I want to ackknowledge that it may be program dependent, and individual programs may have their own focus abilities.
However,
On several games of which I have not been able to find a solution, when clicking on the other monitor, removing focus from a full screen program, that program is minimized to the task bar. Windowed programs, boarderless windowed, and other sized windows do not have this behavior. Only those programs internally set to “full screen” are minimized on de-focus.
Is there a way to turn this behavior OFF in Plamsa 5?
I have searched the interwebs and found it lacking. Short of disabling the compositor, which seems to work fine otherwise, I would like to know if there is a way to stop Plasma from doing anything to any full screen program.
In the most likely case this is the application’s chosen behavior.
I’ve been clicking out of fullscreen windows on multi monitor setup for years without these being affected, e.g. browsers, video players, presentation software.
It might be possible to counter-act the appllcation’s behavior with KWin’s window rules.
To set those up you need to get into the window menu, e.g. right-clicking the taskbar entry, right-clicking the titlebar when not fullscreen, ALT+F3 when the window is focused.
Under “More Actions” you’ll find “Configure Special Window Settings” and “Configure Special Application Settings”.
The primary values are for detecting the window, e.g. which properties does a window need to have to apply the rest of the rules.
You can add those additional rules with “Add Property”. One of them is “Fullscreen”.
Theoretically this should allow you to force these windows to remain fullscreen at all times but it is hard to tell what the result will be if the application “fights back” or “gets confused” when its request to minimize is not fulfilled.