if(typeof Widget == "undefined") Widget = {};

Widget.Fader = Class.create();

Widget.Fader.prototype = {

	/**

	 * The Widget.Fader class constructor. <br />

	 * @constructor Widget.Fader

	 * @param {string|img element} img The id of or actual image element to be faded

	 * @param {array(string)} list  An array of paths (relative or absolute) of the images

	 * @param {object} [options] An object of options.

	 */

	initialize: function(img, list, options) {

		this.img = $(img);

		this.list = list;



		/**

		 * The default options object.

		 * @class

		 * @param {string} [id] The id used as queue scope. (default: img.id)

		 * @param {float} [fadeInDuration] The time in seconds of the fade in. (default: 2.5)

		 * @param {float} [fadeOutDuration] The time in seconds of the fade out. (default: 1.5)

		 * @param {float} [displayDuration] The time in seconds that the image is not faded out after being faded in. (default: 2.5)

		 * @param {bool} [autoSize] Set true if the image should be sized to it's container. Maintains aspect ratio. (default: false)

		 * @param {bool} [autoStart] If false the Blender will not start until Blender#start is called. (default: true)

		 * @param {object} [attributes] An associative array of attributes given to the image. (default: {})

		 * @param {string} [dir] The directory that all images reside in. Used as a prefix for the image src. (default: null)

		 * @param {function} [beforeFade] A function that is called before the image is faded. 2 parameters are passed: 1. the image; 2. a boolean indicating if the image is being faded in (true) or out (false) (default: null)

		 * @param {int} [startIndex] The index of the first new image to be shown. (default: 0)

		 */

		this.options = Object.extend({

			id: this.img.id,

			fadeInDuration: 1.0,

			fadeOutDuration: -10.0,

			displayDuration: 10.0,

			autoSize: false,

			autoStart: true,

			attributes: {},

			dir: "",

			beforeFade: null,

			startIndex: 0

		}, options || {});

		this.options.attributes["id"] = this.options.id;



		this.index = this.options.startIndex;

		this.container = $(this.img.parentNode);

		this.loadedObserver = this.loaded.bind(this);

		this.fadeInObserver = this.fadeIn.bind(this);

		this.nextObserver = this.next.bind(this);



		if(this.options.autoStart) {

			setTimeout(this.start.bind(this), this.options.displayDuration * 1000);

		}

	},

	/**

	 * Starts the fading if the autoStart option was set to false or after a call to stop.

	 */

	start: function() {

		this.stopped = false;

		this.next();

	},

	/**

	 * Stops the fading and sets the opacity of the current image to 100%.

	 */

	stop: function() {

		this.stopped = true;

		try { clearTimeout(this.timeout); } catch(ex) { }

		try { Effect.Queues.get(this.options.id).each(function(effect) { effect.cancel() }) } catch(ex) { }

		if(this.oldImg) {

			this.img = this.oldImg;

			--this.index;

		}

		Element.setOpacity(this.img, 1);

	},



	next: function() {

		this.oldImg = this.img;

		if(this.stopped || this.list.length == 0) {

			return;

		}

		++this.index;

		if(this.index >= this.list.length) {

			this.index = 0;

		}

		this.img = new Element("img", this.options.attributes);

		Event.observe(this.img, "load", this.loadedObserver);

		this.img.src = this.options.dir + this.list[this.index];

	},

	/**

	 * Event listener for image loaded

	 * @private

	 */

	loaded: function() {

		Event.stopObserving(this.img, "load", this.loadedObserver);

		if(typeof this.options.beforeFade == "function") {

			this.options.beforeFade(this.oldImg, false);

		}

		new Effect.Opacity(this.oldImg, { duration: this.options.fadeOutDuration, from: 1.0, to: 0.0, queue: { scope: this.options.id } });

		this.timeout = setTimeout(this.fadeInObserver, this.options.fadeOutDuration * 1000);

	},

	/**

	 * Event listener for fadeIn

	 * @private

	 */

	fadeIn: function() {

		if(typeof this.options.beforeFade == "function") {

			this.options.beforeFade(this.img, true);

		}

		this.img.id = this.id;

		Element.setOpacity(this.img, 0);

		if(this.options.autoSize) {

			this.resize(this.img);

		}

		this.container.replaceChild(this.img, this.oldImg);

		this.oldImg = null;

		new Effect.Opacity(this.img, { duration: this.options.fadeInDuration, from: 0.0, to: 1.0, queue: { scope: this.options.id } });

		this.timeout = setTimeout(this.nextObserver, (this.options.fadeInDuration + this.options.displayDuration) * 1000);

	},

	/**

	 * Resize the image to the container while maintaining aspect ratio

	 * @private

	 */

	resize: function(img) {

		var dim = this.container.getDimensions();

		dim.width -= parseInt(this.container.getStyle("padding-left")) +

			parseInt(this.container.getStyle("padding-right")) +

			parseInt(this.container.getStyle("border-left-width")) +

			parseInt(this.container.getStyle("border-right-width"));

		dim.height -= parseInt(this.container.getStyle("padding-top")) +

			parseInt(this.container.getStyle("padding-bottom")) +

			parseInt(this.container.getStyle("border-top-width")) +

			parseInt(this.container.getStyle("border-bottom-width"));



		var dw = dim.width / img.width;

		var dh = dim.height / img.height;

		var w1 = img.width * dh;

		var h1 = img.height * dw;



		if(dw > dh) {

			img.width = w1;

			img.height = dim.height;

		} else {

			img.width = dim.width;

			img.height = h1;

		}

	}

};

/**

 * @deprecated

 **/

var Fader = Widget.Fader;