d2-ui
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/**
* Copyright (c) 2013-present, 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 EventListener
* @typechecks
*/
var emptyFunction = require('./emptyFunction');
/**
* Upstream version of event listener. Does not take into account specific
* nature of platform.
*/
var EventListener = {
/**
* Listen to DOM events during the bubble phase.
*
* @param {DOMEventTarget} target DOM element to register listener on.
* @param {string} eventType Event type, e.g. 'click' or 'mouseover'.
* @param {function} callback Callback function.
* @return {object} Object with a `remove` method.
*/
listen: function (target, eventType, callback) {
if (target.addEventListener) {
target.addEventListener(eventType, callback, false);
return {
remove: function () {
target.removeEventListener(eventType, callback, false);
}
};
} else if (target.attachEvent) {
target.attachEvent('on' + eventType, callback);
return {
remove: function () {
target.detachEvent('on' + eventType, callback);
}
};
}
},
/**
* Listen to DOM events during the capture phase.
*
* @param {DOMEventTarget} target DOM element to register listener on.
* @param {string} eventType Event type, e.g. 'click' or 'mouseover'.
* @param {function} callback Callback function.
* @return {object} Object with a `remove` method.
*/
capture: function (target, eventType, callback) {
if (target.addEventListener) {
target.addEventListener(eventType, callback, true);
return {
remove: function () {
target.removeEventListener(eventType, callback, true);
}
};
} else {
if (__DEV__) {
console.error('Attempted to listen to events during the capture phase on a ' + 'browser that does not support the capture phase. Your application ' + 'will not receive some events.');
}
return {
remove: emptyFunction
};
}
},
registerDefault: function () {}
};
module.exports = EventListener;