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32 lines
1.1 KiB
32 lines
1.1 KiB
"use strict"; |
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/** |
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* Copyright (c) 2013-present, Facebook, Inc. |
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* |
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* This source code is licensed under the MIT license found in the |
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* LICENSE file in the root directory of this source tree. |
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* |
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*/ |
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var TouchEventUtils = { |
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/** |
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* Utility function for common case of extracting out the primary touch from a |
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* touch event. |
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* - `touchEnd` events usually do not have the `touches` property. |
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* http://stackoverflow.com/questions/3666929/ |
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* mobile-sarai-touchend-event-not-firing-when-last-touch-is-removed |
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* |
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* @param {Event} nativeEvent Native event that may or may not be a touch. |
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* @return {TouchesObject?} an object with pageX and pageY or null. |
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*/ |
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extractSingleTouch: function extractSingleTouch(nativeEvent) { |
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var touches = nativeEvent.touches; |
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var changedTouches = nativeEvent.changedTouches; |
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var hasTouches = touches && touches.length > 0; |
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var hasChangedTouches = changedTouches && changedTouches.length > 0; |
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return !hasTouches && hasChangedTouches ? changedTouches[0] : hasTouches ? touches[0] : nativeEvent; |
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} |
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}; |
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module.exports = TouchEventUtils; |