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 Awesome New Mozilla Technologies You’ve Never Heard Of

    My trip to Mozilla Summit 2013 was incredible.  I've spent so much time focusing on my project that I had lost sight of all of the great work Mozillians were putting out.  MozSummit provided the perfect reminder of how brilliant my colleagues are and how much...

  • By
    Being a Dev Dad

    I get asked loads of questions every day but I'm always surprised that they're rarely questions about code or even tech -- many of the questions I get are more about non-dev stuff like what my office is like, what software I use, and oftentimes...

Incredible Demos

  • By
    Geolocation API

    One interesting aspect of web development is geolocation; where is your user viewing your website from? You can base your language locale on that data or show certain products in your store based on the user's location. Let's examine how you can...

  • By
    Create a CSS Cube

    CSS cubes really showcase what CSS has become over the years, evolving from simple color and dimension directives to a language capable of creating deep, creative visuals.  Add animation and you've got something really neat.  Unfortunately each CSS cube tutorial I've read is a bit...

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!