Animating max-height with CSS transitions
CssCss TransitionsCss AnimationsCss Problem Overview
I want to create an expand/collapse animation that's powered only by classnames (javascript is used to toggle the classnames).
I'm giving one class max-height: 4em; overflow: hidden;
and the other max-height: 255em;
(I also tried the value none
, which didn't animate at all)
this to animate: transition: max-height 0.50s ease-in-out;
I used CSS transitions to switch between them, but the browser seems to be animating all those extra em
's, so it creates a delay in the collapse effect.
Is there a way of doing it (in the same spirit - with css classnames) that doesn't have that side-effect (I can put a lower pixel count, but that obviously has drawbacks, since it might cut off legit text - that's the reason for the big value, so it doesn't cut off legit long text, only ridiculously long ones)
See the jsFiddle - http://jsfiddle.net/wCzHV/1/ (click on the text container)
Css Solutions
Solution 1 - Css
Fix delay solution:
Put cubic-bezier(0, 1, 0, 1) transition function for element.
scss
.text {
overflow: hidden;
max-height: 0;
transition: max-height 0.5s cubic-bezier(0, 1, 0, 1);
&.full {
max-height: 1000px;
transition: max-height 1s ease-in-out;
}
}
css
.text {
overflow: hidden;
max-height: 0;
transition: max-height 0.5s cubic-bezier(0, 1, 0, 1);
}
.text.full {
max-height: 1000px;
transition: max-height 1s ease-in-out;
}
Solution 2 - Css
This is an old question but I just worked out a way to do it and wanted to stick it somewhere so I know where to find it should I need it again :o)
So I needed an accordion with clickable "sectionHeading" divs that reveal/hide corresponding "sectionContent" divs. The section content divs have variable heights, which creates a problem as you can't animate height to 100%. I've seen other answers suggesting animating max-height instead but this means sometimes you get delays when the max-height you use is larger than the actual height.
The idea is to use jQuery on load to find and explicitly set the heights of the "sectionContent" divs. Then add a css class 'noHeight' to each a click handler to toggle it:
$(document).ready(function() {
$('.sectionContent').each(function() {
var h = $(this).height();
$(this).height(h).addClass('noHeight');
});
$('.sectionHeader').click(function() {
$(this).next('.sectionContent').toggleClass('noHeight');
});
});
For completeness, the relevant css classes:
.sectionContent {
overflow: hidden;
-webkit-transition: all 0.3s ease-in;
-moz-transition: all 0.3s ease-in;
-o-transition: all 0.3s ease-in;
transition: all 0.3s ease-in;
}
.noHeight {
height: 0px !important;
}
Now the height transitions work without any delays.
Solution 3 - Css
In case anyone is reading this, I have not found a solution and went with an expand-only effect (which was achieved by moving the transition
style to the expanded class definition)
Solution 4 - Css
The solution is actually quite simple. Make a child div, that has the content. The parent div will be the one that expands collapses.
On load the parent div will have a max-height. when toggling, you can check the child height by writing document.querySelector('.expand-collapse-inner').clientHeight;
and set the maxheight with javascript.
In your CSS, you will have this
.parent {
transition: max-height 250ms;
}
Solution 5 - Css
Use display:flex. This will work:
.parent > div {
display: flex;
flex-direction: column;
height: 0px;
max-height: 0px;
opacity: 0;
overflow: hidden;
transition: all 0.3s;
}
.parent > div.active {
opacity: 1;
height: 100%;
max-height: none; /* important for animation */
}
Solution 6 - Css
You can accomplish this just fine using jQuery Transit:
$(function () {
$(".paragraph").click(function () {
var expanded = $(this).is(".expanded");
if (expanded)
{
$(this).transition({ 'max-height': '4em', overflow: 'hidden' }, 500, 'in', function () {$(this).removeClass("expanded"); });
}
else
{
$(this).transition({ 'max-height': $(this).get(0).scrollHeight, overflow: ''}, 500, 'out', function () { $(this).addClass("expanded"); });
}
});
});
You can definitely tidy it up a bit to your liking, but that should do what you want.