Just had to reboot because of some message in Pd about input being grabbed. At that point: keyboard was dead. All other app menus were dead, except the system menu with the reboot option.

I apologize that I couldn't copy/paste the error text because 1/ ctrl-c obviously dead (keyboard inactive); 2/ RMC in the Tk error window was inactive; 3/ I couldn't even copy/paste a temp filename from any other app to save it.

Why does this happen and how to prevent it?

Sorry but it's quite upsetting to be in the middle of something and Tk breaks user input globally.

hjh

@ddw_music Are you running a virtual Machine or VNC on your system?
The message in Tk I see available is "another application has grabbed keyboard or pointer (code)"
What OS?

@whale-av said:

@ddw_music Are you running a virtual Machine or VNC on your system?
The message in Tk I see available is "another application has grabbed keyboard or pointer (code)"
What OS?

Linux.

I was running VirtualBox at that time... huh, I guess that's it.

GUI frameworks other than Tk seem to have no trouble though.

hjh

@ddw_music It's not really a failing in Tk. It could be a "failing" in the Pd windowing implementation of Tk.
But where should focus go? You were presumably using Pd when the focus was grabbed by the VM. I think the VM was being an unhelpful bully if you were not interacting with it at the time.
Different OS's handle focus differently.
Windows (the clue is in the name) is strictly windows.
Unix was never intended to have any windows and hacks everything in Window Managers to make itself user friendly. They all have different behaviours.

You could ask on the list for a rewrite for Pd, but I doubt that anyone would take it up.
You could do the mod yourself, but it's "complicated".......
https://wiki.tcl-lang.org/page/Don't+do+that
David.

@whale-av said:

But where should focus go? You were presumably using Pd when the focus was grabbed by the VM. I think the VM was being an unhelpful bully if you were not interacting with it at the time.

One thing that's unclear to me is how the VM could have grabbed focus at that moment. The VM was on workspace 1; Pd was on workspace 2. There's no way to have both Pd and the VM simultaneously visible in that case. When it went wrong (I think...), I'm pretty sure I was on workspace 2 interacting with Pd.

Another perhaps plausible scenario is that the VM was supposed to release focus when I switched to workspace 2 but maybe, under some strange conditions, it doesn't, and then a click in Pd triggers the warning box to pop up.

Anyway I've never seen this with any app other than Pd.

hjh