I have this element that starts hidden and then gets animated with a css transition on a click event.
I know the display property cannot be animated, so what I do is remove the class that applies the display:none, and then make the change that triggers the css transition, like so:
popin.classList.remove('hidden') // removes the display:none property
setTimeout(() => {
popin.classList.remove('closed') // triggers transition
}, 10)
See this fiddle: http://jsfiddle.net/wre2674p/6/ for a full example.
I've found out that in order to work, the 2nd step must be done asynchronously. Put it in a setTimeout and it works...sort of. In Chrome, any timeout duration works (even 0).
For Firefox and Edge, the behavior varies. For 100ms, it works every time. But for a timeout of e.g. 10ms, the transition works only maybe 50% of times. Since it delays the animation, I wish to keep it as low as possible, while ensuring it works consistently.
I suspect it is related to reflow/repaint occurring when changing display property from none to block, but I lack details on these subjects to full understand what's happening and how to prevent it. Any idea?
Remove the hidden class from CSS and HTML, remove timeout from js. There is no need to display none the #popin since you already have overflow hidden. The transition can be triggered directly, you are over complicating things
document.getElementById('toggle').addEventListener('click', function(e){
let source = e.currentTarget
source.disabled = true
let popin = document.getElementById('popin')
if (popin.classList.contains('closed')){
popin.classList.remove('closed')
}
else{
popin.classList.add('closed')
}
setTimeout(() => {
source.disabled = false
}, 850)
})
body{
overflow: hidden;
}
#popin{
display: block;
position: absolute;
top: 0;
right: 0;
width: 400px;
height: 100vh;
/*transform: translate(0, 0);*/
transition: opacity 800ms;
opacity: 1;
background: lightgreen;
}
#popin.closed{
opacity: 0;
z-index: -1;
pointer-events: none;
}
<button id="toggle">toggle</button>
<div id="popin" class="closed">
<h1>Popin</h1>
</div>
Related
I cannot figure out why a composite transition (opacity and height) on the same element does not follow the expected duration. However, this issue happens only the very first time is run, then begins to work perfectly.
UPDATE:
I found a slimmer way to demonstrate the problem.
By click the "start" button, the box at the right turns immediately transparent, and does not fade slowly as the left one.
$("button").on("click", function() {
doNative();
doJQuery();
});
function doNative() {
const elem = document.getElementById("bn");
elem.style.opacity = 0;
elem.style.height = 0;
elem.style.transitionDuration = "2s";
elem.style.transitionProperty = "opacity, height";
}
function doJQuery() {
const elem = $("#bj");
elem.css({
opacity: 0,
height: 0,
"transition-duration": "2s",
"transition-property": "opacity, height",
});
}
.block {
width: 200px;
font-size: 24px;
font-family: Tahoma;
display: inline-block;
margin: 10px;
border: 1px solid gray;
}
.initial {
opacity: 1;
height: 200px;
}
<script src="https://code.jquery.com/jquery-3.3.1.min.js"></script>
<div>
<button>start</button>
</div>
<div>
<div class="block">
<div id="bn" class="initial">This box is collapsed using the native transition API</div>
</div>
<div class="block">
<div id="bj" class="initial">This box is collapsed using the jQuery transition API</div>
</div>
</div>
LEGACY CONTENT (no relevant anymore):
Here is just a snippet to depict the context:
items.css({
opacity: 0,
height: 0,
"transition-duration": transitionDuration + "ms",
"transition-property": "opacity, height"
});
To better clarify the actual and the expected behavior, have a look at this pen: https://codepen.io/highfield/pen/dKLKKo
Once run, by pressing the "hide" button, the "Items" block disappears immediately, but the expected behavior is to fade along a certain interval.
After this initial weird phase, the "show" and "hide" functions behave perfectly as expected.
I also noticed that by removing the "height" from the "transition-property" CSS field, the opacity will fade correctly.
How to patch this problem?
The transition properties must be set on the target element before performing any transitions. To make that initial animation work too, you should set a basic transition definition to the #s1 element in CSS.
Finally, I've found where the problem is.
It seems that the order of the fields matters, but I don't understand why the native version works fine, even in a random order. By changing the jQuery version as follows, the transitions behave correctly:
function doJQuery() {
const elem = $("#bj");
elem.css({
"transition-duration": "2s",
"transition-property": "opacity, height",
opacity: 0,
height: 0,
});
}
I was reading this article http://semisignal.com/?p=5298 and the author wrote that
"Reflow needs to be triggered before the invisible class is removed in order for the transition to work as expected. "
My questions are :
1) Why does reflow need to be triggered?
2) I understand that we should avoid using reflow, if that is true why is the author suggesting to use reflow in order to make the transition work?
3) Instead of using reflow, is there a different method to make the transition work?
Thank you.
(Effectively: "Why can't I easily use transitions with the display property")
Short Answer:
CSS Transitions rely on starting or static properties of an element. When an element is set to display: none; the document (DOM) is rendered as though the element doesn't exist. This means when it's set to display: block; - There are no starting values for it to transition.
Longer Answer:
Reflow needs to be triggered because elements set to display: none; are not drawn in the document yet. This prevents transitions from having a starting value/initial state. Setting an element to display: none; makes the document render as if the element isn't there at all.
He suggest reflowing because it's generally accepted to hide and show elements with display: none; and display: block; - typically after the element has been requested by an action (tab or button click, callback function, timeout function, etc.). Transitions are a huge bonus to UX, so reflowing is a relatively simple way to allow these transitions to occur. It doesn't have an enormous impact when you use simple transitions on simple sites, so for general purposes you can trigger a reflow, even if technically you shouldn't. Think of the guy's example like using unminified JavaScript files in a production site. Can you? Sure! Should you? Probably not, but for most cases, it won't make a hugely noticeable difference.
There are different options available that prevent reflowing, or are generally easier to use than the method in the link you provided. Take the following snippet for a few examples:
A: This element is set to height: 0; and overflow: hidden;. When shown, it's set to height: auto;. We apply the animation to only the opacity. This gives us a similar effect, but we can transition it without a reflow because it's already rendered in the document and gives the transitions initial values to work with.
B: This element is the same as A, but sets the height to a defined size.
A and B work well enough for fading in elements, but because we set the height from auto/100px to 0 instantly, they appear to collapse on "fade out"
C: This element is hidden and we attempt to transition the child. You can see that this doesn't work either and requires a reflow to be triggered.
D: This element is hidden and we animate the child. Since the animation keyframes give a defined starting and ending value, this works much better. However note that the black box snaps into view because it's still attached to the parent.
E: This works similarly to D but we run everything off the child, which doesn't solve our "black box" issue we had with D.
F: This is probably the best of both worlds solution. We move the styling off the parent onto the child. We can trigger the animation off of the parent, and we can control the display property of the child and animate the transition as we want. The downside to this being you need use animation keyframes instead of transitions.
G: While I don't know if this triggers a reflow inside the function as I haven't parsed it myself, you can just simply use jQuery's .fadeToggle() function to accomplish all of this with a single line of JavaScript, and is used so often (or similar JS/jQuery fadeIn/fadeOut methods) that the subject of reflowing doesn't come up all that often.
Examples:
Here's a CodePen: https://codepen.io/xhynk/pen/gerPKq
Here's a Snippet:
jQuery(document).ready(function($){
$('button:not(#g)').click(function(){
$(this).next('div').toggleClass('show');
});
$('#g').click(function(){
$(this).next('div').stop().fadeToggle(2000);
});
});
* { box-sizing: border-box; }
button {
text-align: center;
width: 400px;
}
div {
margin-top: 20px;
background: #000;
color: #fff;
}
.a,
.b {
overflow: hidden;
height: 0;
opacity: 0;
transition: opacity 3s;
}
.a.show {
height: auto;
opacity: 1;
}
.b.show {
height: 100px;
opacity: 1;
}
.c,
.d {
display: none;
}
.c.show,
.d.show {
display: block;
}
.c div {
opacity: 0;
transition: 3s all;
}
.c.show div {
opacity: 1;
}
.d div {
opacity: 0;
}
.d.show div {
animation: fade 3s;
}
#keyframes fade {
from { opacity: 0; }
to { opacity: 1; }
}
.e div {
display: none;
}
.e.show div {
display: block;
animation: fade 3s;
}
.f {
background: transparent;
}
.f div {
background: #000;
display: none;
}
.f.show div {
display: block;
animation: fade 3s;
}
.g {
display: none;
}
<button id="a">A: Box Height: Auto</button>
<div class="a">This<br/>Has<br/>Some Strange<br/><br/>Content<br>But<br>That doesn't really<br>Matter<br/>Because shown,<br/>I'll be<br/>AUTO</div>
<button id="b">B: Box Height: 100px</button>
<div class="b">Content For 2</div>
<button id="c">C: Hidden - Child Transitions (bad)</button>
<div class="c"><div>Content<br/>For<br/>3<br/></div></div>
<div style="clear: both;"></div>
<button id="d">D: Hidden - Child Animates (Better)</button>
<div class="d"><div>Content<br/>For<br/>4<br/></div></div>
<div style="clear: both;"></div>
<button id="e">E: Hidden - Child Hidden & Animates</button>
<div class="e"><div>Content<br/>For<br/>5<br/></div></div>
<button id="f">F: Child Has BG & Animates (Works)</button>
<div class="f"><div>Content<br/>For<br/>5<br/></div></div>
<div style="clear: both;"></div>
<button id="g">G: This uses fadeToggle to avoid this</button>
<div class="g">I animate with<br/>JavaScript</div>
<footer>I'm just the footer to show the bottom of the document.</footer>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
So I'm trying to create a box that has two layers: The front layer and the back layer. They're going to be stacked on top of each other so the back layer is hidden by default.
When you hover over the top of the box (front layer technically), then the front layer is supposed to slide up revealing the back layer. I tried to do this by using .slideUp() and .slideDown() but it kept bugging out revealing both layers at the same time. So then I switched to just .slideUp() and .fadeIn() but that didn't seem to help too much.
As you can see, it sometimes shows both divs when it's not supposed to and it also slides multiple times randomly. How could I make this more efficient?
Here is a JsFiddle
UPDATE:
Questions seeking debugging help ("why isn't this code working?") must
include the desired behavior, a specific problem or error and the
shortest code necessary to reproduce it in the question itself.
Questions without a clear problem statement are not useful to other
readers.
That is the reason people are voting to close this answer... What does this question not have, from that list?
Desired behavior? - Check
Specific problem? - Check
Shortest code necessary? - Check
Clear problem? - check
You don't really need to use slideUp and slideDown, you can achieve the slide effect by using the transform and transition CSS3 properties.
Updated JS fiddle: https://jsfiddle.net/9uw2q24h/3/
Javascript:
$('.outer').hover(function() {
$(this).children('.front').addClass('front-up');
}, function() {
$(this).children('.front').removeClass('front-up');
});
CSS:
.outer {
position: relative;
.front,
.back {
text-align: center;
width: 100%;
}
.back {
display: block;
}
.front {
position: absolute;
transition: 0.5s ease;
}
.front-up {
transform: translateY(-100%);
}
}
If you have to support older browsers, make sure to add the vendor prefixes to the transition and tranform rules (-webkit-, -moz-, etc.).
You can do this like:
var running = false;
$('.outer').hover(function() {
if (!running) {
running = true;
$(this).children('.front').slideUp(function() {
$(this).next('.back').slideDown(function() {
running = false;
});
});
}
}, function() {
if (!running) {
running = true;
$(this).children('.back').slideUp(function() {
$(this).prev('.front').slideDown(function() {
running = false;
});
});
}
});
Explanation: as soon as the animation starts you save the status in a variable in order to avoid conflicts (otherwise it will be called again). Additionally with the slideDown and slideUp combined you have a much smoother animation. You had a not very nice flickering with your combination of fadeOut and slideDown
Fiddle: https://jsfiddle.net/dL7ckq6b/
With a slight tweak to your CSS, specifically making your elements' position property absolute, will cause your back element to be behind your front element from the start, now you only have to show/hide your front element.
Javascript:
$('.outer').hover(function() {
$('.front').slideUp();
console.log("IN");
}, function() {
$('.front').slideDown();
console.log("OUT");
});
I did also update the CSS to more clearly show the effect happening.
CSS:
.outer {
.front,
.back {
text-align: center;
position: absolute;
padding: 20px 10px;
border: 2px solid yellow;
}
.front {
z-index: 10;
background-color: red;
}
.back {
z-index: 0;
background-color: blue;
}
}
Here is the JSFiddle: https://jsfiddle.net/z8e7eb4b/
I have quite a few page effects on the load, and they can cause the page to disfigure on load. To stop this, I'm fading the body in and out. However, it only works when display:none; is attributed to the body section of the CSS.
CSS
body {
position: relative;
min-height: 100%;
margin: 0 0 0 0;
padding: 0 0 0 0;
border-collapse: collapse;
font-size: 12px;
display: none;
}
JS
window.onload = function () {
$('body').fadeIn();
main(); // my effect function
};
window.onbeforeunload = function () {
$('body').fadeOut();
};
I'm using a the design editor in VS 2015 and I can't see my pages because display:none; is set.
Is there any reason it's not working without display:none;?
fadeIn animates the opacity from its current state to 1 (i.e. no transparency).
If the element is completely hidden, that will be a transition from 0 to 1. If the element has a 50% opacity, it will be a transition from 0.5 to 1.
If, on the other hand, the element is already visible, there will be no animation at all, as the element is already at the target state.
This is my jfiddle
And this is my actual code
$card.animate({
left: "1000px"
}, 500, function(){
$card.hide(500);
});
(I dont know why 'left' didnt work on jfiddle) Basically ive got a container with 5 $cards there. When user swipes the card (already implemented) the animate() is triggered and the card slides to the rightand then disappears. How can I implement such thing in CSS animations instead of using Jquery? Ive read that CSS animations run faster (and I proved it on my mobile device, the hide() runs really slow)... Any help or advice will be appreciated
First of all, create a class that you can trigger via jQuery that will have the animation.
Then, using you have two options: transition or animation. Transitions are simpler and more direct, but you can do more with animations.
Here is how I would suggest to do it: a transition for the movement, and an animation to recreate the hide() function.
#keyframes hide {
99% { display: auto; }
100%{ display: none; opacity: 0; }
}
.myelement {
transition: all .5s;
position: absolute;
left: 0;
}
.myelement.toLeft {
left: 2000px;
animation: hide .5s 1 forwards;
}
To trigger it, simply do this:
$(".myelement").addClass("toLeft");
Here is a working JSFiddle.
And like #MohitBhardwaj said, it is necessary for you to set position to absolute, relative, or static in order for positioning (i.e., the left property) to work.
It's also important to note that a transition needs an initial value. I added left: 0 to do this. Otherwise, (with a CSS transition) it would simply jump to 2000px because there is no starting point.
Also, because 2000px as a left value is very large, I suggest you change the parent element's scroll to overflow: hidden, so that the extraneous scroll bar doesn't appear.
Your left didn't work, because you need to set position to a value other than static (which is default) for it to work.
As for using CSS, you can add a class instead of animating in jQuery. This class can change the transition which you can set in css as per your requirements.
var my_div = $('.myelement');
my_div.on('click', function() {
var $this = $(this);
$this.addClass("gone");
setTimeout(function(){
$this.hide();
}, 600 );
})
#mywrapper
{
overflow: hidden;
}
.myelement {
height: 200px;
width: 200px;
background-color: red;
opacity: 1;
position: relative;
transition: all 0.5s ease;
opacity: 1;
left: 0px;
}
.myelement.gone
{
left: 500px;
opacity: 0;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<div id="mywrapper">
<div class="myelement">
Click me please
</div>
</div>