A more reliable way to check if device uses touch or mouse.

tactus.js

// https://blogs.perficientdigital.com/2017/11/21/detecting-the-use-of-a-touch-screen/

// Usage: isTouch().then( (result) ) {
//  if (result) console.log("Yep, uses touch");
//  else console.log("Nope, uses mouse");
//}

// Set a variable detecting the existence of touch events
var _hasEvents = 'ontouchstart' in window || navigator.msMaxTouchPoints > 0;
var _isTouchCached = null;

// Default isTouch check
export function isTouch() {
  return new Promise(function (resolve, reject) {
    if (_isTouchCached != null) {
      resolve(_isTouchCached);
    } 
    // If the browser supports touch events
    if (_hasEvents) {
      // Add the mouse/touch event listeners
      _addListeners(resolve, reject);
    }
    else {
      // If the browser doesn't support touch events
      resolve(false);
    }
  });
}

// The function to add the mouse/touch event listeners
function _addListeners(resolve, reject) {
  window.touch_promise = resolve;

  // Add the mouse event listener
  window.addEventListener('mousemove', _checkForMouse);

  // Add the touch event listener
  window.addEventListener('touchstart', _checkForTouch);
}

function _checkForMouse(e) {
  // Remove the mouse/touch event listeners
  _removeListeners();

  _isTouchCached = false;
  e.currentTarget.touch_promise(false);
}

function _checkForTouch(e) {
  // Remove the mouse/touch event listeners
  _removeListeners();

  _isTouchCached = true;
  e.currentTarget.touch_promise(true);
}

// The function to remove the mouse/touch event listeners
function _removeListeners() {
  // Remove the mouse event listener
  window.removeEventListener('mousemove', _checkForMouse);

  // Remove the touch event listener
  window.removeEventListener('touchstart', _checkForTouch);
}
export default { isTouch };