and error.
I've created this nice looking travel landing page, https://portfolioprime.github.io/Nature%20carousel/glidejs.html with a thumbnail carousel which uses Glide.js, which is really cool and works well. The carousel moves to the left and has arrow buttons to manually control the slide.
But I've been trying to implement a vanilla JS carousel slider,but I am failing miserably. Been struggling for 2 days and the best I can achieve is getting a single carousel item moving left and right. See https://portfolioprime.github.io/Nature%20carousel/.
What I'd like is to get the carousel sliding left automatically, with arrow buttons to manually control the slider.
I'm targeting all the carousel-items with querySelectorAll('.carousel-items') and adding left:-274px to the carousel container glide__slides.
Here's my JS code.
// var & event-listener buttons
document.querySelector(".left").addEventListener("click", slideLeft);
document.querySelector(".right").addEventListener("click", slideRight);
// Function slide left
function slideLeft(left) {
document.querySelector('.glide__slides').style.left = left;
}
// Function slide left
function slideRight(right) {
document.querySelector('.glide__slides').style.left = right;
}
Secondly, I'd like to have an active carousel-item, which when active automatically changes the background Image.
Right now I have the hero.style.background = var; and I've got it changing onclick with onclick = function('01.jpg') on each carousel item.
Here's the code.
// Change Hero Img
function heroChange(hmmm) {
var hero = document.querySelector('.hero');
hero.style.background = hmmm;
}
So I guess I would add EventListeners to the carousel-items and add an active class to the carousel-item like so,
var slides = document.querySelectorAll('.carousel-items');
function changeBgImg() {
slides.forEach(s => s.classList.remove('active');
this.classList.add('active');
//change the bg image === this
//But I have no idea how to do that
}
Thirdly I've got the content, background and carousel indicators using the same functions above but it seems like really dirty code. The HTML has each .carousel-item, there are ten of them, calling 4 functions each. It looks like this:
<div class="glide hero-carousel">
<div class="glide__track" data-glide-el="track">
<ul class="glide__slides">
<li class="glide__slide carousel-item"
onclick="heroChange('url(images/02.jpg) bottom/cover no-repeat');
number('01');
h4('Destination Shire');
h1('Valley<br> of Dreams');">
<div class="carousel-text">
<p>Destination Shire</p>
<h3>Valley<br> of Dreams</h3>
</div>
</li>
<li class="glide__slide carousel-item"
onclick="heroChange('url(images/03.jpg) bottom/cover no-repeat');
number('02');
h4('Destination Westwood');
h1('Misty<br> Woodlands');">
<div class="carousel-text">
<p>Destination Westwood</p>
<h3>Misty<br> Woodlands</h3>
</div>
</li>
</ul>
</div>
</div>
So it looks pretty yucky. It works though, but I would love to find a more elegant way of achieving this by putting all of these functions into one function that does each part in sequence.
Lastly, I'd want to get transition on-click animations going but that's another kettle of fish entirely.
So that's it. Whew!
Thanks for taking the time guys, I appreciate it. Any help you can provide is going to make me a better designer. There are actually a bunch of projects I have will benefit from the answers.
If you can provide help with at least Part 2 & 3: cleaning up the code into 1 function and getting the bg-image changing on the active class that would be a big big help.
There's just so much that JS can do and I'm not finding the answers on Google and youTube.
Thank you again.
An Update:
I have edited the slider by by using margin-left as shown by this question:
vanilla javascript carousel not sliding
// var & event-listener buttons
document.querySelector(".left").addEventListener("click", slideLeft);
document.querySelector(".right").addEventListener("click", slideRight);
let marginLeft = 0;
const slides = document.querySelector('.glide__slides');
// Function slide left
function slideLeft() {
marginLeft += 264;
slides.style.marginLeft = marginLeft + 'px';
console.log(getComputedStyle(slides).marginLeft);
}
// Function slide Right
function slideRight() {
marginLeft -= 264;
slides.style.marginLeft = marginLeft + 'px';
console.log(getComputedStyle(slides).marginLeft);
}
This has now got the carousel moving manually 1 slide at a time.
Still not fully understanding why my previous code above didn't work. If anyone can explain that to me that would be great.
I'm still left with some issues:
Autosliding and looping at the end of the slides.
Having the active slider change the background automatically. At this point it only changes onclick.
Finding a way to tidy up the function calls and functions.

The question asks for various ideas on how to simplify code and how to use native JavaScript to create a slider that rolls continuously.
The code originally used glider and it may be something simpler would be sufficient to get the desired result, for example using animationend event to change the background when a slide gets to the left hand side. However, eating the elephant slowly I'll tackle the yucky code (part 3) first.
Although the HTML looks rather daunting, 4 calls on a click for every li element for example, it is currently what is required so let's investigate creating it at run time. This gives us more easily maintainable code. For example, if we want to remove a slide, or alter the order of slides or add one we can just alter the slider array defined below and JavaScript will do the rest.
Part 1 of the question asked about sliding. We slide the whole ul element using CSS animation defined something like this, where 33vw is the total width of a slide (inc. margins/padding)
#keyframes sliding0 {
0% { left: 0; }
30% { left: 0; }
100% { left: -33vw; }
}
and we add an event listener to the element to trap animationend events because when the ul has slid one slide's width we want to change the hero image, and we want to put the slide that has just disappeared onto the back of the infinie sliding will work. We then set the animation running again.
See the snippet for details on how this and other events are dealt with. It also shows how the changeHero function can work which was part 2 of the question. Note, the snippet works more or less in the SO environment, though occasionally hover action is partially ignored. Running the code on your own machine it should be fine though.
<!DOCTYPE html>
<html>
<head>
<style>
#keyframes sliding0 {
0% { left: 0; }
30% { left: 0; }
100% { left: -33vw; }
}
#keyframes sliding1 {
0% { left: 0; }
30% { left: 0; }
100% { left: -33vw; }
}
body {
background-repeat: no-repeat no-repeat;
background-size: cover;
background-position: center center;
}
div .glide_track {
position: relative;
width: 100vw;
overflow-x: hidden;
}
ul {
position:relative;
left: 0;
width: 330vw;
height:100vh;
animation-name: sliding0;
animation-duration: 3s;
animation-delay: 0s;
animation-iteration-count: 1;
animation-timing-function: linear;
margin: 0;
padding: 0;
list-style-type: none;
}
li {
position: relative;
left:0;
top:0;
float:left;
width: 32vw;
height:30vw;
display: inline-block;
margin: 0;
margin-right: 1vw;
padding: 0;
background-size: cover;
background-repeat: no-repeat no-repeat;
background-position: center center;
}
</style>
</head>
<body>
<script>
// we put the two lots of text and the image url for each slide in an array in the order they are to be shown
// this makes it easier to maintain when you want to add or remove a slide or change their order
// we only have one slider at the moment but this makes it more general
// these are the offsets in the array describing a slide. Done as indexes rather than named as easier to set up sliders array
const img = 0;
const text1 = 1;
const text2 = 2;
const sliders = [
[
['https://ahweb.org.uk/boxfordmosaic.jpg','Shire','Valley<br> of Dreams'],
['https://ahweb.org.uk/gear-in-turbine-house-reading.jpg','Westwood','Misty Woodlands'],
['https://ahweb.org.uk/tricycle-in-abbey-ruins.jpg','Shire','Valley<br> of Dreams'],
['https://ahweb.org.uk/boxfordmosaic.jpg','Shire','Valley<br> of Dreams'],
['https://ahweb.org.uk/gear-in-turbine-house-reading.jpg','Westwood','Misty Woodlands'],
['https://ahweb.org.uk/tricycle-in-abbey-ruins.jpg','Shire','Valley<br> of Dreams'],
['https://ahweb.org.uk/boxfordmosaic.jpg','Shire','Valley<br> of Dreams'],
['https://ahweb.org.uk/gear-in-turbine-house-reading.jpg','Westwood','Misty Woodlands'],
['https://ahweb.org.uk/tricycle-in-abbey-ruins.jpg','Shire','Valley<br> of Dreams'],
['https://ahweb.org.uk/tricycle-in-abbey-ruins.jpg','Shire','Valley<br> of Dreams']
]
];
// go through each slider and create its outer divs and its ul element
sliders.forEach(createSlider);
function createSlider(slider,sliderno) {
const div1 = document.createElement('DIV');
const div2 = document.createElement('DIV');
const ul = document.createElement('UL');
div1.classList.add("glide","hero-carousel");
div2.classList.add("glide_track");
div2.setAttribute("data-glide-el","track");
div1.appendChild(div2);
div2.appendChild(ul);
document.body.appendChild(div1);
ul.classList.add("glide__slides");
ul.addEventListener("animationend", animationEnd);
slider.forEach(createLi);
function createLi(slide,slideNo) {
const li = document.createElement('LI');
li.classList.add("glide__slide","carousel-item");
li.style.backgroundImage='url('+slide[img]+')';
li.addEventListener("click",slideClicked);
li.addEventListener("mouseover",slideHovered);
li.addEventListener("mouseout",slideUnhovered);
li.setAttribute('data-slideno','0' + slideNo);//! needs generalising if you have >10 slides !
ul.appendChild(li);
const div = document.createElement('DIV');
const p = document.createElement('P');
const h3 = document.createElement('H3');
p.innerHTML = slide[text1];
div.appendChild(p);
h3.innerHTML = slide[text2];
div.appendChild(h3);
li.appendChild(div);
}
}
// this is for testing, in real version use whatever required (i.e. whichever element is to have the hero image)
function ahHeroChange(backgroundImage) {
document.body.style.background = backgroundImage + " bottom/cover no-repeat";
}
function slideClicked(event) {
var slide = event.target;
var slideNo = slide.getAttribute('data-slideno');
// make the hero image the same as the slide's
ahHeroChange(slide.style.backgroundImage);
/* I don't know what these functions do - they were executed in the original on a click
number(slideno);
h4(slide.firstElementChild.querySelector('p').innerHTML);// text1 of the slide is passed to h4
h1(slide.firstElementChild.querySelector('h3').innerHTML;// text2 of the slide is passed to h1
*/
}
function slideHovered(event) {
var slide = event.target;
var slider = slide.parentElement;
slider.style.animationPlayState = 'paused';
ahHeroChange(slide.style.backgroundImage);
}
function slideUnhovered(event) {
var slide = event.target;
var slider = slide.parentElement;
//restore the hero image to the first one in the slider
ahHeroChange(slider.firstElementChild.style.backgroundImage);
//get the animation running again
slider.style.animationPlayState = 'running';
}
function animationEnd(event) {
//find the element that was clicked (it will be a ul element representing a slider)
var slider = event.target;
//take the first slide off the list and put it back at the end
slider.append(this.firstElementChild);
//change the hero image to the slide which is now the leftmost - use modified heroChange in the final version
document.body.style.backgroundImage = this.firstElementChild.style.backgroundImage;
// toggle the animationName (to an identical keyframes action) to force the animation to start again
slider.style.animationName='sliding'+(Number(event.animationName.replace('sliding',''))+1)%2;
}
</script>
</body>
</html>

transition for addclass only works after first time

I basically have some social media icons at the top of the page, that later become fixed.
I want them to fade in, I was using CSS. Everything I tried using JS did the same thing or didn't work.
Here is my JS:
jQuery(document).scroll(function() {
var y = jQuery(document).scrollTop(), //get page y value
social = jQuery(".socialnetworks"),
headerHeight = jQuery(".bg-cover").height();
if(y >= headerHeight + 500) {
social.css({opacity : 0});
social.addClass("fixedsocialnetworks");
} else {
social.removeClass("fixedsocialnetworks");
}
});
And my CSS
.fixedsocialnetworks {
position: fixed!important;
top: 200px!important;
z-index:10;
left:30px;
opacity:1!important;
transition: opacity 400ms;
}
So I set the opacity to 0, then add a class that sets the opacity to 1, and has the transition.
So it works, but it doesn't work the first time on scroll, it works every other time after the first. Why? How do I fix this?

Scrolling Two Divs Using JQuery/Javascript

Wrapper - Overflow Hidden
Div One: Sidebar
Div Two: Main Content
Div Two will have a normal scroll. Div One I wish to have no visible scroll however when you scroll Div One it scrolls Div Two.
Upon Div One's height hitting the bottom, it will no longer scroll and visa-versa for scrolling back up.
This will result in the sidebar always being visible at the side. Before you ask, I've tried all positioning types to get this to work resulting in many failed attempts.
My live demo can be seen here: http://rafflebananza.com/admin/newadmin.html#
Note I've tried to make a JSFiddle simplified but my maths does not seem to work in there the same. Please suggest whether I should fork all my page to there or whatnot for future visitors needing the same help.
Overview
Scrolling in the wrapper will scroll sidebar to point x only (x being the sidebars height) then stopping but will continue to allow the content to be scrolled. Visa-versa for scrolling back up.
Somewhat half way there...
var scrollTop = (window.pageYOffset !== undefined) ? window.pageYOffset : (document.documentElement || document.body.parentNode || document.body).scrollTop,
position = document.body.scrollTop;
function scrollD() {
var scroll = document.body.scrollTop;
if (scroll > position) {
// Scrolling Down Functions
} else {
// Scrolling Up Functions
}
position = scroll;
}

Updated the answer to match OPs requirements.
I downloaded your website in its current state and made the following changes to your code:
var scrollY = 0;
$(window).scroll(function() {
var sideNav = $('.SideNav'); // The side navigation
var wScrollY = $(this).scrollTop(); // Current scroll position of Window
var navHeight = sideNav.height(); // Height of the Navigation
var StageHeight = $(window).height() - 46; // The display space
if(sideNav.height() > StageHeight) { // Do the following if the side navigation is higher than the display space
var spaceLeft = sideNav.height() - StageHeight; // spaceLeft -> how many pixel left before fixing navigation when scrolling
if(scrollY < wScrollY) { // Scroll direction is down
if (wScrollY >= spaceLeft) // If scroll top > space left -> fixate navigation at the bottom, otherwise scroll with the content
sideNav.css({top:46-spaceLeft+wScrollY});
if (wScrollY <= 46) // Set top strict to 46. Sometimes there is white space left, caused by the scroll event.
sideNav.css({top:46});
} else { // Scroll direction is up
var sideNavTop;
if (sideNav.offset().top < 0) {
sideNavTop = Math.pow(sideNav.offset().top); // if top is negative, make it positive for comparison
} else {
sideNavTop = sideNav.offset().top;
}
if (sideNavTop > (46+wScrollY)) // Fixate the header if top of navigation appears
sideNav.css({top:46+wScrollY});
}
} else {
sideNav.css({top:46+wScrollY}); // Fixate always
}
scrollY = wScrollY;
});
This will let you scroll your side navigation up until its end. Then fixate. If you scroll up, it will still be fixated until your reach the point, where the navigation must scrolled back to its original position.
You can check the edited version here: http://pastebin.com/Zkx4pSKe
Just copy the raw code into a blank html page and try it out.
It's a bit messy and maybe not the best solution, but it works.

Ok, here you go:
var $sidebar = $('.sidebar'),
$window = $(window),
previousScroll = 0;
$window.on('scroll', function (e) {
if ($window.scrollTop() - previousScroll > 0) {
$sidebar.css({
'top': Math.max($window.scrollTop() + $window.height() - $sidebar.outerHeight(true), parseInt($sidebar.css('top'))) + 'px'
});
} else {
$sidebar.css({
'top': Math.min($window.scrollTop(), parseInt($sidebar.css('top'))) + 'px'
});
}
previousScroll = $window.scrollTop();
});
http://jsfiddle.net/7nwzcpqk/1/

i might have misunderstood your desired result incorrectly but you can see if this works for you :
.SideNav {
position: fixed; // you currently have this as position:absolute;
}

You don't need nor a wrapper element nor jQuery. I assume that you are using a wrapper because you want to have the top bar placed there. I think there is a better way to do it by using simply three divs.
The top bar has to be fixed (to be always visible) and of full width.
The side bar also has to be fixed (to be always visible) with a top margin of the height of the top bar.
The content needs just a left padding (width of side bar) and top padding (height of top bar).
Here is the example code (http://jsfiddle.net/zckfwL4p/):
HTML
<div id="top_bar"></div>
<div id="side_bar">links here</div>
<div id="content"></div>
CSS
body {
margin:0px;
padding:0px;
}
#side_bar {
width:50px;
position: fixed;
left:0px;
top:20px;
background-color:blue;
}
#top_bar {
position:fixed;
height:20px;
left:0px;
right:0px;
background-color:red;
}
#content {
position:relative;
padding-left:55px;
padding-top:25px;
}

How to make text appear on scroll in html

Hello, I want a certain text to appear when I scroll past it or when I scroll until the point where the text is. The effect when appearing should be somewhat like the first effect on the top of the website http://namanyayg.com/.
I want the effect in minimal code with pure CSS and JS i.e no jQuery.
I was thinking that maybe I would use something like a display:none property for a span and then when you scroll past it the display becomes block but I dont know how to trigger the effect using javascript.
Any help would be appreciated.

First wrap whatever your text or content that you want to show on scroll, in one div so that you can show hide the div depending upon the scroll. Write two classes for your target div.
Your CSS:
/*Use this class when you want your content to be hidden*/
.BeforeScroll
{
height: 100px; /*Whatever you want*/
width: 100%; /*Whatever you want*/
.
.
display: none;
}
/*Use this class when you want your content to be shown after some scroll*/
.AfterScroll
{
height: 100px; /*Whatever you want*/
width: 100%; /*Whatever you want*/
.
.
display: block;
}
Your HTML:
<!--Set class BeforeScoll to your target div-->
<div id = "divToShowHide" class = "BeforeScroll">Content you want to show hide on scroll</div>
Your Script:
<!--include these script in head section or wherever you want-->
<script src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.10.1/jquery-ui.min.js" type="text/javascript"></script>
<script type = "text/javascript">
$(document).ready(function(){
//Take your div into one js variable
var div = $("#divToShowHide");
//Take the current position (vertical position from top) of your div in the variable
var pos = div.position();
//Now when scroll event trigger do following
$(window).scroll(function () {
var windowpos = $(window).scrollTop();
//Now if you scroll more than 100 pixels vertically change the class to AfterScroll
// I am taking 100px scroll, you can take whatever you need
if (windowpos >= (pos.top - 100)) {
div.addClass("AfterScroll");
}
//If scroll is less than 100px, remove the class AfterScroll so that your content will be hidden again
else {
s.removeClass("AfterScroll");
}
//Note: If you want the content should be shown always once you scroll and do not want to hide it again when go to top agian, no need to write the else part
});
});
</script>
Hope it will solve your problem.

I would recommend this plugin
http://johnpolacek.github.io/superscrollorama/
Edit:
I don't know how no one noticed that the solution had to be made without using external libraries like jQuery. However, the solution is extremely easy with basic functionality. Find it here
HTML:
<div id="parent-div">
<div id="child-div">
Psst .. I am here!!
</div>
</div>
CSS:
#parent-div
{
position:relative;
height:3000px;
width:300px;
background-color:red;
}
#child-div
{
color:white;
position:relative;
top:1000px;
width:300px;
display:none;
text-align:center;
}
JS:
var body=document.getElementsByTagName("body")[0];
var parent=document.getElementById("parent-div");
var child=document.getElementById("child-div");
body.onscroll = function(){
//console.log(documenhttps://fiddle.jshell.net/3urv0tp0/#tidyt.getElementById("child-div").style.top)
if(document.documentElement.scrollTop>=child.offsetTop)//Adjust Tolerance as you want
{
child.style.display="block"
}
};

I was looking for this either. Here i was trying to make "show text after scrolling to (number)px with fade effect". I wish it will work as it works for me :) The animation will be playing again if u scroll back to it, idk how to make it just one like in web u showed xd (i will edit if I find out)
window.addEventListener("scroll", function() {showFunction()});
function showFunction() {
if (document.body.scrollTop > 900 || document.documentElement.scrollTop > 900) {
document.getElementById("toptexts2").style.display = "block";
} else {
document.getElementById("toptexts2").style.display = "none";
}
}
.toptexts2 {
animation: fadeEffect 3s; /* fading effect takes 3s */
}
#keyframes fadeEffect { /* from 0 to full opacity */
from {opacity: 0;}
to {opacity: 1;}
}
<div class="toptexts2" id="toptexts2">
<div>Hi!</div>
<div>↓ go down ↓</div>
</div>

I like this:
var doc = document, dE = doc.documentElement, bod = doc.body;
function E(e){
return doc.getElementById(e);
}
function xy(e, d){
if(!d)d = 'Top';
d = 'offset'+d;
var r = e[d];
while(e.offsetParent){
e = e.offsetParent; r += e[d];
}
return r;
}
function x(e){
return xy(e, 'Left');
}
function y(e){
return xy(e);
}
var txt = E('theId'), txtS = txt.style;
onscroll = function(){
var left = dE.scrollLeft || bod.scrollLeft || 0;
var top = dE.scrollTop || bod.scrollTop || 0;
var w = innerWidth || dE.clientWidth || bod.clientWidth;
var h = innerHeight || dE.clientHeight || bod.clientHeight;
if(top > y(txt)-h){
txtS.display = 'none';
}
else{
txtS.display = 'block';
}
}
I left the left stuff in there, just in case, but you can probably remove it.

var div=$("#divtochange");
$(window).scroll(function () {
var windowpos = $(window).scrollTop();
//---check the console to acurately see what the positions you need---
console.log(windowpos);
//---------------------
//Enter the band you want the div to be displayed
if ((windowpos >= 0) && (windowpos <= 114)){
div.addClass("AfterScroll");
}
else{
div.removeClass("AfterScroll");
}