d2-ui
Version:
235 lines (207 loc) • 7.88 kB
JavaScript
/**
* Copyright 2013-present, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD-style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*
* @providesModule EventPluginHub
*/
;
var EventPluginRegistry = require('./EventPluginRegistry');
var EventPluginUtils = require('./EventPluginUtils');
var ReactErrorUtils = require('./ReactErrorUtils');
var accumulateInto = require('./accumulateInto');
var forEachAccumulated = require('./forEachAccumulated');
var invariant = require('fbjs/lib/invariant');
/**
* Internal store for event listeners
*/
var listenerBank = {};
/**
* Internal queue of events that have accumulated their dispatches and are
* waiting to have their dispatches executed.
*/
var eventQueue = null;
/**
* Dispatches an event and releases it back into the pool, unless persistent.
*
* @param {?object} event Synthetic event to be dispatched.
* @param {boolean} simulated If the event is simulated (changes exn behavior)
* @private
*/
var executeDispatchesAndRelease = function (event, simulated) {
if (event) {
EventPluginUtils.executeDispatchesInOrder(event, simulated);
if (!event.isPersistent()) {
event.constructor.release(event);
}
}
};
var executeDispatchesAndReleaseSimulated = function (e) {
return executeDispatchesAndRelease(e, true);
};
var executeDispatchesAndReleaseTopLevel = function (e) {
return executeDispatchesAndRelease(e, false);
};
/**
* This is a unified interface for event plugins to be installed and configured.
*
* Event plugins can implement the following properties:
*
* `extractEvents` {function(string, DOMEventTarget, string, object): *}
* Required. When a top-level event is fired, this method is expected to
* extract synthetic events that will in turn be queued and dispatched.
*
* `eventTypes` {object}
* Optional, plugins that fire events must publish a mapping of registration
* names that are used to register listeners. Values of this mapping must
* be objects that contain `registrationName` or `phasedRegistrationNames`.
*
* `executeDispatch` {function(object, function, string)}
* Optional, allows plugins to override how an event gets dispatched. By
* default, the listener is simply invoked.
*
* Each plugin that is injected into `EventsPluginHub` is immediately operable.
*
* @public
*/
var EventPluginHub = {
/**
* Methods for injecting dependencies.
*/
injection: {
/**
* @param {array} InjectedEventPluginOrder
* @public
*/
injectEventPluginOrder: EventPluginRegistry.injectEventPluginOrder,
/**
* @param {object} injectedNamesToPlugins Map from names to plugin modules.
*/
injectEventPluginsByName: EventPluginRegistry.injectEventPluginsByName
},
/**
* Stores `listener` at `listenerBank[registrationName][id]`. Is idempotent.
*
* @param {object} inst The instance, which is the source of events.
* @param {string} registrationName Name of listener (e.g. `onClick`).
* @param {function} listener The callback to store.
*/
putListener: function (inst, registrationName, listener) {
!(typeof listener === 'function') ? process.env.NODE_ENV !== 'production' ? invariant(false, 'Expected %s listener to be a function, instead got type %s', registrationName, typeof listener) : invariant(false) : void 0;
var bankForRegistrationName = listenerBank[registrationName] || (listenerBank[registrationName] = {});
bankForRegistrationName[inst._rootNodeID] = listener;
var PluginModule = EventPluginRegistry.registrationNameModules[registrationName];
if (PluginModule && PluginModule.didPutListener) {
PluginModule.didPutListener(inst, registrationName, listener);
}
},
/**
* @param {object} inst The instance, which is the source of events.
* @param {string} registrationName Name of listener (e.g. `onClick`).
* @return {?function} The stored callback.
*/
getListener: function (inst, registrationName) {
var bankForRegistrationName = listenerBank[registrationName];
return bankForRegistrationName && bankForRegistrationName[inst._rootNodeID];
},
/**
* Deletes a listener from the registration bank.
*
* @param {object} inst The instance, which is the source of events.
* @param {string} registrationName Name of listener (e.g. `onClick`).
*/
deleteListener: function (inst, registrationName) {
var PluginModule = EventPluginRegistry.registrationNameModules[registrationName];
if (PluginModule && PluginModule.willDeleteListener) {
PluginModule.willDeleteListener(inst, registrationName);
}
var bankForRegistrationName = listenerBank[registrationName];
// TODO: This should never be null -- when is it?
if (bankForRegistrationName) {
delete bankForRegistrationName[inst._rootNodeID];
}
},
/**
* Deletes all listeners for the DOM element with the supplied ID.
*
* @param {object} inst The instance, which is the source of events.
*/
deleteAllListeners: function (inst) {
for (var registrationName in listenerBank) {
if (!listenerBank[registrationName][inst._rootNodeID]) {
continue;
}
var PluginModule = EventPluginRegistry.registrationNameModules[registrationName];
if (PluginModule && PluginModule.willDeleteListener) {
PluginModule.willDeleteListener(inst, registrationName);
}
delete listenerBank[registrationName][inst._rootNodeID];
}
},
/**
* Allows registered plugins an opportunity to extract events from top-level
* native browser events.
*
* @return {*} An accumulation of synthetic events.
* @internal
*/
extractEvents: function (topLevelType, targetInst, nativeEvent, nativeEventTarget) {
var events;
var plugins = EventPluginRegistry.plugins;
for (var i = 0; i < plugins.length; i++) {
// Not every plugin in the ordering may be loaded at runtime.
var possiblePlugin = plugins[i];
if (possiblePlugin) {
var extractedEvents = possiblePlugin.extractEvents(topLevelType, targetInst, nativeEvent, nativeEventTarget);
if (extractedEvents) {
events = accumulateInto(events, extractedEvents);
}
}
}
return events;
},
/**
* Enqueues a synthetic event that should be dispatched when
* `processEventQueue` is invoked.
*
* @param {*} events An accumulation of synthetic events.
* @internal
*/
enqueueEvents: function (events) {
if (events) {
eventQueue = accumulateInto(eventQueue, events);
}
},
/**
* Dispatches all synthetic events on the event queue.
*
* @internal
*/
processEventQueue: function (simulated) {
// Set `eventQueue` to null before processing it so that we can tell if more
// events get enqueued while processing.
var processingEventQueue = eventQueue;
eventQueue = null;
if (simulated) {
forEachAccumulated(processingEventQueue, executeDispatchesAndReleaseSimulated);
} else {
forEachAccumulated(processingEventQueue, executeDispatchesAndReleaseTopLevel);
}
!!eventQueue ? process.env.NODE_ENV !== 'production' ? invariant(false, 'processEventQueue(): Additional events were enqueued while processing ' + 'an event queue. Support for this has not yet been implemented.') : invariant(false) : void 0;
// This would be a good time to rethrow if any of the event handlers threw.
ReactErrorUtils.rethrowCaughtError();
},
/**
* These are needed for tests only. Do not use!
*/
__purge: function () {
listenerBank = {};
},
__getListenerBank: function () {
return listenerBank;
}
};
module.exports = EventPluginHub;