I'm working on CSS and web development,but just face a something which i really don't understand it:
.header{
position: absolute;
width:60%;
top: 20%;
left: 50%;
transform: translateX(-50%);<------ executed after animation
text-align: center;
animation: moveUp 2s;
animation-fill-mode: backwards;
}
#keyframes moveUp{
0%{
opacity: 0;
transform:translateY(2rem);
}
100%{
opacity: 1;
transform: translateY(0rem);
}
}
so my problem here is the indicated line doesn't apply on ".header" until the animation gets applied in other word it applies animation first then translate -50% ,is there a priority of execution here or it is different thing?
Usually the styles are parsed from top to bottom, however this isn't the issue here.
What is happening in your case is the transform is being applied initially, but then it is being overridden by the animation. Once the animation is over, the element is reverting back to its default style which has the transform.
Essentially, even though the transform is applied at first, you don't see it until the element reverts to it after the end of the animation.
The only solution if you want to have the transform during the animation, is to include it in the animation itself.
#keyframes moveUp {
0 % {
opacity: 0;
transform: translate(-50%, 2rem);
}
100 % {
opacity: 1;
transform: translate(-50%, 0);
}
}
EDIT: To clarify, the order at which the styles are applied does not matter. Whether the animation or the transform is applied first, the result will be the same.
I think a source of your confusion is that the first transform is a translateX while the animation only does translateY. In both cases what is changing is the value of the transform property of the element. Therefore which axis the translation is on doesn't matter. First you set transform: translateX(-50%), but then once the animation kicks in, transform becomes translateY(2rem). The translateX part is removed from the transform, unless you include it in the animation like I have shown.
This is my code, including the animation in the CSS portion and the H1 element i want to apply it to.
In fact, there's nothing wrong with the animation, but left doesn't have any impact on a static-positioned h1 actually.
Have you tried to change that left to margin-left, or add position: relative to h1? Like this: http://plnkr.co/edit/x6JythFhtrF8UFeqKtyG?p=preview
Plus, I believe you wanna make it run infinitely, otherwise the alternate cannot be observed, therefore you might wanna put in infinite as the animation-iteration-count
h1 {
position: relative; /* TRY TO ADD THIS */
animation: enter 5s linear alternate infinite; /* OPTIONAL infinite */
}
#keyframes enter {
from {
left: 0em;
}
to {
left: 20em;
}
}
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: 0ï¼›
}
25% {
opacity: 0.5;
}
to {
transform: scale(1);
opacity: 0.5;
}
}
#keyframes two {
from {
opacity: 0.5ï¼›
}
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>
So, I understand how to perform both CSS3 transitions and animations. What is not clear, and I've googled, is when to use which.
For example, if I want to make a ball bounce, it is clear that animation is the way to go. I could provide keyframes and the browser would do the intermediates frames and I'll have a nice animation going.
However, there are cases when a said effect can be achieved either way. A simple and common example would be implement the facebook style sliding drawer menu:
This effect can be achieved through transitions like so:
.sf-page {
-webkit-transition: -webkit-transform .2s ease-out;
}
.sf-page.out {
-webkit-transform: translateX(240px);
}
http://jsfiddle.net/NwEGz/
Or, through animations like so:
.sf-page {
-webkit-animation-duration: .4s;
-webkit-transition-timing-function: ease-out;
}
.sf-page.in {
-webkit-animation-name: sf-slidein;
-webkit-transform: translate3d(0, 0, 0);
}
.sf-page.out {
-webkit-animation-name: sf-slideout;
-webkit-transform: translateX(240px);
}
#-webkit-keyframes sf-slideout {
from { -webkit-transform: translate3d(0, 0, 0); }
to { -webkit-transform: translate3d(240px, 0, 0); }
}
#-webkit-keyframes sf-slidein {
from { -webkit-transform: translate3d(240px, 0, 0); }
to { -webkit-transform: translate3d(0, 0, 0); }
}
http://jsfiddle.net/4Z5Mr/
With HTML that looks like so:
<div class="sf-container">
<div class="sf-page in" id="content-container">
<button type="button">Click Me</button>
</div>
<div class="sf-drawer">
</div>
</div>
And, this accompanying jQuery script:
$("#content-container").click(function(){
$("#content-container").toggleClass("out");
// below is only required for css animation route
$("#content-container").toggleClass("in");
});
What I'd like to understand is what are the pros and cons of these approaches.
One obvious difference is that animating is taking a whole lot more code.
Animation gives better flexibility. I can have different animation for sliding out and in
Is there something that can be said about performance. Do both take advantage of h/w acceleration?
Which is more modern and the way going forward
Anything else you could add?
It looks like you've got a handle on how to do them, just not when to do them.
A transition is an animation, just one that is performed between two distinct states - i.e. a start state and an end state. Like a drawer menu, the start state could be open and the end state could be closed, or vice versa.
If you want to perform something that does not specifically involve a start state and an end state, or you need more fine-grained control over the keyframes in a transition, then you've got to use an animation.
I'll let the definitions speak for themselves (according to Merriam-Webster):
Transition: A movement, development, or evolution from one form, stage, or style to another
Animation: Endowed with life or the qualities of life; full of movement
The names appropriately fit their purposes in CSS
So, the example you gave should use transitions because it is only a change from one state to another
A shorter answer, straight on point:
Transition:
Needs a triggering element (:hover, :focus etc.)
Only 2 animation states (start and end)
Used for simpler animations (buttons, dropdown menus and so on)
Easier to create but not so many animation/effect possibilities
Animation #keyframes:
It can be used for endless animations
Can set more than 2 states
No boundaries
Both use CPU acceleration for a much smoother effect.
Animation takes a lot more code unless you're using the same transition over and over, in which case an animation would be better.
You can have different effects for sliding in and out without an animation. Just have a different transition on both the original rule and the modified rule:
.two-transitions {
transition: all 50ms linear;
}
.two-transitions:hover {
transition: all 800ms ease-out;
}
Animations are just abstractions of transitions, so if the transition is hardware accelerated, the animation will be. It makes no difference.
Both are very modern.
My rule of thumb is if I use the same transition three times, it should probably be an animation. This is easier to maintain and alter in the future. But if you are only using it once, it is more typing to make the animation and maybe not worth it.
Animations are just that - a smooth behavior of set of properties. In other words it specifies what should happen to a set of element's properties. You define an animation and describe how this set of properties should behave during the animation process.
Transitions on the other side specify how a property (or properties) should perform their change. Each change. Setting a new value for certain property, be it with JavaScript or CSS, is always a transition, but by default it is not smooth. By setting transition in the css style you define different (smooth) way to perform these changes.
It can be said that transitions define a default animation that should be performed every time the specified property has changed.
Is there something that can be said about performance. Do both take
advantage of h/w acceleration?
In modern browsers, h/w acceleration occurs for the properties filter, opacity and transform. This is for both CSS Animations and CSS Transitions.
.yourClass {
transition: all 0.5s;
color: #00f;
margin: 50px;
font-size: 20px;
cursor: pointer;
}
.yourClass:hover {
color: #f00;
}
<p class="yourClass"> Hover me </p>
CSS3 Transitions brought frontend developers a significant ability to modify the appearance and behavior of an element as relative to a change in his state. CSS3 animations extends this ability and allow to modify the appearance and behavior of an element in multiple keyframes, so transitions provides us the ability to change from one state to another, while that animations can set multiple points of transition within different keyframes.
So, let's look at this transition sample where applied a transition with 2 points, start point at left: 0 and an end point at left: 500px
.container {
background: gainsboro;
border-radius: 6px;
height: 300px;
position: relative;
}
.ball {
transition: left 2s linear;
background: green;
border-radius: 50%;
height: 50px;
position: absolute;
width: 50px;
left: 0px;
}
.container:hover .ball{
left: 500px;
}
<div class="container">
<figure class="ball"></figure>
</div>
The above can be also created via animation like so:
#keyframes slide {
0% {
left: 0;
}
100% {
left: 500px;
}
}
.container {
background: gainsboro;
border-radius: 6px;
height: 200px;
position: relative;
}
.ball {
background: green;
border-radius: 50%;
height: 50px;
position: absolute;
width: 50px;
}
.container:hover .ball {
animation: slide 2s linear;
}
<div class="container">
<figure class="ball"></figure>
</div>
And if we would like another in-between point, it would be possible to achieve only via animation, we can add another keyFrame to achieve this and this is the real power of animation over transition:
#keyframes slide {
0% {
left: 0;
}
50% {
left: 250px;
top: 100px;
}
100% {
left: 500px;
}
}
.container {
background: gainsboro;
border-radius: 6px;
height: 200px;
position: relative;
}
.ball {
background: green;
border-radius: 50%;
height: 50px;
position: absolute;
width: 50px;
}
.container:hover .ball {
animation: slide 2s linear;
}
<div class="container">
<figure class="ball"></figure>
</div>
transition can go reverse from middle of the way, but animation replay the keyframes from start to end.
const transContainer = document.querySelector(".trans");
transContainer.onclick = () => {
transContainer.classList.toggle("trans-active");
}
const animContainer = document.querySelector(".anim");
animContainer.onclick = () => {
if(animContainer.classList.contains("anim-open")){
animContainer.classList.remove("anim-open");
animContainer.classList.add("anim-close");
}else{
animContainer.classList.remove("anim-close");
animContainer.classList.add("anim-open");
}
}
*{
font: 16px sans-serif;
}
p{
width: 100%;
background-color: #ff0;
}
.sq{
width: 80px;
height: 80px;
margin: 10px;
background-color: #f00;
display: flex;
justify-content: center;
align-items: center;
}
.trans{
transition: width 3s;
}
.trans-active{
width: 200px;
}
.anim-close{
animation: closingAnimation 3s forwards;
}
.anim-open{
animation: openingAnimation 3s forwards;
}
#keyframes openingAnimation {
from{width: 80px}
to{width: 200px}
}
#keyframes closingAnimation {
from{width: 200px}
to{width: 80px}
}
<p>Try click them before reaching end of movement:</p>
<div class="sq trans">Transition</div>
<div class="sq anim">Animation</div>
in addition, if you want the javascript to listen for end of transition, you'll get one event for each property that you change.
for example transition: width 0.5s, height 0.5s. the transitionend event will trigger two times, one for width and one for height.
Just a summary, thanks to this post, there are 5 main differences between CSS transitions vs CSS animations:
1/ CSS transitions:
Animate an object from one state to another, implicitly by browser
Cannot loop
Need a trigger to run (:hover, :focus)
Simple, less code, limited powerful
Easy to work in JavaScript
2/ CSS animations:
Freely switch between multiple states, with various properties and time frame
Can loop
Don’t need any kind of external trigger
More complex, more code, more flexible
Hard to work in JavaScript due to syntax for manipulating keyframes
I believe CSS3 animation vs CSS3 transition will give you the answer you want.
Basically below are some takeaways :
If performance is a concern, then choose CSS3 transition.
If state is to be maintained after each transition, then choose CSS3 transition.
If the animation needs to be repeated, choose CSS3 animation. Because it supports animation-iteration-count.
If a complicated animation is desired. Then CSS3 animation is preferred.
Don't bother yourself which is better. My give away is that, if you can solve your problem with just one or two lines of code then just do it rather than writing bunch of codes that will result to similar behavior.
Anyway, transition is like a subset of animation. It simply means transition can solve certain problems while animation on the other hand can solve all problems.
Animation enables you to have control of each stage starting from 0% all the way to 100% which is something transition cannot really do.
Animation require you writing bunch of codes while transition uses one or two lines of code to perform the same result depending on what you are working on.
Coming from the point of JavaScript, it is best to use transition. Anything that involve just two phase i.e. start and finish use transition.
Summary, if it is stressful don't use it since both can produce similar result
First of all, sorry if the title is wrong because I don't know if these are actually called rotating loaders or not. This is what I am talking about: JSFiddle
I have 2 problems with these loaders,
in .chrome-loader, if I set height: 50px; width: 50px;, and and in .ring-maker set top: 2.5px; left: 2.5px it doesn't work very well. Does px unit support values upto 2 decimal places? I guess they don't. So what can I do to fix it? I basically want to make it of same size as the ones above. Perhaps, some other unit?
For .win8-loader I set this CSS animation for first dot.
#-webkit-keyframe win8dot1 {
0% {left: -10px;}
33% {left: 500px;}
66% {left: 780px;}
100% {left: 1280px;}
}
But it doesn't work. The first dot doesn't even move.
PS: are names like abc1-de2 allowed for keyframes?
You have to correct 2 problems
Your CSS
.win8-loader .dot1 { -webkit-animation: win8-dot1 2.5s infinite linear; }
#-webkit-keyframe win8dot1 {
corrected:
.win8-loader .dot1 { -webkit-animation: win8dot1 2.5s infinite linear; }
#-webkit-keyframes win8dot1 {