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
    JavaScript Promise API

    While synchronous code is easier to follow and debug, async is generally better for performance and flexibility. Why "hold up the show" when you can trigger numerous requests at once and then handle them when each is ready?  Promises are becoming a big part of the JavaScript world...

  • By
    Responsive Images: The Ultimate Guide

    Chances are that any Web designers using our Ghostlab browser testing app, which allows seamless testing across all devices simultaneously, will have worked with responsive design in some shape or form. And as today's websites and devices become ever more varied, a plethora of responsive images...

Incredible Demos

  • By
    Chris Coyier’s Favorite CodePen Demos

    David asked me if I'd be up for a guest post picking out some of my favorite Pens from CodePen. A daunting task! There are so many! I managed to pick a few though that have blown me away over the past few months. If you...

  • By
    Introducing MooTools ScrollSpy

    I've been excited to release this plugin for a long time. MooTools ScrollSpy is a unique but simple MooTools plugin that listens to page scrolling and fires events based on where the user has scrolled to in the page. Now you can fire specific...

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!