Touch Swipe like Swipe Left, Swipe Right, Swipe Up and Swipe Down events for touch devices in Javascript

touch swipe events for touch devices in javascript.js

var xDown = null;
var yDown = null;
document.addEventListener('touchstart', handleTouchStart, false);
document.addEventListener('touchmove', handleTouchMove, false);

function handleTouchStart(evt) {
    xDown = evt.touches[0].clientX;
    yDown = evt.touches[0].clientY;
};

function handleTouchMove(evt) {
    if (!xDown || !yDown) {
        return;
    }

    var xUp = evt.touches[0].clientX;
    var yUp = evt.touches[0].clientY;

    var xDiff = xDown - xUp;
    var yDiff = yDown - yUp;

    if (Math.abs(xDiff) > Math.abs(yDiff)) {
        if (xDiff > 0) {
            // swipe right direction
        }
        else {
            // swipe left direction
        }
    }
    else {
        if (yDiff > 0) {
            // swipe down direction
        }
        else {
            // swipe up direction
        }
    }

    /* reset values */
    xDown = null;
    yDown = null;
};