'transform3d' not working with position: fixed children

Question

I have a situation where, in normal CSS circumstances, a fixed div would be positioned exactly where it is specified (top:0px, left:0px).

This does not seem to be respected if I have a parent that has a translate3d transform. Am I not seeing something? I have tried other webkit-transform like style and transform origin options but had no luck.

I have attached a JSFiddle with an example where I would have expected the yellow box be at the top corner of the page rather than inside of the container element.

You can find below a simplified version of the fiddle:

#outer {
    position:relative; 
    -webkit-transform:translate3d(0px, 20px , 0px); 
    height: 300px; 
    border: 1px solid #5511FF; 
    padding: 10px;
    background: rgba(100,180,250, .8); 
    width: 80%;
}
#middle{
    position:relative; 
    border: 1px dotted #445511; 
    height: 300px; 
    padding: 5px;
    background: rgba(250,10,255, .6);
}
#inner {
    position: fixed; 
    top: 0px;
    box-shadow: 3px 3px 3px #333; 
    height: 20px; 
    left: 0px;
    background: rgba(200,180,80, .8); 
    margin: 5px; 
    padding: 5px;
}

<div id="container">
    Blue: Outer, <br>
    Purple: Middle<br>
    Yellow: Inner<br>
    <div id="outer"> 
        <div id="middle">
            <div id="inner">
                Inner block
            </div>
        </div>
    </div>
</div>

How can I make translate3d work with fixed-positioned children?

Answer 1

This is because the transform creates a new local coordinate system, as per W3C spec:

In the HTML namespace, any value other than none for the transform results in the creation of both a stacking context and a containing block. The object acts as a containing block for fixed positioned descendants.

This means that fixed positioning becomes fixed to the transformed element, rather than the viewport.

There's not currently a work-around that I'm aware of.

It is also documented on Eric Meyer's article: Un-fixing Fixed Elements with CSS Transforms.

Answer 2

As Bradoergo suggested, just get the window scrollTop and add it to the absolute position top like:

function fix_scroll() {
  var s = $(window).scrollTop();
  var fixedTitle = $('#fixedContainer');
  fixedTitle.css('position','absolute');
  fixedTitle.css('top',s + 'px');
}fix_scroll();

$(window).on('scroll',fix_scroll);

This worked for me anyway.

Answer 3

I had a flickering on my fixed top nav when items in the page were using transform, the following applied to my top nav resolved the jumping/flickering issue:

#fixedTopNav {
    position: fixed;
    top: 0;
    transform: translateZ(0);
    -webkit-transform: translateZ(0);
}

Thanks to this answer on SO

Answer 4

In Firefox and Safari you can use position: sticky; instead of position: fixed; but it will not work in other browsers. For that you need javascript.

Answer 5

In my opinion, the best method to deal with this is to apply the same translate, but break children that need to be fixed out of their parent (translated) element; and then apply the translate to a div inside the position: fixed wrapper.

The results look something like this (in your case):

<div style='position:relative; border: 1px solid #5511FF; 
            -webkit-transform:translate3d(0px, 20px , 0px); 
            height: 100px; width: 200px;'> 

</div>
<div style='position: fixed; top: 0px; 
            box-shadow: 3px 3px 3px #333; 
            height: 20px; left: 0px;'>
    <div style='-webkit-transform:translate3d(0px, 20px, 0px);'>
        Inner block
    </div>
</div>

JSFiddle: https://jsfiddle.net/hju4nws1/

While this may not be ideal for some use cases, typically if you're fixing a div you probably could care less about what element is its parent/where it falls in the inheritance tree in your DOM, and seems to solve most of the headache - while still allowing both translate and position: fixed to live in (relative) harmony.

Answer 6

I ran across the same problem. The only difference is that my element with 'position: fixed' had its 'top' and 'left' style properties set from JS. So I was able to apply a fix:

var oRect = oElement.getBoundingClientRect();

oRect object will contain real (relative to view port) top and left coordinates. So you can adjust your actual oElement.style.top and oElement.style.left properties.

Answer 7

I have an off canvas sidebar that uses -webkit-transform: translate3d. This was preventing me from placing a fixed footer on the page. I resolved the issue by targeting a class on the html page that is added to the tag on initialization of the sidebar and then writing a css :not qualifier to state "-webkit-transform: none;" to the html tag when that class is not present on the html tag. Hope this helps someone out there with this same issue!

Answer 8

Try to apply opposite transform to the child element:

<div style='position:relative; border: 1px solid #5511FF; 
            -webkit-transform:translate3d(0px, 20px , 0px); 
            height: 100px; width: 200px;'> 
    <div style='position: fixed; top: 0px; 
                -webkit-transform:translate3d(-100%, 0px , 0px); 
                box-shadow: 3px 3px 3px #333; 
                height: 20px; left: 0px;'>
        Inner block
    </div>
</div>

Answer 9

Add a dynamic class while the element transforms.$('#elementId').addClass('transformed'). Then go on to declare in css,

.translat3d(@x, @y, @z) { 
     -webkit-transform: translate3d(@X, @y, @z); 
             transform: translate3d(@x, @y, @z);
      //All other subsidaries as -moz-transform, -o-transform and -ms-transform 
}

then

#elementId { 
      -webkit-transform: none; 
              transform: none;
}

then

.transformed {
    #elementId { 
        .translate3d(0px, 20px, 0px);
    }
}

Now position: fixed when provided with a top and z-index property values on a child element just work fine and stay fixed until the parent element transforms. When the transformation is reverted the child element pops as fixed again. This should easen the situation if you are actually using a navigation sidebar that toggles open and closes upon a click, and you have a tab-set which should stay sticky as you scroll down the page.

Answer 10

One way to deal with this is to apply the same transform to the fixed element:

<br>
<div style='position:relative; border: 1px solid #5511FF; 
            -webkit-transform:translate3d(0px, 20px , 0px); 
            height: 100px; width: 200px;'> 
    <div style='position: fixed; top: 0px; 
                -webkit-transform:translate3d(0px, 20px , 0px); 
                box-shadow: 3px 3px 3px #333; 
                height: 20px; left: 0px;'>
        Inner block
    </div>
</div>