Backstretch

Backstretch is a simple jQuery plugin that allows you to add a dynamically-resized, slideshow-capable background image to any page or element. The image will stretch to fit the page/element, and will automatically resize as the window/element size changes.

Demo

There are a couple of examples included with this package, or feel free to check it out live on the project page itself.

Setup

Include the jQuery library (version 1.7 or newer) and Backstretch plugin files in your webpage (preferably at the bottom of the page, before the closing BODY tag):

<script src="//ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
<script src="jquery.backstretch.min.js"></script>
<script>
  // To attach Backstrech as the body's background
  $.backstretch("path/to/image.jpg");

  // You may also attach Backstretch to a block-level element
  $(".foo").backstretch("path/to/image.jpg");

  // Or, to start a slideshow, just pass in an array of images
  $(".foo").backstretch([
    "path/to/image.jpg",
    "path/to/image2.jpg",
    "path/to/image3.jpg"    
  ], {duration: 4000});
</script>

Options

Slideshow API

Once you’ve instantiated a Backstretch slideshow, there are many actions that you can perform it:

// Start a slideshow
$('.foo').backstretch([
  'path/to/image.jpg',
  'path/to/image2.jpg',
  'path/to/image3.jpg'
]);

// Pause the slideshow
$('.foo').backstretch("pause");

// Advance to the next slide
$('.foo').backstretch("next");

Public Variables

Sometimes, you’ll want to access Backstretch’s images after you’ve instantiated the plugin. For example, perhaps you’d like to be able add more images to a slideshow. Doing so is easy. You can access the images array as follows:

$('.foo').backstretch([
  'path/to/image.jpg',
  'path/to/image2.jpg',
  'path/to/image3.jpg'
]);

// Access the instance
var instance = $('.foo').data('backstretch');

// Then, you can manipulate the images array directly
instance.images.push('path/to/image4.jpg')

Additionally, the current index of a slideshow is available through the instance as well:

$("body").data("backstretch").index;

Events

backstretch.before

Backstretch will fire a “backstretch.before” event before a new image loads, triggering a function that is passed the event, Backstretch instance, and index of the image that will be displayed. If you listen for that event, you can, for example, coordinate other changes to coincide with your slideshow.

$(window).on("backstretch.before", function (e, instance, index) {
  // If we wanted to stop the slideshow after it reached the end
  if (index === instance.images.length - 1) {
    instance.pause();
  };
});

backstretch.after

Backstretch will also fire a “backstretch.after” event after the new images has completed loading.

$(window).on("backstretch.after", function (e, instance, index) {
  // Do something
});