Softly Transition HTML Images with Javascript - javascript

I am trying to use JS to switch images, the code does what it is supposed to and switches the images, however, I want a fade out-fade in effect to the image transition. I tried to declare a CSS Transition for opacity and change the opacity first, which didn't work, then I tried to change the opacity with plain JS, however that didn't work either, what would be the best way to achieve this?
My Poorly Designed Image Change Code:
image = [
"image_1.png",
"image_2.png",
"image_3.jpeg"
];
updateImg = async() => {
console.log("Pulling Image Change")
var img = document.getElementById("img-pan");
console.log(`Got ${img} with current src ${img.src}`)
var exi_bool = false;
for(i = 0; i < image.length - 1; i++) {
if(img.src.endsWith(image[i])) { exi_bool = true; console.log(`Found current src to == image[${i}]`) ;break; }
}
if(!exi_bool) {
img.src = image[0];
}else {
if(i < image.length - 1) { i++ }else { i = 0 }
img.src = image[i];
}
}

If I understood well, before you replace the image add a class that define the opacity to 0.3 for example.
document.getElementById("MyElement").classList.add('MyClass');
when the image change you remove the class.
document.getElementById("MyElement").classList.remove('MyClass');
Note that your image has to be set on css as opacity: 1 and transition x seconds.

Will use css style animation, just change class name, is simple to use and build.
but when css animation start to change css property,no way could change same property but other css animation.
let imgArray = [
'https://fakeimg.pl/100x100/f00',
'https://fakeimg.pl/100x100/0f0',
'https://fakeimg.pl/100x100/00f'
];
let img = document.getElementsByTagName('img')[0];
//only two function
async function fadeOut(element) {
element.className = 'fade-out';
}
async function fadeIn(element) {
element.className = 'fade-in';
}
//
let i = 0;
function loop() {
img.src = imgArray[i % 3];
i++;
fadeIn(img).then(res => {
setTimeout(() => {
fadeOut(img).then(res => {
setTimeout(() => {
loop();
}, 1000);
})
}, 1000);
})
}
loop();
img {
position: relative;
left: 0; /* or use transform */
opacity: 1;
transition: 1s;
width: 100px;
display: block;
margin: auto;
}
.fade-in {
animation: fade-in 1s;
}
#keyframes fade-in {
0% {
left: 100px; /* or use transform */
opacity: 0;
}
100% {
left: 0; /* or use transform */
opacity: 1;
}
}
.fade-out {
animation: fade-out 1s both;
}
#keyframes fade-out {
0% {
left: 0; /* or use transform */
opacity: 1;
}
100% {
left: -100px; /* or use transform */
opacity: 0;
}
}
<img src="https://fakeimg.pl/100x100/#f00">

Related

Setting timeout function based on animation delay

I need to set my .screens to be display: none until the point when its animation starts. Each one has a separate animation-delay so what I hope to achieve is that a function will check how long the animation delay is and that will then determine the length of the setTimeout function.
Example:
If .screens has an animation delay of 3 seconds, then after 3 seconds I want display to change from none to block.
Code of the function I have written so far is below:
var screens = document.getElementsByClassName('screen');
for (var i=0;i<screens.length;i++){
if (screens[i].style.animationDelay >=0){
setTimeout(function(){
this.style.display = "block";
}, this.style.animationDelay);
}
}
You can try this. (You can skip the first part, it is there just to generate screens with random animationDelay)
const generateScreens = () => {
for (let i = 0; i < 5; i++) {
let el = document.createElement('div');
el.className = 'screen';
el.style.animationDelay = Math.floor(Math.random() * 5) + 's';
document.body.appendChild(el);
}
}
generateScreens();
// code that you have asked for starts here
const screens = document.getElementsByClassName('screen');
[...screens].forEach(item => {
const delay = item.style.animationDelay.slice(0, item.style.animationDelay.length - 1);
setTimeout(() => {
item.style.display = 'block';
}, delay * 1000);
});
div.screen {
width: 40px;
height: 40px;
background: red;
border: 1px solid black;
display: none;
}
Since you cannot animate the state/value from none to block of the display property, you can instead do it with the visibility: hidden / visibility: visible pair, and of course you could also do it with the opacity: 0 / opacity: 1:
.screen {
visibility: hidden;
animation: animate forwards;
}
.screen:first-child {animation-delay: 1s}
.screen:nth-child(2) {animation-delay: 2s}
.screen:nth-child(3) {animation-delay: 3s}
#keyframes animate {
to {visibility: visible}
}
<div class="screen">1</div>
<div class="screen">2</div>
<div class="screen">3</div>
Then you can just target the .screen elements with the :nth-child or :nth-of-type selectors.

Opacity or fadein effect on img from array after click / javascript

I have, a problem getting opacity with transition on img after clicking and changing the photo.
I made a simple slider, which takes pictures from the array.
How to add opacity from 0 to 1, with transition 1s?
I tried to add styles in js and css but it still doesn't work.
I'm sitting a few hours on it.
<button id="prev" class="btn-navi"></button>
<div id="my-image-slider"></div>
<button id="next" class="btn-navi"></button>
#cert #my-image-slider{
height: 200px;
width: 150px;
background-color: aqua;
/*opacity: 0;*/
/*transition: all 3s ease;*/
}
#cert #my-image-slider img{
height: 100%;
width: 100%;
opacity: 0.1;
transition: all 2s ease;
}
var images = [];
images.push("<img src ='img/dyplom1.jpg'>");
images.push("<img src ='img/dyplom2.jpg'>");
images.push("<img src ='img/dyplom3.jpg'>");
var curIndex = 0 ;
var mainDiv = document.getElementById("my-image-slider");
var nextBtn = document.getElementById("next");
var prevBtn = document.getElementById("prev");
mainDiv.innerHTML = images[0];
function getElement() {
mainDiv.innerHTML = images[curIndex];
/*images.style.opacity = 1;*/
};
function goNext() {
var nextIndex = curIndex + 1;
if (nextIndex === images.length) {
return 0;
} else {
return nextIndex;
}
};
nextBtn.addEventListener("click", function () {
curIndex = goNext();
getElement();
});
function goPrev() {
var prevIndex = curIndex - 1;
if (prevIndex === -1) {
return images.length-1;
} else {
return prevIndex;
}
};
prevBtn.addEventListener("click", function () {
curIndex = goPrev();
images.style.opacity = 1;
getElement();
});
I haven't tested anything but i think you could use #keyframes in css.
make keyframe add it to some class and then add/remove that class with js.
here is keyframes link:
https://css-tricks.com/snippets/css/keyframe-animation-syntax/

Change of opacity using css transition and vanilla JavaScript works only when fading out

This codepen shows my problem: http://codepen.io/PiotrBerebecki/pen/pNvpdG
When the user clicks on the big button the css opacity is reduced to 0. Since I've applied the following rule: transition: opacity 0.5s ease-in-out; the fade out animation is smooth.
I would like to achieve the same smooth transition when the next button fades in.
However for some reason the next button appears suddenly without any transition.
Would you know what causes the issue and how to fix it?
console.clear();
(function() {
// Data for the app
const model = {
buttons: ['tomato', 'blue'],
currentButton: -1
};
// Logic for the app
const controller = {
init: function() {
view.init();
},
getButtonName: function() {
model.currentButton = (model.currentButton + 1) % model.buttons.length;
return model.buttons[model.currentButton];
}
};
// View for the app
const view = {
init: function() {
this.root = document.getElementById('root');
this.showNext();
},
animationDelay: 500,
showNext: function() {
// Get next button name
const buttonName = controller.getButtonName();
// Create button DOM element
const buttonElement = document.createElement('div');
buttonElement.className = 'button';
buttonElement.id = buttonName;
buttonElement.textContent = buttonName;
buttonElement.style.opacity = 0;
// Add event listender for the button
buttonElement.addEventListener('click', event => {
// Reduce opacity
buttonElement.style.opacity = 0;
// Remove the button from DOM
setTimeout(() => {
this.root.removeChild(buttonElement);
}, this.animationDelay + 10);
// Start the function to show next button
setTimeout(() => {
this.showNext();
}, this.animationDelay + 20);
});
// Add button to DOM
this.root.appendChild(buttonElement);
// Show button by increasing opacity
buttonElement.style.opacity = 1;
}
};
// Start the app
controller.init();
}());
#tomato {
background: tomato;
}
#blue {
background: DeepSkyBlue;
}
.button {
transition: opacity 0.5s ease-in-out;
width: 100%;
height: 50vh;
border: solid 3px black;
cursor: pointer;
}
<div id="root"></div>
This should work , Code pen link: http://codepen.io/saa93/pen/gLbvmQ
You would need to add this instead of directly setting opacity to 1
// Show button by increasing opacity
buttonElement.style.opacity = 0;
setTimeout(() => {
buttonElement.style.opacity = 1;
}, this.animationDelay + 20);
Add a class (in the Snippet is .active) add the following:
CSS
.button {
opacity: 0;
transition: opacity 0.5s ease-in-out;
width: 100%;
height: 50vh;
border: solid 3px black;
cursor: pointer;
}
.button.active {
opacity: 1;
transition: opacity 0.5s ease-in-out;
}
JavaScript
...
// Reduce opacity
buttonElement.classList.toggle('active');
buttonElement.style.opacity = 0;
...
// Show button by increasing opacity
buttonElement.classList.toggle('active');
buttonElement.style.opacity = 1;
SNIPPET
console.clear();
(function() {
// Data for the app
const model = {
buttons: ['tomato', 'blue'],
currentButton: -1
};
// Logig for the app
const controller = {
init: function() {
view.init();
},
getButtonName: function() {
model.currentButton = (model.currentButton + 1) % model.buttons.length;
return model.buttons[model.currentButton];
}
};
// View for the app
const view = {
init: function() {
this.root = document.getElementById('root');
this.showNext();
},
animationDelay: 500,
showNext: function() {
// Get next button name
const buttonName = controller.getButtonName();
// Create button DOM element
const buttonElement = document.createElement('div');
buttonElement.className = 'button';
buttonElement.id = buttonName;
buttonElement.textContent = buttonName;
buttonElement.style.opacity = 0;
// Add event listender for the button
buttonElement.addEventListener('click', event => {
// Reduce opacity
buttonElement.classList.toggle('active');
buttonElement.style.opacity = 0;
// Remove the button from DOM
setTimeout(() => {
this.root.removeChild(buttonElement);
}, this.animationDelay + 10);
// Start the function to show next button
setTimeout(() => {
this.showNext();
}, this.animationDelay + 20);
});
// Add button to DOM
this.root.appendChild(buttonElement);
// Show button by increasing opacity
buttonElement.classList.toggle('active');
buttonElement.style.opacity = 1;
}
};
// Start the app
controller.init();
}());
#tomato {
background: tomato;
}
#blue {
background: DeepSkyBlue;
}
.button {
opacity: 0;
transition: opacity 0.5s ease-in-out;
width: 100%;
height: 50vh;
border: solid 3px black;
cursor: pointer;
}
.button.active {
opacity: 1;
transition: opacity 0.5s ease-in-out;
}
<div id="root"></div>
after this.root.appendChild(buttonElement);
you should set opacity to 0 and let the browser time to render before buttonElement.style.opacity = 1;
BTW I think removing and adding the element of not a good way to do this
.button {
width: 100%;
height: 50vh;
border: solid 3px black;
cursor: pointer;
animation-name: example;
animation-duration:3.5s;
}
#keyframes example {
0% {opacity:1}
50% {opacity:0}
100% {opacity:1}
}
What U really want is to use animation like this:JSFIDDLE EXAMPLE
This way the animation does all this timing and opacity back and forth using the css only

How to convert a jQuery fade effect in CSS?

I have the following code which is going to fade some images but I am interested if there is a way to handle this in CSS.
$("#top").stop(true, true).delay(0).fadeTo(fadeTime * 100, 0);
$("#back").stop(true, true).delay(0).fadeTo(fadeTime * 100, 1, function () {
if (curLoop < loops) {
if (curImg < imgNo) {
prevImg = curImg
curImg++
} else {
prevImg = imgNo
curImg = 1;
curLoop++console.log("LOOP");
}
document.getElementById("back").style.opacity = 0;
document.getElementById("top").style.opacity = 1;
document.getElementById("back").src = "frames/frame_" + curImg + ".jpg";
document.getElementById("top").src = "frames/frame_" + prevImg + ".jpg";
} else {
console.log("STOPPED");
window.clearInterval(myVarSTD);
}
if (!initialized) {
myVarSTD = setInterval(function () {
startAnimation()
}, delay * 1000);
initialized = true;
}
});
You can't loop through image sources in a pure CSS animation but the below fade effect is possible with CSS3 animations. Here the front and back images are absolutely positioned and using opacity animation they are faded in and out in an infinite loop. I have used 2 div with background-image but you could do the same for img element also.
Refer inline comments within the snippet for more explanation of the animation's CSS code.
.front,
.back {
position: absolute; /* absolute positioning puts them one on top of other */
height: 200px;
width: 200px;
animation: fade-in-out 10s linear infinite; /* first is animation keyframe's name, second is the duration of the animation, third is timing function and fourth is iteration count */
}
.front {
background-image: url(http://lorempixel.com/200/200/nature/1);
}
.back {
background-image: url(http://lorempixel.com/200/200/nature/2);
z-index: -1; /* keeps the element behind the front */
animation-delay: 5s; /* delay is equal to half the animation duration because the back has to fade-in once the front has faded-out at 50% */
}
#keyframes fade-in-out { /* animation settings */
0%, 100% {
opacity: 1; /* at start and end, the image is visible */
}
50% {
opacity: 0; /* at the mid point of the animation, the image is invisible */
}
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/prefixfree/1.0.7/prefixfree.min.js"></script>
<div class='front'></div>
<div class='back'></div>
Yes, it is. Your code capture some elements using getElementById as back and top.
You can use the following code to change CSS properties of those elements:
$('#back').css({'opacity':'1'});
Implemented in your code:
$("#top").stop(true, true).delay(0).fadeTo(fadeTime*100, 0);
$("#back").stop(true, true).delay(0).fadeTo(fadeTime*100, 1, function(){
if(curLoop<loops){
if(curImg<imgNo){
prevImg = curImg
curImg++
}else{
prevImg = imgNo
curImg = 1;
curLoop++
console.log("LOOP");
}
$('#back').css({'opacity':'0'});
$('#top').css({'opacity':'1'});
document.getElementById("back").src = "frames/frame_"+curImg+".jpg";
document.getElementById("top").src = "frames/frame_"+prevImg+".jpg";
}else{
console.log("STOPPED");
window.clearInterval(myVarSTD);
}
if(!initialized){
myVarSTD = setInterval(function(){startAnimation()},delay*1000);
initialized = true;
}
});
jQuery Transit is an awesome plugin which mimics jQuery's animation functions but in CSS. You get a much higher framerate using CSS too!

Changing css animation in javascript

I have a blinking red box in my html it uses css animations. I want to to be able to change it from blinking red and white to green and white. I know this can be done on id elements by using getElementbyId but how would get access to the green aminated box in the css.
The red box looks like this:
#-webkit-keyframes 'noConnection'
{
1% { background-color: red; }
33% { background: white; }
66% { background: red; }
100% { background: white; }
}
The green is this:
#-webkit-keyframes 'Connection'
{
1% { background-color: green; }
33% { background: white; }
66% { background: green; }
100% { background: white; }
}
The animate looks like this:
#animate {
height: 15px;
width: 15px;
}
.cssanimations #animate {
-webkit-animation-direction: normal;
-webkit-animation-duration: 5s;
-webkit-animation-iteration-count: infinite;
-webkit-animation-name: Connection;
-webkit-animation-timing-function: ease;
and I think I have to change the attribute -webkit-animation-name: from javascript to do this but I dont know how to get a handle on it to change it.
Or would I be better off creating a duplicate #animate and renaming it using the getElementById?
Here is a simple web page that demonstrates how to use Javascript to modify a CSS animation. It contains a simple div, and a little Javascript causes the div to move randomly around the page.
In your specific case, you just need to touch up the line that calls "insertRule" to insert your new blinking rule.
<html><head><style></style></head>
<body>
<div id="mymovingdiv">
<h1>Moving Div</h1>
<p>And some little text too</p>
</div>
<script>
function animatedMove(id, xStart, yStart, xEnd, yEnd, secs)
{
// Remove any CSS rules inserted by a previous call to this method
let rulename = `AnimMove${id}`;
let ss = document.styleSheets; // all stylesheets
for (let i = 0; i < ss.length; ++i) { // for each stylesheet...
for (let j = ss[i].cssRules.length - 1; j > 0; j--) { // for each rule...
if (ss[i].cssRules[j].name === rulename) { // does the name match?
ss[i].deleteRule(j);
}
}
}
// Insert a CSS rule for this animation
document.styleSheets[0].insertRule(`#keyframes ${rulename} { 0% { left: ${xStart}px; top: ${yStart}px; } 100% { left: ${xEnd}px; top: ${yEnd}px } }`);
// Remove any CSS rules inserted by a previous call to this method
for (let i = 0; i < ss.length; ++i) { // for each stylesheet...
for (let j = ss[i].cssRules.length - 1; j > 0; j--) { // for each rule...
if (ss[i].cssRules[j].name === rulename) { // does the name match?
ss[i].deleteRule(j);
}
}
}
// Insert a CSS rule for this animation
document.styleSheets[0].insertRule(`#keyframes ${rulename} { 0% { left: ${xStart}px; top: ${yStart}px; } 100% { left: ${xEnd}px; top: ${yEnd}px } }`);
// assign the animation to our element
let el = document.getElementById(id);
el.style.position = 'absolute';
el.style.animation = `${rulename} ${secs}s`;
// Make the element stay where the animation ends
el.style.left = `${xEnd}px`;
el.style.top = `${yEnd}px`;
// Re-clone the element, to reset the animation
el.parentNode.replaceChild(el.cloneNode(true), el);
}
let x = 0;
let y = 0;
function randomMove()
{
let newX = Math.floor(Math.random() * 800);
let newY = Math.floor(Math.random() * 600);
animatedMove('mymovingdiv', x, y, newX, newY, 1);
x = newX;
y = newY;
}
setInterval(randomMove, 1000);
</script>
</body>
</html>
The easiest way to do this is to created two classes in CSS and then toggle between the two.
So something like:
.connection {
animation: 'Connection' 5s ease infinite
}
.no-connection {
animation 'noConnection' 5s ease infinite
}
And then use Javascript to toggle between the two
function toggleConnectionStatus(){
var element = document.getElementById('animate');
if(/* connection is active */) element.className = 'connection';
else element.className = 'no-connection'
}

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