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
    Regular Expressions for the Rest of Us

    Sooner or later you'll run across a regular expression. With their cryptic syntax, confusing documentation and massive learning curve, most developers settle for copying and pasting them from StackOverflow and hoping they work. But what if you could decode regular expressions and harness their power? In...

  • By
    5 HTML5 APIs You Didn’t Know Existed

    When you say or read "HTML5", you half expect exotic dancers and unicorns to walk into the room to the tune of "I'm Sexy and I Know It."  Can you blame us though?  We watched the fundamental APIs stagnate for so long that a basic feature...

Incredible Demos

  • By
    9 Mind-Blowing Canvas Demos

    The <canvas> element has been a revelation for the visual experts among our ranks.  Canvas provides the means for incredible and efficient animations with the added bonus of no Flash; these developers can flash their awesome JavaScript skills instead.  Here are nine unbelievable canvas demos that...

  • By
    HTML5&#8217;s window.postMessage API

    One of the little known HTML5 APIs is the window.postMessage API.  window.postMessage allows for sending data messages between two windows/frames across domains.  Essentially window.postMessage acts as cross-domain AJAX without the server shims. Let's take a look at how window.postMessage works and how you...

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!