JQUERY BACKGROUND FULL PAGE SLIDESHOW jQuery.js

/*! Backstretch - v2.0.3 - 2012-11-30
* http://srobbin.com/jquery-plugins/backstretch/
* Copyright (c) 2012 Scott Robbin; Licensed MIT */

;(function ($, window, undefined) {
'use strict';

/* PLUGIN DEFINITION
* ========================= */

$.fn.backstretch = function (images, options) {
// We need at least one image
if (images === undefined || images.length === 0) {
$.error("No images were supplied for Backstretch");
}

/*
* Scroll the page one pixel to get the right window height on iOS
* Pretty harmless for everyone else
*/
if ($(window).scrollTop() === 0 ) {
window.scrollTo(0, 0);
}

return this.each(function () {
var $this = $(this)
, obj = $this.data('backstretch');

// If we've already attached Backstretch to this element, remove the old instance.
if (obj) {
// Merge the old options with the new
options = $.extend(obj.options, options);

// Remove the old instance
obj.destroy(true);
}

obj = new Backstretch(this, images, options);
$this.data('backstretch', obj);
});
};

// If no element is supplied, we'll attach to body
$.backstretch = function (images, options) {
// Return the instance
return $('body')
.backstretch(images, options)
.data('backstretch');
};

// Custom selector
$.expr[':'].backstretch = function(elem) {
return $(elem).data('backstretch') !== undefined;
};

/* DEFAULTS
* ========================= */

$.fn.backstretch.defaults = {
centeredX: true // Should we center the image on the X axis?
, centeredY: true // Should we center the image on the Y axis?
, duration: 5000 // Amount of time in between slides (if slideshow)
, fade: 0 // Speed of fade transition between slides
};

/* STYLES
*
* Baked-in styles that we'll apply to our elements.
* In an effort to keep the plugin simple, these are not exposed as options.
* That said, anyone can override these in their own stylesheet.
* ========================= */
var styles = {
wrap: {
left: 0
, top: 0
, overflow: 'hidden'
, margin: 0
, padding: 0
, height: '100%'
, width: '100%'
, zIndex: -999999
}
, img: {
position: 'absolute'
, display: 'none'
, margin: 0
, padding: 0
, border: 'none'
, width: 'auto'
, height: 'auto'
, maxWidth: 'none'
, zIndex: -999999
}
};

/* CLASS DEFINITION
* ========================= */
var Backstretch = function (container, images, options) {
this.options = $.extend({}, $.fn.backstretch.defaults, options || {});

/* In its simplest form, we allow Backstretch to be called on an image path.
* e.g. $.backstretch('/path/to/image.jpg')
* So, we need to turn this back into an array.
*/
this.images = $.isArray(images) ? images : [images];

// Preload images
$.each(this.images, function () {
$('')[0].src = this;
});

// Convenience reference to know if the container is body.
this.isBody = container === document.body;

/* We're keeping track of a few different elements
*
* Container: the element that Backstretch was called on.
* Wrap: a DIV that we place the image into, so we can hide the overflow.
* Root: Convenience reference to help calculate the correct height.
*/
this.$container = $(container);
this.$wrap = $('

').css(styles.wrap).appendTo(this.$container);
this.$root = this.isBody ? supportsFixedPosition ? $(window) : $(document) : this.$container;

// Non-body elements need some style adjustments
if (!this.isBody) {
// If the container is statically positioned, we need to make it relative,
// and if no zIndex is defined, we should set it to zero.
var position = this.$container.css('position')
, zIndex = this.$container.css('zIndex');

this.$container.css({
position: position === 'static' ? 'relative' : position
, zIndex: zIndex === 'auto' ? 0 : zIndex
, background: 'none'
});

// Needs a higher z-index
this.$wrap.css({zIndex: -999998});
}

// Fixed or absolute positioning?
this.$wrap.css({
position: this.isBody && supportsFixedPosition ? 'fixed' : 'absolute'
});

// Set the first image
this.index = 0;
this.show(this.index);

// Listen for resize
$(window).on('resize.backstretch', $.proxy(this.resize, this))
.on('orientationchange.backstretch', $.proxy(function () {
// Need to do this in order to get the right window height
if (this.isBody && window.pageYOffset === 0) {
window.scrollTo(0, 1);
this.resize();
}
}, this));
};

/* PUBLIC METHODS
* ========================= */
Backstretch.prototype = {
resize: function () {
try {
var bgCSS = {left: 0, top: 0}
, rootWidth = this.isBody ? this.$root.width() : this.$root.innerWidth()
, bgWidth = rootWidth
, rootHeight = this.isBody ? ( window.innerHeight ? window.innerHeight : this.$root.height() ) : this.$root.innerHeight()
, bgHeight = bgWidth / this.$img.data('ratio')
, bgOffset;

// Make adjustments based on image ratio
if (bgHeight >= rootHeight) {
bgOffset = (bgHeight - rootHeight) / 2;
if(this.options.centeredY) {
bgCSS.top = '-' + bgOffset + 'px';
}
} else {
bgHeight = rootHeight;
bgWidth = bgHeight * this.$img.data('ratio');
bgOffset = (bgWidth - rootWidth) / 2;
if(this.options.centeredX) {
bgCSS.left = '-' + bgOffset + 'px';
}
}

this.$wrap.css({width: rootWidth, height: rootHeight})
.find('img:not(.deleteable)').css({width: bgWidth, height: bgHeight}).css(bgCSS);
} catch(err) {
// IE7 seems to trigger resize before the image is loaded.
// This try/catch block is a hack to let it fail gracefully.
}

return this;
}

// Show the slide at a certain position
, show: function (index) {
// Validate index
if (Math.abs(index) > this.images.length - 1) {
return;
} else {
this.index = index;
}

// Vars
var self = this
, oldImage = self.$wrap.find('img').addClass('deleteable')
, evt = $.Event('backstretch.show', {
relatedTarget: self.$container[0]
});

// Pause the slideshow
clearInterval(self.interval);

// New image
self.$img = $('')
.css(styles.img)
.bind('load', function (e) {
var imgWidth = this.width || $(e.target).width()
, imgHeight = this.height || $(e.target).height();

// Save the ratio
$(this).data('ratio', imgWidth / imgHeight);

// Show the image, then delete the old one
// "speed" option has been deprecated, but we want backwards compatibilty
$(this).fadeIn(self.options.speed || self.options.fade, function () {
oldImage.remove();

// Resume the slideshow
if (!self.paused) {
self.cycle();
}

// Trigger the event
self.$container.trigger(evt, self);
});

// Resize
self.resize();
})
.appendTo(self.$wrap);

// Hack for IE img onload event
self.$img.attr('src', self.images[index]);
return self;
}

, next: function () {
// Next slide
return this.show(this.index < this.images.length - 1 ? this.index + 1 : 0); } , prev: function () { // Previous slide return this.show(this.index === 0 ? this.images.length - 1 : this.index - 1); } , pause: function () { // Pause the slideshow this.paused = true; return this; } , resume: function () { // Resume the slideshow this.paused = false; this.next(); return this; } , cycle: function () { // Start/resume the slideshow if(this.images.length > 1) {
// Clear the interval, just in case
clearInterval(this.interval);

this.interval = setInterval($.proxy(function () {
// Check for paused slideshow
if (!this.paused) {
this.next();
}
}, this), this.options.duration);
}
return this;
}

, destroy: function (preserveBackground) {
// Stop the resize events
$(window).off('resize.backstretch orientationchange.backstretch');

// Clear the interval
clearInterval(this.interval);

// Remove Backstretch
if(!preserveBackground) {
this.$wrap.remove();
}
this.$container.removeData('backstretch');
}
};

/* SUPPORTS FIXED POSITION?
*
* Based on code from jQuery Mobile 1.1.0
* http://jquerymobile.com/
*
* In a nutshell, we need to figure out if fixed positioning is supported.
* Unfortunately, this is very difficult to do on iOS, and usually involves
* injecting content, scrolling the page, etc.. It's ugly.
* jQuery Mobile uses this workaround. It's not ideal, but works.
*
* Modified to detect IE6
* ========================= */

var supportsFixedPosition = (function () {
var ua = navigator.userAgent
, platform = navigator.platform
// Rendering engine is Webkit, and capture major version
, wkmatch = ua.match( /AppleWebKit\/([0-9]+)/ )
, wkversion = !!wkmatch && wkmatch[ 1 ]
, ffmatch = ua.match( /Fennec\/([0-9]+)/ )
, ffversion = !!ffmatch && ffmatch[ 1 ]
, operammobilematch = ua.match( /Opera Mobi\/([0-9]+)/ )
, omversion = !!operammobilematch && operammobilematch[ 1 ]
, iematch = ua.match( /MSIE ([0-9]+)/ )
, ieversion = !!iematch && iematch[ 1 ];

return !(
// iOS 4.3 and older : Platform is iPhone/Pad/Touch and Webkit version is less than 534 (ios5)
((platform.indexOf( "iPhone" ) > -1 || platform.indexOf( "iPad" ) > -1 || platform.indexOf( "iPod" ) > -1 ) && wkversion && wkversion < 534) || // Opera Mini (window.operamini && ({}).toString.call( window.operamini ) === "[object OperaMini]") || (operammobilematch && omversion < 7458) || //Android lte 2.1: Platform is Android and Webkit version is less than 533 (Android 2.2) (ua.indexOf( "Android" ) > -1 && wkversion && wkversion < 533) || // Firefox Mobile before 6.0 - (ffversion && ffversion < 6) || // WebOS less than 3 ("palmGetResource" in window && wkversion && wkversion < 534) || // MeeGo (ua.indexOf( "MeeGo" ) > -1 && ua.indexOf( "NokiaBrowser/8.5.0" ) > -1) ||

// IE6
(ieversion && ieversion <= 6) ); }()); }(jQuery, window));