@blockv/sdk/lib/internal/DataPool/EventEmitter.js

Allows web apps to display and interact with vatoms.

"use strict";

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

//
// EventEmitter class - This class provides simple event functionality for classes, with Promise support.
//
//	Usage for once-off event listeners:
//
//		myObj.when("closed").then(function(data) {
//			alert("Closed! " + data);
//		});
//
//
//	Usage for permanent event listeners:
//
//		myObj.on("closed", function(data) {
//			alert("Closed! " + data);
//		});
//
//
//	Usage when triggering an event from a subclass:
//
//		this.emit("closed", "customData");
//
class EventEmitter {
  /** Adds an event listener. If callback is null, a Promise will be returned. Note that if using the Promise
   *  it will only be triggered on the first event emitted. */
  when(eventName, callback = null) {
    // Make sure event listener object exists
    this._eventListeners = this._eventListeners || {}; // Make sure event listener array exists

    this._eventListeners[eventName] = this._eventListeners[eventName] || []; // Check if using promise form

    if (callback) {
      // Just add the callback
      this._eventListeners[eventName].push(callback);
    } else {
      // Return the promise
      return new Promise((onSuccess, onFail) => {
        // Promise callbacks can only be used once
        onSuccess._removeAfterCall = true; // Add success handler to event listener array

        this._eventListeners[eventName].push(onSuccess);
      });
    }
  }
  /** Synonyms */


  on() {
    return this.when.apply(this, arguments);
  }

  addEventListener() {
    return this.when.apply(this, arguments);
  }
  /** Remove event listener */


  removeEventListener(eventName, callback) {
    // Make sure event listener object exists
    this._eventListeners = this._eventListeners || {}; // Make sure event listener array exists

    this._eventListeners[eventName] = this._eventListeners[eventName] || []; // Find and remove it

    for (var i = 0; i < this._eventListeners[eventName].length; i++) if (this._eventListeners[eventName][i] == callback) this._eventListeners[eventName].splice(i--, 1);
  }

  off() {
    return this.removeEventListener.apply(this, arguments);
  }
  /** Triggers an event. Each argument after the first one will be passed to event listeners */


  emit(eventName, ...args) {
    // Setup the once-off promise if one of it's events were triggered
    //if (eventName == "success" || eventName == "failed")
    //	this._setupPromise();
    // Get list of callbacks
    var callbacks = this._eventListeners && this._eventListeners[eventName] || []; // Call events

    for (var callback of callbacks) {
      // Call it
      callback.apply(this, args);
    } // Remove callbacks that can only be called once


    for (var i = 0; i < callbacks.length; i++) if (callbacks[i]._removeAfterCall) callbacks.splice(i--, 1);
  }
  /** Synonyms */


  trigger() {
    return this.emit.apply(this, arguments);
  }

  triggerEvent() {
    return this.emit.apply(this, arguments);
  }

} // Apply as a mixin to a class or object


exports.default = EventEmitter;

EventEmitter.mixin = function (otherClass) {
  for (var prop in EventEmitter.prototype) if (EventEmitter.prototype.hasOwnProperty(prop)) otherClass[prop] = EventEmitter.prototype[prop];
};