Position: absolute and parent height?

Question

I have some containers and their children are only absolute / relatively positioned. How to set containers height so their children will be inside of them?

Here's the code:

HTML

<section id="foo">
    <header>Foo</header>
    <article>
        <div class="one"></div>
        <div class="two"></div>
    </article>
</section>    

<div style="clear:both">Clear won't do.</div>
<!-- I want to have a gap between sections here -->

<section id="bar">
    <header>bar</header>
    <article>
        <div class="one"></div><div></div>
        <div class="two"></div>
    </article>
</section>  

CSS

article {
    position: relative;
}

.one {
    position: absolute;
    top: 10px;
    left: 10px;
    background: red;
    width: 30px;
    height: 30px;
}

.two {
    position: absolute;
    top: 10px;
    right: 10px;
    background: blue;
    width: 30px;
    height: 30px;
}

Here's a jsfiddle. I want "bar" text to appear between 4 squares, not behind them.

http://jsfiddle.net/Ht9Qy/

Any easy fixes?

Note that I don't know height of these children, and I can't set height: xxx for containers.

Solution 1

If I understand what you're trying to do correctly, then I don't think this is possible with CSS while keeping the children absolutely positioned.

Absolutely positioned elements are completely removed from the document flow, and thus their dimensions cannot alter the dimensions of their parents.

If you really had to achieve this affect while keeping the children as position: absolute, you could do so with JavaScript by finding the height of the absolutely positioned children after they have rendered, and using that to set the height of the parent.

Alternatively, just use float: left/float:right and margins to get the same positioning effect while keeping the children in the document flow, you can then use overflow: hidden on the parent (or any other clearfix technique) to cause its height to expand to that of its children.

article {
    position: relative;
    overflow: hidden;
}

.one {
    position: relative;
    float: left;
    margin-top: 10px;
    margin-left: 10px;
    background: red;
    width: 30px;
    height: 30px;
}

.two {
    position: relative;
    float: right;
    margin-top: 10px;
    margin-right: 10px;
    background: blue;
    width: 30px;
    height: 30px;
}

Solution 2

Here is my workaround,
In your example you can add a third element with "same styles" of .one & .two elements, but without the absolute position and with hidden visibility:

HTML

<article>
   <div class="one"></div>
   <div class="two"></div>
   <div class="three"></div>
</article>

CSS

.three{
    height: 30px;
    z-index: -1;
    visibility: hidden;
    width:0!important; /* if you got unnecessary horizontal scroll*/
}

Solution 3

You can do that with a grid:

article {
    display: grid;
}

.one {
    grid-area: 1 / 1 / 2 / 2;
}

.two {
    grid-area: 1 / 1 / 2 / 2;
}

Solution 4

This is a late answer, but by looking at the source code, I noticed that when the video is fullscreen, the "mejs-container-fullscreen" class is added to the "mejs-container" element. It is thus possible to change the styling based on this class.

.mejs-container.mejs-container-fullscreen {
    // This rule applies only to the container when in fullscreen
    padding-top: 57%;
}

Also, if you wish to make your MediaElement video fluid using CSS, below is a great trick by Chris Coyier: http://css-tricks.com/rundown-of-handling-flexible-media/

Just add this to your CSS:

.mejs-container {
    width: 100% !important;
    height: auto !important;
    padding-top: 57%;
}
.mejs-overlay, .mejs-poster {
    width: 100% !important;
    height: 100% !important;
}
.mejs-mediaelement video {
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    width: 100% !important;
    height: 100% !important;
}

I hope it helps.

Solution 5

This kind of layout problem can be solved with flexbox now, avoiding the need to know heights or control layout with absolute positioning, or floats. OP's main question was how to get a parent to contain children of unknown height, and they wanted to do it within a certain layout. Setting height of the parent container to "fit-content" does this; using "display: flex" and "justify-content: space-between" produces the section/column layout I think the OP was trying to create.

<section id="foo">
    <header>Foo</header>
    <article>
        <div class="main one"></div>
        <div class="main two"></div>
    </article>
</section>    

<div style="clear:both">Clear won't do.</div>

<section id="bar">
    <header>bar</header>
    <article>
        <div class="main one"></div><div></div>
        <div class="main two"></div>
    </article>
</section> 

* { text-align: center; }
article {
    height: fit-content ;
    display: flex;
    justify-content: space-between;
    background: whitesmoke;
}
article div { 
    background: yellow;     
    margin:20px;
    width: 30px;
    height: 30px;
    }

.one {
    background: red;
}

.two {
    background: blue;
}

I modified the OP's fiddle: http://jsfiddle.net/taL4s9fj/

css-tricks on flexbox: https://css-tricks.com/snippets/css/a-guide-to-flexbox/

View more solutions

Comments

[Ian Devlin]

Do not use <center>! It's been deprecated.

[frzsombor]

...since HTML4 (A.D. 1997)

[TeemuK]

For anyone stumbling here, trying to figure why your margin-left: -16px & overflow: hidden trick doesn't work. I didn't take into consideration that I had also right padding, so I needed margin-right: -16px. Also I used width: 100vw for the container, dunno if needed.

[Kashkashio]

You are a freaking genius. Thank you! This seems the only way to maintain the height of an absolute element without setting a fixed value. Brilliant.

[SwankyLegg]

fit-content is what solved this for me!