Drag and Drop Z-Index Stacking

By  on  
MooTools Drag Opacity

In an example for a previous post, I showed you how to use opacity during a drag'n'drop transaction. One bit I didn't account for was element stacking and bringing the most recent element to the top of the stack. To do so, we'll need to use a variable that represents the highest zIndex, which we'll be incrementing.

The MooTools JavaScript

window.addEvent('domready',function() {
	var zIndex = 2;
	$$('.draggable').each(function(el) {
		var drag = new Drag.Move(el,{
			grid: false,
			preventDefault: true,
			onStart: function() {
				el.setStyle('z-index',zIndex++); //increment!
			}
		});
	});
});

As you probably expected, the process is as simple as it gets. Correct stacking order is incredibly important as you don't want items to be wrongly buried.

Recent Features

  • By
    5 More HTML5 APIs You Didn’t Know Existed

    The HTML5 revolution has provided us some awesome JavaScript and HTML APIs.  Some are APIs we knew we've needed for years, others are cutting edge mobile and desktop helpers.  Regardless of API strength or purpose, anything to help us better do our job is a...

  • By
    Page Visibility API

    One event that's always been lacking within the document is a signal for when the user is looking at a given tab, or another tab. When does the user switch off our site to look at something else? When do they come back?

Incredible Demos

  • By
    Create a Sheen Logo Effect with CSS

    I was inspired when I first saw Addy Osmani's original ShineTime blog post.  The hover sheen effect is simple but awesome.  When I started my blog redesign, I really wanted to use a sheen effect with my logo.  Using two HTML elements and...

  • By
    Web Notifications API

    Every UI framework has the same set of widgets which have become almost essential to modern sites: modals, tooltips, button varieties, and notifications.  One problem I find is each site having their own widget colors, styles, and more -- users don't get a consistent experience.  Apparently the...

Discussion

  1. I believe z++ should actually be zIndex++ … or you get fail ;)

  2. This Friday’s dumbass mistake brought to you by…lack of sleep.

  3. Nice idea, although it does not seem to work for me (tested in Chrome/Windows).

    Either way, I think you should do pre-increment instead of post-increment, to assign the incremented value to the element: el.setStyle('z-index', ++zIndex). That way you wont need to start the variable in 2 :)

  4. Is it just me or did your original referenced topic use z-index stacking as well?

  5. Have a look at the footer on my homepage. I have incorporated dragging functions with jquery for the 4 items. I had hover z-index replace at one point but removed it because it was not realistic with solid gears :) THX

  6. @Brian Klepper: I meant 6 items.. :0

  7. daniele

    hi dav, is it possible to write draggable events into a db?

Wrap your code in <pre class="{language}"></pre> tags, link to a GitHub gist, JSFiddle fiddle, or CodePen pen to embed!