H5移动端判断是否切出浏览器

pageShowOrHide(showCb, hideCb) {
    //切换后台倒计时停止问题
    var hidden, state, visibilityChange;
    if (typeof document.hidden !== "undefined") {
        hidden = "hidden";
        visibilityChange = "visibilitychange";
        state = "visibilityState";
    } else if (typeof document.mozHidden !== "undefined") {
        hidden = "mozHidden";
        visibilityChange = "mozvisibilitychange";
        state = "mozVisibilityState";
    } else if (typeof document.msHidden !== "undefined") {
        hidden = "msHidden";
        visibilityChange = "msvisibilitychange";
        state = "msVisibilityState";
    } else if (typeof document.webkitHidden !== "undefined") {
        hidden = "webkitHidden";
        visibilityChange = "webkitvisibilitychange";
        state = "webkitVisibilityState";
    }
    var cb = function() {
        if (document[state] == hidden) {
            hideCb && hideCb();
            console.log('hide');
        } else {
            showCb && showCb();
            console.log('show');
        }
    };
    document.removeEventListener(visibilityChange, cb, false);
    document.addEventListener(visibilityChange, cb, false);
}