Develop Reference

mousedown and touchstart not registering on mobile devices

I have created the following simple image comparison slider - modified from the version on w3schools (I know my mistake to use their code).
This all works fine on a desktop but when I try to use it on a mobile, nothing happens - it doesn't even register the console.log on the mousedown/touchstart (when I press on the slider button with my finger).
I was wondering if anyone could spot anything obvious with why it isn't working on mobile devices
(() => {
$.fn.imageComparisonSlider = function() {
var returnValue = this.each((index, item) => {
var $container = $(this);
var $overlay = $container.find('.image-comparison-slider__bottom-image');
var $slider = $('<span class="image-comparison-slider__slider"></span>');
var $window = $(window);
var touchStarted = false;
var width = $container.outerWidth();
$container.prepend($slider);
$container.on('mousedown touchstart', '.image-comparison-slider__slider', event => {
event.preventDefault();
console.log('touchstart');
touchStarted = true;
});
$window.on("mousemove touchmove", windowEvent => {
if (touchStarted) {
// get the cursor's x position:
let pos = getCursorPos(windowEvent);
// prevent the slider from being positioned outside the image:
if (pos < 0) pos = 0;
if (pos > width) pos = width;
// execute a function that will resize the overlay image according to the cursor:
slide(pos);
}
});
$window.on('mouseup touchend', event => {
event.preventDefault();
touchStarted = false;
});
function getCursorPos(e) {
var thisEvent = e || window.event;
// calculate the cursor's x coordinate, relative to the image
return thisEvent.pageX - $container.offset().left;
}
function slide(x) {
// set the width of the overlay
$overlay.width(width - x);
// position the slider
$slider[0].style.left = x + 'px';
}
function resetSlider() {
$overlay.width('50%');
$slider[0].style.left = $overlay.width() + 'px'
width = $container.outerWidth();
}
});
return returnValue;
};
})($);
$('.image-comparison-slider__container').imageComparisonSlider();
.image {
display: block;
width: 100%;
}
.image-comparison-slider__title {
text-align: center;
}
.image-comparison-slider__container,
.image-comparison-slider__image-holder {
position: relative;
}
.image-comparison-slider__bottom-image {
position: absolute;
overflow: hidden;
top: 0;
right: 0;
bottom: 0;
z-index: 1;
width: 50%;
}
.image-comparison-slider__caption {
position: absolute;
padding: 1rem;
color: white;
background: rgba(0, 0, 0, 0.6);
z-index: 2;
white-space: nowrap;
}
.image-comparison-slider__top-image .image-comparison-slider__caption {
top: 0;
left: 0;
}
.image-comparison-slider__bottom-image .image-comparison-slider__caption {
bottom: 0;
right: 0;
}
.image-comparison-slider__image {
display: block;
z-index: 1;
}
.image-comparison-slider__bottom-image .image {
position: absolute;
right: 0;
top: 0;
height: 100%;
width: auto;
}
.image-comparison-slider__slider {
position: absolute;
z-index: 3;
cursor: ew-resize;
/*set the appearance of the slider:*/
width: 50px;
height: 50px;
background-color: rgba(255, 96, 38, 0.8);
border-radius: 50%;
top: 50%;
left: 50%;
display: flex;
justify-content: center;
align-items: center;
transform: translate(-50%, -50%);
}
.image-comparison-slider__slider:after {
content: "< >";
color: white;
font-weight: bold;
font-size: 25px;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="image-comparison-slider__container">
<div class="image-comparison-slider__image-holder image-comparison-slider__top-image">
<img src="https://www.fillmurray.com/g/400/300" alt="A test image 1" class="image">
<div class="image-comparison-slider__caption">Left Image</div>
</div>
<div class="image-comparison-slider__image-holder image-comparison-slider__bottom-image">
<img src="https://www.fillmurray.com/400/300" alt="A test image 2" class="image">
<div class="image-comparison-slider__caption">Right Image</div>
</div>
</div>
Fiddle link for code

Ok have managed to fix this - the touch wasn't registering because of the transform so I changed that and just used negative margin as the button was a fixed size.
I then had to fix the thisEvent.pageX for android - so did a check with isNaN and then set it to e.originalEvent.touches[0].pageX if it was true.
Working version:
(() => {
$.fn.imageComparisonSlider = function() {
var returnValue = this.each((index, item) => {
var $container = $(this);
var $overlay = $container.find('.image-comparison-slider__bottom-image');
var $slider = $('<span class="image-comparison-slider__slider"></span>');
var $window = $(window);
var touchStarted = false;
var width = $container.outerWidth();
$container.prepend($slider);
$container.on('mousedown touchstart', '.image-comparison-slider__slider', event => {
event.preventDefault();
console.log('touchstart');
touchStarted = true;
});
$window.on("mousemove touchmove", windowEvent => {
if (touchStarted) {
// get the cursor's x position:
let pos = getCursorPos(windowEvent);
// prevent the slider from being positioned outside the image:
if (pos < 0) pos = 0;
if (pos > width) pos = width;
// execute a function that will resize the overlay image according to the cursor:
slide(pos);
}
});
$window.on('mouseup touchend', event => {
event.preventDefault();
touchStarted = false;
});
function getCursorPos(e) {
var thisEvent = e || window.event;
let xVal = thisEvent.pageX;
if (isNaN(xVal)) {
xVal = e.originalEvent.touches[0].pageX;
}
// calculate the cursor's x coordinate, relative to the image
return xVal - $container.offset().left;
}
function slide(x) {
// set the width of the overlay
$overlay.width(width - x);
// position the slider
$slider[0].style.left = x + 'px';
}
function resetSlider() {
$overlay.width('50%');
$slider[0].style.left = $overlay.width() + 'px'
width = $container.outerWidth();
}
});
return returnValue;
};
})($);
$('.image-comparison-slider__container').imageComparisonSlider();
.image {
display: block;
width: 100%;
}
.image-comparison-slider__title {
text-align: center;
}
.image-comparison-slider__container,
.image-comparison-slider__image-holder {
position: relative;
}
.image-comparison-slider__bottom-image {
position: absolute;
overflow: hidden;
top: 0;
right: 0;
bottom: 0;
z-index: 1;
width: 50%;
}
.image-comparison-slider__caption {
position: absolute;
padding: 1rem;
color: white;
background: rgba(0, 0, 0, 0.6);
z-index: 2;
white-space: nowrap;
}
.image-comparison-slider__top-image .image-comparison-slider__caption {
top: 0;
left: 0;
}
.image-comparison-slider__bottom-image .image-comparison-slider__caption {
bottom: 0;
right: 0;
}
.image-comparison-slider__image {
display: block;
z-index: 1;
}
.image-comparison-slider__bottom-image .image {
position: absolute;
right: 0;
top: 0;
height: 100%;
width: auto;
}
.image-comparison-slider__slider {
position: absolute;
z-index: 3;
cursor: ew-resize;
width: 50px;
height: 50px;
background-color: rgba(255, 96, 38, 0.8);
border-radius: 50%;
top: 50%;
left: 50%;
display: flex;
justify-content: center;
align-items: center;
margin: -25px 0 0 -25px;
}
.image-comparison-slider__slider:after {
content: "< >";
color: white;
font-weight: bold;
font-size: 25px;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="image-comparison-slider__container">
<div class="image-comparison-slider__image-holder image-comparison-slider__top-image">
<img src="https://www.fillmurray.com/g/400/300" alt="A test image 1" class="image">
<div class="image-comparison-slider__caption">Left Image</div>
</div>
<div class="image-comparison-slider__image-holder image-comparison-slider__bottom-image">
<img src="https://www.fillmurray.com/400/300" alt="A test image 2" class="image">
<div class="image-comparison-slider__caption">Right Image</div>
</div>
</div>

Skrollr image flickers and some images doesnt load in chrome

I am using Skrollr librabry. In the start it works fine,but as I'm scrolling down,I am experiencing flickering and images do not load. The content of my website are just images. Works fine on firefox, but not on Chrome. Could you please help me. I am using approximately 190 images. Is that an issue?
I am using async calls to fetch the data,and every image is being loaded before the skrollr is rendered.
Here's my working example : https://jsfiddle.net/if_true/v1mLhutc/7/
html
<body>
<div id="fakeloader"></div>
<div style="transform: translate3d(0,0,0);"></div>
<div class="DESKScreen">
<div id="info" hidden="hidden">0</div>
<section id="slide">
<div class="bcg"></div>
</section>
</div>
</body>
CSS
*,:before,:after {
-moz-box-sizing:border-box;
-webkit-box-sizing:border-box;
box-sizing:border-box;
-webkit-backface-visibility:hidden;
backface-visibility: hidden;
}
#info{
position: fixed;
top: 20px;
left: 20px;
background-color: rgba(0, 0, 0, 0.5);
color: #fff;
padding: 20px;
z-index: 9999;
}
body {
margin: 0;
width: 100%;
height: 100%;
}
html{
width: 100%;
height: 100%;
}
section {
width: 100%;
max-width: 100%;
height: 100%;
position: fixed;
left: 0;
right: 0;
margin: auto;
}
#slide .bcg {
height: 100%;
width: 100%;
background-size: 100%;
background-position: center top;
background-attachment: fixed;
position: absolute;
transform:translateZ(0)
}
.img{
background-size: cover;
background-repeat: no-repeat;
background-position: center;
display: table;
margin: auto;
max-height: 100vh !important;
height: 100% !important;
}
.item {
width: 100%;
position: absolute;
opacity: 1;
}
`Js`
$(document).ready(function() {
DivImage("sup");
var s = skrollr.init({
render: function(data) {
console.log(data.curTop);
}
});
//Check the screen size.
(function() {
if (screen.width < 768) {
$("#fullpage").fullpage({
//scrollingSpeed: 0,
});
$(".DESKScreen").css("display", "none");
} else if (screen.width > 768) {
$(".MObileScreen").css("display", "none");
}
})();
//Fakeloader for the loadtime
function loader() {
$("#fakeloader").fakeLoader({
timeToHide: 4000,
bgColor: "#e74c3c",
spinner: "spinner2"
});
}
loader();
});
function DivImage(name) {
//console.log(name);
//a counter to set for div id
let counter = 0;
//create the urls based on a nr
var Images = makeUrls();
//first create the div and pass the counter to it
CreateDiv(Images);
}
function makeUrls() {
let base = "images/";
let rest = ".jpg";
let result = [];
for (let i = 0; i < 191; i++) {
let baseNr = 1 + i;
if (baseNr === 2000) {
console.log("base");
} else {
result.push(base + baseNr + rest);
}
}
return result;
}
function CreateDiv(images) {
// debugger;
var from = 0,
to = 0;
let result = [];
for (let i of images) {
var newDiv = $('<div class="img-div"></div>');
newDiv.css({
backgroundImage: `url(${i})`
});
newDiv.attr("data--" + from + "-top", "opacity: 0;");
from += 125;
newDiv.attr("data--" + from + "-top", "opacity: 0;");
from += 125;
newDiv.attr("data--" + from + "-top", "opacity: 1;");
newDiv.attr("data-anchor-target", "#slide");
newDiv.attr("data-skrollr-decks-speed", "300");
$("#slide").append($(newDiv));
}
}

Pure JS + CSS Slideshow with z-Index: Glitch on last Slide

I try to build a Slideshow in JS + CSS and it works pretty well except one visual glitch. The Transition to the last slides seems somehow broken.
But I couldn't figure out what the problem is. If I comment out the "offset" transition on the last slide, the error doesn't occure.
This is the codeine I am talking about: https://codepen.io/marianbreitmeyer/pen/paeYgZ
The Block of code I mentioned is this one:
const showNext = function() {
clicked = true;
for (i = 0; i <= slides.length-1; i++) {
if( parseInt(slides[i].style.zIndex) === slides.length) {
console.log(slides[i].innerHTML);
triggerAnimation(slides[i], 'offcanvas');
} else if (parseInt(slides[i].style.zIndex) === slides.length-1) {
//the line below triggers the problem
triggerAnimation(slides[i], 'offset');
}
}
};
Maybe someone with more experience could help me :)

Your code might be more simple:
const btn = document.getElementsByClassName('arrow')[0];
const slides = document.getElementsByClassName('slide');
slides[slides.length - 1].classList.add('offset', 'next');
btn.addEventListener("click", function(e) {
var o, n;
for (var i = 0; i < slides.length; i++) {
if (slides[i].classList.contains('offset')) {
slides[i].classList.remove('offset', 'next')
slides[i].classList.add('offcanvas');
o = (slides[i - 1] || slides[slides.length - 1]);
n = (slides[i - 2] || slides[slides.length + i - 2]);
}
if (slides[i].offsetLeft < -slides[i].offsetWidth) {
slides[i].classList.remove('offcanvas', 'next');
}
}
o.classList.add('offset');
n.classList.add('next');
}, false);
.container {
width: 100%;
height: 100vh;
background: brown;
position: relative;
}
body {
text-align: center;
font-size: 2rem;
}
.slide {
position: absolute;
top: 0;
left: 90%;
width: 100%;
height: 100%;
}
.slide:nth-child(1) {
background: pink;
}
.slide:nth-child(2) {
background: blue;
}
.slide:nth-child(3) {
background: green;
}
.slide:nth-child(4) {
background: grey;
}
.slide:nth-child(5) {
background: yellow;
}
.slide.next {z-index:1}
.slide.offset {
left: -10%;
z-index: 2;
transition: left .65s ease-in-out;
}
.slide.offcanvas {
left: -110%;
z-index: 2;
transition: left .65s ease-in-out;
}
.arrow {
position: absolute;
right: 5%;
top: 25px;
z-index: 9;
height: 50px;
width: 50px;
cursor: pointer;
}
.arrow:hover path {
transform: translate(16px, 0px);
}
path {
position: absolute;
top: 0;
left: 0;
transition: all .2s ease-in-out;
}
<div class="container">
<div class="slide">1 = pink</div>
<div class="slide">2 = blue</div>
<div class="slide">3 = green</div>
<div class="slide">4 = grey</div>
<div class="slide">5 = yellow</div>
<svg xmlns="http://www.w3.org/2000/svg" class="arrow"><path d="M19.443 5.17L30.138 15.5H-.095v1h30.233L19.443 26.829l.696.719L32.095 16 20.139 4.451z"/></svg>
</div>

JavaScript slideshow isn't working as intended

I made this little Slideshow with HTML/CSS/JS. Most of it is working but there is one thing which I can't figure out. How do I make it so the text above each image fits the img itself when autosliding is on? Right now it only shows the right title for each img when i manually click through. Any help is appreciated. Many thanks in advance.
var uniqueRandoms = [];
var indexCount = 0;
var allImagesAndText = ["Seltene römische Goldmünze", "Römische Funde", "Römische Wandmalerei", "Tutanchamun", "Cheops Pyramide", "Ägyptische Malerei"];
var total = allImagesAndText.length - 1;
function makeUniqueRandom() {
if (!uniqueRandoms.length) {
for (var i = indexCount; i <= total; i++) {
uniqueRandoms.push(i);
}
}
var index = Math.floor(Math.random() * uniqueRandoms.length);
var val = uniqueRandoms[index];
uniqueRandoms.splice(index, 1);
return val;
}
function slide(x) {
if(indexCount + x >= 0 && indexCount + x <= total) {
clearInterval(sliderInterval);
indexCount += x;
var Image = document.getElementById('img');
Image.src = "images/img" + indexCount + ".jpg";
update_dom();
sliderInterval = window.setInterval( slideA, 3000);
}
}
function update_dom() {
var left_holder = document.getElementById('left_holder');
var right_holder = document.getElementById('right_holder');
ChangeText(indexCount);
if(indexCount == 0) {
left_holder.style.display = "none";
} else if (indexCount == total) {
right_holder.style.display = "none";
} else {
right_holder.style.display = "block";
left_holder.style.display = "block";
}
}
function slideA() {
var Image = document.getElementById('img');
imagescount = makeUniqueRandom();
Image.src = "images/img" + imagescount + ".jpg";
update_dom();
}
function ChangeText(imgNum) {
document.getElementById("text1").innerHTML = allImagesAndText[imgNum];
}
window.addEventListener("load", function() {
update_dom();
sliderInterval = window.setInterval( slideA, 3000);
document.getElementById("right").addEventListener("click", function() {
slide(1);
});
document.getElementById("left").addEventListener("click", function() {
slide(-1);
});
});
#slideshow {
height: 450px;
width: 650px;
margin: 20px auto;
position: relative;
z-index: 1;
border: 10px solid #000;
border-radius: 10px;
}
#img {
height: 450px;
width: 650px;
}
#left_holder {
height: 450px;
width: 100px;
position: absolute;
left: 0px;
top: 0px;
}
#right_holder {
height: 450px;
width: 100px;
position: absolute;
right: 0px;
top: 0px;
}
.left {
height: 50px;
width: 50px;
position: absolute;
top: 40%;
left: 0px;
}
.right {
height: 50px;
width: 50px;
position: absolute;
top: 40%;
right: 0px;
}
#text1 {
position: absolute;
color: #fff;
font-size: 32px;
background-color: #000;
opacity: 0.5;
left: 37%;
z-index: 2;
}
<div id="slideshow">
<div id="text1">Text</div>
<img src="images/img0.jpg" />
<div id="left_holder">
<img id="left" class="left" src="images/arrow_left.png" />
</div>
<div id="right_holder">
<img id="right" class="right" src="images/arrow_right.png" />
</div>
</div>

Smoke Trail Effect - Javascript

How can one make a smooth smoke trail effect with Javascript, out of the code I attached? The trail should follow an object, but have the position the object had a moment ago. The code I attached does have some sort of trail effect, but it is not smooth. Can give the trail a position using something like this: position:trail = position:object, 5 ms ago?
var left = parseInt(document.getElementById("thingy").style.left);
setInterval(fly, 10);
function fly() {
if (left > 300) {
left = 300;
};
left++;
document.getElementById("thingy").style.left = left + "px";
}
setInterval(trail, 100);
function trail() {
document.getElementById("trail").style.left = left + "px";
}
<div id="thingy" style="position:absolute; top:100px; left: 0px; width: 100px; height: 100px; background-color:#000000;"></div>
<div id="trail" style="position:absolute; top:125px; left: 0px; width: 50px; height: 50px; background-color:#CCCCCC; z-index: -10;"></div>
If it is possible I would like to stay out of jQuery.

This solution clones the element each time it moves.
CSS3 transitions are used on the cloned nodes' background to simulate a smoke trail.
The code ensures there are never more than 100 cloned nodes.
var thingy= document.getElementById('thingy'),
left = thingy.offsetLeft,
shadows= [],
delta= 4;
setInterval(fly, 10);
function fly() {
var shadow= thingy.cloneNode();
shadow.classList.add('shadow');
shadow.style.backgroundColor= 'silver';
document.body.appendChild(shadow);
setTimeout(function() {
shadow.style.backgroundColor= 'white';
},100);
shadows.push(shadow);
if(shadows.length>100) {
shadows[0].parentNode.removeChild(shadows[0]);
shadows.shift();
}
if(left+delta > document.body.offsetWidth-thingy.offsetWidth || left < 0) {
delta= -delta;
}
left+= delta;
thingy.style.left = left + 'px';
}
body {
margin: 0;
padding: 0;
}
#thingy {
position: absolute;
top: 100px;
left: 0px;
width: 100px;
height: 100px;
background-color: orange;
border-radius: 50%;
}
.shadow {
transition: all 1s;
z-index: -1;
}
<div id="thingy"></div>
Update
For a "smokier" effect, you can use random values for the cloned nodes' width, height, transition, etc., like I've done in this Snippet:
var thingy= document.getElementById('thingy'),
tleft = thingy.offsetLeft,
ttop = thingy.offsetTop,
smokes= [],
deltaX= deltaY= 2;
setInterval(fly, 10);
function fly() {
if(Math.random()>0.5) {
var smoke= thingy.cloneNode();
smoke.classList.add('smoke');
smoke.style.background= 'gray';
smoke.style.opacity= 0.2;
smoke.style.transition= Math.random()+'s';
smoke.style.width= Math.random()*thingy.offsetWidth+'px';
smoke.style.height= Math.random()*thingy.offsetHeight+'px';
smoke.style.marginTop= smoke.offsetHeight+'px';
smoke.style.borderRadius= (Math.random()*25+25)+'%';
document.body.appendChild(smoke);
setTimeout(function() {
smoke.style.opacity= 0;
},100);
smokes.push(smoke);
if(smokes.length>20) {
smokes[0].parentNode.removeChild(smokes[0]);
smokes.shift();
}
}
if(tleft+deltaX > document.body.offsetWidth-thingy.offsetWidth || tleft < 0) {
deltaX= -deltaX;
}
if(ttop +deltaY > document.body.offsetHeight-thingy.offsetHeight || ttop < 0) {
deltaY= -deltaY;
}
tleft+= deltaX;
ttop += deltaY;
thingy.style.left = tleft + 'px';
thingy.style.top = ttop + 'px';
}
body {
margin: 0;
padding: 0;
background: black;
height: 100vh;
}
#thingy {
position: absolute;
top: 100px;
left: 0px;
width: 100px;
height: 100px;
background-color: orange;
border-radius: 50%;
}
.smoke {
z-index: -1;
}
<div id="thingy"></div>