页面可见性事件 - 标签页被隐藏或显示

visibilitychange.js

(function(document) { // title提示
    var titleTime;
    var oldTitle = document.title;
    var shortcut = document.getElementById('shortcut');

    document.addEventListener('visibilitychange', function() {
        if (document.hidden) {
            document.title = '(●—●)咦，去哪儿啊？';
            clearTimeout(titleTime);
            shortcut.href = 'images/fail.ico';
        } else {
            document.title = '(/≧▽≦/)欢迎回来！ - ' + oldTitle;
            shortcut.href = 'images/favicon.ico';
            titleTime = setTimeout(function() {
                document.title = oldTitle;
            }, 2e3);
        }
    })
})(document);