Pause app when unfocused

[mfluehr]

I'm making a game, and I'd like it to pause whenever the window loses focus. I've been using WindowEvent::Focused for this, but it's not perfect. The problem I have is that media keys (such as volume up/down) are counted as removing focus. How can I detect "real" focus loss, like clicking on another window, but ignore media keys?

Interestingly, the media keys still grab focus even when I disable the media key OSD. I'm on Linux, but want a cross-platform solution.

[mfluehr]

Other things that might help track focus include WindowEvent::Occluded, Window.is_minimized, and Window.is_visible, but none quite cover what I need. Moreover, cross-OS support is flaky.