Javascript Swipe Events

swipeEvents.js

function getSwipeEvent(deltaX, deltaY) {
  switch(true) {
    case deltaX >= 50: return new Event('swipeLeft');
    case deltaX <= -50: return new Event('swipeRight');
    case deltaY >= 50: return new Event('swipeUp');
    case deltaY <= -50: return new Event('swipeDown');
  }
}

function swipeEvents() {
  var startX, startY;

  function touchstart(event) {
    var touches = event.touches;
    if (touches && touches.length) {
      startX = touches[0].pageX;
      startY = touches[0].pageY;
      document.addEventListener('touchmove', touchmove);
    }
  }

  document.addEventListener('touchstart', touchstart);

  function touchmove(event) {
    var touches = event.touches;

    if (touches && touches.length) {
      event.preventDefault();

      var
        deltaX = startX - touches[0].pageX,
        deltaY = startY - touches[0].pageY,
        swipeEvent = getSwipeEvent(deltaX, deltaY);

      if (swipeEvent) document.dispatchEvent(swipeEvent);

      if (Math.abs(deltaX) >= 50 || Math.abs(deltaY) >= 50) {
        document.removeEventListener('touchmove', touchmove);
      }
    }
  }
};

bindEvents.js

    swipeEvents();
    document.addEventListener("swipeDown",  function(event) {
      event.preventDefault();
      moveUp();
    });

    document.addEventListener("swipeUp", function(event){
      event.preventDefault();
      moveDown();
    });