Is there a foreground equivalent to background-image in css?

Himmators picture Himmators · Sep 30, 2012 · Viewed 74.1k times · Source

I want to add some shine to an element on webpage. I would prefer if I don't have to add additional html to the page. I want the image to appear in front of the element rather than behind. What's the best way to do this?

Answer

Rob W picture Rob W · Sep 30, 2012

To achieve a "foreground image" without extra HTML code, you can use a pseudo-element (::before / :before) plus the CSS pointer-events. The last property is needed so that the user can actually click through the layer "as if it did not exists".

Here's an example (using a color whose alpha channel is 50% so that you can see that the real elements can actually be focused): http://jsfiddle.net/JxNdT/

​<div id="cont">
Test<br>
<input type="text" placeholder="edit">
</div>​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​
​#cont {
    width: 200px;
    height: 200px;
    border: 1px solid #aaa; /*To show the boundaries of the element*/
}
#cont:before {
    position: absolute;
    content: '';
    background: rgba(0,0,0, 0.5); /*partially transparent image*/
    width: 200px;
    height: 200px;
    pointer-events: none;
}
​

PS. I picked the ::before pseudo-element, because that naturally leads to the correct positioning. If I pick ::after, then I have to add position:relative; to the real element (#cont), and top:0;left:0; to the pseudo-element (::after).


PPS. To get the foreground effect on elements without a fixed size, an additional element is needed. This wrapper element requires the position:relative;display:inline-block; styles. Set the width and height of the pseudo-element to 100%, and the pseudo-element will stretch to the width and height of the wrapper element. Demo: http://jsfiddle.net/JxNdT/1/.