react-native/Libraries/vendor/emitter/EventSubscriptionVendor.js

102 lines
3.1 KiB
JavaScript

/**
* @generated SignedSource<<24d5cc1cdd24704296686faf89dd36cf>>
*
* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
* !! This file is a check-in of a static_upstream project! !!
* !! !!
* !! You should not modify this file directly. Instead: !!
* !! 1) Use `fjs use-upstream` to temporarily replace this with !!
* !! the latest version from upstream. !!
* !! 2) Make your changes, test them, etc. !!
* !! 3) Use `fjs push-upstream` to copy your changes back to !!
* !! static_upstream. !!
* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
*
* @providesModule EventSubscriptionVendor
* @typechecks
*/
'use strict';
var invariant = require('invariant');
/**
* EventSubscriptionVendor stores a set of EventSubscriptions that are
* subscribed to a particular event type.
*/
class EventSubscriptionVendor {
constructor() {
this._subscriptionsForType = {};
this._currentSubscription = null;
}
/**
* Adds a subscription keyed by an event type.
*
* @param {string} eventType
* @param {EventSubscription} subscription
*/
addSubscription(
eventType: String, subscription: EventSubscription): EventSubscription {
invariant(
subscription.subscriber === this,
'The subscriber of the subscription is incorrectly set.');
if (!this._subscriptionsForType[eventType]) {
this._subscriptionsForType[eventType] = [];
}
var key = this._subscriptionsForType[eventType].length;
this._subscriptionsForType[eventType].push(subscription);
subscription.eventType = eventType;
subscription.key = key;
return subscription;
}
/**
* Removes a bulk set of the subscriptions.
*
* @param {?string} eventType - Optional name of the event type whose
* registered supscriptions to remove, if null remove all subscriptions.
*/
removeAllSubscriptions(eventType: ?String) {
if (eventType === undefined) {
this._subscriptionsForType = {};
} else {
delete this._subscriptionsForType[eventType];
}
}
/**
* Removes a specific subscription. Instead of calling this function, call
* `subscription.remove()` directly.
*
* @param {object} subscription
*/
removeSubscription(subscription: Object) {
var eventType = subscription.eventType;
var key = subscription.key;
var subscriptionsForType = this._subscriptionsForType[eventType];
if (subscriptionsForType) {
delete subscriptionsForType[key];
}
}
/**
* Returns the array of subscriptions that are currently registered for the
* given event type.
*
* Note: This array can be potentially sparse as subscriptions are deleted
* from it when they are removed.
*
* TODO: This returns a nullable array. wat?
*
* @param {string} eventType
* @returns {?array}
*/
getSubscriptionsForType(eventType: String): ?Array {
return this._subscriptionsForType[eventType];
}
}
module.exports = EventSubscriptionVendor;