Parallax Scrolling (Inception Style) in Website Display Effects - javascript

I want to create one page website using a Parallax effect like this one: Parallax Effect. I did all my research but I didn't find any example explaining how to do it, or what is the name of this parallax effect. I really need help!
This effect zooms into the page on scroll, as shown in the GIF below.
Here's what I have so far:
html {
height: 600vh;
overflow: -moz-scrollbars-vertical;
overflow-y: scroll;
}
body {
padding: 0;
margin: 0;
width: 100vw;
height: 100vh;
display: flex;
flex-direction: column;
position: fixed;
align-items: center;
justify-content: end;
}
#parent {
padding: 0;
margin: 0;
height: 600vh;
width: 100vw;
display: flex;
flex-direction: column;
transform-style: preserve-3d;
perspective: 250px;
}
.page {
padding: 0;
margin: 0;
height: 100vh;
width: 100vw;
position: absolute;
background: rgba(0, 0, 0, 0.1);
text-align: center;
box-shadow: inset 5px 5px red, inset -5px -5px red;
}
.page:nth-child(1) {
transform: scale(1);
}
.page:nth-child(2) {
bottom: -98%;
transform: translate3d(0, 0, -500px);
}
.page:nth-child(3) {
bottom: -196%;
transform: translate3d(0, 0, -1000px);
}
.page:nth-child(4) {
bottom: -294%;
transform: translate3d(0, 0, -1500px);
}
.page:nth-child(5) {
bottom: -392%;
transform: translate3d(0, 0, -2000px);
}
.page:nth-child(6) {
bottom: -490%;
transform: translate3d(0, 0, -2500px);
}
<div id="parent">
<div class="page">Page 1</div>
<div class="page">Page 2</div>
<div class="page">Page 3</div>
<div class="page">Page 4</div>
<div class="page">Page 5</div>
<div class="page">Page 6</div>
</div>
I am stuck at the animation via JavaScript part:
On body scroll the pages should scale to a maximum and then disappear one after the other,
The next page page2 should take the place of page1 and so on. To make the scroll sticky, scroll-snap-type: y; can be used.

I'm not quite sure what you'd call this scrolling effect - scaling page scrolling? - but it can be achieved in modern browsers with the CSS scale transform and a little JavaScript.
Style your page sections
I stacked my sections on top of each other by giving them a position absolute and fixing their CSS coordinates.
HTML:
<section style="background-color: red;">
<h1>This is section number one!!</h1>
</section>
<section style="background-color: blue;">
<h1>This is section number two!!</h1>
</section>
CSS:
html, body {
position: relative;
margin: 0;
height: 100%;
overflow: hidden;
}
section {
position: absolute;
width: 100%;
height: 100%;
left: 0; right: 0;
top: 0; bottom: 0;
text-align: center;
}
Set the initial scale of each section.
I wanted each section to be one third the size of the previous section. This meant the scale of the first section would be 1; the scale of the second would be 1/3; the third would be 1/9, the fourth 1/27 and so on. Therefore, if n is the index number of each section, the sections should be scaled by (1/3)^n. Scaling the sections is quite easy with the CSS3 transform feature.
JavaScript:
document.addEventListener( 'DOMContentLoaded', function() {
var sections = document.getElementsByTagName( 'section' ),
i = 0;
for ( i; i < sections.length; i++ ) {
sections[i].style.transform = 'scale(' + Math.pow( 1/3, i ) + ')';
}
} );
Alter the scale on scroll
Since the page does not overflow we need to listen to the wheel event. We must also keep a variable consisting of how far we've scrolled between a minimum (0) and a maximum (I picked 1000; you can change sensitivity of the scroll with a larger or smaller value). When the wheel event occurs we find how much the user has scrolled from the event's deltaY property, adjust our scroll counter by that much, and scale our sections accordingly.
To calculate how much we must scale each section is only a little more complex than calculating the initial scales. It's still a power of 1/3, although we must now subtract the scale multiplied by the total number of sections divided by the maximum counter value from our n.
You might also like to use requestAnimationFrame for a smoother experience.
JavaScript:
var counter = 0,
counter_max = 1000,
total = document.getElementsByTagName( 'section' ).length;
window.addEventListener( 'wheel', function( e ) {
counter += e.deltaY;
if ( counter > counter_max ) counter = counter_max;
if ( counter < 0 ) counter = 0;
requestAnimationFrame( applyScale );
} );
function applyScale() {
var sections = document.getElementsByTagName( 'section' ),
i = 0;
for ( i; i < sections.length; i++ ) {
var scale = Math.pow( 1/3, i - counter * total / counter_max );
sections[i].style.transform = 'scale(' + scale + ')';
}
}
Result
A pen that implements the above may be found at https://codepen.io/jla-/pen/aMNgxy
This should be a useful framework to get you started. Adding the anchors at the top of the page would involve a click listener that animates the counter variable to the appropriate value, calling the applyScale function on each animation frame.

Related

CSS position elements along ring of a circle [duplicate]

How can I position several <img> elements into a circle around another and have those elements all be clickable links as well? I want it to look like the picture below, but I have no idea how to achieve that effect.
Is this even possible?
2020 solution
Here's a more modern solution I use these days.
I start off by generating the HTML starting from an array of images. Whether the HTML is generated using PHP, JS, some HTML preprocessor, whatever... this matters less as the basic idea behind is the same.
Here's the Pug code that would do this:
//- start with an array of images, described by url and alt text
- let imgs = [
- {
- src: 'image_url.jpg',
- alt: 'image alt text'
- } /* and so on, add more images here */
- ];
- let n_imgs = imgs.length;
- let has_mid = 1; /* 0 if there's no item in the middle, 1 otherwise */
- let m = n_imgs - has_mid; /* how many are ON the circle */
- let tan = Math.tan(Math.PI/m); /* tangent of half the base angle */
.container(style=`--m: ${m}; --tan: ${+tan.toFixed(2)}`)
- for(let i = 0; i < n_imgs; i++)
a(href='#' style=i - has_mid >= 0 ? `--i: ${i}` : null)
img(src=imgs[i].src alt=imgs[i].alt)
The generated HTML looks as follows (and yes, you can write the HTML manually too, but it's going to be a pain to make changes afterwards):
<div class="container" style="--m: 8; --tan: 0.41">
<a href='#'>
<img src="image_mid.jpg" alt="alt text"/>
</a>
<a style="--i: 1">
<img src="first_img_on_circle.jpg" alt="alt text"/>
</a>
<!-- the rest of those placed on the circle -->
</div>
In the CSS, we decide on a size for the images, let's say 8em. The --m items are positioned on a circle and it's if they're in the middle of the edges of a polygon of --m edges, all of which are tangent to the circle.
If you have a hard time picturing that, you can play with this interactive demo which constructs the incircle and circumcircle for various polygons whose number of edges you pick by dragging the slider.
This tells us that the size of the container must be twice the radius of the circle plus twice half the size of the images.
We don't yet know the radius, but we can compute it if we know the number of edges (and therefore the tangent of half the base angle, precomputed and set as a custom property --tan) and the polygon edge. We probably want the polygon edge to be a least the size of the images, but how much we leave on the sides is arbitrary. Let's say we have half the image size on each side, so the polygon edge is twice the image size. This gives us the following CSS:
.container {
--d: 6.5em; /* image size */
--rel: 1; /* how much extra space we want between images, 1 = one image size */
--r: calc(.5*(1 + var(--rel))*var(--d)/var(--tan)); /* circle radius */
--s: calc(2*var(--r) + var(--d)); /* container size */
position: relative;
width: var(--s); height: var(--s);
background: silver /* to show images perfectly fit in container */
}
.container a {
position: absolute;
top: 50%; left: 50%;
margin: calc(-.5*var(--d));
width: var(--d); height: var(--d);
--az: calc(var(--i)*1turn/var(--m));
transform:
rotate(var(--az))
translate(var(--r))
rotate(calc(-1*var(--az)))
}
img { max-width: 100% }
See the old solution for an explanation of how the transform chain works.
This way, adding or removing an image from the array of images automatically arranges the new number of images on a circle such that they're equally spaced out and also adjusts the size of the container. You can test this in this demo.
OLD solution (preserved for historical reasons)
Yes, it is very much possible and very simple using just CSS. You just need to have clear in mind the angles at which you want the links with the images (I've added a piece of code at the end just for showing the angles whenever you hover one of them).
You first need a wrapper. I set its diameter to be 24em (width: 24em; height: 24em; does that), you can set it to whatever you want. You give it position: relative;.
You then position your links with the images in the center of that wrapper, both horizontally and vertically. You do that by setting position: absolute; and then top: 50%; left: 50%; and margin: -2em; (where 2em is half the width of the link with the image, which I've set to be 4em - again, you can change it to whatever you wish, but don't forget to change the margin in that case).
You then decide on the angles at which you want to have your links with the images and you add a class deg{desired_angle} (for example deg0 or deg45 or whatever). Then for each such class you apply chained CSS transforms, like this:
.deg{desired_angle} {
transform: rotate({desired_angle}) translate(12em) rotate(-{desired_angle});
}
where you replace {desired_angle} with 0, 45, and so on...
The first rotate transform rotates the object and its axes, the translate transform translates the object along the rotated X axis and the second rotate transform brings back the object into position.
The advantage of this method is that it is flexible. You can add new images at different angles without altering the current structure.
CODE SNIPPET
.circle-container {
position: relative;
width: 24em;
height: 24em;
padding: 2.8em;
/*2.8em = 2em*1.4 (2em = half the width of a link with img, 1.4 = sqrt(2))*/
border: dashed 1px;
border-radius: 50%;
margin: 1.75em auto 0;
}
.circle-container a {
display: block;
position: absolute;
top: 50%; left: 50%;
width: 4em; height: 4em;
margin: -2em;
}
.circle-container img { display: block; width: 100%; }
.deg0 { transform: translate(12em); } /* 12em = half the width of the wrapper */
.deg45 { transform: rotate(45deg) translate(12em) rotate(-45deg); }
.deg135 { transform: rotate(135deg) translate(12em) rotate(-135deg); }
.deg180 { transform: translate(-12em); }
.deg225 { transform: rotate(225deg) translate(12em) rotate(-225deg); }
.deg315 { transform: rotate(315deg) translate(12em) rotate(-315deg); }
<div class='circle-container'>
<a href='#' class='center'><img src='image.jpg'></a>
<a href='#' class='deg0'><img src='image.jpg'></a>
<a href='#' class='deg45'><img src='image.jpg'></a>
<a href='#' class='deg135'><img src='image.jpg'></a>
<a href='#' class='deg180'><img src='image.jpg'></a>
<a href='#' class='deg225'><img src='image.jpg'></a>
<a href='#' class='deg315'><img src='image.jpg'></a>
</div>
Also, you could further simplify the HTML by using background images for the links instead of using img tags.
EDIT: example with fallback for IE8 and older (tested in IE8 and IE7)
Here is the easy solution without absolute positioning:
.container .row {
margin: 20px;
text-align: center;
}
.container .row img {
margin: 0 20px;
}
<div class="container">
<div class="row">
<img src="https://ssl.gstatic.com/s2/oz/images/faviconr2.ico" alt="" width="64" height="64">
<img src="https://ssl.gstatic.com/s2/oz/images/faviconr2.ico" alt="" width="64" height="64">
</div>
<div class="row">
<img src="https://ssl.gstatic.com/s2/oz/images/faviconr2.ico" alt="" width="64" height="64">
<img src="https://ssl.gstatic.com/s2/oz/images/faviconr2.ico" alt="" width="64" height="64">
<img src="https://ssl.gstatic.com/s2/oz/images/faviconr2.ico" alt="" width="64" height="64">
</div>
<div class="row">
<img src="https://ssl.gstatic.com/s2/oz/images/faviconr2.ico" alt="" width="64" height="64">
<img src="https://ssl.gstatic.com/s2/oz/images/faviconr2.ico" alt="" width="64" height="64">
</div>
</div>
http://jsfiddle.net/mD6H6/
Using the solution proposed by #Ana:
transform: rotate(${angle}deg) translate(${radius}px) rotate(-${angle}deg)
I created the following jsFiddle that places circles dynamically using plain JavaScript (jQuery version also available).
The way it works is rather simple:
document.querySelectorAll( '.ciclegraph' ).forEach( ( ciclegraph )=>{
let circles = ciclegraph.querySelectorAll( '.circle' )
let angle = 360-90, dangle = 360 / circles.length
for( let i = 0; i < circles.length; ++i ){
let circle = circles[i]
angle += dangle
circle.style.transform = `rotate(${angle}deg) translate(${ciclegraph.clientWidth / 2}px) rotate(-${angle}deg)`
}
})
.ciclegraph {
position: relative;
width: 500px;
height: 500px;
margin: calc(100px / 2 + 0px);
}
.ciclegraph:before {
content: "";
position: absolute;
top: 0; left: 0;
border: 2px solid teal;
width: calc( 100% - 2px * 2);
height: calc( 100% - 2px * 2 );
border-radius: 50%;
}
.ciclegraph .circle {
position: absolute;
top: 50%; left: 50%;
width: 100px;
height: 100px;
margin: calc( -100px / 2 );
background: teal;
border-radius: 50%;
}
<div class="ciclegraph">
<div class="circle"></div>
<div class="circle"></div>
<div class="circle"></div>
<div class="circle"></div>
<div class="circle"></div>
<div class="circle"></div>
</div>
Building off #Ana's excellent answer, I created this dynamic version that allows you to add and remove elements from the DOM and maintain proportionate spacing between the elements - check out my fiddle: https://jsfiddle.net/skwidbreth/q59s90oy/
var list = $("#list");
var updateLayout = function(listItems) {
for (var i = 0; i < listItems.length; i++) {
var offsetAngle = 360 / listItems.length;
var rotateAngle = offsetAngle * i;
$(listItems[i]).css("transform", "rotate(" + rotateAngle + "deg) translate(0, -200px) rotate(-" + rotateAngle + "deg)")
};
};
$(document).on("click", "#add-item", function() {
var listItem = $("<li class='list-item'>Things go here<button class='remove-item'>Remove</button></li>");
list.append(listItem);
var listItems = $(".list-item");
updateLayout(listItems);
});
$(document).on("click", ".remove-item", function() {
$(this).parent().remove();
var listItems = $(".list-item");
updateLayout(listItems);
});
#list {
background-color: blue;
height: 400px;
width: 400px;
border-radius: 50%;
position: relative;
}
.list-item {
list-style: none;
background-color: red;
height: 50px;
width: 50px;
position: absolute;
top: 50%;
left: 50%;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
<ul id="list"></ul>
<button id="add-item">Add item</button>
Here is a version I made in React from the examples here.
CodeSandbox Example
import React, { useRef, useEffect } from "react";
import "./styles.css";
export default function App() {
const graph = useRef(null);
useEffect(() => {
const ciclegraph = graph.current;
const circleElements = ciclegraph.childNodes;
let angle = 360 - 90;
let dangle = 360 / circleElements.length;
for (let i = 0; i < circleElements.length; i++) {
let circle = circleElements[i];
angle += dangle;
circle.style.transform = `rotate(${angle}deg) translate(${ciclegraph.clientWidth /
2}px) rotate(-${angle}deg)`;
}
}, []);
return (
<div className="App">
<div className="ciclegraph" ref={graph}>
<div className="circle" />
<div className="circle" />
<div className="circle" />
<div className="circle" />
<div className="circle" />
<div className="circle" />
</div>
</div>
);
}
You can certainly do it with pure css or use JavaScript. My suggestion:
If you already know that the images number will never change just calculate your styles and go with plain css (pros: better performances, very reliable)
If the number can vary either dynamically in your app or just may vary in the future go with a Js solution (pros: more future-proof)
I had a similar job to do, so I created a script and open sourced it here on Github for anyone who might need it. It just accepts some configuration values and simply outputs the CSS code you need.
If you want to go for the Js solution here's a simple pointer that can be useful to you. Using this html as a starting point being #box the container and .dot the image/div in the middle you want all your other images around:
Starting html:
<div id="box">
<div class="dot"></div>
<img src="my-img.jpg">
<!-- all the other images you need-->
</div>
Starting Css:
#box{
width: 400px;
height: 400px;
position: relative;
border-radius: 100%;
border: 1px solid teal;
}
.dot{
position: absolute;
border-radius: 100%;
width: 40px;
height: 40px;
left: 50%;
top: 50%;
margin-left: -20px;
margin-top: -20px;
background: rebeccapurple;
}
img{
width: 40px;
height: 40px;
position: absolute;
}
You can create a quick function along these lines:
var circle = document.getElementById('box'),
imgs = document.getElementsByTagName('img'),
total = imgs.length,
coords = {},
diam, radius1, radius2, imgW;
// get circle diameter
// getBoundingClientRect outputs the actual px AFTER transform
// using getComputedStyle does the job as we want
diam = parseInt( window.getComputedStyle(circle).getPropertyValue('width') ),
radius = diam/2,
imgW = imgs[0].getBoundingClientRect().width,
// get the dimensions of the inner circle we want the images to align to
radius2 = radius - imgW
var i,
alpha = Math.PI / 2,
len = imgs.length,
corner = 2 * Math.PI / total;
// loop over the images and assign the correct css props
for ( i = 0 ; i < total; i++ ){
imgs[i].style.left = parseInt( ( radius - imgW / 2 ) + ( radius2 * Math.cos( alpha ) ) ) + 'px'
imgs[i].style.top = parseInt( ( radius - imgW / 2 ) - ( radius2 * Math.sin( alpha ) ) ) + 'px'
alpha = alpha - corner;
}
You can see a live example here
There is no way to magically place clickable items in a circle around another element with CSS.
The way how I would do this is by using a container with position:relative;. And then place all the elements with position:absolute; and using top and left to target it's place.
Even though you haven't placed jquery in your tags it might be best to use jQuery / javascript for this.
First step is placing your center image perfectly in the center of the container using position:relative;.
#centerImage {
position:absolute;
top:50%;
left:50%;
width:200px;
height:200px;
margin: -100px 0 0 -100px;
}
After that you can place the other elements around it by using an offset() of the centerImage minus the offset() of the container. Giving you the exact top and left of the image.
var left = $('#centerImage').offset().left - $('#centerImage').parent().offset().left;
var top = $('#centerImage').offset().top - $('#centerImage').parent().offset().top;
$('#surroundingElement1').css({
'left': left - 50,
'top': top - 50
});
$('#surroundingElement2').css({
'left': left - 50,
'top': top
});
$('#surroundingElement3').css({
'left': left - 50,
'top': top + 50
});
What I've done here is placing the elements relative to the centerImage. Hope this helps.
You could do it like this: fiddle
Don't mind the positioning, its a quick example
The first step is to have 6 long columnar boxes:
The second step is to use position: absolute and move them all into the middle of your container:
And now rotate them around the pivot point located at the bottom center. Use :nth-child to vary rotation angles:
div {
transform-origin: bottom center;
#for $n from 0 through 7 {
&:nth-child(#{$n}) {
rotate: (360deg / 6) * $n;
}
}
Now all you have to do is to locate your images at the far end of every column, and compensate the rotation with an anti-rotation :)
Full source:
<div class="flower">
<div class="petal">1</div>
<div class="petal">2</div>
<div class="petal">3</div>
<div class="petal">4</div>
<div class="petal">5</div>
<div class="petal">6</div>
</div>
.flower {
width: 300px;
height: 300px;
// We need a relative position
// so that children can have "position:abolute"
position: relative;
.petal {
// Make sure petals are visible
border: 1px solid #999;
// Position them all in one point
position: absolute; top: 0; left: 50%;
display: inline-block;
width: 30px; height: 150px;
// Rotation
transform-origin: bottom center;
#for $n from 0 through 7 {
&:nth-child(#{$n}) {
// Petal rotation
$angle: (360deg / 6) * $n;
rotate: $angle;
// Icon anti-rotation
.icon { rotate: -$angle; }
}
}
}
}
See CodePen

Maintain aspect ratio of a video when resizing the browser

I'm working on a Video editing tool, and I need to maintain the 16:9 aspect ratio of the video when resizing the screen horizontally and vertically. So far I got it to work as expected when resizing horizontally, and when resizing down vertically, but can't get it to work when sizing up vertically. The Javascript code I used to calculate the height of the video and resize it is below (notice how the else clause is empty because that's where the code should go):
const calculateHeight = () => {
// Get the other elements on the page
const header = document.querySelector('.main-navigation');
const meshTopBar = document.querySelector('.mesh__top-bar');
const footer = document.querySelector('.mesh__bottom-bar');
// Get the section to apply the window height to it
const mainSection = document.querySelector('.insert-level-container');
// Get the video elements
const editor = document.querySelector('.mesh__insert-editor-container');
const video = document.querySelector('.mesh__insert-editor-video-container');
// Apply the height to the main section by calculating the window height minus the other elements' height
if(mainSection !== null) {
mainSection.style.height = (window.innerHeight - header.offsetHeight - meshTopBar.offsetHeight - footer.offsetHeight) + 'px';
}
// This should be the ideal height for the video
video.style.minHeight = ((video.offsetWidth * 9) / 16) + 'px';
// If the video height is bigger than the section height (calculated above), then resize it
if(video.offsetHeight + 115 > mainSection.offsetHeight) {
video.style.minHeight = video.offsetHeight - 1 + 'px';
editor.style.maxWidth = video.offsetHeight * 16 / 9 + 'px';
} else {
// This is where the logic for the vertical resizing should go
}
}
The relevant CSS for these items is:
.mesh__insert-editor-container {
margin-left: auto;
margin-right: auto;
}
.mesh__insert-editor-video-container {
position: relative;
width: 100%:
}
And the HTML:
<section class="mesh__insert-editor-container flex__one flex-container flex-column horizontally-left-aligned" id="video-main-container">
<div class="mesh__insert-editor-video-container flex-container horizontally-right-aligned flex-wrap">
<video class="mesh__insert-editor-video-placeholder"></video>
</div>
</section>
All this code is:
Get the height of all the elements on the page, sum them and calculate the main section height by subtracting that height;
If the video height gets bigger than the section height, I reduce its height by -1px each time the window gets resized, and calculate the new width.
All the above code is giving me this result, which works great for most scenarios, but I need the video to size up when the condition on the if statement is not met. Everything I tried inside the else statement gets "jumpy".
Any better alternatives to solve this would be much appreciated. Thanks all!
The CSS aspect ratio trick might be a good solution: https://css-tricks.com/aspect-ratio-boxes/
The approach takes advantage of a quirk in CSS where padding based on a percentage value will be relative to the element's width. Create a container using this trick, the important bit is this line:
padding-top: calc(9/16 * 100%);
The value is calculating the correct height based on the aspect ratio you want (9 tall over 16 wide in this case) and generating it relative to the width of the element by multiplying by 100%.
With the container maintaining aspect ratio, just place the content inside an absolute positioned inner div and you should be good. This solution is fully responsive at that point.
* { box-sizing: border-box }
.outer-max-width {
max-width: 960px;
margin: 0 auto;
}
.aspect-ratio-box {
width: 100%;
padding-top: calc(9/16 * 100%);
position: relative;
border: 2px solid red; /* for demo visibility, remove */
}
.aspect-ratio-box-content {
position: absolute;
width: 100%;
top: 0;
left: 0;
border: 2px solid blue; /* for demo visibility, remove */
}
.video-placeholder {
display: block;
width: 100%;
height: auto;
}
<div class="outer-max-width">
<div class="aspect-ratio-box">
<div class="aspect-ratio-box-content">
<img class="video-placeholder" src="https://placeimg.com/640/360/nature" />
</div>
</div>
</div>
Got it to work! I used this amazing CSS-only solution: https://codepen.io/EightArmsHQ/pen/BvNzrm similar to BugsArePeopleToo's suggestion, from eightarmshq:
.content{
position: absolute;
top: 0;
bottom: 0;
width: 100%;
height: 100%;
background: #555;
box-shadow: inset 1vh 1vh 10vh 0 rgba(0,0,0,0.5);
display: flex;
box-sizing: border-box;
border: 25px solid #cecece;
}

Trying to make continuous JavaScript slider

The problem with my slider is that when it gets to the last slide and i click next it jumps over the two slides to get to the first one. Similarly when i am on the first slide and click previous, it jumps over slides to get to the last one. I would like to make it that when i get to the last slide and click NEXT the first slide would come from the right to left. (similar concept for the PREVIOUS button on first slide). I tried using insertBefore() and appendChild() for the slides but couldn't figure it out...
Here is my code:
// Slider
const slider_wrapp = document.querySelector('.tract-slider');
const slider = document.querySelector('.tract-slider-wrapp');
var slide = document.getElementsByClassName('tract-slide');
const leftBtn = document.querySelector('.slide-left');
const rightBtn = document.querySelector('.slide-right');
let swWidth = slider_wrapp.clientWidth;
let sliderWidth = swWidth * slide.length;
let slideWidth = 0;
slider.style.width = sliderWidth + "px";
for (var i = 0; i < slide.length; i++) {
slide.item(i).style.width = swWidth + "px";
}
function moveRight() {
slideWidth === sliderWidth - swWidth ? slideWidth = 0 : slideWidth += swWidth;
slider.style.transform = "translateX(" + (-slideWidth) + "px)";
}
function moveLeft() {
slideWidth === 0 ? slideWidth = sliderWidth - swWidth : slideWidth -= swWidth;
slider.style.transform = "translateX(" + (-slideWidth) + "px)";
}
rightBtn.addEventListener("click", function() {
moveRight();
});
leftBtn.addEventListener("click", function() {
moveLeft();
});
.tract-slider {
width: 100%;
height: 75vh;
position: relative;
overflow: hidden;
}
.tract-slider-wrapp {
height: 100%;
position: relative;
-webkit-transition: all 350ms cubic-bezier(.08, .13, 0, .81);
-o-transition: all 350ms cubic-bezier(.08, .13, 0, .81);
transition: all 350ms cubic-bezier(.08, .13, 0, .81);
}
.tract-slide {
height: 100%;
float: left;
position: relative;
display: block;
background-position: center;
-webkit-background-size: cover;
background-size: cover;
}
.tract-slide:nth-child(1) {
background-image: url("https://static.pexels.com/photos/126282/pexels-photo-126282.jpeg");
}
.tract-slide:nth-child(2) {
background-image: url("https://static.pexels.com/photos/29017/pexels-photo-29017.jpg");
}
.tract-slide:nth-child(3) {
background-image: url("https://static.pexels.com/photos/70760/dandelion-dandelion-seeds-taraxacum-fluffy-70760.jpeg");
}
.tract-slider-control {
position: absolute;
left: 0;
bottom: 0;
background: #ffffff;
padding: 1em;
}
.tract-slider-btn {
display: inline-block;
cursor: pointer;
margin-left: 1em;
}
.tract-slider-btn:nth-child(1) {
margin-left: 0;
}
<div class="tract-slider">
<div class="tract-slider-wrapp">
<div class="tract-slide"></div>
<div class="tract-slide"></div>
<div class="tract-slide"></div>
</div>
<div class="tract-slider-control">
<div class="tract-slider-btn slide-left">Prev</div>
<div class="tract-slider-btn slide-right">Next</div>
</div>
</div>
PS. Please use JavaScript for solution
Creating an infinite slider means you need to move your slides around in DOM so they give the impression of a continuous track.
The first thing you need to change is having their backgrounds tied up to their position in DOM. If we want to slide back from first slide to the last one, we need to take the last slide, prepend it before the first one but, considering your current CSS, that will change the backgrounds of all slides, as they are currently bound to their position in DOM (...:nth-child {background-image:...}...).
The second thing that needs changing is positioning the slides into the slider track. If they're floated, whenever we change their order, all the rest of the slides will be affected. By positioning them with position:absolute each slide moves independently, without affecting the others, so it's easier to rearrange them while keeping control.
Long story short, I started from scratch and placed all methods inside a single object: theSlider.
The reset() function does the heavy lifting: it puts before class on first element, current on second and after on all the rest. So you have to put the "last" slide first, because the slider will start with it appended before the "current" one.
The sliding is done by applying go-left and go-right classes to the track. After the transition is done, I just move the first/last slide into the new position, depending on case, and run reset() again (which strips all classes and reapplies them based on new positions).
Animations are handled by CSS. All JavaScript does is apply/remove classes and move the slides in DOM.
var theSlider = {
track : document.querySelector('.tract-slider-wrapp'),
// has to match `transition-duration` in CSS:
duration : 600,
reset : function() {
var slides = document.querySelectorAll('.tract-slider-wrapp > div');
for (var i = 0; i < slides.length; i++) {
slides[i].className = '';
slides[i].classList.add(i > 1? 'after' : (i ? 'current':'before'))
}
},
init : function() {
theSlider.reset();
theSlider.track.classList.remove('not-loaded')
},
next : function() {
theSlider.track.classList.add('go-right');
setTimeout(function(){
var firstSlide = document.querySelector('.tract-slider-wrapp > div:first-child');
theSlider.track.appendChild(firstSlide);
theSlider.reset();
theSlider.track.classList.remove('go-right')
},theSlider.duration)
},
prev : function() {
theSlider.track.classList.add('go-left');
setTimeout(function() {
var lastSlide = document.querySelector('.tract-slider-wrapp > div:last-child');
theSlider.track.insertBefore(lastSlide, theSlider.track.firstChild);
theSlider.reset();
theSlider.track.classList.remove('go-left')
},theSlider.duration)
},
prevButton : document.querySelector('.slide-left'),
nextButton : document.querySelector('.slide-right')
};
window.addEventListener("load", theSlider.init);
theSlider.prevButton.addEventListener('click', theSlider.prev);
theSlider.nextButton.addEventListener('click', theSlider.next);
.tract-slider {
width: 100%;
height: 75vh;
position: relative;
overflow: hidden;
background-color: #f5f5f5;
}
.tract-slider-wrapp {
height: 100%;
transition: all 350ms cubic-bezier(.08, .13, 0, .81);
opacity: 1;
}
.tract-slider-wrapp.not-loaded {
opacity: 0;
}
.tract-slider-wrapp>div {
height: 100%;
position: absolute;
background: transparent no-repeat 50% 50% /cover;
width: 100%;
}
.tract-slider-wrapp > div.before {
margin-left: -100%;
}
.tract-slider-wrapp > div.current + div {
margin-left: 100%;
}
.tract-slider-wrapp > div.after ~ div {
opacity: 0;
}
.tract-slider-control {
position: absolute;
width: 100%;
z-index: 1;
top: 50%;
display: flex;
justify-content: space-between;
transform: translateY(-50%);
}
.tract-slider-control div {
background-color: rgba(0,0,0,.35);
padding: .5rem 1rem;
color: white;
cursor: pointer;
}
.tract-slider-control :first-child {
border-radius: 0 17px 17px 0;
}
.tract-slider-control :last-child {
border-radius: 17px 0 0 17px;
}
body {
margin: 0;
}
.go-right div {
transform: translateX(-100%);
}
.go-left div {
transform: translateX(100%);
}
.go-right div, .go-left div {
transition-property: transform;
transition-timing-function: cubic-bezier(.4,0,.2,1);
/* has to match `duration` in js: */
transition-duration: 600ms;
}
<div class="tract-slider">
<div class="tract-slider-wrapp not-loaded">
<div style="background-image:url('https://static.pexels.com/photos/126282/pexels-photo-126282.jpeg')"></div>
<div style="background-image:url('https://static.pexels.com/photos/29017/pexels-photo-29017.jpg')"></div>
<div style="background-image:url('https://static.pexels.com/photos/70760/dandelion-dandelion-seeds-taraxacum-fluffy-70760.jpeg')"></div>
</div>
<div class="tract-slider-control">
<div class="tract-slider-btn slide-left">Prev</div>
<div class="tract-slider-btn slide-right">Next</div>
</div>
</div>
If you want to change the animation duration you need to change it in both js and css.
The only current limitation is it needs at least 3 slides to work. I guess it could be adjusted to work with only two slides by: cloning the "inactive" slide into third position, removing the clone after transition and cloning the other one.
ToDo's:
prefix CSS so it works in more browsers
replace .classList.add('whatever') with .className += ' whatever' and
.classList.remove('whatever') with .className.replace('whatever', '') if you want to show IE some love.
I told the above just to tell you this: if you want to get going, don't reinvent the wheel.
It's great you use vanilla javascript. But sooner or later you'll end up writing your own wrappers for common things. Depending on how good you are/have become, you'll write your own, limited, custom version of jQuery. Allow me to put things into perspective: Google included a lite version of jQuery into AngularJS. It's that good.
You, as an single developer, do not stand a chance at writing a better, more streamlined and tested version of it. And besides, you don't have to. Use your skill and abilities to go forward, not sideways.

CSS Box Shadow Overlap

I made a sliding puzzle in CSS, which you can view in this fiddle
The issue is that I wanted the tiles to have a drop shadow onto the gray background, but I didn't want the shadows to overlap other tiles, since they're all on the same level.
I've seen this question on StackOverflow, which is really asking the same thing, but I can't seem to get any of the solutions working.
I cannot cover the overlap with a pseudo-element, because they have background images whose background positions are set in JavaScript. While I could set them using complex CSS selectors that use nth-child, I'd rather keep it in JS for now.
I cannot put the shadow on a pseudo-element underneath the tile, because I don't know, actually. I tried it in the Fiddle I linked, but it's not working.
Any help would be appreciated. Thanks!
// This is the location of the empty square. At the start it's at 2, 2
var emptyRow = 2;
var emptyCol = 2;
// i and j, as passed in, are the tiles' original coordinates
var makeMoveHandler = function (tile, i, j) {
// row and col, as made here in closure, are the tiles up-to-date coordinates
var row = i;
var col = j;
// The click handler
return function () {
var rowOffset = Math.abs(emptyRow - row);
var colOffset = Math.abs(emptyCol - col);
// Move the tile to the vacant place next to it
if (rowOffset == 1 && colOffset == 0 || rowOffset == 0 && colOffset == 1) {
tile.style.transform = `translate(${emptyCol * 200}px, ${emptyRow * 200}px)`;
// Swap the two coordinates
[row, emptyRow] = [emptyRow, row];
[col, emptyCol] = [emptyCol, col];
}
}
};
var initTiles = function () {
// Get all of the rows
var rows = document.querySelectorAll('.row');
// Go through the rows
for (let i = 0; i < rows.length; ++i) {
var row = rows.item(i);
// Go through the tiles on each row
var tiles = row.querySelectorAll('.tile');
for (let j = 0; j < tiles.length; ++j) {
var tile = tiles.item(j);
// Add the click listener to the tile
tile.addEventListener('click', makeMoveHandler(tile, i, j));
// Set the location of the tile
tile.style.transform = `translate(${j * 200}px, ${i * 200}px)`;
// Set what part of the background to show on the tile
tile.style.backgroundPosition = `${600 - j * 200}px ${600 - i * 200}px`;
}
}
};
// Initialize the tiles
initTiles();
#puzzle {
width: 600px;
height: 600px;
display: flex;
background-color: gray;
border: 5px solid blue;
}
.tile {
width: 200px;
height: 200px;
border: 1px solid black;
background-image: url('http://www.lovethispic.com/uploaded_images/123553-Beautiful-Scene.jpg');
position: absolute;
background-size: 600px 600px;
transition: transform 300ms;
}
.tile:before {
background: transparent;
content: "";
position: absolute;
top: 0;
bottom: 0;
left: 0;
right: 0;
z-index: -100;
box-shadow: 0 0 40px #000;
}
<div id="puzzle">
<div class="row">
<div class="tile"></div>
<div class="tile"></div>
<div class="tile"></div>
</div>
<div class="row">
<div class="tile"></div>
<div class="tile"></div>
<div class="tile"></div>
</div>
<div class="row">
<div class="tile"></div>
<div class="tile"></div>
</div>
</div>
You can use filter: drop-shadow(0 0 40px #000) on a new element which contains all your rows and tiles:
<div id="puzzle">
<div class="puzzle-inner" style="filter:drop-shadow(0 0 40px #000);">
<div class="row"> ...
This works on the accumulated 'silhouette' of it's contained elements.
This won't work on the #puzzle element itself, as it has a background set which will be included in the silhouette.
I finally found 2 methods of solving the problem, both aren't very pretty. I couldn't have a box-shadow, and I had come to terms with that. I could, however, create a pseudo-element that contained a picture of a box-shadow, so I did that.
I couldn't live with the idea that the browser would have to download an entirely separate image just for a shadow, so I made an approximation of a box-shadow using CSS3 gradients, which work (at least, in Chrome).
A snippet for the (sort of) simulated box-shadow:
div {
width: 200px;
height: 200px;
margin: 50px;
background-color: green;
position: relative;
opacity: 0.5;
}
div:before {
position: absolute;
content: '';
left: -20px;
right: -20px;
top: 0;
bottom: 0;
background: linear-gradient(90deg, transparent 220px, black 220px, transparent 240px ),
linear-gradient(-90deg, transparent 220px, black 220px, transparent 240px );
z-index: -1;
}
div:after {
position: absolute;
content: '';
top: -20px;
bottom: -20px;
left: 0;
right: 0;
background: linear-gradient(0deg, transparent 220px, black 220px, transparent 240px ),
linear-gradient(180deg, transparent 220px, black 220px, transparent 240px );
z-index: -1;
}
<div></div>
A JSFiddle with the sliding puzzle result, since it doesn't work properly in the snippets here.

Making text scroll at different speed in a simple jquery parallax example

I am following this parallax tutorial that uses only jQuery. I slightly modified the HTML:
<section id="home" data-type="background" data-speed="10">
<article data-speed="1">One</article>
<article data-speed="20">Two</article>
</section>
<section id="about" data-type="background" data-speed="10">
</section>
css
#home {
background: url(home-bg.jpg) 50% 0 repeat fixed; min-height: 1000px;
height: 1000px;
margin: 0 auto;
width: 100%;
max-width: 1920px;
position: relative;
}
#home article {
height: 458px;
position: absolute;
text-align: center;
top: 150px;
width: 100%;
}
#about {
background: url(about-bg.jpg) 50% 0 repeat fixed; min-height: 1000px;
height: 1000px;
margin: 0 auto;
width: 100%;
max-width: 1920px;
position: relative;
-webkit-box-shadow: 0 0 50px rgba(0,0,0,0.8);
box-shadow: 0 0 50px rgba(0,0,0,0.8);
}
#about article {
height: 458px;
position: absolute;
text-align: center;
top: 150px;
width: 100%;
}
And the jQuery:
$(document).ready(function(){
// Cache the Window object
$window = $(window);
$('section[data-type="background"]').each(function(){
var $bgobj = $(this); // assigning the object
$(window).scroll(function() {
// Scroll the background at var speed
// the yPos is a negative value because we're scrolling it UP!
var yPos = -($window.scrollTop() / $bgobj.data('speed'));
// Put together our final background position
var coords = '50% '+ yPos + 'px';
// Move the background
$bgobj.css({ backgroundPosition: coords });
}); // window scroll Ends
});
});
This code moves everything in a section at the same speed, but I would like to have the <article> text move at a variable speed different (defined in the <article data-speed>) from the background image.
I wasn't sure how to move the text because background-position is for images, and I tried adjusting top but that didn't have any effect. I also tried setting transform: translateZ(); on the article css, but this also did not work.
How can I add different speeds to the <article> texts? I'd also like to stick to jQuery in the spirit of the example.
try modifying markup always wrapping the article with a section, for ex.:
<section id="about" data-speed="4" data-type="background">
<article>One</article>
</section>
<section id="home" data-speed="20" data-type="background" >
<article >Two</article>
</section>
edit--explanation
this is the source of your parallax jquery script:
$(document).ready(function(){
// Cache the Window object
$window = $(window);
$('section[data-type="background"]').each(function(){
var $bgobj = $(this); // assigning the object
$(window).scroll(function() {
// Scroll the background at var speed
// the yPos is a negative value because we're scrolling it UP!
var yPos = -($window.scrollTop() / $bgobj.data('speed'));
// Put together our final background position
var coords = '50% '+ yPos + 'px';
// Move the background
$bgobj.css({ backgroundPosition: coords });
}); // window scroll Ends
});
});
as you can tell what it's doing is slowing down the scroll of the section[data-type="background"] with a factor of data('speed');
This kind of script is built in a way to have one layer of parallax, if you want more parallax layers check wagersfield's parallax script

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