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How to make image slider respond to thumb swipe

Hi I am using the basic W3 slideshow layout but It is not very good for the mobile version of my site.
I searched very hard to find a solution to this but it's always download some plug-in to make it work or something that doesn't respond very well to swipes
$('.slider').on('touchstart', function(event) {
const xClick = event.originalEvent.touches[0].pageX;
$(this).one('touchmove', function(event) {
const xMove = event.originalEvent.touches[0].pageX;
const sensitivityInPx = 5;
if (Math.floor(xClick - xMove) > sensitivityInPx) {
$(this).slider('next');
}
else if (Math.floor(xClick - xMove) < -sensitivityInPx) {
$(this).slider('prev');
}
});
$(this).on('touchend', function() {
$(this).off('touchmove');
});
});
let slideIndex = 1;
showSlides(slideIndex);
function plusSlides(n) {
showSlides(slideIndex += n);
}
function currentSlide(n) {
showSlides(slideIndex = n);
}
function showSlides(n) {
let i;
let slides = document.getElementsByClassName("mySlides");
let dots = document.getElementsByClassName("dot");
if (n > slides.length) {
slideIndex = 1
}
if (n < 1) {
slideIndex = slides.length
}
for (i = 0; i < slides.length; i++) {
slides[i].style.display = "none";
}
for (i = 0; i < dots.length; i++) {
dots[i].className = dots[i].className.replace(" active", "");
}
slides[slideIndex - 1].style.display = "block";
dots[slideIndex - 1].className += " active";
}
* {
box-sizing: border-box
}
html,
body {
width: 100%;
height: 100%;
margin: 0;
}
body {
margin: 0;
font-family: Arial, Helvetica, sans-serif;
}
.mySlides {
display: none
}
img {
vertical-align: middle;
}
/* Slideshow container */
.slideshow-container {
padding: 10px;
max-width: 1000px;
position: relative;
margin: auto;
-webkit-overflow-scrolling: touch;
}
/* Next & previous buttons */
.prev,
.next {
cursor: pointer;
position: absolute;
top: 50%;
width: auto;
padding: 16px;
margin-top: -22px;
color: white;
font-weight: bold;
font-size: 18px;
transition: 0.6s ease;
border-radius: 0 3px 3px 0;
user-select: none;
}
/* Position the "next button" to the right */
.next {
right: 0;
border-radius: 3px 0 0 3px;
}
/* On hover, add a black background color with a little bit see-through */
.prev:hover,
.next:hover {
background-color: rgba(0, 0, 0, 0.8);
}
/* Caption text */
.text {
color: #f2f2f2;
font-size: 15px;
padding: 8px 12px;
position: absolute;
bottom: 8px;
width: 100%;
text-align: center;
}
/* Number text (1/3 etc) */
.numbertext {
color: #f2f2f2;
font-size: 12px;
padding: 8px 12px;
position: absolute;
top: 0;
}
/* The dots/bullets/indicators */
.dot {
cursor: pointer;
height: 15px;
width: 15px;
margin: 0 2px;
background-color: #bbb;
border-radius: 50%;
display: inline-block;
transition: background-color 0.6s ease;
}
.active,
.dot:hover {
background-color: #717171;
}
/* Fading animation */
.fade {
animation-name: fade;
animation-duration: 1.5s;
}
#keyframes fade {
from {
opacity: .4
}
to {
opacity: 1
}
}
/* On smaller screens, decrease text size */
#media only screen and (max-width: 300px) {
.prev,
.next,
.text {
font-size: 11px
}
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div id="slider" class="slideshow-container">
<!-- images -->
<div class="mySlides fade">
<!-- <div class="numbertext">1 / 3</div> -->
<img src="http://upload.wikimedia.org/wikipedia/commons/7/73/Lion_waiting_in_Namibia.jpg" style="width:100%">
<div class="text">Caption Text</div>
</div>
<div class="mySlides fade">
<img src="http://upload.wikimedia.org/wikipedia/commons/7/73/Lion_waiting_in_Namibia.jpg" style="width:100%">
</div>
<div class="mySlides fade">
<img src="http://upload.wikimedia.org/wikipedia/commons/7/73/Lion_waiting_in_Namibia.jpg" style="width:100%">
</div>
<div class="mySlides fade">
<img src="http://upload.wikimedia.org/wikipedia/commons/7/73/Lion_waiting_in_Namibia.jpg" style="width:100%">
</div>
<a class="prev" onclick="plusSlides(-1)">❮</a>
<a class="next" onclick="plusSlides(1)">❯</a>
</div>
<br>
<div style="text-align:center">
<!-- dots-->
<span class="dot" onclick="currentSlide(1)"></span>
<span class="dot" onclick="currentSlide(2)"></span>
<span class="dot" onclick="currentSlide(3)"></span>
<span class="dot" onclick="currentSlide(4)"></span>
</div>

Even though this is not pure Js and it is a different approach
I found that flickity.js and css is good for mobile and it's just 2 ajax calls like jquery
https://flickity.metafizzy.co/api.html
<script src="//cdnjs.cloudflare.com/ajax/libs/flickity/1.0.0/flickity.pkgd.js"></script>
<link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/flickity/1.0.0/flickity.css">
HTML
<div class="carousel">
<div class="carousel-cell"></div>
<div class="carousel-cell"></div>
<div class="carousel-cell"></div>
<div class="carousel-cell"></div>
<div class="carousel-cell"></div>
<div class="carousel-cell"></div>
<div class="carousel-cell"></div>
<div class="carousel-cell"></div>
</div>
CSS
/* external css: flickity.css */
* { box-sizing: border-box; }
body { font-family: sans-serif; }
.carousel {
background: #FAFAFA;
}
.carousel-cell {
width: 28%;
height: 200px;
margin-right: 10px;
background: #8C8;
border-radius: 5px;
counter-increment: carousel-cell;
}
/* cell number */
.carousel-cell:before {
display: block;
text-align: center;
content: counter(carousel-cell);
line-height: 200px;
font-size: 80px;
color: white;
}
.button {
font-size: 22px;
}
.button-group {
margin-bottom: 20px;
}
Js
// external js: flickity.pkgd.js
var flkty = new Flickity( '.carousel', {
groupCells: true
});
var buttonGroup = document.querySelector('.button-group');
var buttons = buttonGroup.querySelectorAll('.button');
buttons = fizzyUIUtils.makeArray( buttons );
buttonGroup.addEventListener( 'click', function( event ) {
// filter for button clicks
if ( !matchesSelector( event.target, '.button' ) ) {
return;
}
var index = buttons.indexOf( event.target );
flkty.selectCell( index );
});

Like i wrote in the comments, you have two typos: $(this).one('touchmove and .slider, which has to be $(this).on('touchmove and #slider.
But the main problem is your function slider(), which isn't defined. But you can use the function plusSlides(), that you are already using for the next and prev buttons.
Furthermore the touchmove event is firing very often until the touchend event is fired. Therefor the function plusSlides() is called multiple times. To fix this, stop the touchmove event listener when the function plusSlides() is called.
Working example:
$('#slider').on('touchstart', function(event) {
const xClick = event.originalEvent.touches[0].pageX;
$(this).on('touchmove', function(event) {
const xMove = event.originalEvent.touches[0].pageX;
const sensitivityInPx = 5;
if (Math.floor(xClick - xMove) > sensitivityInPx) {
plusSlides(1);
$(this).off('touchmove');
}
else if (Math.floor(xClick - xMove) < -sensitivityInPx) {
plusSlides(-1);
$(this).off('touchmove');
}
});
});
let slideIndex = 1;
showSlides(slideIndex);
function plusSlides(n) {
showSlides(slideIndex += n);
}
function currentSlide(n) {
showSlides(slideIndex = n);
}
function showSlides(n) {
let i;
let slides = document.getElementsByClassName("mySlides");
let dots = document.getElementsByClassName("dot");
if (n > slides.length) {
slideIndex = 1
}
if (n < 1) {
slideIndex = slides.length
}
for (i = 0; i < slides.length; i++) {
slides[i].style.display = "none";
}
for (i = 0; i < dots.length; i++) {
dots[i].className = dots[i].className.replace(" active", "");
}
slides[slideIndex - 1].style.display = "block";
dots[slideIndex - 1].className += " active";
}
* {
box-sizing: border-box
}
html,
body {
width: 100%;
height: 100%;
margin: 0;
}
body {
margin: 0;
font-family: Arial, Helvetica, sans-serif;
}
.mySlides {
display: none
}
img {
vertical-align: middle;
}
/* Slideshow container */
.slideshow-container {
padding: 10px;
max-width: 1000px;
position: relative;
margin: auto;
-webkit-overflow-scrolling: touch;
}
/* Next & previous buttons */
.prev,
.next {
cursor: pointer;
position: absolute;
top: 50%;
width: auto;
padding: 16px;
margin-top: -22px;
color: white;
font-weight: bold;
font-size: 18px;
transition: 0.6s ease;
border-radius: 0 3px 3px 0;
user-select: none;
}
/* Position the "next button" to the right */
.next {
right: 0;
border-radius: 3px 0 0 3px;
}
/* On hover, add a black background color with a little bit see-through */
.prev:hover,
.next:hover {
background-color: rgba(0, 0, 0, 0.8);
}
/* Caption text */
.text {
color: #f2f2f2;
font-size: 15px;
padding: 8px 12px;
position: absolute;
bottom: 8px;
width: 100%;
text-align: center;
}
/* Number text (1/3 etc) */
.numbertext {
color: #f2f2f2;
font-size: 12px;
padding: 8px 12px;
position: absolute;
top: 0;
}
/* The dots/bullets/indicators */
.dot {
cursor: pointer;
height: 15px;
width: 15px;
margin: 0 2px;
background-color: #bbb;
border-radius: 50%;
display: inline-block;
transition: background-color 0.6s ease;
}
.active,
.dot:hover {
background-color: #717171;
}
/* Fading animation */
.fade {
animation-name: fade;
animation-duration: 1.5s;
}
#keyframes fade {
from {
opacity: .4
}
to {
opacity: 1
}
}
/* On smaller screens, decrease text size */
#media only screen and (max-width: 300px) {
.prev,
.next,
.text {
font-size: 11px
}
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div id="slider" class="slideshow-container">
<!-- images -->
<div class="mySlides fade">
<!-- <div class="numbertext">1 / 3</div> -->
<img src="http://upload.wikimedia.org/wikipedia/commons/7/73/Lion_waiting_in_Namibia.jpg" style="width:100%">
<div class="text">Caption Text</div>
</div>
<div class="mySlides fade">
<img src="http://upload.wikimedia.org/wikipedia/commons/7/73/Lion_waiting_in_Namibia.jpg" style="width:100%">
</div>
<div class="mySlides fade">
<img src="http://upload.wikimedia.org/wikipedia/commons/7/73/Lion_waiting_in_Namibia.jpg" style="width:100%">
</div>
<div class="mySlides fade">
<img src="http://upload.wikimedia.org/wikipedia/commons/7/73/Lion_waiting_in_Namibia.jpg" style="width:100%">
</div>
<a class="prev" onclick="plusSlides(-1)">❮</a>
<a class="next" onclick="plusSlides(1)">❯</a>
</div>
<br>
<div style="text-align:center">
<!-- dots-->
<span class="dot" onclick="currentSlide(1)"></span>
<span class="dot" onclick="currentSlide(2)"></span>
<span class="dot" onclick="currentSlide(3)"></span>
<span class="dot" onclick="currentSlide(4)"></span>
</div>

image slide show with both automated and manual controls

The code runs quite well, the only issue i'm experiencing is that it doesn't start until its initiated with the control button. I need it to start sliding as soon as the page is loaded, I think it has to do with the display but i'm not quite sure. Kindly go through my code below and correct as appropriate i'll go to the stars and back to make sacrifices for the pandemic to be over if I get a solution
var slideIndex = 0;
var slides = document.getElementsByClassName("mySlides");
showSlides();
function showSlides() {
var i;
for (i = 0; i < slides.length; i++) {
slides[i].style.display = "none";
}
slideIndex++;
if (slideIndex> slides.length) {slideIndex = 1}
slides[slideIndex-1].style.display = "block";
setTimeout(showSlides, 5000); // Change image every 5 seconds
}
function currentSlide(no) {
var i;
for (i = 0; i < slides.length; i++) {
slides[i].style.display = "none";
}
slideIndex = no;
slides[no-1].style.display = "block";
}
function plusSlides(n) {
var newslideIndex = slideIndex + n;
if(newslideIndex < 4 && newslideIndex > 0){
currentSlide(newslideIndex);
}
}
* {box-sizing:border-box}
/* Slideshow container */
.slideshow-container {
max-width: 1000px;
position: relative;
margin: auto;
}
.mySlides {
display: none;
}
/* Next & previous buttons */
.prev, .next {
cursor: pointer;
position: absolute;
top: 50%;
width: auto;
margin-top: -22px;
padding: 16px;
color: white;
font-weight: bold;
font-size: 18px;
transition: 0.6s ease;
border-radius: 0 3px 3px 0;
}
/* Position the "next button" to the right */
.next {
right: 0;
border-radius: 3px 0 0 3px;
}
/* On hover, add a black background color with a little bit see-through */
.prev:hover, .next:hover {
background-color: rgba(0,0,0,0.8);
}
/* Caption text */
.text {
color: #f2f2f2;
font-size: 15px;
padding: 8px 12px;
position: absolute;
bottom: 8px;
width: 100%;
text-align: center;
}
/* Number text (1/3 etc) */
.numbertext {
color: #f2f2f2;
font-size: 12px;
padding: 8px 12px;
position: absolute;
top: 0;
}
/* The dots/bullets/indicators */
.dot {
cursor:pointer;
height: 13px;
width: 13px;
margin: 0 2px;
background-color: #bbb;
border-radius: 50%;
display: inline-block;
transition: background-color 0.6s ease;
}
.active, .dot:hover {
background-color: #717171;
}
/* Fading animation */
.fade {
-webkit-animation-name: fade;
-webkit-animation-duration: 1.5s;
animation-name: fade;
animation-duration: 1.5s;
}
#-webkit-keyframes fade {
from {display: block;}
to {margin: 0;}
}
#keyframes fade {
from {opacity: .4}
to {opacity: 1}
}
<div class="slideshow-container">
<div class="mySlides fade">
<div class="numbertext">1 / 3</div>
<div style="width:100%;background-color: yellow;height:50px;"> </div>
<div class="text">Caption Text</div>
</div>
<div class="mySlides fade">
<div class="numbertext">2 / 3</div>
<div style="width:100%;background-color: black;height: 50px; "> </div>
<div class="text">Caption Two</div>
</div>
<div class="mySlides fade">
<div class="numbertext">3 / 3</div>
<div style="width:100%;background-color: blue;height: 50px;"> </div>
<div class="text">Caption Three</div>
</div>
<a class="prev" onclick="plusSlides(-1)">❮</a>
<a class="next" onclick="plusSlides(1)">❯</a>
</div>
<br>
<div style="text-align:center">
<span class="dot" onclick="currentSlide(1)"></span>
<span class="dot" onclick="currentSlide(2)"></span>
<span class="dot" onclick="currentSlide(3)"></span>
</div>

HTML/CSS/JavaScript: Can't click slideshow indicator button

I'm new to webpage design and am trying to add indicator dots on my slideshow, so when clicking on them, i can go to the next image.
see this image
image2
I initially followed the instructions on the W3School page: https://www.w3schools.com/howto/howto_js_slideshow.asp
which put the indicator dots under the tag and below the slideshow banner. However, I want to put the dots ON the slideshow banner so I changed the tag to , but then the JavaScript stopped working.
In short, what I'm looking for is like the "another example" slideshow banner on this page: https://www.w3schools.com/w3css/w3css_slideshow.asp
sadly, the code used on that page was incomplete and i can't directly copy and paste it onto my website.
Please help to see what's wrong with my code OR to save your time, simply let me know how to achieve the feature mentioned in the above paragraph. Thank you so much.
<html>
<link rel="stylesheet" href="https://www.w3schools.com/w3css/4/w3.css">
<div class="slideshow-container">
<!-- Full-width images with number and caption text -->
<div class="mySlides">
<img class="img" src="https://res.cloudinary.com/mkconsulting/image/upload/v1545204835/sunset1.jpg" style="width:100%">
<div id="overlay"></div>
<div class="text">abcde</div>
<div class="indicator">
<button class="dot" onclick="currentSlide(1)"></button>
<button class="dot" onclick="currentSlide(2)"></button> </div>
</div>
<div class="mySlides">
<img class="img" src="https://res.cloudinary.com/mkconsulting/image/upload/v1545204834/sunset2.jpg" style="width:100%">
<div id="overlay"></div>
<div class="text text1">abcde</div>
<div class="indicator">
<button class="dot" onclick="currentSlide(1)"></button>
<button class="dot1" onclick="currentSlide()"></button> </div>
</div>
<!-- Next and previous buttons -->
<a class="prev" onclick="plusSlides(-1)">❮</a>
<a class="next" onclick="plusSlides(1)">❯</a>
</div>
</html>
<style>
.slideshow-container {
max-width: 100%;
position: relative;
padding-top:30px;
margin: auto;
height:auto;
}
.img{
height:350px;
}
.mySlides {
display: none;
}
.prev, .next {
cursor: pointer;
position: absolute;
top: 50%;
width: auto;
margin-top: -22px;
padding: 16px;
color: white;
font-weight: bold;
font-size: 18px;
transition: 0.6s ease;
border-radius: 0 3px 3px 0;
user-select: none;
z-index: 2;
}
.next {
right: 0;
border-radius: 3px 0 0 3px;
}
.prev:hover, .next:hover {
background-color: rgba(0,0,0,0.8);
}
.text {
color: #f2f2f2;
font-size: 20px;
padding: 8px 12px;
position: absolute;
bottom: 8px;
width: 100%;
text-align: center;
top:45%;
font-family:'cwTeXYen';
z-index: 2;
}
.text1 {
color: #f2f2f2;
font-size: 40px;
top:35%;
}
.text2 {
font-family:'Noto Sans TC';
color: black;
font-weight:300;
}
.indicator {
color: #f2f2f2;
font-size: 15px;
padding: 8px 12px;
position: absolute;
bottom: 8px;
width: 100%;
text-align: center;
top:85%;
}
.dot {
cursor: pointer;
height: 15px;
width: 15px;
margin: 0 2px;
background-color: transparent;
border-radius: 50%;
transition: background-color 0.6s ease;
border: 1px solid #ffffff;
}
.active, .dot:hover {
background-color: #ffffff;
}
.dot1{
height: 15px;
width: 15px;
background color:white;
border-radius: 50%;
border: 1px solid #ffffff;
margin-left: 2px;
}
#overlay {
position: absolute;
height:50%;
top: 30%;
left: 0;
right: 0;
bottom: 0;
background-color: rgba(0,0,0,0.5); /* Black background with opacity */
z-index: 1;
}
</style>
<script>
var slideIndex = 1;
showSlides(slideIndex);
function plusSlides(n) {
showSlides(slideIndex += n);
}
function currentSlide(n) {
showSlides(slideIndex = n);
}
function showSlides(n) {
var i;
var slides = document.getElementsByClassName("mySlides");
var dots = document.getElementsByClassName("dot");
if (n > slides.length) {slideIndex = 1}
if (n < 1) {slideIndex = slides.length}
for (i = 0; i < slides.length; i++) {
slides[i].style.display = "none";
}
for (i = 0; i < dots.length; i++) {
dots[i].className = dots[i].className.replace(" active", "");
}
slides[slideIndex-1].style.display = "block";
dots[slideIndex-1].className += " active";
}
</script>

how about this:
<!DOCTYPE html>
<html lang="en">
<title>W3.CSS</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<meta charset="UTF-8">
<link rel="stylesheet" href="https://www.w3schools.com/w3css/4/w3.css">
<style>
.mySlides {
display: none
}
.w3-left, .w3-right, .w3-badge {
cursor: pointer
}
.w3-badge {
height: 13px;
width: 13px;
padding: 0
}
.w3-display-container {
position: relative;
}
.myCaptions {
position: absolute;
top: 40%;
left: 50%;
transform: translate(-50%, -50%);
padding: 0.5rem 2rem;
background-color: rgba(255, 255, 255, 0.5);
}
</style>
<body>
<div class="w3-content w3-display-container" style="max-width:800px; text-align: center">
<p class="myCaptions" style="display: none;">Mountains</p>
<p class="myCaptions" style="display: none;">Nature Wide</p>
<p class="myCaptions" style="display: none;">Snow Wide</p>
<img class="mySlides" src="https://www.w3schools.com/w3css/img_mountains_wide.jpg" style="width:100%" alt="image1">
<img class="mySlides" src="https://www.w3schools.com/w3css/img_nature_wide.jpg" style="width:100%" alt="image2">
<img class="mySlides" src="https://www.w3schools.com/w3css/img_snow_wide.jpg" style="width:100%" alt="image3">
<div class="w3-center w3-container w3-section w3-large w3-text-white w3-display-bottommiddle" style="width:100%">
<div class="w3-left w3-hover-text-khaki" onclick="plusDivs(-1)">❮</div>
<div class="w3-right w3-hover-text-khaki" onclick="plusDivs(1)">❯</div>
<span class="w3-badge demo w3-border w3-transparent w3-hover-white" onclick="currentDiv(1)"></span>
<span class="w3-badge demo w3-border w3-transparent w3-hover-white" onclick="currentDiv(2)"></span>
<span class="w3-badge demo w3-border w3-transparent w3-hover-white" onclick="currentDiv(3)"></span>
</div>
</div>
<script>
let slideIndex = 1
showDivs(slideIndex)
function plusDivs (n) {
showDivs(slideIndex += n)
}
function currentDiv (n) {
showDivs(slideIndex = n)
}
function showDivs (n) {
let i
const x = document.getElementsByClassName('mySlides')
const dots = document.getElementsByClassName('demo')
if (n > x.length) {
slideIndex = 1
}
if (n < 1) {
slideIndex = x.length
}
for (i = 0; i < x.length; i++) {
x[i].style.display = 'none'
}
for (i = 0; i < dots.length; i++) {
dots[i].className = dots[i].className.replace(' w3-white', '')
}
x[slideIndex - 1].style.display = 'block'
dots[slideIndex - 1].className += ' w3-white'
// adjust captions
const captions = document.getElementsByClassName('myCaptions')
for (i = 0; i < captions.length; i++) {
captions[i].style.display = 'none'
}
captions[slideIndex-1].style.display = 'block'
}
</script>
</body>
</html>

First image of slideshow does not load

I've just started with CSS and JavaScript, and I tried to make an image slider by looking into w3schools. The slider works, but the first image always comes empty only with the navigation bars being visible.but once I click the next button, it works fine.I'm not understanding what to change with this. Here's the code.
'use strict';
var slideIndex = 1;
function plusSlides(n) {
showSlides(slideIndex += n);
}
function currentSlide(n) {
showSlides(slideIndex = n);
}
function showSlides(n) {
//alert('showslides('+ n +')\nslideIndex='+slideIndex);
var i;
var slides = document.getElementsByClassName("mySlides");
var dots = document.getElementsByClassName("dot");
if (n === undefined) {
n = ++slideIndex;
}
if (n > slides.length) {
slideIndex = 1;
}
if (n < 1) {
slideIndex = slides.length;
}
for (i = 0; i < slides.length; i++) {
slides[i].style.display = "none";
}
for (i = 0; i < dots.length; i++) {
dots[i].className = dots[i].className.replace(" active", "");
}
slides[slideIndex - 1].style.display = "block";
dots[slideIndex - 1].className += " active";
setTimeout(showSlides, 5000); // Change image every 5 seconds
}
* {
box-sizing: border-box;
}
body {
font-family: Verdana, sans-serif;
margin: 0
}
.mySlides {
display: none;
}
img {
vertical-align: middle;
}
/* Slideshow container */
.slideshow-container {
max-width: 1000px;
position: relative;
margin: auto;
}
/* Next & previous buttons */
.prev,
.next {
cursor: pointer;
position: absolute;
top: 50%;
width: auto;
padding: 16px;
margin-top: -22px;
color: white;
font-weight: bold;
font-size: 18px;
transition: 0.6s ease;
border-radius: 0 3px 3px 0;
}
/* Position the "next button" to the right */
.next {
right: 0;
border-radius: 3px 0 0 3px;
}
/* On hover, add a black background color with a little bit see-through */
.prev:hover,
.next:hover {
background-color: rgba(0, 0, 0, 0.8);
}
/* Caption text */
.text {
color: #f2f2f2;
font-size: 15px;
padding: 8px 12px;
position: absolute;
bottom: 8px;
width: 100%;
text-align: center;
}
/* Number text (1/3 etc) */
.numbertext {
color: #f2f2f2;
font-size: 12px;
padding: 8px 12px;
position: absolute;
top: 0;
}
/* The dots/bullets/indicators */
.dot {
cursor: pointer;
height: 15px;
width: 15px;
margin: 0 2px;
background-color: #bbb;
border-radius: 50%;
display: inline-block;
transition: background-color 0.6s ease;
}
.active,
.dot:hover {
background-color: #717171;
}
/* Fading animation */
.fade {
-webkit-animation-name: fade;
-webkit-animation-duration: 1.5s;
animation-name: fade;
animation-duration: 1.5s;
}
#-webkit-keyframes fade {
from {
opacity: .4
}
to {
opacity: 1
}
}
#keyframes fade {
from {
opacity: .4
}
to {
opacity: 1
}
}
/* On smaller screens, decrease text size */
#media only screen and (max-width: 300px) {
.prev,
.next,
.text {
font-size: 11px
}
}
<body>
<?php
include './p1.php';
// put your code here
?>
<div class="slideshow-container">
<div class="mySlides fade">
<div class="numbertext">1 / 3</div>
<img src="pics/bali2.jpg" height="400px" width="800px">
<div class="text">Caption Text</div>
</div>
<div class="mySlides fade">
<div class="numbertext">2 / 3</div>
<img src="pics/brazil1.jpg" height="400px" width="800px">
<div class="text">Caption Two</div>
</div>
<div class="mySlides fade">
<div class="numbertext">3 / 3</div>
<img src="pics/germany.jpg" height="400px" width="800px">
<div class="text">Caption Three</div>
</div>
<a class="prev" onclick="plusSlides(-1)">❮</a>
<a class="next" onclick="plusSlides(1)">❯</a>
</div>
<br>
<div style="text-align:center">
<span class="dot" onclick="currentSlide(1)"></span>
<span class="dot" onclick="currentSlide(2)"></span>
<span class="dot" onclick="currentSlide(3)"></span>
</div>
</body>

The slider works, but the first image always comes empty only with the navigation bars being visible
Just because of you apply css this mySlides on your, so your all div not visble. When you are click on next or previous or slider so particular container are showing.
So you need to apply the style="display: block;" on your first div.
DEMO
var slideIndex = 1,
interval;
function stopAndStart() {
if (interval) {
clearInterval(interval)
}
interval = setInterval(showSlides, 5000); // Change image every 5 seconds;
}
function plusSlides(n) {
showSlides(slideIndex += n);
stopAndStart()
}
function currentSlide(n) {
showSlides(slideIndex = n);
stopAndStart()
}
function showSlides(n) {
var i,
slides = document.getElementsByClassName("mySlides"),
dots = document.getElementsByClassName("dot");
if (n === undefined) {
n = ++slideIndex;
}
if (n > slides.length) {
slideIndex = 1;
}
if (n < 1) {
slideIndex = slides.length;
}
for (i = 0; i < slides.length; i++) {
slides[i].style.display = "none";
}
for (i = 0; i < dots.length; i++) {
dots[i].className = dots[i].className.replace(" active", "");
}
slides[slideIndex - 1].style.display = "block";
dots[slideIndex - 1].className += " active";
}
stopAndStart();
body {
font-family: Verdana, sans-serif;
margin: 0
}
.mySlides {
display: none;
text-align: center;
}
img {
vertical-align: middle;
}
/* Slideshow container */
.slideshow-container {
max-width: 1000px;
position: relative;
margin: auto;
background: burlywood;
}
/* Next & previous buttons */
.prev,
.next {
cursor: pointer;
position: absolute;
top: 50%;
width: auto;
padding: 16px;
margin-top: -22px;
color: white;
font-weight: bold;
font-size: 18px;
transition: 0.6s ease;
border-radius: 0 3px 3px 0;
}
/* Position the "next button" to the right */
.next {
right: 0;
border-radius: 3px 0 0 3px;
}
/* On hover, add a black background color with a little bit see-through */
.prev:hover,
.next:hover {
background-color: rgba(0, 0, 0, 0.8);
}
/* Caption text */
.text {
color: #f2f2f2;
font-size: 15px;
padding: 8px 12px;
position: absolute;
bottom: 8px;
width: 100%;
text-align: center;
}
/* Number text (1/3 etc) */
.numbertext {
color: #f2f2f2;
font-size: 12px;
padding: 8px 12px;
position: absolute;
top: 0;
}
/* The dots/bullets/indicators */
.dot {
cursor: pointer;
height: 15px;
width: 15px;
margin: 0 2px;
background-color: #bbb;
border-radius: 50%;
display: inline-block;
transition: background-color 0.6s ease;
}
.active,
.dot:hover {
background-color: #717171;
}
/* Fading animation */
.fade {
-webkit-animation-name: fade;
-webkit-animation-duration: 1.5s;
animation-name: fade;
animation-duration: 1.5s;
}
#-webkit-keyframes fade {
from {
opacity: .4
}
to {
opacity: 1
}
}
#keyframes fade {
from {
opacity: .4
}
to {
opacity: 1
}
}
/* On smaller screens, decrease text size */
#media only screen and (max-width: 300px) {
.prev,
.next,
.text {
font-size: 11px
}
}
<div class="slideshow-container">
<div class="mySlides fade" style="display: block;">
<div class="numbertext">1 / 3</div>
<img src="https://dummyimage.com/400x400/555985/fff&text=1">
<div class="text">Caption Text</div>
</div>
<div class="mySlides fade">
<div class="numbertext">2 / 3</div>
<img src="https://dummyimage.com/400x400/555985/fff&text=2">
<div class="text">Caption Two</div>
</div>
<div class="mySlides fade">
<div class="numbertext">3 / 3</div>
<img src="https://dummyimage.com/400x400/555985/fff&text=3">
<div class="text">Caption Three</div>
</div>
<a class="prev" onclick="plusSlides(-1)">❮</a>
<a class="next" onclick="plusSlides(1)">❯</a>
</div>
<br>
<div style="text-align:center">
<span class="dot active" onclick="currentSlide(1)"></span>
<span class="dot" onclick="currentSlide(2)"></span>
<span class="dot" onclick="currentSlide(3)"></span>
</div>

Restricting slideshow images to height/width of the slideshow container?

I have a modal image, that when clicked on open a slideshow, with a prev, and next button that are aligned halfway down from the top of the slideshow. When an image is longer than the slideshow container the slideshow becomes longer, rather than the image becoming smaller to fit the slideshow container (but stay centered).
I want it so that the container always stays the same size, and if the image is shorter, then I'd rather it be centered than moving up as it does now. (basically I want the next, and prev buttons to always in the same position, and halfway down the image). I've been stuck on this for a while, and
I've tried some stuff but none of it seems to work.
Note: the 1200x800 image is my standard for what I'd kind of like it to be like, the first pic is an example of too short, last is an example of too long.
Here is the [JSFIDDLE][1]
HTML:
<body>
<h2 style="text-align:center">Modal Albums</h2>
<div class="row">
<div class="column">
<img src="https://www.yosemitehikes.com/images/wallpaper/yosemitehikes.com-bridalveil-winter-1200x800.jpg" style="width:100%" onclick="openModal();currentSlide(1)" class="hover-shadow cursor">
</div>
</div>
<div id="myModal" class="modal">
<span class="close cursor" onclick="closeModal()">×</span>
<div class="modal-content">
<div class="mySlides">
<div class="numbertext">1 / 4</div>
<img src="http://chasingseals.com/wp-content/uploads/2014/02/greenlandBanner2000x800.jpg" style="width:100%">
</div>
<div class="mySlides">
<div class="numbertext">2 / 4</div>
<img src="http://www.catholicevangelism.org/wp-content/uploads/2013/06/1200x800.gif" style="width:100%">
</div>
<div class="mySlides">
<div class="numbertext">3 / 4</div>
<img src="http://www.a1carpet-to.com/wp-content/uploads/2015/08/600x400.png" style="width:100%">
</div>
<div class="mySlides">
<div class="numbertext">4 / 4</div>
<img src="https://support.kickofflabs.com/wp-content/uploads/2016/06/800x1200.png" style="width:100%">
</div>
<a class="prev" onclick="plusSlides(-1)">❮</a>
<a class="next" onclick="plusSlides(1)">❯</a>
</div>
</div>
CSS:
body {
font-family: Verdana, sans-serif;
margin: 0;
}
* {
box-sizing: border-box;
}
.row > .column {
padding: 0 8px;
}
.row:after {
content: "";
display: table;
clear: both;
}
.column {
float: left;
width: 25%;
}
/* The Modal (background) */
.modal {
display: none;
position: fixed;
z-index: 1;
padding-top: 100px;
left: 0;
top: 0;
width: 100%;
height: 100%;
overflow: auto;
background: rgba(0, 0, 0, 0.9);
}
/* Modal Content */
.modal-content {
position: relative;
background-color: rgba(0, 0, 0, 0.9);
margin: auto;
padding: 0;
width: 90%;
max-width: 1200px;
}
/* The Close Button */
.close {
color: white;
position: absolute;
top: 10px;
right: 25px;
font-size: 35px;
font-weight: bold;
}
.close:hover,
.close:focus {
color: #999;
text-decoration: none;
cursor: pointer;
}
.mySlides {
display: none;
}
.cursor {
cursor: pointer
}
/* Next & previous buttons */
.prev,
.next {
cursor: pointer;
position: absolute;
top: 50%;
width: auto;
padding: 16px;
margin-top: -50px;
color: white;
font-weight: bold;
font-size: 20px;
transition: 0.6s ease;
border-radius: 0 3px 3px 0;
user-select: none;
-webkit-user-select: none;
}
/* Position the "next button" to the right */
.next {
right: 0;
border-radius: 3px 0 0 3px;
}
/* On hover, add a black background color with a little bit see-through */
.prev:hover,
.next:hover {
background-color: rgba(0, 0, 0, 0.8);
text-decoration: none;
}
/* Number text (1/3 etc) */
.numbertext {
color: #f2f2f2;
font-size: 12px;
padding: 8px 12px;
position: absolute;
top: 0;
}
img {
margin-bottom: -4px;
}
t img.hover-shadow {
transition: all .2s ease-in-out;
}
.hover-shadow:hover {
transform: scale(1.1);
}
.modal-content {
-webkit-animation-name: zoom;
-webkit-animation-duration: 0.6s;
animation-name: zoom;
animation-duration: 0.6s;
}
#-webkit-keyframes zoom {
from {
-webkit-transform: scale(0)
}
to {
-webkit-transform: scale(1)
}
}
#keyframes zoom {
from {
transform: scale(0)
}
to {
transform: scale(1)
}
}
JS:
function openModal() {
document.getElementById('myModal').style.display = "block";
}
function closeModal() {
document.getElementById('myModal').style.display = "none";
}
var slideIndex = 1;
showSlides(slideIndex);
function plusSlides(n) {
showSlides(slideIndex += n);
}
function currentSlide(n) {
showSlides(slideIndex = n);
}
function showSlides(n) {
var i;
var slides = document.getElementsByClassName("mySlides");
var dots = document.getElementsByClassName("demo");
var captionText = document.getElementById("caption");
if (n > slides.length) {
slideIndex = 1
}
if (n < 1) {
slideIndex = slides.length
}
for (i = 0; i < slides.length; i++) {
slides[i].style.display = "none";
}
for (i = 0; i < dots.length; i++) {
dots[i].className = dots[i].className.replace(" active", "");
}
slides[slideIndex - 1].style.display = "block";
dots[slideIndex - 1].className += " active";
captionText.innerHTML = dots[slideIndex - 1].alt;
}
EDIT:
![What i want it to look like]: https://imgur.com/a/jtmmM
the shaded in part is the actual image, the box I've drawn is the container (which ofc isn't actually visible on the page)

If you add the following CSS this should fix your issue.
I am not sure I understand exactly how you want things to scale.
After your comment I Found this post that may help you using object-fit
You will need to define a height for your container in this case I set it to 200px but you can pick whatever works best for you.
.mySlides {
text-align: center;
height: 200px;
}
.mySlides img {
width: 100%;
max-height:100%;
object-fit: contain;
}
jsfiddle
function openModal() {
document.getElementById('myModal').style.display = "block";
}
function closeModal() {
document.getElementById('myModal').style.display = "none";
}
var slideIndex = 1;
showSlides(slideIndex);
function plusSlides(n) {
showSlides(slideIndex += n);
}
function currentSlide(n) {
showSlides(slideIndex = n);
}
function showSlides(n) {
var i;
var slides = document.getElementsByClassName("mySlides");
// var dots = document.getElementsByClassName("demo");
var captionText = document.getElementById("caption");
if (n > slides.length) {
slideIndex = 1
}
if (n < 1) {
slideIndex = slides.length
}
for (i = 0; i < slides.length; i++) {
slides[i].style.display = "none";
}
/*for (i = 0; i < dots.length; i++) {
dots[i].className = dots[i].className.replace(" active", "");
}*/
slides[slideIndex - 1].style.display = "block";
//dots[slideIndex - 1].className += " active";
//captionText.innerHTML = dots[slideIndex - 1].alt;
}
body {
font-family: Verdana, sans-serif;
margin: 0;
}
* {
box-sizing: border-box;
}
.row>.column {
padding: 0 8px;
}
.row:after {
content: "";
display: table;
clear: both;
}
.column {
float: left;
width: 25%;
}
/* The Modal (background) */
.modal {
display: none;
position: fixed;
z-index: 1;
padding-top: 100px;
left: 0;
top: 0;
width: 100%;
height: 100%;
overflow: auto;
background: rgba(0, 0, 0, 0.9);
}
/* Modal Content */
.modal-content {
position: relative;
background-color: rgba(0, 0, 0, 0.9);
margin: auto;
padding: 0;
width: 90%;
max-width: 1200px;
}
/* The Close Button */
.close {
color: white;
position: absolute;
top: 10px;
right: 25px;
font-size: 35px;
font-weight: bold;
}
.close:hover,
.close:focus {
color: #999;
text-decoration: none;
cursor: pointer;
}
.mySlides {
display: none;
}
.cursor {
cursor: pointer
}
/* Next & previous buttons */
.prev,
.next {
cursor: pointer;
position: absolute;
top: 50%;
width: auto;
padding: 16px;
margin-top: -50px;
color: white;
font-weight: bold;
font-size: 20px;
transition: 0.6s ease;
border-radius: 0 3px 3px 0;
user-select: none;
-webkit-user-select: none;
}
/* Position the "next button" to the right */
.next {
right: 0;
border-radius: 3px 0 0 3px;
}
/* On hover, add a black background color with a little bit see-through */
.prev:hover,
.next:hover {
background-color: rgba(0, 0, 0, 0.8);
text-decoration: none;
}
/* Number text (1/3 etc) */
.numbertext {
color: #f2f2f2;
font-size: 12px;
padding: 8px 12px;
position: absolute;
top: 0;
}
img {
margin-bottom: -4px;
}
t img.hover-shadow {
transition: all .2s ease-in-out;
}
.hover-shadow:hover {
transform: scale(1.1);
}
.modal-content {
-webkit-animation-name: zoom;
-webkit-animation-duration: 0.6s;
animation-name: zoom;
animation-duration: 0.6s;
}
#-webkit-keyframes zoom {
from {
-webkit-transform: scale(0)
}
to {
-webkit-transform: scale(1)
}
}
#keyframes zoom {
from {
transform: scale(0)
}
to {
transform: scale(1)
}
}
.mySlides {
text-align: center;
height: 200px;
}
.mySlides img {
width: 100%;
max-height:100%;
object-fit: contain;
}
<h2 style="text-align:center">Modal Albums</h2>
<span ></span>
<div class="row">
<div class="column">
<img src="https://www.yosemitehikes.com/images/wallpaper/yosemitehikes.com-bridalveil-winter-1200x800.jpg" style="width:100%" onclick="openModal();currentSlide(1)" class="hover-shadow cursor">
</div>
</div>
<div id="myModal" class="modal ">
<span class="close cursor" onclick="closeModal()">×</span>
<div class="modal-content ">
<div class="mySlides">
<div class="numbertext">1 / 4</div>
<img src="http://chasingseals.com/wp-content/uploads/2014/02/greenlandBanner2000x800.jpg" >
</div>
<div class="mySlides">
<div class="numbertext">2 / 4</div>
<img src="http://www.catholicevangelism.org/wp-content/uploads/2013/06/1200x800.gif" >
</div>
<div class="mySlides">
<div class="numbertext">3 / 4</div>
<img src="http://www.a1carpet-to.com/wp-content/uploads/2015/08/600x400.png" >
</div>
<div class="mySlides">
<div class="numbertext">4 / 4</div>
<img src="https://support.kickofflabs.com/wp-content/uploads/2016/06/800x1200.png" >
</div>
<a class="prev" onclick="plusSlides(-1)">❮</a>
<a class="next" onclick="plusSlides(1)">❯</a>
</div>
</div>

Change your img style to ( style ="width:1900px;height:970px" align="middle" )
Example
<div class="mySlides">
<div class="numbertext">1 / 4</div>
<img src="http://chasingseals.com/wp-content/uploads/2014/02/greenlandBanner2000x800.jpg" style ="width:1900px;height:970px" align="middle" >
</div>
And you need to do some changes in CSS too.

Change this in your HTML file ,
<div class="mySlides">
<div class="numbertext">1 / 4</div>
<img src="http://chasingseals.com/wp-content/uploads/2014/02/greenlandBanner2000x800.jpg" style ="width:1900px;height:970px" align="middle" >
</div>