@helpscout/hsds-react/components/Overflow/Overflow.utils.js

React component library for Help Scout's Design System

"use strict";

exports.__esModule = true;
exports.hasContentOverflowX = exports.remapScrollingPlane = exports.isMouseWheelYEvent = void 0;

var _node = require("../../utilities/node");

var isFirefox = function isFirefox() {
  if (!navigator) return false;
  return navigator.userAgent.toLowerCase().indexOf('firefox') > -1;
};
/**
 * Determines if a wheel event came from a mouse or from a trackpad.
 *
 * There is not native way to do this in the browser. To calculate this,
 * various assumptions were made on the delta + threshold values.
 *
 * This function isn't full-proof, as a VERY hard trackpad swipe will
 * result in a true (due to it's higher delta value).
 *
 * Note: This is not effective at all in Firefox, since their delta values
 * are completely off compared to other browsers.
 *
 * @param   {WheelEvent} event
 *
 * @returns {boolean}
 */


var isMouseWheelYEvent = function isMouseWheelYEvent(event) {
  if (event === void 0) {
    event = {};
  }

  var _event = event,
      deltaX = _event.deltaX,
      deltaY = _event.deltaY;
  if (deltaX === undefined || deltaY === undefined) return false; // Wheel scrolls always have an x value of 0

  var neutralX = 0; // Enlarges the data set for more precise calculations

  var wheelMultiplier = 240; // Limiter

  var wheelThreshold = 480; // Values for calculation

  var computedDeltaX = deltaX * (wheelMultiplier * -1);
  var computedDeltaY = Math.abs(deltaY) * wheelMultiplier / 120 * 10;
  if (computedDeltaX !== neutralX) return false;
  return computedDeltaY >= wheelThreshold;
};

exports.isMouseWheelYEvent = isMouseWheelYEvent;

var remapScrollingPlane = function remapScrollingPlane(event) {
  // Scrolling behaviour is strange in Firefox…
  // We'll let Firefox natively handle things.
  // Can't write tests for this in JSDOM.
  // Can't create fixture for JSDOM's built-in Navigator instance.
  if (isFirefox()) return;
  var node = event.currentTarget; // Don't customize native shift + scroll interactions

  if (event.target.shiftKey) return;
  if (!node) return;

  if (Math.abs(event.deltaX) > Math.abs(event.deltaY)) {
    return;
  }

  if (isMouseWheelYEvent(event)) {
    node.scrollLeft += event.deltaY;
  } // Scroll-locking


  if (event.cancelable) event.preventDefault();
};

exports.remapScrollingPlane = remapScrollingPlane;

var hasContentOverflowX = function hasContentOverflowX(node) {
  if (!(0, _node.isNodeElement)(node)) return false;
  return node.clientWidth < node.scrollWidth;
};

exports.hasContentOverflowX = hasContentOverflowX;