bugcore/lib/event/EventListener.js

bugcore is a JavaScript library that provides a foundational architecture for object oriented JS

/*
 * Copyright (c) 2016 airbug Inc. http://airbug.com
 *
 * bugcore may be freely distributed under the MIT license.
 */


//-------------------------------------------------------------------------------
// Annotations
//-------------------------------------------------------------------------------

//@Export('EventListener')

//@Require('Class')
//@Require('Obj')


//-------------------------------------------------------------------------------
// Context
//-------------------------------------------------------------------------------

require('bugpack').context("*", function(bugpack) {

    //-------------------------------------------------------------------------------
    // BugPack
    //-------------------------------------------------------------------------------

    var Class   = bugpack.require('Class');
    var Obj     = bugpack.require('Obj');


    //-------------------------------------------------------------------------------
    // Declare Class
    //-------------------------------------------------------------------------------

    /**
     * @class
     * @extends {Obj}
     */
    var EventListener = Class.extend(Obj, {

        _name: "EventListener",


        //-------------------------------------------------------------------------------
        // Constructor
        //-------------------------------------------------------------------------------

        /**
         * @constructs
         * @param {function(Event)} listenerFunction
         * @param {Object=} listenerContext
         * @param {boolean=} once
         */
        _constructor: function(listenerFunction, listenerContext, once) {

            this._super();


            //-------------------------------------------------------------------------------
            // Private Properties
            //-------------------------------------------------------------------------------

            /**
             * @private
             * @type {function(Event)}
             */
            this.listenerFunction   = listenerFunction;

            /**
             * @private
             * @type {Object}
             */
            this.listenerContext    = listenerContext;

            /**
             * @private
             * @type {boolean}
             */
            this.once               = once;
        },


        //-------------------------------------------------------------------------------
        // Getters and Setters
        //-------------------------------------------------------------------------------

        /**
         * @return {Object}
         */
        getListenerContext: function() {
            return this.listenerContext;
        },

        /**
         * @return {function(Event)}
         */
        getListenerFunction: function() {
            return this.listenerFunction;
        },

        /**
         * @return {boolean}
         */
        getOnce: function() {
            return this.once;
        },


        //-------------------------------------------------------------------------------
        // Convenience Methods
        //-------------------------------------------------------------------------------

        /**
         * @return {boolean}
         */
        isOnce: function(){
            return this.getOnce();
        },


        //-------------------------------------------------------------------------------
        // Obj Methods
        //-------------------------------------------------------------------------------

        /**
         * @override
         * @param {*} value
         * @return {boolean}
         */
        equals: function(value) {
            if (Class.doesExtend(value, EventListener)) {
                return (Obj.equals(value.getListenerFunction(), this.listenerFunction) && Obj.equals(value.getListenerContext(), this.listenerContext));
            }
            return false;
        },

        /**
         * @override
         * @return {number}
         */
        hashCode: function() {
            if (!this._hashCode) {
                this._hashCode = Obj.hashCode("[EventListener]" +
                    Obj.hashCode(this.listenerFunction) + "_" +
                    Obj.hashCode(this.listenerContext));
            }
            return this._hashCode;
        },


        //-------------------------------------------------------------------------------
        // Public Methods
        //-------------------------------------------------------------------------------

        /**
         * @param {Event} event
         */
        hearEvent: function(event) {
            this.listenerFunction.call(this.listenerContext, event);
        }
    });


    //-------------------------------------------------------------------------------
    // Exports
    //-------------------------------------------------------------------------------

    bugpack.export('EventListener', EventListener);
});