如何使用Javascript检测当前窗口是否在另一个窗口后面

Question

Is it possible to detect whether the web browser window is currently covered by another window?

document.hidden and document.visibilityState only changes state on switching tabs or when the entire window is minimized.

document.hasFocus() returns false if the window is visible but not in focus (eg the focus is on the taskbar)

Answer 1

Nope, that's not possible.

There's no way in JavaScript to know how visible the window is.

Answer 2

Browser windows overlapping one another, the position of the browser windows, and which one of them is on top - these functionalities are handled by the operating system.

No matter what code you write for your webpage, you cannot tell if your browser window is overlapped by another.

So yeah, the answer is NO .