检测重点是浏览器地址栏？

有没有办法检测何时将焦点放在地址栏或浏览器搜索栏上？

Is there a way to detect when focus has been put onto the address-bar or the browser-search-bar?

我问，因为我试图保持专注于我的文档中的一个元素，但为该元素添加 blur（）侦听器（调用 focus（）在同一个元素上）在 Safari Mac中运行得很好 - 你可以'当setFocus的超时为0时（插件需要），将焦点放在地址栏上。

I ask because I am trying to keep focus on one element in my document, but adding a blur() listener to that element (which calls focus() on that same element) works too well in Safari Mac -- you can't put focus on the address-bar when you setFocus with a timeout of 0 (necessary for a plugin).