Saying Goodbye to the overflow: hidden Clearing Hack

https://i1.wp.com/1.bp.blogspot.com/_BGE4sL0uhQA/TVKJbZMrKrI/AAAAAAAAAB8/De5yG6iAI6s/s1600/css.png

I’ve been thinking of this for a while now, and it’s finally time to part ways with the overflow: hidden (and overflow: auto) clearing hack. Jeff Starr’s recent and excellent post – The New Clearfix Method – and the ensuing comments were enough to finally prompt me to write about it here. (And since I started writing this, Jonathan Snook has started a Twitter dialog about overflow vs. clearfix).

While the clearfix method is a tried and true hack, I’ve always disliked muddying up my HTML markup with crufty “clearfix” classes strewn about. So I ended up using overflow: hidden as much as I could. But overflow: hidden is not without its drawbacks. Although there is no extra class to apply in the HTML (win!), there may be situations when you want to have child elements positioned partially (or entirely) outside of their overflow: hidden wielding parent (or other ancestor) container. In these cases, the container with overflow: hidden will clip the element that you’re trying to partially (or entirely) position outside of it. (Case in point: If you use suckerfish dropdowns, try setting overflow: hidden on the outermost list).

So although overflow: hidden is not usable in all situations, I used to prefer it over using the “clearfix” class method. But in reality I ended up with both: I had overflow: hidden where I could get away with it, and “clearfix” classes where I couldn’t use overflow: hidden. It bothered me a bit to mix and match two different clearing methods, but I was happy to have fewer “clearfix” classes violating my otherwise semantic markup Kumbaya festival.

Then in his presentation at An Event Apart 2008 in San Francisco, Dan Cederholm suggest using the class name “group” rather than “clearfix” – a suggestion which later made it into his book Handcrafted CSS. It’s a minor thing, but I do like the improved semantics (in most cases) of the “group” class name over the “clearfix” class name, so I adopted this approach and felt okay about using it as a fallback when overflow: hidden wasn’t feasible.

In his talk and in his book, Cederholm also walks through the “big long list” idea of applying the rules for the clearfix (renamed to “group”) class directly to the selectors that need them in the CSS.

Big Long List

This keeps the HTML more pure while avoiding the drawbacks of overflow – a total win-win. But it does mean extra bloat in the CSS. Probably okay for smaller sites, but it can quickly get unruly with larger sites. I tried this approach on a few projects and decided the CSS bloat was indeed too much, so I stuck with the mix of overflow: hidden and the “group” class.

The Catalyst

But I’m now saying goodbye to overflow: hidden and the deciding factor for me is CSS3. Specifically box-shadow. At least in the sense that box-shadow was the first property I noticed being negatively impacted by the use of overflow: hidden. Like the positioned child elements mentioned above, box-shadow can get clipped when the parent (or other ancestor) element has overflow applied.

And there are several other things to consider as we move forward using more CSS3. Text-shadow and transform can also potentially be clipped by overflow: hidden (see the demo).

Example of overflow:hidden clipping a box-shadow

As we rely more and more on CSS3 properties we can rely less and less on overflow as a clearing method. So I’ll be abandoning overflow and relying upon clearfix (Jeff Starr edition) via a mix of the “.group” class in the markup and the “big long list” approach.

Suggested Reading

Quoted from: http://fordinteractive.com/2009/12/goodbye-overflow-clearing-hack/

onmouseover cursor using firefox: SOLVED!!

QUoting from David Harrison @webdeveloper.com:

It’s not hand, it’s pointer. M$ decided to throw caution to the wind and employ some MORE non-standard code. You don’t need to say onmouseover though since the rule will only apply to when the mouse is over the element anyway, so just do this:<some-tag style=”cursor:pointer;cursor:hand;”></some-tag>You have to specify pointer first, then hand. IE5 trips up because it doesn’t understand pointer (IE6 understands pointer though).
FYI, you didn’t reference the element properly either, should have been “this.style.cursor=’whatever’;”.

Thanks,

 

Create a Lightbox effect only with CSS – no javascript needed

Create a Lightbox effect only with CSS – no javascript needed

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You may call it Lightbox, or Greybox, or Thickbox, but it’s always the same effect.

When you are on a page, and click on a photo or trig some event, a Lightbox is an effect that fades the pagein the background to show you new content in the foreground.

I mean this effect

Lightbox

In the upper example, when clicking on a photo the site fades to black and shows the photo, in the lower one when clicking on “login” the site fades to white and shows the login form.

There are tons of Lightbox scripts in the web, each one with its unique features and limitations, but all require massive use of Javascript or the installation of javascript frameworks.

In some cases, there are “lightweight” versions with “only” 40KB of Javascript.

This example does not want to compete with those scripts, but if you are looking for a simple, 100% CSS, 0% javascript lightbox, this may help you.

Features of this Lightbox:

100% CSS as said
You can insert any content in it (some scripts out there only allow images)

That’s all. Did you need something more? Think wisely…

Let’s start with the CSS

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.black_overlay{
	display: none;
	position: absolute;
	top: 0%;
	left: 0%;
	width: 100%;
	height: 100%;
	background-color: black;
	z-index:1001;
	-moz-opacity: 0.8;
	opacity:.80;
	filter: alpha(opacity=80);
}

.white_content {
	display: none;
	position: absolute;
	top: 25%;
	left: 25%;
	width: 50%;
	height: 50%;
	padding: 16px;
	border: 16px solid orange;
	background-color: white;
	z-index:1002;
	overflow: auto;
}

The black_overlay class is the layer that will make the web page seem to fade. It’s a black 80% opaque background as long and wide as the browser that will overlay the web page (look at the z-index) and at the moment is not shown (look at the display).

The white content class is the layer with the photo/login screen/whatever you want to appear in the Lightbox overlay. It’s a white layer to be placed over the black_overlay layer (look at the z-index, greater than the black_overlay one). The overflow allows you to have a scrollable content.

In the html file, put this line just before the tag

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<div id="light">Hi, I am an happy lightbox</div><div id="fade"></div>

Now, trig the action you want to open the Lightbox and insert this code:

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document.getElementById('light').style.display='block';document.getElementById('fade').style.display='block';

For example, in a link would be:

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<a href = "javascript:void(0)" onclick = "document.getElementById('light').style.display='block';document.getElementById('fade').style.display='block'">Click me</a>

Remember to include in the lightbox the code to close it, for example

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<a href = "javascript:void(0)" onclick = "document.getElementById('light').style.display='none';document.getElementById('fade').style.display='none'">Hide me</a>

A complete example page could be

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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
	<head>
		<title>LIGHTBOX EXAMPLE</title>
		<style>
		.black_overlay{
			display: none;
			position: absolute;
			top: 0%;
			left: 0%;
			width: 100%;
			height: 100%;
			background-color: black;
			z-index:1001;
			-moz-opacity: 0.8;
			opacity:.80;
			filter: alpha(opacity=80);
		}
		.white_content {
			display: none;
			position: absolute;
			top: 25%;
			left: 25%;
			width: 50%;
			height: 50%;
			padding: 16px;
			border: 16px solid orange;
			background-color: white;
			z-index:1002;
			overflow: auto;
		}
	</style>
	</head>
	<body>
		<p>This is the main content. To display a lightbox click <a href = "javascript:void(0)" onclick = "document.getElementById('light').style.display='block';document.getElementById('fade').style.display='block'">here</a></p>
		<div id="light">This is the lightbox content. <a href = "javascript:void(0)" onclick = "document.getElementById('light').style.display='none';document.getElementById('fade').style.display='none'">Close</a></div>
		<div id="fade"></div>
	</body>
</html>

That you can find up and running in this page.

In this example everything is static and preloaded, but you can easily add some php/ajax code to make it more dynamic while keeping the effect 100% CSS based.

Hope you will find it useful, should you use it in one of your works send me a comment and I’ll feature your site as example.

source: emanueleferonato.com