ImageLoded JQuery Plugin

/*!
 * jQuery imagesLoaded plugin v2.1.1
 * http://github.com/desandro/imagesloaded
 *
 * MIT License. by Paul Irish et al.
 */

/*jshint curly: true, eqeqeq: true, noempty: true, strict: true, undef: true, browser: true */
/*global jQuery: false */

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

// blank image data-uri bypasses webkit log warning (thx doug jones)
var BLANK = 'data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///ywAAAAAAQABAAACAUwAOw==';

$.fn.imagesLoaded = function( callback ) {
    var $this = this,
        deferred = $.isFunction($.Deferred) ? $.Deferred() : 0,
        hasNotify = $.isFunction(deferred.notify),
        $images = $this.find('img').add( $this.filter('img') ),
        loaded = [],
        proper = [],
        broken = [];

    // Register deferred callbacks
    if ($.isPlainObject(callback)) {
        $.each(callback, function (key, value) {
            if (key === 'callback') {
                callback = value;
            } else if (deferred) {
                deferred[key](value);
            }
        });
    }

    function doneLoading() {
        var $proper = $(proper),
            $broken = $(broken);

        if ( deferred ) {
            if ( broken.length ) {
                deferred.reject( $images, $proper, $broken );
            } else {
                deferred.resolve( $images );
            }
        }

        if ( $.isFunction( callback ) ) {
            callback.call( $this, $images, $proper, $broken );
        }
    }

    function imgLoadedHandler( event ) {
        imgLoaded( event.target, event.type === 'error' );
    }

    function imgLoaded( img, isBroken ) {
        // don't proceed if BLANK image, or image is already loaded
        if ( img.src === BLANK || $.inArray( img, loaded ) !== -1 ) {
            return;
        }

        // store element in loaded images array
        loaded.push( img );

        // keep track of broken and properly loaded images
        if ( isBroken ) {
            broken.push( img );
        } else {
            proper.push( img );
        }

        // cache image and its state for future calls
        $.data( img, 'imagesLoaded', { isBroken: isBroken, src: img.src } );

        // trigger deferred progress method if present
        if ( hasNotify ) {
            deferred.notifyWith( $(img), [ isBroken, $images, $(proper), $(broken) ] );
        }

        // call doneLoading and clean listeners if all images are loaded
        if ( $images.length === loaded.length ) {
            setTimeout( doneLoading );
            $images.unbind( '.imagesLoaded', imgLoadedHandler );
        }
    }

    // if no images, trigger immediately
    if ( !$images.length ) {
        doneLoading();
    } else {
        $images.bind( 'load.imagesLoaded error.imagesLoaded', imgLoadedHandler )
        .each( function( i, el ) {
            var src = el.src;

            // find out if this image has been already checked for status
            // if it was, and src has not changed, call imgLoaded on it
            var cached = $.data( el, 'imagesLoaded' );
            if ( cached && cached.src === src ) {
                imgLoaded( el, cached.isBroken );
                return;
            }

            // if complete is true and browser supports natural sizes, try
            // to check for image status manually
            if ( el.complete && el.naturalWidth !== undefined ) {
                imgLoaded( el, el.naturalWidth === 0 || el.naturalHeight === 0 );
                return;
            }

            // cached images don't fire load sometimes, so we reset src, but only when
            // dealing with IE, or image is complete (loaded) and failed manual check
            // webkit hack from http://groups.google.com/group/jquery-dev/browse_thread/thread/eee6ab7b2da50e1f
            if ( el.readyState || el.complete ) {
                el.src = BLANK;
                el.src = src;
            }
        });
    }

    return deferred ? deferred.promise( $this ) : $this;
};

})(jQuery);