Files
react/src/core/ReactEventTopLevelCallback.js
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2.7 KiB
JavaScript

/**
* Copyright 2013 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* @providesModule ReactEventTopLevelCallback
* @typechecks static-only
*/
"use strict";
var ExecutionEnvironment = require('ExecutionEnvironment');
var ReactEventEmitter = require('ReactEventEmitter');
var ReactID = require('ReactID');
var ReactInstanceHandles = require('ReactInstanceHandles');
var getEventTarget = require('getEventTarget');
/**
* @type {boolean}
* @private
*/
var _topLevelListenersEnabled = true;
/**
* Top-level callback creator used to implement event handling using delegation.
* This is used via dependency injection in `ReactEventEmitter.ensureListening`.
*/
var ReactEventTopLevelCallback = {
/**
* Sets whether or not any created callbacks should be enabled.
*
* @param {boolean} enabled True if callbacks should be enabled.
*/
setEnabled: function(enabled) {
_topLevelListenersEnabled = !!enabled;
},
/**
* @return {boolean} True if callbacks are enabled.
*/
isEnabled: function() {
return _topLevelListenersEnabled;
},
/**
* Creates a callback for the supplied `topLevelType` that could be added as
* a listener to the document. The callback computes a `topLevelTarget` which
* should be the root node of a mounted React component where the listener
* is attached.
*
* @param {string} topLevelType Record from `EventConstants`.
* @return {function} Callback for handling top-level events.
*/
createTopLevelCallback: function(topLevelType) {
return function(nativeEvent) {
if (!_topLevelListenersEnabled) {
return;
}
// TODO: Remove when synthetic events are ready, this is for IE<9.
if (nativeEvent.srcElement &&
nativeEvent.srcElement !== nativeEvent.target) {
nativeEvent.target = nativeEvent.srcElement;
}
var topLevelTarget = ReactInstanceHandles.getFirstReactDOM(
getEventTarget(nativeEvent)
) || ExecutionEnvironment.global;
var topLevelTargetID = ReactID.getID(topLevelTarget) || '';
ReactEventEmitter.handleTopLevel(
topLevelType,
topLevelTarget,
topLevelTargetID,
nativeEvent
);
};
}
};
module.exports = ReactEventTopLevelCallback;