gistfile1.js

/**
 * @class IndexController
 * @abstract
 * Used primarily for index tracking on slideshows and slideshow-like components
 */
NS('GT.src').IndexController = Class.extend(function () {
    'use strict';
	return {
		/**
		 * @constructor
		 */
		init: function () {
			// default is on 0
			this.index = 0;
			this.lastIndex = 0;
			this.maxIndex = 0;
			this.isInfinite = false;
		},
		/**
		 * Proceeds to next index value going forward, invokes `setIndex`
		 * Does nothing if conditions aren't met
		 * @return {undefined}
		 */
		next: function () {
			if (this.index < this.maxIndex) {
				this.setIndex(this.index + 1);
			} else if (this.isInfinite === true) {
				this.setIndex(0);
			}
		},
		/**
		 * Proceeds to next index value going backwards, invokes `setIndex`
		 * Does nothing if conditions aren't met
		 * @return {undefined}
		 */
		back: function () {
			if (this.index > 0) {
				this.setIndex(this.index - 1);
			} else if (this.isInfinite === true) {
				this.setIndex(this.maxIndex);
			}
		},
		/**
		 * Sets index, defines previous index, invokes `action`
		 */
		setIndex: function (index) {
			// set a last index for point of references in `action`
			this.lastIndex = this.index;
			// defined new index
			this.index = index;
			// invoke action which may have animation
			this.action();
		},
		/**
		 * Return current index
		 * @return {number}
		 */
		getIndex: function () {
			return this.index;
		},
		/**
		 * Stub method, overridable method
		 */
		action: function () {},
		/**
		 * Set max index
		 * @param {number} number
		 * @return {undefined}
		 */
		setMaxIndex: function (number) {
			this.maxIndex = number;
		},
		/**
		 * Set max index
		 * @param {number} number
		 * @return {undefined}
		 */
		getMaxIndex: function (number) {
			return this.maxIndex;
		},
		/**
		 * Enables/Disables infinite next/back methods
		 * @param {boolean} isInfinite
		 * @return {undefined}
		 */
		setInfinity: function (isInfinite) {
			this.isInfinite = isInfinite;
		}
	};
}());