phaser/src/gameobjects/GameObject.js

/**
 * @author       Richard Davey <rich@photonstorm.com>
 * @copyright    2018 Photon Storm Ltd.
 * @license      {@link https://github.com/photonstorm/phaser/blob/master/license.txt|MIT License}
 */

var Class = require('../utils/Class');
var Components = require('./components');
var DataManager = require('../data/DataManager');
var EventEmitter = require('eventemitter3');

/**
 * @classdesc
 * The base class that all Game Objects extend.
 * You don't create GameObjects directly and they cannot be added to the display list.
 * Instead, use them as the base for your own custom classes.
 *
 * @class GameObject
 * @memberOf Phaser.GameObjects
 * @extends EventEmitter
 * @constructor
 * @since 3.0.0
 *
 * @param {Phaser.Scene} scene - The Scene to which this Game Object belongs.
 * @param {string} type - A textual representation of the type of Game Object, i.e. `sprite`.
 */
var GameObject = new Class({

    Extends: EventEmitter,

    initialize:

    function GameObject (scene, type)
    {
        EventEmitter.call(this);

        /**
         * The Scene to which this Game Object belongs.
         * Game Objects can only belong to one Scene.
         *
         * @name Phaser.GameObjects.GameObject#scene
         * @type {Phaser.Scene}
         * @protected
         * @since 3.0.0
         */
        this.scene = scene;

        /**
         * A textual representation of this Game Object, i.e. `sprite`.
         * Used internally by Phaser but is available for your own custom classes to populate.
         *
         * @name Phaser.GameObjects.GameObject#type
         * @type {string}
         * @since 3.0.0
         */
        this.type = type;

        /**
         * The name of this Game Object.
         * Empty by default and never populated by Phaser, this is left for developers to use.
         *
         * @name Phaser.GameObjects.GameObject#name
         * @type {string}
         * @default ''
         * @since 3.0.0
         */
        this.name = '';

        /**
         * The active state of this Game Object.
         * A Game Object with an active state of `true` is processed by the Scenes UpdateList, if added to it.
         * An active object is one which is having its logic and internal systems updated.
         *
         * @name Phaser.GameObjects.GameObject#active
         * @type {boolean}
         * @default true
         * @since 3.0.0
         */
        this.active = true;

        /**
         * The Tab Index of the Game Object.
         * Reserved for future use by plugins and the Input Manager.
         *
         * @name Phaser.GameObjects.GameObject#tabIndex
         * @type {integer}
         * @default -1
         * @since 3.0.0
         */
        this.tabIndex = -1;

        /**
         * A Data Manager.
         * It allows you to store, query and get key/value paired information specific to this Game Object.
         * `null` by default. Automatically created if you use `getData` or `setData` or `setDataEnabled`.
         *
         * @name Phaser.GameObjects.GameObject#data
         * @type {Phaser.Data.DataManager}
         * @default null
         * @since 3.0.0
         */
        this.data = null;

        /**
         * The flags that are compared against `RENDER_MASK` to determine if this Game Object will render or not.
         * The bits are 0001 | 0010 | 0100 | 1000 set by the components Visible, Alpha, Transform and Texture respectively.
         * If those components are not used by your custom class then you can use this bitmask as you wish.
         *
         * @name Phaser.GameObjects.GameObject#renderFlags
         * @type {integer}
         * @default 15
         * @since 3.0.0
         */
        this.renderFlags = 15;

        /**
         * A bitmask that controls if this Game Object is drawn by a Camera or not.
         * Not usually set directly. Instead call `Camera.ignore`.
         *
         * @name Phaser.GameObjects.GameObject#cameraFilter
         * @type {number}
         * @default 0
         * @since 3.0.0
         */
        this.cameraFilter = 0;

        /**
         * If this Game Object is enabled for input then this property will contain an InteractiveObject instance.
         * Not usually set directly. Instead call `GameObject.setInteractive()`.
         *
         * @name Phaser.GameObjects.GameObject#input
         * @type {?Phaser.Input.InteractiveObject}
         * @default null
         * @since 3.0.0
         */
        this.input = null;

        /**
         * If this Game Object is enabled for physics then this property will contain a reference to a Physics Body.
         *
         * @name Phaser.GameObjects.GameObject#body
         * @type {?Phaser.Physics.Body}
         * @default null
         * @since 3.0.0
         */
        this.body = null;

        //  Tell the Scene to re-sort the children
        this.scene.sys.queueDepthSort();
    },

    /**
     * Sets the `active` property of this Game Object and returns this Game Object for further chaining.
     * A Game Object with its `active` property set to `true` will be updated by the Scenes UpdateList.
     *
     * @method Phaser.GameObjects.GameObject#setActive
     * @since 3.0.0
     *
     * @param {boolean} value - True if this Game Object should be set as active, false if not.
     * 
     * @return {Phaser.GameObjects.GameObject} This GameObject.
     */
    setActive: function (value)
    {
        this.active = value;

        return this;
    },

    /**
     * Sets the `name` property of this Game Object and returns this Game Object for further chaining.
     * The `name` property is not populated by Phaser and is presented for your own use.
     *
     * @method Phaser.GameObjects.GameObject#setName
     * @since 3.0.0
     *
     * @param {string} value - The name to be given to this Game Object.
     * 
     * @return {Phaser.GameObjects.GameObject} This GameObject.
     */
    setName: function (value)
    {
        this.name = value;

        return this;
    },

    /**
     * [description]
     *
     * @method Phaser.GameObjects.GameObject#setDataEnabled
     * @since 3.0.0
     *
     * @return {Phaser.GameObjects.GameObject} This GameObject.
     */
    setDataEnabled: function ()
    {
        if (!this.data)
        {
            this.data = new DataManager(this);
        }

        return this;
    },

    /**
     * This is a quick chainable alias to the `DataProxy.set` method.
     * It allows you to set a key and value in this Game Objects data store.
     *
     * @method Phaser.GameObjects.GameObject#setData
     * @since 3.0.0
     *
     * @param {string} key - The key of the property to be stored.
     * @param {any} value - The value to store with the key. Can be a string, number, array or object.
     * 
     * @return {Phaser.GameObjects.GameObject} This GameObject.
     */
    setData: function (key, value)
    {
        if (!this.data)
        {
            this.data = new DataManager(this);
        }

        this.data.set(key, value);

        return this;
    },

    /**
     * This is a quick alias to the `DataProxy.get` method to remain consistent with `setData`.
     *
     * @method Phaser.GameObjects.GameObject#getData
     * @since 3.0.0
     *
     * @param {string} key - The key of the property to be retrieved.
     * 
     * @return {any} The data, if present in the Data Store.
     */
    getData: function (key)
    {
        if (!this.data)
        {
            this.data = new DataManager(this);
        }

        return this.data.get(key);
    },

    /**
     * Pass this Game Object to the Input Manager to enable it for Input.
     *
     * @method Phaser.GameObjects.GameObject#setInteractive
     * @since 3.0.0
     *
     * @param {any} [shape] - A geometric shape that defines the hit area for the Game Object. If not specified a Rectangle will be used.
     * @param {function} [callback] - A callback to be invoked when the Game Object is interacted with.
     * @param {boolean} [dropZone=false] - Should this Game Object be treated as a drop zone target?
     * 
     * @return {Phaser.GameObjects.GameObject} This GameObject.
     */
    setInteractive: function (shape, callback, dropZone)
    {
        this.scene.sys.input.enable(this, shape, callback, dropZone);

        return this;
    },

    /**
     * To be overridden by custom GameObjects. Allows base objects to be used in a Pool.
     *
     * @method Phaser.GameObjects.GameObject#update
     * @since 3.0.0
     */
    update: function ()
    {
    },

    /**
     * Returns a JSON representation of the Game Object.
     *
     * @method Phaser.GameObjects.GameObject#toJSON
     * @since 3.0.0
     *
     * @return {object} A JSON representation of the Game Object.
     */
    toJSON: function ()
    {
        return Components.ToJSON(this);
    },

    /**
     * Compares the renderMask with the renderFlags to see if this Game Object will render or not.
     *
     * @method Phaser.GameObjects.GameObject#willRender
     * @since 3.0.0
     *
     * @return {boolean} True if the Game Object should be rendered, otherwise false.
     */
    willRender: function ()
    {
        return (GameObject.RENDER_MASK === this.renderFlags);
    },

    /**
     * Destroys this Game Object removing it from the Display List and Update List and
     * severing all ties to parent resources.
     * 
     * Also removes itself from the Input Manager and Physics Manager if previously enabled.
     * 
     * Use this to remove a Game Object from your game if you don't ever plan to use it again.
     * As long as no reference to it exists within your own code it should become free for
     * garbage collection by the browser.
     * 
     * If you just want to temporarily disable an object then look at using the
     * Game Object Pool instead of destroying it, as destroyed objects cannot be resurrected.
     *
     * @method Phaser.GameObjects.GameObject#destroy
     * @since 3.0.0
     */
    destroy: function ()
    {
        // this gameobject had been destroyed
        if (this.scene === undefined)
        {        
            return;
        }

        if (this.preDestroy)
        {
            this.preDestroy.call(this);
        }

        var sys = this.scene.sys;

        sys.displayList.remove(this);
        sys.updateList.remove(this);

        if (this.input)
        {
            sys.input.clear(this);
            this.input = undefined;
        }

        if (this.data)
        {
            this.data.destroy();

            this.data = undefined;
        }

        if (this.body)
        {
            this.body.destroy();
            this.body = undefined;
        }

        //  Tell the Scene to re-sort the children
        sys.queueDepthSort();

        this.active = false;
        this.visible = false;

        this.scene = undefined;

        this.emit('destroy');
                
        this.removeAllListeners();
    }

});

/**
 * The bitmask that `GameObject.renderFlags` is compared against to determine if the Game Object will render or not.
 *
 * @constant {integer} RENDER_MASK
 * @memberOf Phaser.GameObjects.GameObject
 * @default
 */
GameObject.RENDER_MASK = 15;

module.exports = GameObject;