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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 EventListener = require('fbjs/lib/EventListener');
var ExecutionEnvironment = require('fbjs/lib/ExecutionEnvironment');
var PooledClass = require('./PooledClass');
var ReactDOMComponentTree = require('./ReactDOMComponentTree');
var ReactUpdates = require('./ReactUpdates');
var getEventTarget = require('./getEventTarget');
var getUnboundedScrollPosition = require('fbjs/lib/getUnboundedScrollPosition');
/**
* Find the deepest React component completely containing the root of the
* passed-in instance (for use when entire React trees are nested within each
* other). If React trees are not nested, returns null.
*/
function findParent(inst) {
// TODO: It may be a good idea to cache this to prevent unnecessary DOM
// traversal, but caching is difficult to do correctly without using a
// mutation observer to listen for all DOM changes.
while (inst._hostParent) {
inst = inst._hostParent;
}
var rootNode = ReactDOMComponentTree.getNodeFromInstance(inst);
var container = rootNode.parentNode;
return ReactDOMComponentTree.getClosestInstanceFromNode(container);
}
// Used to store ancestor hierarchy in top level callback
function TopLevelCallbackBookKeeping(topLevelType, nativeEvent) {
this.topLevelType = topLevelType;
this.nativeEvent = nativeEvent;
this.ancestors = [];
}
_assign(TopLevelCallbackBookKeeping.prototype, {
destructor: function () {
this.topLevelType = null;
this.nativeEvent = null;
this.ancestors.length = 0;
}
});
PooledClass.addPoolingTo(TopLevelCallbackBookKeeping, PooledClass.twoArgumentPooler);
function handleTopLevelImpl(bookKeeping) {
var nativeEventTarget = getEventTarget(bookKeeping.nativeEvent);
var targetInst = ReactDOMComponentTree.getClosestInstanceFromNode(nativeEventTarget);
// Loop through the hierarchy, in case there's any nested components.
// It's important that we build the array of ancestors before calling any
// event handlers, because event handlers can modify the DOM, leading to
// inconsistencies with ReactMount's node cache. See #1105.
var ancestor = targetInst;
do {
bookKeeping.ancestors.push(ancestor);
ancestor = ancestor && findParent(ancestor);
} while (ancestor);
for (var i = 0; i < bookKeeping.ancestors.length; i++) {
targetInst = bookKeeping.ancestors[i];
ReactEventListener._handleTopLevel(bookKeeping.topLevelType, targetInst, bookKeeping.nativeEvent, getEventTarget(bookKeeping.nativeEvent));
}
}
function scrollValueMonitor(cb) {
var scrollPosition = getUnboundedScrollPosition(window);
cb(scrollPosition);
}
var ReactEventListener = {
_enabled: true,
_handleTopLevel: null,
WINDOW_HANDLE: ExecutionEnvironment.canUseDOM ? window : null,
setHandleTopLevel: function (handleTopLevel) {
ReactEventListener._handleTopLevel = handleTopLevel;
},
setEnabled: function (enabled) {
ReactEventListener._enabled = !!enabled;
},
isEnabled: function () {
return ReactEventListener._enabled;
},
/**
* Traps top-level events by using event bubbling.
*
* @param {string} topLevelType Record from `EventConstants`.
* @param {string} handlerBaseName Event name (e.g. "click").
* @param {object} element Element on which to attach listener.
* @return {?object} An object with a remove function which will forcefully
* remove the listener.
* @internal
*/
trapBubbledEvent: function (topLevelType, handlerBaseName, element) {
if (!element) {
return null;
}
return EventListener.listen(element, handlerBaseName, ReactEventListener.dispatchEvent.bind(null, topLevelType));
},
/**
* Traps a top-level event by using event capturing.
*
* @param {string} topLevelType Record from `EventConstants`.
* @param {string} handlerBaseName Event name (e.g. "click").
* @param {object} element Element on which to attach listener.
* @return {?object} An object with a remove function which will forcefully
* remove the listener.
* @internal
*/
trapCapturedEvent: function (topLevelType, handlerBaseName, element) {
if (!element) {
return null;
}
return EventListener.capture(element, handlerBaseName, ReactEventListener.dispatchEvent.bind(null, topLevelType));
},
monitorScrollValue: function (refresh) {
var callback = scrollValueMonitor.bind(null, refresh);
EventListener.listen(window, 'scroll', callback);
},
dispatchEvent: function (topLevelType, nativeEvent) {
if (!ReactEventListener._enabled) {
return;
}
var bookKeeping = TopLevelCallbackBookKeeping.getPooled(topLevelType, nativeEvent);
try {
// Event queue being processed in the same cycle allows
// `preventDefault`.
ReactUpdates.batchedUpdates(handleTopLevelImpl, bookKeeping);
} finally {
TopLevelCallbackBookKeeping.release(bookKeeping);
}
}
};
module.exports = ReactEventListener;
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