infamous/core/Observable.js

A CSS3D/WebGL UI library.

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = void 0;

var _Mixin = _interopRequireDefault(require("./Mixin"));

var _lowclass = _interopRequireDefault(require("lowclass"));

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

var _default = (0, _Mixin.default)(Base => (0, _lowclass.default)('Observable').extends(Base, ({
  Super
}) => ({
  on(eventName, callback, context) {
    if (!this._eventMap) this._eventMap = new Map();

    let callbacks = this._eventMap.get(eventName);

    if (!callbacks) this._eventMap.set(eventName, callbacks = []);
    if (typeof callback == 'function') callbacks.push([callback, context]); // save callback associated with context
    else throw new Error('Expected a function in callback argument of Observable#on.');
  },

  off(eventName, callback) {
    if (!this._eventMap || !this._eventMap.has(eventName)) return;

    const callbacks = this._eventMap.get(eventName);

    const index = callbacks.findIndex(tuple => tuple[0] === callback);
    if (index == -1) return;
    callbacks.splice(index, 1);
    if (callbacks.length === 0) this._eventMap.delete(eventName);
    if (this._eventMap.size === 0) this._eventMap = null;
  },

  trigger(eventName, data) {
    if (!this._eventMap || !this._eventMap.has(eventName)) return;

    const callbacks = this._eventMap.get(eventName);

    let tuple = undefined;
    let callback = undefined;
    let context = undefined;

    for (let i = 0, len = callbacks.length; i < len; i += 1) {
      tuple = callbacks[i];
      callback = tuple[0];
      context = tuple[1];
      callback.call(context, data);
    }
  },

  // alias for trigger
  triggerEvent(...args) {
    return this.trigger(...args);
  }

})));

exports.default = _default;