modules/preloader/injected/EventEmitter3.js
(function() {
'use strict';
var has = Object.prototype.hasOwnProperty,
prefix = '~';
/**
* Constructor to create a storage for our `EE` objects.
* An `Events` instance is a plain object whose properties are event names.
*
* @constructor
* @api private
*/
function Events() {}
//
// We try to not inherit from `Object.prototype`. In some engines creating an
// instance in this way is faster than calling `Object.create(null)` directly.
// If `Object.create(null)` is not supported we prefix the event names with a
// character to make sure that the built-in object properties are not
// overridden or used as an attack vector.
//
if (Object.create) {
Events.prototype = Object.create(null);
//
// This hack is needed because the `__proto__` property is still inherited in
// some old browsers like Android 4, iPhone 5.1, Opera 11 and Safari 5.
//
if (!new Events().__proto__) prefix = false;
}
/**
* Representation of a single event listener.
*
* @param {Function} fn The listener function.
* @param {Mixed} context The context to invoke the listener with.
* @param {Boolean} [once=false] Specify if the listener is a one-time listener.
* @constructor
* @api private
*/
function EE(fn, context, once) {
this.fn = fn;
this.context = context;
this.once = once || false;
}
/**
* Minimal `EventEmitter` interface that is molded against the Node.js
* `EventEmitter` interface.
*
* @constructor
* @api public
*/
function EventEmitter() {
this._events = new Events();
this._eventsCount = 0;
}
/**
* Return an array listing the events for which the emitter has registered
* listeners.
*
* @returns {Array}
* @api public
*/
EventEmitter.prototype.eventNames = function eventNames() {
var names = [],
events,
name;
if (this._eventsCount === 0) return names;
for (name in (events = this._events)) {
if (has.call(events, name)) names.push(prefix ? name.slice(1) : name);
}
if (Object.getOwnPropertySymbols) {
return names.concat(Object.getOwnPropertySymbols(events));
}
return names;
};
/**
* Return the listeners registered for a given event.
*
* @param {String|Symbol} event The event name.
* @param {Boolean} exists Only check if there are listeners.
* @returns {Array|Boolean}
* @api public
*/
EventEmitter.prototype.listeners = function listeners(event, exists) {
var evt = prefix ? prefix + event : event,
available = this._events[evt];
if (exists) return !!available;
if (!available) return [];
if (available.fn) return [available.fn];
for (var i = 0, l = available.length, ee = new Array(l); i < l; i++) {
ee[i] = available[i].fn;
}
return ee;
};
/**
* Calls each of the listeners registered for a given event.
*
* @param {String|Symbol} event The event name.
* @returns {Boolean} `true` if the event had listeners, else `false`.
* @api public
*/
EventEmitter.prototype.emit = function emit(event, a1, a2, a3, a4, a5) {
var evt = prefix ? prefix + event : event;
if (!this._events[evt]) return false;
var listeners = this._events[evt],
len = arguments.length,
args,
i;
if (listeners.fn) {
if (listeners.once)
this.removeListener(event, listeners.fn, undefined, true);
switch (len) {
case 1:
return listeners.fn.call(listeners.context), true;
case 2:
return listeners.fn.call(listeners.context, a1), true;
case 3:
return listeners.fn.call(listeners.context, a1, a2), true;
case 4:
return listeners.fn.call(listeners.context, a1, a2, a3), true;
case 5:
return listeners.fn.call(listeners.context, a1, a2, a3, a4), true;
case 6:
return listeners.fn.call(listeners.context, a1, a2, a3, a4, a5), true;
}
for (i = 1, args = new Array(len - 1); i < len; i++) {
args[i - 1] = arguments[i];
}
listeners.fn.apply(listeners.context, args);
} else {
var length = listeners.length,
j;
for (i = 0; i < length; i++) {
if (listeners[i].once)
this.removeListener(event, listeners[i].fn, undefined, true);
switch (len) {
case 1:
listeners[i].fn.call(listeners[i].context);
break;
case 2:
listeners[i].fn.call(listeners[i].context, a1);
break;
case 3:
listeners[i].fn.call(listeners[i].context, a1, a2);
break;
case 4:
listeners[i].fn.call(listeners[i].context, a1, a2, a3);
break;
default:
if (!args)
for (j = 1, args = new Array(len - 1); j < len; j++) {
args[j - 1] = arguments[j];
}
listeners[i].fn.apply(listeners[i].context, args);
}
}
}
return true;
};
/**
* Add a listener for a given event.
*
* @param {String|Symbol} event The event name.
* @param {Function} fn The listener function.
* @param {Mixed} [context=this] The context to invoke the listener with.
* @returns {EventEmitter} `this`.
* @api public
*/
EventEmitter.prototype.on = function on(event, fn, context) {
var listener = new EE(fn, context || this),
evt = prefix ? prefix + event : event;
if (!this._events[evt]) (this._events[evt] = listener), this._eventsCount++;
else if (!this._events[evt].fn) this._events[evt].push(listener);
else this._events[evt] = [this._events[evt], listener];
return this;
};
/**
* Add a one-time listener for a given event.
*
* @param {String|Symbol} event The event name.
* @param {Function} fn The listener function.
* @param {Mixed} [context=this] The context to invoke the listener with.
* @returns {EventEmitter} `this`.
* @api public
*/
EventEmitter.prototype.once = function once(event, fn, context) {
var listener = new EE(fn, context || this, true),
evt = prefix ? prefix + event : event;
if (!this._events[evt]) (this._events[evt] = listener), this._eventsCount++;
else if (!this._events[evt].fn) this._events[evt].push(listener);
else this._events[evt] = [this._events[evt], listener];
return this;
};
/**
* Remove the listeners of a given event.
*
* @param {String|Symbol} event The event name.
* @param {Function} fn Only remove the listeners that match this function.
* @param {Mixed} context Only remove the listeners that have this context.
* @param {Boolean} once Only remove one-time listeners.
* @returns {EventEmitter} `this`.
* @api public
*/
EventEmitter.prototype.removeListener = function removeListener(
event,
fn,
context,
once
) {
var evt = prefix ? prefix + event : event;
if (!this._events[evt]) return this;
if (!fn) {
if (--this._eventsCount === 0) this._events = new Events();
else delete this._events[evt];
return this;
}
var listeners = this._events[evt];
if (listeners.fn) {
if (
listeners.fn === fn &&
(!once || listeners.once) &&
(!context || listeners.context === context)
) {
if (--this._eventsCount === 0) this._events = new Events();
else delete this._events[evt];
}
} else {
for (var i = 0, events = [], length = listeners.length; i < length; i++) {
if (
listeners[i].fn !== fn ||
(once && !listeners[i].once) ||
(context && listeners[i].context !== context)
) {
events.push(listeners[i]);
}
}
//
// Reset the array, or remove it completely if we have no more listeners.
//
if (events.length)
this._events[evt] = events.length === 1 ? events[0] : events;
else if (--this._eventsCount === 0) this._events = new Events();
else delete this._events[evt];
}
return this;
};
/**
* Remove all listeners, or those of the specified event.
*
* @param {String|Symbol} [event] The event name.
* @returns {EventEmitter} `this`.
* @api public
*/
EventEmitter.prototype.removeAllListeners = function removeAllListeners(
event
) {
var evt;
if (event) {
evt = prefix ? prefix + event : event;
if (this._events[evt]) {
if (--this._eventsCount === 0) this._events = new Events();
else delete this._events[evt];
}
} else {
this._events = new Events();
this._eventsCount = 0;
}
return this;
};
//
// Alias methods names because people roll like that.
//
EventEmitter.prototype.off = EventEmitter.prototype.removeListener;
EventEmitter.prototype.addListener = EventEmitter.prototype.on;
//
// This function doesn't apply anymore.
//
EventEmitter.prototype.setMaxListeners = function setMaxListeners() {
return this;
};
//
// Expose the prefix.
//
EventEmitter.prefixed = prefix;
//
// Allow `EventEmitter` to be imported as module namespace.
//
EventEmitter.EventEmitter = EventEmitter;
//
// Expose the module.
//
if ('undefined' !== typeof module) {
module.exports = EventEmitter;
}
window.EventEmitter = EventEmitter;
})();