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/**
* 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.
*
*/
'use strict';
var _assign = require('object-assign');
var PooledClass = require('./PooledClass');
var emptyFunction = require('fbjs/lib/emptyFunction');
var warning = require('fbjs/lib/warning');
var didWarnForAddedNewProperty = false;
var isProxySupported = typeof Proxy === 'function';
var shouldBeReleasedProperties = ['dispatchConfig', '_targetInst', 'nativeEvent', 'isDefaultPrevented', 'isPropagationStopped', '_dispatchListeners', '_dispatchInstances'];
/**
* @interface Event
* @see http://www.w3.org/TR/DOM-Level-3-Events/
*/
var EventInterface = {
type: null,
target: null,
// currentTarget is set when dispatching; no use in copying it here
currentTarget: emptyFunction.thatReturnsNull,
eventPhase: null,
bubbles: null,
cancelable: null,
timeStamp: function (event) {
return event.timeStamp || Date.now();
},
defaultPrevented: null,
isTrusted: null
};
/**
* Synthetic events are dispatched by event plugins, typically in response to a
* top-level event delegation handler.
*
* These systems should generally use pooling to reduce the frequency of garbage
* collection. The system should check `isPersistent` to determine whether the
* event should be released into the pool after being dispatched. Users that
* need a persisted event should invoke `persist`.
*
* Synthetic events (and subclasses) implement the DOM Level 3 Events API by
* normalizing browser quirks. Subclasses do not necessarily have to implement a
* DOM interface; custom application-specific events can also subclass this.
*
* @param {object} dispatchConfig Configuration used to dispatch this event.
* @param {*} targetInst Marker identifying the event target.
* @param {object} nativeEvent Native browser event.
* @param {DOMEventTarget} nativeEventTarget Target node.
*/
function SyntheticEvent(dispatchConfig, targetInst, nativeEvent, nativeEventTarget) {
if (process.env.NODE_ENV !== 'production') {
// these have a getter/setter for warnings
delete this.nativeEvent;
delete this.preventDefault;
delete this.stopPropagation;
}
this.dispatchConfig = dispatchConfig;
this._targetInst = targetInst;
this.nativeEvent = nativeEvent;
var Interface = this.constructor.Interface;
for (var propName in Interface) {
if (!Interface.hasOwnProperty(propName)) {
continue;
}
if (process.env.NODE_ENV !== 'production') {
delete this[propName]; // this has a getter/setter for warnings
}
var normalize = Interface[propName];
if (normalize) {
this[propName] = normalize(nativeEvent);
} else {
if (propName === 'target') {
this.target = nativeEventTarget;
} else {
this[propName] = nativeEvent[propName];
}
}
}
var defaultPrevented = nativeEvent.defaultPrevented != null ? nativeEvent.defaultPrevented : nativeEvent.returnValue === false;
if (defaultPrevented) {
this.isDefaultPrevented = emptyFunction.thatReturnsTrue;
} else {
this.isDefaultPrevented = emptyFunction.thatReturnsFalse;
}
this.isPropagationStopped = emptyFunction.thatReturnsFalse;
return this;
}
_assign(SyntheticEvent.prototype, {
preventDefault: function () {
this.defaultPrevented = true;
var event = this.nativeEvent;
if (!event) {
return;
}
if (event.preventDefault) {
event.preventDefault();
// eslint-disable-next-line valid-typeof
} else if (typeof event.returnValue !== 'unknown') {
event.returnValue = false;
}
this.isDefaultPrevented = emptyFunction.thatReturnsTrue;
},
stopPropagation: function () {
var event = this.nativeEvent;
if (!event) {
return;
}
if (event.stopPropagation) {
event.stopPropagation();
// eslint-disable-next-line valid-typeof
} else if (typeof event.cancelBubble !== 'unknown') {
// The ChangeEventPlugin registers a "propertychange" event for
// IE. This event does not support bubbling or cancelling, and
// any references to cancelBubble throw "Member not found". A
// typeof check of "unknown" circumvents this issue (and is also
// IE specific).
event.cancelBubble = true;
}
this.isPropagationStopped = emptyFunction.thatReturnsTrue;
},
/**
* We release all dispatched `SyntheticEvent`s after each event loop, adding
* them back into the pool. This allows a way to hold onto a reference that
* won't be added back into the pool.
*/
persist: function () {
this.isPersistent = emptyFunction.thatReturnsTrue;
},
/**
* Checks if this event should be released back into the pool.
*
* @return {boolean} True if this should not be released, false otherwise.
*/
isPersistent: emptyFunction.thatReturnsFalse,
/**
* `PooledClass` looks for `destructor` on each instance it releases.
*/
destructor: function () {
var Interface = this.constructor.Interface;
for (var propName in Interface) {
if (process.env.NODE_ENV !== 'production') {
Object.defineProperty(this, propName, getPooledWarningPropertyDefinition(propName, Interface[propName]));
} else {
this[propName] = null;
}
}
for (var i = 0; i < shouldBeReleasedProperties.length; i++) {
this[shouldBeReleasedProperties[i]] = null;
}
if (process.env.NODE_ENV !== 'production') {
Object.defineProperty(this, 'nativeEvent', getPooledWarningPropertyDefinition('nativeEvent', null));
Object.defineProperty(this, 'preventDefault', getPooledWarningPropertyDefinition('preventDefault', emptyFunction));
Object.defineProperty(this, 'stopPropagation', getPooledWarningPropertyDefinition('stopPropagation', emptyFunction));
}
}
});
SyntheticEvent.Interface = EventInterface;
if (process.env.NODE_ENV !== 'production') {
if (isProxySupported) {
/*eslint-disable no-func-assign */
SyntheticEvent = new Proxy(SyntheticEvent, {
construct: function (target, args) {
return this.apply(target, Object.create(target.prototype), args);
},
apply: function (constructor, that, args) {
return new Proxy(constructor.apply(that, args), {
set: function (target, prop, value) {
if (prop !== 'isPersistent' && !target.constructor.Interface.hasOwnProperty(prop) && shouldBeReleasedProperties.indexOf(prop) === -1) {
process.env.NODE_ENV !== 'production' ? warning(didWarnForAddedNewProperty || target.isPersistent(), "This synthetic event is reused for performance reasons. If you're " + "seeing this, you're adding a new property in the synthetic event object. " + 'The property is never released. See ' + 'https://fb.me/react-event-pooling for more information.') : void 0;
didWarnForAddedNewProperty = true;
}
target[prop] = value;
return true;
}
});
}
});
/*eslint-enable no-func-assign */
}
}
/**
* Helper to reduce boilerplate when creating subclasses.
*
* @param {function} Class
* @param {?object} Interface
*/
SyntheticEvent.augmentClass = function (Class, Interface) {
var Super = this;
var E = function () {};
E.prototype = Super.prototype;
var prototype = new E();
_assign(prototype, Class.prototype);
Class.prototype = prototype;
Class.prototype.constructor = Class;
Class.Interface = _assign({}, Super.Interface, Interface);
Class.augmentClass = Super.augmentClass;
PooledClass.addPoolingTo(Class, PooledClass.fourArgumentPooler);
};
PooledClass.addPoolingTo(SyntheticEvent, PooledClass.fourArgumentPooler);
module.exports = SyntheticEvent;
/**
* Helper to nullify syntheticEvent instance properties when destructing
*
* @param {object} SyntheticEvent
* @param {String} propName
* @return {object} defineProperty object
*/
function getPooledWarningPropertyDefinition(propName, getVal) {
var isFunction = typeof getVal === 'function';
return {
configurable: true,
set: set,
get: get
};
function set(val) {
var action = isFunction ? 'setting the method' : 'setting the property';
warn(action, 'This is effectively a no-op');
return val;
}
function get() {
var action = isFunction ? 'accessing the method' : 'accessing the property';
var result = isFunction ? 'This is a no-op function' : 'This is set to null';
warn(action, result);
return getVal;
}
function warn(action, result) {
var warningCondition = false;
process.env.NODE_ENV !== 'production' ? warning(warningCondition, "This synthetic event is reused for performance reasons. If you're seeing this, " + "you're %s `%s` on a released/nullified synthetic event. %s. " + 'If you must keep the original synthetic event around, use event.persist(). ' + 'See https://fb.me/react-event-pooling for more information.', action, propName, result) : void 0;
}
}
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