handle wheel event

handleWheel.js

(function (w, modName, time) {
    var st
        ,modName = modName || 'handleWheel'
        ,_run  = 1
        ,time = time || 100
        ;
    function getWheelDir(e) {
        var delta = 0;
        e =window.event || e;
 
        if (e.wheelDelta) {
            delta = e.wheelDelta/120; 
        } else if (e.detail) {
            delta = -e.detail/3;
        }
        return delta ;
    }
 
    w[modName] = function (doUp, doDown) {
        function _handleWheel(e) {
            if (_run) {
                _run = 0;
                setTimeout(function () {
                    _run = 1;
                }, time);

                var dir = getWheelDir(e);
 
                if (dir >0) {
                    (typeof doUp == 'function') && doUp()
                }else {
                    (typeof doDown == 'function') && doDown()
                }
            }
        }
        window.onmousewheel = document.onmousewheel = _handleWheel;
        if (window.addEventListener) {
            window.addEventListener('DOMMouseScroll', _handleWheel, false);
        }
    }
})(window, 'handleWheel', 100);
//此处将组件注册入指定对象中，下面是参数说明
/**
 * @param {Object} arg1 指定注入的对象，可以填window或者其他
 * @param {String} arg2 组件名称，你写成啥，后面就调用啥，默认是handleWheel
 * @param {Number} arg3 时间系统，组件中模拟了underscore的throttle特性，以避免事件的频繁触发,据统计，100ms是很合适的
 **/
 
//invoke
//这里的handleWheel就是上面传入的第二个参数
handleWheel(function () {
    console.log('up') ;
}, function () {
    console.log('down') ;
})