Window focus stealing has been around for a long time, there's a
Wikipedia article on it, it's been asked a few times on
SuperUser and there's apparently a ForegroundLockTimeout
registry value that may assist. But it probably doesn't.
The fact is that some applications don't respect system settings, and steal focus
anyway.
You can probably write code to take your focus back, possibly even fast enough to
avoid the thieving app from receiving dangerous input.
AutoHotkey, is,
once again, ideally suited, and this problem is certainly under discussion
on their forum.
So I stole the code from
here (thanks SKAN
and r0lZ) and a tiny
bit from here (thanks
Chris), and we've
a means not to stop focus stealing (sorry, haven't given that a go yet) but at least
to record a history of focused windows so we can see exactly what process / window
it was that stole focus and intercepted our keystroke. What the hell did we just
authorize? Well, we can know.
Install AutoHotkey, then download
the script. Execute it and you've now a history of windows that
have come into focus. Drop a shortcut to
"C:\path\to\AutoHotkey.exe" "C:\path\to\windowHistory.ahk"
into your start menu startup folder to always have it running. Now find and double
click the new AHK icon in the notification area to open the script window, from
the View menu select Variables and their contents. At
the bottom you will see the variable winNum, which is the most recent
recorded window index.
The last 30 windows and their processes are listed here, saved to these variables
in a loop. Go to the one matching the winNum value for the latest and
count backward to see the windows in focus prior (after zero you jump back to twenty-nine).
The number after process names is the PID or
process identifier, you can match this to an exact process in task manager
(you may need to turn on the PID column from the view menu).
This is crude and not much more than a copy paste job, but it demonstrates that
we don't have to live with these frustrations, we can take action.
;)