spatial-navigation/lib/Event.js

A javascript-based implementation of Spatial Navigation.

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});

var _createClass = function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; }();

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

var DispatchedEvent = function () {
  function DispatchedEvent() {
    _classCallCheck(this, DispatchedEvent);

    this.propagationStopped = false;
  }

  _createClass(DispatchedEvent, [{
    key: "isPropagationStopped",
    value: function isPropagationStopped() {
      return this.propagationStopped;
    }
  }, {
    key: "stopPropagation",
    value: function stopPropagation() {
      this.propagationStopped = true;
    }
  }]);

  return DispatchedEvent;
}();

var Event = function () {
  function Event(name) {
    _classCallCheck(this, Event);

    this.name = name;
    this.handlers = {};
  }

  _createClass(Event, [{
    key: "addHandler",
    value: function addHandler(handler) {
      var priority = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 1;

      if (!(priority in this.handlers)) {
        this.handlers[String(priority)] = [];
      }
      this.handlers[String(priority)].push(handler);
    }
  }, {
    key: "removeHandler",
    value: function removeHandler(handler) {
      var priority = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 1;

      // TODO why we need to create new array by property?
      if (!(priority in this.handlers)) {
        this.handlers[String(priority)] = [];
      }

      var handlerIndex = this.handlers[priority].indexOf(handler);

      if (~handlerIndex) {
        // TODO why return result
        return this.handlers[priority].splice(handlerIndex, 1);
      }
    }

    /**
     * Call all handlers in all priorities
     *
     * @param eventArgs
     */
    // TODO why whe not using ...eventArgs? In EventAggregator we passing ...eventArgs, so here we use only first parameter

  }, {
    key: "call",
    value: function call(eventArgs) {
      if (!Object.keys(this.handlers).length) {
        return;
      }

      var dispatchedEvent = new DispatchedEvent();

      for (var priority in this.handlers) {
        if (!this.handlers.hasOwnProperty(priority)) {
          continue;
        }

        // TODO why isPropagationStopped used twice? Is it if propagation will be stopped in time of iteration?
        if (dispatchedEvent.isPropagationStopped()) {
          continue;
        }

        this.handlers[priority].forEach(function (handler) {
          // TODO why isPropagationStopped used twice?
          // if (dispatchedEvent.isPropagationStopped()) {
          //   break
          // }

          // TODO why whe not using ...eventArgs?
          // TODO why we passing dispatchedEvent? We never use it!?
          handler(eventArgs, dispatchedEvent);
        });
      }
    }
  }]);

  return Event;
}();

exports.default = Event;
module.exports = exports["default"];