server/ServerItemGroup.js

  1. 'use strict';
  3. const { EventEmitter } = require('node:events');
  4. const { Message, Item } = require('../shared.js');
  5. const { Hittable, Identifiable } = require('../mixins.js');
  7. /**
  8.  * HACK to get around jsdoc bug that causes mixed methods and properties to be
  9.  * duplicated.
  10.  *
  11.  * @class __ServerItemGroup
  12.  * @private
  13.  * @mixes module:mixins.Hittable
  14.  * @mixes module:mixins.Identifiable
  15.  */
  17. /**
  18.  * The ServerItemGroup provides operations for the server to locate and move
  19.  * several different elements around.
  20.  *
  21.  * @memberof module:server
  22.  * @extends module:shared.WamsElement
  23.  * @extends __ServerItemGroup
  24.  *
  25.  * @param {Namespace} namespace - Socket.io namespace for publishing changes.
  26.  * @param {Object} values - User-supplied data detailing the elements.
  27.  * Properties on this object that line up with {@link module:shared.Element}
  28.  * members will be stored. Any other properties will be ignored.
  29.  */
  30. class ServerItemGroup extends Identifiable(Hittable(Item)) {
  31.   constructor(namespace, values = {}) {
  32.     super(values);
  34.     /**
  35.      * Socket.io namespace for publishing updates.
  36.      *
  37.      * @type {Namespace}
  38.      */
  39.     this.namespace = namespace;
  41.     // Notify subscribers immediately.
  42.     if (!this.items) throw Error('Items must be passed to ServerItemGroup.');
  44.     // calculate based on elements positions;
  45.     this.setMeasures();
  47.     this.setParentForItems();
  48.   }
  50.   on(eventName, listener) {
  51.     this.items.forEach((item) => {
  52.       item.on(eventName, (event) => {
  53.         event.target = this;
  54.         return listener(event);
  55.       });
  56.     });
  57.   }
  59.   /*
  60.    * Publish a general notification about the status of the group.
  61.    */
  62.   _emitPublication() {
  63.     this.namespace.emit(Message.UD_ITEM, this);
  64.   }
  66.   moveTo(x, y) {
  67.     const offsetX = x - this.x;
  68.     const offsetY = y - this.y;
  69.     this.x = x;
  70.     this.y = y;
  71.     this.items.forEach((item) => item.moveBy(offsetX, offsetY));
  72.   }
  74.   moveBy(dx, dy) {
  75.     this.x = this.x + dx;
  76.     this.y = this.y + dy;
  77.     this.items.forEach((item) => item.moveBy(dx, dy));
  78.   }
  80.   /**
  81.    * Update children items to have parent property.
  82.    *
  83.    */
  84.   setParentForItems() {
  85.     this.items.forEach((item) => {
  86.       item.parent = this;
  87.       this.namespace.emit(Message.SET_PARENT, { id: item.id, parent: this.id });
  88.     });
  89.   }
  91.   setMeasures() {
  92.     // calculate x, y, width and height
  93.     // of the group
  94.     let minX = Number.MAX_SAFE_INTEGER;
  95.     let minY = Number.MAX_SAFE_INTEGER;
  96.     let maxX = -Number.MAX_SAFE_INTEGER;
  97.     let maxY = -Number.MAX_SAFE_INTEGER;
  98.     this.items.forEach((el) => {
  99.       minX = Math.min(minX, el.x);
  100.       minY = Math.min(minY, el.y);
  101.       maxX = Math.max(maxX, el.x + el.width);
  102.       maxY = Math.max(maxY, el.y + el.height);
  103.     });
  104.     this.x = minX;
  105.     this.y = minY;
  106.     // this.width = maxX - minX;
  107.     this.height = maxY - minY;
  108.   }
  109. }
  111. Object.assign(ServerItemGroup.prototype, EventEmitter.prototype);
  113. module.exports = ServerItemGroup;