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
    39 Shirts – Leaving Mozilla

    In 2001 I had just graduated from a small town high school and headed off to a small town college. I found myself in the quaint computer lab where the substandard computers featured two browsers: Internet Explorer and Mozilla. It was this lab where I fell...

  • 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
    CSS 3D Folding Animation

    Google Plus provides loads of inspiration for front-end developers, especially when it comes to the CSS and JavaScript wonders they create. Last year I duplicated their incredible PhotoStack effect with both MooTools and pure CSS; this time I'm going to duplicate...

  • By
    CSS Columns

    One major gripe that we've always had about CSS is that creating layouts seems to be more difficult than it should be. We have, of course, adapted and mastered the techniques for creating layouts, but there's no shaking the feeling that there should be a...

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!