EventTarget.js
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/**
* Expose the _EventTarget class.
*/
module.exports = _EventTarget;
function _EventTarget() {
// Do nothing if called for a native EventTarget object..
if (typeof this.addEventListener === 'function') {
return;
}
this._listeners = {};
this.addEventListener = _addEventListener;
this.removeEventListener = _removeEventListener;
this.dispatchEvent = _dispatchEvent;
}
Object.defineProperties(_EventTarget.prototype, {
listeners: {
get: function () {
return this._listeners;
}
}
});
function _addEventListener(type, newListener) {
var
listenersType,
i, listener;
if (!type || !newListener) {
return;
}
listenersType = this._listeners[type];
if (listenersType === undefined) {
this._listeners[type] = listenersType = [];
}
for (i = 0; !!(listener = listenersType[i]); i++) {
if (listener === newListener) {
return;
}
}
listenersType.push(newListener);
}
function _removeEventListener(type, oldListener) {
var
listenersType,
i, listener;
if (!type || !oldListener) {
return;
}
listenersType = this._listeners[type];
if (listenersType === undefined) {
return;
}
for (i = 0; !!(listener = listenersType[i]); i++) {
if (listener === oldListener) {
listenersType.splice(i, 1);
break;
}
}
if (listenersType.length === 0) {
delete this._listeners[type];
}
}
function _dispatchEvent(event) {
var
type,
listenersType,
dummyListener,
stopImmediatePropagation = false,
i, listener;
if (!event || typeof event.type !== 'string') {
throw new Error('`event` must have a valid `type` property');
}
// Do some stuff to emulate DOM Event behavior (just if this is not a
// DOM Event object)
if (event._yaeti) {
event.target = this;
event.cancelable = true;
}
// Attempt to override the stopImmediatePropagation() method
try {
event.stopImmediatePropagation = function () {
stopImmediatePropagation = true;
};
} catch (error) {}
type = event.type;
listenersType = (this._listeners[type] || []);
dummyListener = this['on' + type];
if (typeof dummyListener === 'function') {
dummyListener.call(this, event);
}
for (i = 0; !!(listener = listenersType[i]); i++) {
if (stopImmediatePropagation) {
break;
}
listener.call(this, event);
}
return !event.defaultPrevented;
}