Detect mouse direction and cancel hovers

mouse-direction-cancel-hovers.js

// depends on modernizr and jquery
if ($('html').hasClass('no-touchevents')) {
    var hoverDelay = 17;
    var hoverTimeouts = [];
    var hoverDelayTO = 0;
    function processHoverTimeouts () {
        hoverTimeouts.forEach(function (timeout) {
            timeout();
        });
        hoverTimeouts = [];
    }
    function addHoverTimeout (timeout) {
        hoverTimeouts.push(timeout);
        clearTimeout(hoverDelayTO);
        hoverDelayTO = setTimeout(processHoverTimeouts, hoverDelay);
    }
    var time = Date.now();
    var mX = 0;
    var mY = 0;
    $('body').on('mousemove', function (e) {
        var delta = Date.now() - time;
        var mA = 0; // mouse direction (in radians)
        if (delta >= 40) {
            if (e.pageY == mY && e.pageX == mX) {
                return;
            }
            mA = Math.atan2(e.pageY - mY, e.pageX - mX);
            mX = e.pageX;
            mY = e.pageY;
        }
        if (hoverTimeouts.length && mA < 1.5 && mA > -1.5) {
            clearTimeout(hoverDelayTO);
            hoverDelayTO = setTimeout(processHoverTimeouts, hoverDelay);
        }
    });
    $('li.on-the-side').on('mouseleave', function (e) {
        var el = $(e.currentTarget);
        if (window.innerWidth < 1024) {
            return true;
        }
        addHoverTimeout(function () {
            el.parents('ul').find('li.on-the-side').removeClass('is-active');
        });
    });
    $('li.on-the-side').on('mouseenter', function (e) {
        var el = $(e.currentTarget);
        if (window.innerWidth < 1024) {
            return true;
        }
        addHoverTimeout(function () {
            el.addClass('is-active');
        });
    });
}