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Sleeping
; | |
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 | |
* @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 {*} context The context to invoke the listener with. | |
* @param {Boolean} [once=false] Specify if the listener is a one-time listener. | |
* @constructor | |
* @private | |
*/ | |
function EE(fn, context, once) { | |
this.fn = fn; | |
this.context = context; | |
this.once = once || false; | |
} | |
/** | |
* Add a listener for a given event. | |
* | |
* @param {EventEmitter} emitter Reference to the `EventEmitter` instance. | |
* @param {(String|Symbol)} event The event name. | |
* @param {Function} fn The listener function. | |
* @param {*} context The context to invoke the listener with. | |
* @param {Boolean} once Specify if the listener is a one-time listener. | |
* @returns {EventEmitter} | |
* @private | |
*/ | |
function addListener(emitter, event, fn, context, once) { | |
if (typeof fn !== 'function') { | |
throw new TypeError('The listener must be a function'); | |
} | |
var listener = new EE(fn, context || emitter, once) | |
, evt = prefix ? prefix + event : event; | |
if (!emitter._events[evt]) emitter._events[evt] = listener, emitter._eventsCount++; | |
else if (!emitter._events[evt].fn) emitter._events[evt].push(listener); | |
else emitter._events[evt] = [emitter._events[evt], listener]; | |
return emitter; | |
} | |
/** | |
* Clear event by name. | |
* | |
* @param {EventEmitter} emitter Reference to the `EventEmitter` instance. | |
* @param {(String|Symbol)} evt The Event name. | |
* @private | |
*/ | |
function clearEvent(emitter, evt) { | |
if (--emitter._eventsCount === 0) emitter._events = new Events(); | |
else delete emitter._events[evt]; | |
} | |
/** | |
* Minimal `EventEmitter` interface that is molded against the Node.js | |
* `EventEmitter` interface. | |
* | |
* @constructor | |
* @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} | |
* @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. | |
* @returns {Array} The registered listeners. | |
* @public | |
*/ | |
EventEmitter.prototype.listeners = function listeners(event) { | |
var evt = prefix ? prefix + event : event | |
, handlers = this._events[evt]; | |
if (!handlers) return []; | |
if (handlers.fn) return [handlers.fn]; | |
for (var i = 0, l = handlers.length, ee = new Array(l); i < l; i++) { | |
ee[i] = handlers[i].fn; | |
} | |
return ee; | |
}; | |
/** | |
* Return the number of listeners listening to a given event. | |
* | |
* @param {(String|Symbol)} event The event name. | |
* @returns {Number} The number of listeners. | |
* @public | |
*/ | |
EventEmitter.prototype.listenerCount = function listenerCount(event) { | |
var evt = prefix ? prefix + event : event | |
, listeners = this._events[evt]; | |
if (!listeners) return 0; | |
if (listeners.fn) return 1; | |
return listeners.length; | |
}; | |
/** | |
* 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`. | |
* @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 {*} [context=this] The context to invoke the listener with. | |
* @returns {EventEmitter} `this`. | |
* @public | |
*/ | |
EventEmitter.prototype.on = function on(event, fn, context) { | |
return addListener(this, event, fn, context, false); | |
}; | |
/** | |
* Add a one-time listener for a given event. | |
* | |
* @param {(String|Symbol)} event The event name. | |
* @param {Function} fn The listener function. | |
* @param {*} [context=this] The context to invoke the listener with. | |
* @returns {EventEmitter} `this`. | |
* @public | |
*/ | |
EventEmitter.prototype.once = function once(event, fn, context) { | |
return addListener(this, event, fn, context, true); | |
}; | |
/** | |
* 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 {*} context Only remove the listeners that have this context. | |
* @param {Boolean} once Only remove one-time listeners. | |
* @returns {EventEmitter} `this`. | |
* @public | |
*/ | |
EventEmitter.prototype.removeListener = function removeListener(event, fn, context, once) { | |
var evt = prefix ? prefix + event : event; | |
if (!this._events[evt]) return this; | |
if (!fn) { | |
clearEvent(this, evt); | |
return this; | |
} | |
var listeners = this._events[evt]; | |
if (listeners.fn) { | |
if ( | |
listeners.fn === fn && | |
(!once || listeners.once) && | |
(!context || listeners.context === context) | |
) { | |
clearEvent(this, 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 clearEvent(this, evt); | |
} | |
return this; | |
}; | |
/** | |
* Remove all listeners, or those of the specified event. | |
* | |
* @param {(String|Symbol)} [event] The event name. | |
* @returns {EventEmitter} `this`. | |
* @public | |
*/ | |
EventEmitter.prototype.removeAllListeners = function removeAllListeners(event) { | |
var evt; | |
if (event) { | |
evt = prefix ? prefix + event : event; | |
if (this._events[evt]) clearEvent(this, 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; | |
// | |
// 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; | |
} | |