@livelybone/mouse-wheel/lib/es/index.js

A module for bind mouse-wheel event. typescript supported

/**
 * Bundle of @livelybone/mouse-wheel
 * Generated: 2020-05-16
 * Version: 4.2.1
 * License: MIT
 * Author: 2631541504@qq.com
 */

var prefix = '';
var $addEventListener = 'addEventListener';
var $removeEventListener = 'removeEventListener';
var support = 'wheel';

if (typeof window !== 'undefined' && typeof document !== 'undefined') {
  // detect event model
  if ('addEventListener' in window) {
    $addEventListener = 'addEventListener';
    $removeEventListener = 'removeEventListener';
  } else {
    $addEventListener = 'attachEvent';
    $removeEventListener = 'detachEvent';
    prefix = 'on';
  } // detect available wheel event


  if ('onwheel' in document.createElement('div')) {
    // "Wheel" is supported by most higher versions of browsers
    // 各个厂商的高版本浏览器都支持"wheel"
    support = 'wheel';
  } else if (window.onmousewheel !== undefined) {
    // Webkit and IE always support "mousewheel"
    // Webkit 和 IE一定支持"mousewheel"
    support = 'mousewheel';
  } else {
    // Low version of firefox
    // 低版本firefox
    support = 'DOMMouseScroll';
  }
}

function dealOriginalEvent(ev) {
  var originalEvent = ev || window.event; // create a normalized event object

  var event = {
    // keep a ref to the original event object
    originalEvent: originalEvent,
    timeStamp: originalEvent.timeStamp,
    target: originalEvent.target || originalEvent.srcElement,
    type: 'wheel',
    deltaMode: originalEvent.type === 'MozMousePixelScroll' ? 0 : 1,
    deltaX: 0,
    deltaY: 0,
    deltaZ: 0,
    preventDefault: function preventDefault() {
      if (originalEvent.preventDefault) originalEvent.preventDefault();else originalEvent.returnValue = false;
    }
  }; // calculate deltaY (and deltaX) according to the event

  if (support === 'mousewheel') {
    event.deltaY = -1 / 40 * originalEvent.wheelDelta;

    if (originalEvent.wheelDeltaX) {
      // Webkit also support wheelDeltaX
      event.deltaX = -1 / 40 * originalEvent.wheelDeltaX;
    }
  } else {
    event.deltaY = originalEvent.detail;
  }

  return event;
}

function getExHeight(elem) {
  var el = elem instanceof Window ? document.documentElement : elem;
  var fontSize = window.getComputedStyle(el).fontSize || '16px';
  return parseInt(fontSize, 10);
}

function $addWheelListener(element, eventName, listener) {
  var $options = arguments.length > 3 && arguments[3] !== undefined ? arguments[3] : {};
  var options = {
    debounceTime: $options.debounceTime || 0,
    interval: $options.interval || 500,
    useCapture: $options.useCapture || false
  };
  var timer;
  var lastTime = 0;

  function $listener(ev) {
    var e = support === 'wheel' ? ev : dealOriginalEvent(ev);
    var timeDelta = e.timeStamp - lastTime;
    var type = 'wheelMove';
    if (timeDelta < options.debounceTime) return;
    if (timeDelta > options.interval) type = 'wheelStart'; // deltaMode: https://developer.mozilla.org/zh-CN/docs/Web/API/WheelEvent/deltaMode

    var scale = 1;

    if (e.deltaMode === 1) {
      scale = getExHeight(element);
    } else if (e.deltaMode === 2) {
      scale = window.innerHeight;
    }

    var dTime = type !== 'wheelStart' ? timeDelta : 0;
    listener({
      dx: e.deltaX * scale || 0,
      dy: e.deltaY * scale || 0,
      dz: e.deltaZ * scale || 0,
      dTime: dTime,
      originalEvent: e,
      type: type
    });
    lastTime = e.timeStamp;
    clearTimeout(timer);
    timer = setTimeout(function () {
      listener({
        dx: 0,
        dy: 0,
        dz: 0,
        dTime: dTime + options.interval,
        originalEvent: {
          timeStamp: e.timeStamp + options.interval
        },
        type: 'wheelEnd'
      });
    }, options.interval);
  }

  var addListener = element[$addEventListener];
  addListener(prefix + eventName, $listener, options.useCapture);
  return function () {
    var removeListener = element[$removeEventListener];
    removeListener(prefix + eventName, $listener, options.useCapture);
  };
}

var bind = function bind(element, listener, options) {
  /* eslint-disable no-param-reassign */
  if (typeof element === 'function') {
    options = listener;
    listener = element;
    element = window;
  }

  if (support === 'DOMMouseScroll') {
    // handle MozMousePixelScroll in older Firefox
    return $addWheelListener(element, 'MozMousePixelScroll', listener, options);
  }

  return $addWheelListener(element, support, listener, options);
};

export { bind };