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reValuate/node_modules/fbjs/lib/ReactWheelHandler.js
2021-04-02 02:24:13 +03:00

109 lines
2.9 KiB
JavaScript

/**
* Copyright (c) 2013-present, Facebook, Inc.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* This is utility that hanlds onWheel events and calls provided wheel
* callback with correct frame rate.
*
* @typechecks
*/
'use strict';
var emptyFunction = require("./emptyFunction");
var normalizeWheel = require("./normalizeWheel");
var requestAnimationFramePolyfill = require("./requestAnimationFramePolyfill");
var ReactWheelHandler =
/*#__PURE__*/
function () {
/**
* onWheel is the callback that will be called with right frame rate if
* any wheel events happened
* onWheel should is to be called with two arguments: deltaX and deltaY in
* this order
*/
function ReactWheelHandler(
/*function*/
onWheel,
/*boolean|function*/
handleScrollX,
/*boolean|function*/
handleScrollY,
/*?boolean|?function*/
stopPropagation) {
this._animationFrameID = null;
this._deltaX = 0;
this._deltaY = 0;
this._didWheel = this._didWheel.bind(this);
if (typeof handleScrollX !== 'function') {
handleScrollX = handleScrollX ? emptyFunction.thatReturnsTrue : emptyFunction.thatReturnsFalse;
}
if (typeof handleScrollY !== 'function') {
handleScrollY = handleScrollY ? emptyFunction.thatReturnsTrue : emptyFunction.thatReturnsFalse;
}
if (typeof stopPropagation !== 'function') {
stopPropagation = stopPropagation ? emptyFunction.thatReturnsTrue : emptyFunction.thatReturnsFalse;
}
this._handleScrollX = handleScrollX;
this._handleScrollY = handleScrollY;
this._stopPropagation = stopPropagation;
this._onWheelCallback = onWheel;
this.onWheel = this.onWheel.bind(this);
}
var _proto = ReactWheelHandler.prototype;
_proto.onWheel = function onWheel(
/*object*/
event) {
var normalizedEvent = normalizeWheel(event);
var deltaX = this._deltaX + normalizedEvent.pixelX;
var deltaY = this._deltaY + normalizedEvent.pixelY;
var handleScrollX = this._handleScrollX(deltaX, deltaY);
var handleScrollY = this._handleScrollY(deltaY, deltaX);
if (!handleScrollX && !handleScrollY) {
return;
}
this._deltaX += handleScrollX ? normalizedEvent.pixelX : 0;
this._deltaY += handleScrollY ? normalizedEvent.pixelY : 0;
event.preventDefault();
var changed;
if (this._deltaX !== 0 || this._deltaY !== 0) {
if (this._stopPropagation()) {
event.stopPropagation();
}
changed = true;
}
if (changed === true && this._animationFrameID === null) {
this._animationFrameID = requestAnimationFramePolyfill(this._didWheel);
}
};
_proto._didWheel = function _didWheel() {
this._animationFrameID = null;
this._onWheelCallback(this._deltaX, this._deltaY);
this._deltaX = 0;
this._deltaY = 0;
};
return ReactWheelHandler;
}();
module.exports = ReactWheelHandler;