Use *ngFor index to calculate animation delay - css

Could seem a duplicate of this question, but actually I am trying to affect the animation-delay property, not the animation timing itself.
I have an Angular template that creates list items by looping through them:
<div class="list-item" *ngFor="let item of items; let i = index" [attr.data-index]="i" style="animation-delay: {{ (i) + 's' }}"></div>
As you can see I already have the index and was hoping to use that to increment the animation delay on each element. But when I test in chrome, the style property isn't even computed, even though the index attribute is applied correctly. The animation, which I have specified in CSS, works fine, but the delay isn't applied:
.list-item {
animation: appear 0.3s ease-out forwards;
}
#keyframes appear
{
0%
{
top: 550px;
opacity: 0;
}
10%
{
opacity: 1;
}
100%
{
top: 30px;
opacity: 1;
}
}

Try Using ngStyle Directive:
[ngStyle]="{'animation-delay': i + 's'}"
Hope that works well, If not , please share a working example on stackblitz

Related

How can I animate my less from "display: block" to "display: none"?

I have a less file that hide and display an element like the following:
.cmp-accordion__panel {
&--hidden {
display: none;
}
&--expanded {
display: block;
-webkit-animation: slide-down 0.5s ease-out;
-moz-animation: slide-down 0.5s ease-out;
}
}
#-webkit-keyframes slide-down {
0% {
opacity: 0;
-webkit-transform: translateY(-5%);
}
100% {
opacity: 1;
-webkit-transform: translateY(0);
}
}
#-moz-keyframes slide-down {
0% {
opacity: 0;
-moz-transform: translateY(-5%);
}
100% {
opacity: 1;
-moz-transform: translateY(0);
}
}
In my JavaScript, I toggle the class name of the element between "cmp-accordion__panel--hidden" and "cmp-accordion__panel--expanded" if the event is triggered. I use keyframe and opacity to animate the transition from "display:none" to "display:block".
However, when I go from "display:block" to "display:none" to hide the element, the effect happens INSTANTLY. What should I add to animate the hiding?
As already said, is not possible animate or transition from display:block; to display: none; but this could be simulated in another way and is not necessary to use CSS animations, simply CSS transitions (in addition, is not necessary anymore to use vendor-prefixes to declare transitions or animations).
Please, look at this working example:
HTML (I inserted a fake content to create an element with a relative big height)
<div class="cmp-accordion__panel--expanded">
b<br>b<br>b<br>b<br>b<br>b<br>b<br>b<br>b<br>b<br>b<br>b<br>b<br>b<br>b<br>b<br>b<br>b<br>b<br>b
</div>
LESS
[class*="cmp-accordion__panel"] {
border:solid 1px red;
overflow:hidden;
transition:opacity 0.3s ease-out, max-height 0.8s ease-out;
}
.cmp-accordion__panel {
&--hidden {
max-height:0;
opacity:0;
}
&--expanded {
opacity:1;
max-height:1000px;
}
}
Please note that, thanks to attribute partial value selector I added also some rules that apply to both *--hidden and *--expanded classes (I personally prefer a general class and an addition of a second one in some cases, instead of switching between two, but I did not want to change too much your approach).
The key rule is switching between two values of max-height property, from a 0 value to another "enough big" one. If you effectively know final height of the element you can simply use also height property, but in case of dynamic content, max-height did the trick.
Please note also the presence of overflow:hidden; applied to both classes, to simulate height changes.
Finally, animation effect relies only on a CSS transition applied to opacity and max-height properties, with different timings to enhance effect.
You cannot animate or transition from display: block; to display: none;, so you will need to remove this if you wish to animate it.
To ensure it fades and is removed you should animate the visibilty and opacity attributes.
Alternatively if you are using jQuery you can use the .fadeOut() function.
MDN - CSS Visibility
jQuery - fadeOut()

Combine multiple animations

I'm trying to combine several parts of animation together by clicking a button. Here's an example:
.element {
background-color: black;
display: block;
width: 160px;
height: 160px;
border-radius: 80%;
}
.one {
animation: one 1.5s ease 1 forwards;
}
.two {
animation: two 1s forwards;
}
#keyframes one {
from {
transform: scale(0.25);
opacity: 0;
}
25% {
opacity: 0.5;
}
to {
transform: scale(1);
opacity: 0.5;
}
}
#keyframes two {
from {
opacity: 0.5;
}
to {
opacity: 0;
}
}
I'm trying to combine these two animation: one and two. My way of doing this was to use JS: classList.add('.two') when I clicked the button. But the problem was: at the moment I added the class, the element changed to its default opacity which was 1.
To solve this, I added a new class contained styles which were actually clones of final styles of the first animation. And after the second part was finished, I had to remove the class list to prepared for the first animation to be played.
So my question is, is there a better way of doing this?
Here is a CodePen Demo
I just realised a problem with this: If I start the second animation before the first one was finished, there would be a discontinuity (the circle would just turns to a larger one all of a sudden).
The demo can be found from the above link, thanks!
Can I combine these two animations?
I assume by combine you mean producing forward (on click of add animation) and reverse (on click of remove animation) animations using the same keyframe rules. It's possible to achieve but for that both the forward and reverse animations should be exactly the same (but in opposite directions). When it is same, we can use animation-direction: reverse to achieve reverse effect with same keyframes.
Here, the forward animation has a transform change whereas the reverse doesn't and hence adding animation-direction: reverse would not produce the same effect as the original snippet. Moreover, coding it is not as easy as just adding a property also, a lot of work is needed like mentioned here.
What is the reason for the other two issues?
The reason for both the issues (that is, the element getting opacity: 1 immediately when the remove button is clicked and element getting full size when remove button is clicked while forward animation is still happening) are the same. When you remove the animation on an element (by removing the class) it immediately snaps to the size specified outside of the animation.
For the first case, the size is the one that is mentioned under .element (as .one is removed) and its opacity is default 1 because there is no opacity setting in it. For the second case, when the .one is removed and .two is added, the animation is removed and so the element's size is as specified in .element and the opacity is as specified in .two (because that is later in CSS file).
So what else is the alternate?
When both forward and reverse effects are required and the animation doesn't have any intermediate states (that is, there is only a start state and an end state) then it is better to use transitions instead of animations. The reason is because transitions automatically produce the reverse effect on removal of the class (unlike animations where the reverse animation needs to be written as a separate keyframe and added to the element).
Below is a sample snippet showing how you can achieve a similar effect using just one class without the need for writing keyframes.
var theBut = document.getElementById('butt');
var theBut2 = document.getElementById('butt2');
theBut.addEventListener('click', function a() {
document.querySelector('.element').classList.add('one');
});
theBut2.addEventListener('click', function b() {
document.querySelector('.element').classList.remove('one');
});
.element {
background-color: #d91e57;
display: block;
width: 160px;
height: 160px;
border-radius: 90%;
transform: scale(0.25);
opacity: 0;
transition: opacity 2s, transform .1s 2s;
}
.one {
transform: scale(1);
opacity: 0.5;
transition: all 2s;
}
<div class="element">
</div>
<button id="butt">add animation</button>
<button id='butt2'>remove animation</button>

Is it possible to use the nth-child value as a parameter in a property? (and how)

Short description (tl;dr;)
Is there a "pure CSS" way (not Less/Sass) of using the value of the nth-child inside the CSS properties? Something like this:
span.anim:nth-child(N) { animation-delay: N * 0.5s; }
If there is, how can I do it? If there is not, how could I mimic it in a clean way? (I'm sure that I'm over-complicating things here)
Long description
I was creating a simple animation in which letters fade in while rotating. For that, I was using a combination of javascript (with jQuery) and CSS, but that created some problems (see below); so I tried to move to a CSS-only solution, and that ended in a large amount of rules.
This (simplified) CSS is common to both solutions:
span.anim {
font-size:30px;
opacity:0;
animation: anim 1s;
animation-fill-mode: forwards;
}
#keyframes anim {
from {
transform: rotate(0deg);
opacity:0;
}
to {
transform: rotate(360deg);
opacity:1;
}
}
Using JavaScript + CSS
My JavaScript code looks like this:
var aux = $("#animate").text();
$("#animate").text("");
for (var x = 0; x < aux.length; x++) {
setTimeout('$("#animate").append("<span class=\'anim\'>' + aux[x] + '</span>")', 500 * x);
}
This works great... unless the user moves to a different tab, then the animation messes up, and the result is unexpected. You can see it on this JSFiddle: http://jsfiddle.net/e7b9ygk4/ (run the script, move to a different tab, and go back after a few seconds).
Using only CSS
I can achieve the same effect by breaking the element in smaller elements (this is the part I feel I'm over-complicating), and then applying the animation to each element with a different delay:
span.anim:nth-child(1) { -webkit-animation-delay:0.5s; }
span.anim:nth-child(2) { -webkit-animation-delay:1.0s; }
span.anim:nth-child(3) { -webkit-animation-delay:1.5s; }
span.anim:nth-child(4) { -webkit-animation-delay:2.0s; }
span.anim:nth-child(5) { -webkit-animation-delay:2.5s; }
span.anim:nth-child(6) { -webkit-animation-delay:3.0s; }
span.anim:nth-child(7) { -webkit-animation-delay:3.5s; }
span.anim:nth-child(8) { -webkit-animation-delay:4.0s; }
span.anim:nth-child(9) { -webkit-animation-delay:4.5s; }
span.anim:nth-child(10) { -webkit-animation-delay:5.0s; }
span.anim:nth-child(11) { -webkit-animation-delay:5.5s; }
span.anim:nth-child(12) { -webkit-animation-delay:6.0s; }
span.anim:nth-child(13) { -webkit-animation-delay:6.5s; }
span.anim:nth-child(14) { -webkit-animation-delay:7.0s; }
span.anim:nth-child(15) { -webkit-animation-delay:7.5s; }
span.anim:nth-child(16) { -webkit-animation-delay:8.0s; }
This works great, even if the user moves to a different tab, but it results in a lot of unnecessary code (both HTML and CSS, although it could be simplified using JavaScript). You can see it working on this JSFiddle: http://jsfiddle.net/f5my3sm1/.
My gut tells me that this could be achieved using Sass/Less, but I want to know if there is a simple "pure CSS" way of doing this, something that could be achieved (hopefully) with a single rule like:
span.anim:nth-child(N) { animation-delay: N * 0.5s; }
CSS variables have almost universal support on all modern browsers and can achieve virtually the same desired effect as #GreatBlake's answer using attr plus more. Instead of defining data in a user-defined attribute, you can define it as a custom property in the style attribute and get the value of those custom properties using the var() function:
span.anim {
display: inline-block;
font-size: 30px;
opacity: 0;
animation: fade-in-and-rotate 1s;
animation-fill-mode: forwards;
animation-delay: calc(var(--n) * 0.5s);
}
#keyframes fade-in-and-rotate {
from {
transform: rotate(0deg);
opacity: 0;
}
to {
transform: rotate(360deg);
opacity: 1;
}
}
<span class="anim" style="--n: 0">zero</span>
<span class="anim" style="--n: 1">one</span>
<span class="anim" style="--n: 2">two</span>
<span class="anim" style="--n: 3">three</span>
<span class="anim" style="--n: 4">four</span>
This code snippet also sets span.anim's display property to inline-block for the question's provided rotate animation to work.
There is a very experimental CSS function for using attributes as properties for an element. Currently it only works on pseudo elements, so you'd have to consider coming up with some kind of clever re-working of your markup in this use case.
You could put the offset in a data-attribute on your markup (or with JS), and then use something like the following:
/* attr(name, units, fallback) */
span.anim {animation-delay: attr(offset, 1) * 0.5s;}
<span class="anim" offset="0"></span>
<span class="anim" offset="1"></span>
<span class="anim" offset="2"></span>
<span class="anim" offset="3"></span>
<span class="anim" offset="4"></span>
Please keep in mind that this is still a ways off from being widely accepted, and like I mentioned before, the above syntax wouldn't work currently because it would need to use pseudo elements like :after.
At the very least, it's something fun to think about.

CSS Animations - change a property without a transition?

I have a case where I need an element to appear for a second and then disappear, and I must not use javascript for it, so I'm trying to make it work with CSS.
Here's an example:
#-webkit-keyframes slide-one-pager {
0% { left: 0; }
50% { left: 100px; }
100% { left: 0; }
}
So in this example the property will gradually transition from 0 to 100 and back to 0. However, I need to get rid of that transition, so the property stays at 0 and gets to 100 as soon as it hits 50%. It doesn't work if I say left: 0; at 49%, because there is still a transition.
Another example, slightly more different than my original question, but if I find a solution for it it will do as well:
#-webkit-keyframes slide-one-pager {
0% { display: none; }
50% { display: block; }
75% { display: block; }
100% { display: none; }
}
Here I want to show an element for a period of time. No, using opacity is not an option, because the element is still there and is still clickable, and I need access to elements below. Unfortunately the "display" property doesn't seem to accept animating. If anyone can think of a solution how to show and hide an element with an animation (without transition!) I will be extremely grateful.
Any ideas?
You can use step-start or step-end (graphs) in your animation configuration so the curve will act like a "steps" (not curvy) so there will be no visual transition between frames, thus the animation will just "jump" between frames.
Example CSS:
animation:1s move infinite step-end;
The above example will call the move keyframes (which I didn't write because it's irrelevant), and will loop on the frames endlessly with the "step" argument which was described earlier, without a transitioned curve.
#keyframes foo{
0%{ margin-left:0 }
50%{ margin-left:50% }
}
div{
width: 50px;
height: 50px;
background: black;
border-radius: 50%;
animation:1s foo infinite;
}
input:checked + div{
animation-timing-function: step-end;
}
<label>
<input type='checkbox' checked /> Disable Animation transition
<div></div>
</label>
👉 Cool demo using this technique
I searched the same thing as you actually.
You can set a greatful parameters in animation, called animation-timing-function allowing you to set perfectly and mathematicaly the animation : With bezier curve values or, if, like me, you're not that good mathematician, a parameter call "step()".
For an example, in none shorthand writing :
.hiding {
animation-name:slide-one-pager;
animation-duration:2s;
animation-timing-function:steps(1);
}
By default, the value of this parameter is set to 0, meaning no steps.
You can read more about this interesting feature here : https://developer.mozilla.org/en-US/docs/Web/CSS/timing-function
And here a shorthand notation for your animation:
.hiding {
animation:slide-one-pager 2s steps(1);
}
For me, it works fine at least on firefox 23.0.1.
Even if I think you solved the problem since one year, maybe could help some people like me here :)
I made it using the -webkit-animation-fill-mode: forwards; property, that stops the animation at 100% without returning the element to the original state. I made up a fiddle with a working example, you can check it out here.
Although in the fiddle you can find a better example, I basically did this (Assuming absolute positioned elements):
.hiding {
-webkit-animation: slide-one-pager 2s;
-webkit-animation-fill-mode: forwards;
}
#-webkit-keyframes slide-one-pager {
0% { left: 0; }
49% { left: 0; }
50% { left: -100px; }
100% { left: -100px; }
}​
It just jumps from 0 to -100 in the middle of the transition (49% -> 50% as you 'suggested' :P), and stays there at 100%. As said, with -webkit-animation-fill-mode: forwards; the element will stay as in 100% without going back to it's original state.
I don't know if it'll work in your scenario, but I believe there'd be an easy solution if it doesn't.
You can use this:
animation: typing 1s cubic-bezier(1,-1, 0, 2) infinite;

css3 transition animation on load?

Is it possible to use CSS3 transition animation on page load without using Javascript?
This is kind of what I want, but on page load:
image-slider.html
What I found so far
CSS3 transition-delay, a way to delay effects on elements. Only works on hover.
CSS3 Keyframe, works on load but are extremly slow. Not useful because of that.
CSS3 transition is fast enough but don't animate on page load.
You can run a CSS animation on page load without using any JavaScript; you just have to use CSS3 Keyframes.
Let's Look at an Example...
Here's a demonstration of a navigation menu sliding into place using CSS3 only:
#keyframes slideInFromLeft {
0% {
transform: translateX(-100%);
}
100% {
transform: translateX(0);
}
}
header {
/* This section calls the slideInFromLeft animation we defined above */
animation: 1s ease-out 0s 1 slideInFromLeft;
background: #333;
padding: 30px;
}
/* Added for aesthetics */ body {margin: 0;font-family: "Segoe UI", Arial, Helvetica, Sans Serif;} a {text-decoration: none; display: inline-block; margin-right: 10px; color:#fff;}
<header>
Home
About
Products
Contact
</header>
Break it down...
The important parts here are the keyframe animation which we call slideInFromLeft...
#keyframes slideInFromLeft {
0% {
transform: translateX(-100%);
}
100% {
transform: translateX(0);
}
}
...which basically says "at the start, the header will be off the left hand edge of the screen by its full width and at the end will be in place".
The second part is calling that slideInFromLeft animation:
animation: 1s ease-out 0s 1 slideInFromLeft;
Above is the shorthand version but here is the verbose version for clarity:
animation-duration: 1s; /* the duration of the animation */
animation-timing-function: ease-out; /* how the animation will behave */
animation-delay: 0s; /* how long to delay the animation from starting */
animation-iteration-count: 1; /* how many times the animation will play */
animation-name: slideInFromLeft; /* the name of the animation we defined above */
You can do all sorts of interesting things, like sliding in content, or drawing attention to areas.
Here's what W3C has to say.
Very little Javascript is necessary:
window.onload = function() {
document.body.className += " loaded";
}
Now the CSS:
.fadein {
opacity: 0;
-moz-transition: opacity 1.5s;
-webkit-transition: opacity 1.5s;
-o-transition: opacity 1.5s;
transition: opacity 1.5s;
}
body.loaded .fadein {
opacity: 1;
}
I know the question said "without Javascript", but I think it's worth pointing out that there is an easy solution involving one line of Javascript.
It could even be inline Javascript, something like that:
<body onload="document.body.className += ' loaded';" class="fadein">
That's all the JavaScript that's needed.
I think I have found a sort of work around for the OP question - instead of a transition beginning 'on.load' of the page - I found that using an animation for an opacity fade in had the same effect, (I was looking for the same thing as OP).
So I wanted to have the body text fade in from white(same as site background) to black text colour on page load - and I've only been coding since Monday so I was looking for an 'on.load' style thing code, but don't know JS yet - so here is my code that worked well for me.
#main p {
animation: fadein 2s;
}
#keyframes fadein {
from { opacity: 0}
to { opacity: 1}
}
And for whatever reason, this doesn't work for .class only #id's(at least not on mine)
Hope this helps - as I know this site helps me a lot!
CSS only with a delay of 3s
a few points to take here:
multiple animations in one call
we create a wait animation that just delays the actual one (the second one in our case).
Code:
header {
animation: 3s ease-out 0s 1 wait, 0.21s ease-out 3s 1 slideInFromBottom;
}
#keyframes wait {
from { transform: translateY(20px); }
to { transform: translateY(20px); }
}
#keyframes slideInFromBottom {
from { transform: translateY(20px); opacity: 0; }
to { transform: translateY(0); opacity: 1; }
}
Well, this is a tricky one.
The answer is "not really".
CSS isn't a functional layer. It doesn't have any awareness of what happens or when. It's used simply to add a presentational layer to different "flags" (classes, ids, states).
By default, CSS/DOM does not provide any kind of "on load" state for CSS to use. If you wanted/were able to use JavaScript, you'd allocate a class to body or something to activate some CSS.
That being said, you can create a hack for that. I'll give an example here, but it may or may not be applicable to your situation.
We're operating on the assumption that "close" is "good enough":
<html>
<head>
<!-- Reference your CSS here... -->
</head>
<body>
<!-- A whole bunch of HTML here... -->
<div class="onLoad">OMG, I've loaded !</div>
</body>
</html>
Here's an excerpt of our CSS stylesheet:
.onLoad
{
-webkit-animation:bounceIn 2s;
}
We're also on the assumption that modern browsers render progressively, so our last element will render last, and so this CSS will be activated last.
add this to your css for fade in animation
body{animation: 2s ease-out 0s 1 FadeIn;}
#keyframes FadeIn {
0% {
opacity:0;
}
100% {
opacity:1;
}
}
increase the ease-out time if you want it to load slower
Even simplier solution (still with [one line inline] javascript):
Use this as the body tag:
Note that body. or this. did not work for me. Only the long ; querySelector allow the use of classList.remove (Linux Chromium)
<body class="onload" onload="document.querySelector('body').classList.remove('onload')">
and add this line on top of your other css rules.
body.onload *{ transform: none !important; }
Take note that this can apply to opacity (as requested by OP [other posters] ) simply by using opacity as a transition trigger instead. (might even work on any other css ruling in the same fashion and you can use multiple class for explicity delay between triggering)
The logic is the same. Enforce no transform (with :none !importanton all child element of body.onloadand once the document is loaded remove the class to trigger all transition on all elements as specified in your css.
FIRST ANSWER BELOW (SEE EDIT ABOVE FOR SHORTER ANSWER)
Here is a reverse solution:
Make your html layout and set the css accordingly to your final result (with all the transformation you want).
Set the transition property to your liking
add a class (eg: waitload) to the elements you want to transform AFTER load. The CSS keyword !important is the key word here.
Once the document is loaded, use JS to remove the class from the elements to to start transformation (and remove the transition: none override).
Works with multiple transition on multiple elements. Did not try cross-browser compatibility.
div {
width: fit-content;
}
#rotated {
transform: rotate(-50deg)/* any other transformation */
;
transition: 6s;
}
#translated {
transform: translate(90px)/* any other transformation */
;
transition: 6s;
}
.waitload {
transform: none !important;
}
<div id='rotated' class='waitload'>
rotate after load
</div>
<div id='translated' class='waitload'>
trasnlate after load
</div>
<script type="text/javascript">
document.addEventListener('DOMContentLoaded', init);
function init() {
[...document.querySelectorAll('.waitload')]
.map(e => e.classList.remove('waitload'));
}
</script>
Similar to #Rolf's solution, but skip reference to external functions or playing with class. If opacity is to remain fixed to 1 once loaded, simply use inline script to directly change opacity via style. For example
<body class="fadein" onload="this.style.opacity=1">
where CSS sytle "fadein" is defined per #Rolf,defining transition and setting opacity to initial state (i.e. 0)
the only catch is that this does not work with SPAN or DIV elements, since they do not have working onload event
start it with hover of body than It will start when the mouse first moves on the screen, which is mostly within a second after arrival, the problem here is that it will reverse when out of the screen.
html:hover #animateelementid, body:hover #animateelementid {rotate ....}
thats the best thing I can think of: http://jsfiddle.net/faVLX/
fullscreen: http://jsfiddle.net/faVLX/embedded/result/
Edit see comments below:
This will not work on any touchscreen device because there is no hover, so the user won't see the content unless they tap it. – Rich Bradshaw
Ok I have managed to achieve an animation when the page loads using only css transitions (sort of!):
I have created 2 css style sheets:
the first is how I want the html styled before the animation...
and the second is how I want the page to look after the animation has been carried out.
I don't fully understand how I have accomplished this but it only works when the two css files (both in the head of my document) are separated by some javascript as follows.
I have tested this with Firefox, safari and opera. Sometimes the animation works, sometimes it skips straight to the second css file and sometimes the page appears to be loading but nothing is displayed (perhaps it is just me?)
<link media="screen,projection" type="text/css" href="first-css-file.css" rel="stylesheet" />
<script language="javascript" type="text/javascript" src="../js/jQuery JavaScript Library v1.3.2.js"></script>
<script type='text/javascript'>
$(document).ready(function(){
// iOS Hover Event Class Fix
if((navigator.userAgent.match(/iPhone/i)) || (navigator.userAgent.match(/iPod/i)) ||
(navigator.userAgent.match(/iPad/i))) {
$(".container .menu-text").click(function(){ // Update class to point at the head of the list
});
}
});
</script>
<link media="screen,projection" type="text/css" href="second-css-file.css" rel="stylesheet" />
Here is a link to my work-in-progress website: http://www.hankins-design.co.uk/beta2/test/index.html
Maybe I'm wrong but I thought browsers that do not support css transitions should not have any issues as they should skip straight to the second css file without delay or duration.
I am interested to know views on how search engine friendly this method is. With my black hat on I suppose I could fill a page with keywords and apply a 9999s delay on its opacity.
I would be interested to know how search engines deal with the transition-delay attribute and whether, using the method above, they would even see the links and information on the page.
More importantly I would really like to know why this is not consistent each time the page loads and how I can rectify this!
I hope this can generate some views and opinions if nothing else!
If anyone else had problems doing two transitions at once, here's what I did. I needed text to come from top to bottom on page load.
HTML
<body class="existing-class-name" onload="document.body.classList.add('loaded')">
HTML
<div class="image-wrapper">
<img src="db-image.jpg" alt="db-image-name">
<span class="text-over-image">DB text</span>
</div>
CSS
.text-over-image {
position: absolute;
background-color: rgba(110, 186, 115, 0.8);
color: #eee;
left: 0;
width: 100%;
padding: 10px;
opacity: 0;
bottom: 100%;
-webkit-transition: opacity 2s, bottom 2s;
-moz-transition: opacity 2s, bottom 2s;
-o-transition: opacity 2s, bottom 2s;
transition: opacity 2s, bottom 2s;
}
body.loaded .text-over-image {
bottom: 0;
opacity: 1;
}
Don't know why I kept trying to use 2 transition declarations in 1 selector and (not really) thinking it would use both.
You could use custom css classes (className) instead of the css tag too.
No need for an external package.
import React, { useState, useEffect } from 'react';
import { css } from '#emotion/css'
const Hello = (props) => {
const [loaded, setLoaded] = useState(false);
useEffect(() => {
// For load
setTimeout(function () {
setLoaded(true);
}, 50); // Browser needs some time to change to unload state/style
// For unload
return () => {
setLoaded(false);
};
}, [props.someTrigger]); // Set your trigger
return (
<div
css={[
css`
opacity: 0;
transition: opacity 0s;
`,
loaded &&
css`
transition: opacity 2s;
opacity: 1;
`,
]}
>
hello
</div>
);
};
Not really, as CSS is applied as soon as possible, but the elements might not be drawn yet. You could guess a delay of 1 or 2 seconds, but this won't look right for most people, depending on the speed of their internet.
In addition, if you want to fade something in for instance, it would require CSS that hides the content to be delivered. If the user doesn't have CSS3 transitions then they would never see it.
I'd recommend using jQuery (for ease of use + you may wish to add animation for other UAs) and some JS like this:
$(document).ready(function() {
$('#id_to_fade_in')
.css({"opacity":0}) // Set to 0 as soon as possible – may result in flicker, but it's not hidden for users with no JS (Googlebot for instance!)
.delay(200) // Wait for a bit so the user notices it fade in
.css({"opacity":1}); // Fade it back in. Swap css for animate in legacy browsers if required.
});
Along with the transitions added in the CSS. This has the advantage of easily allowing the use of animate instead of the second CSS in legacy browsers if required.

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