How do I automatically send SIGSTOP to workspace apps when switching away from a workspace?

lkraav
518 ●17 ●33 ●48

I read somewhere in i3bar documentation or code or whatnot that it automatically sends SIGSTOP to i3status when in hidden mode. I think that's wonderful and would like to have the same thing for some background Wine apps that hammer the CPU when I don't need them to (hello Picasa 3).

So when I switch away from workspace 4, SIGSTOP should be sent to x+1 processes. When I switch back to workspace 4, SIGCONT is sent sent to x+1 processes.

Any suggestions?

Comments

I know that endre and Merovius from #i3 have scripts to do this for firefox.

Michael (Aug 27 '13)edit

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answered Sep 10 '14

f8l

86 ●1 ●2 http://f8l.netne.net/

You can subscribe to workspace event with IPC. Whenever you catch the workspace focus event do the following:

Remember the id of old workspace.
Send GET_TREE.
For each container in old workspace:
1. Get the container's client X11 window ID (window in the TREE reply).
2. Query the _NET_WM_PID with xprop.
3. Send SIGSTOP to that pid.

This is a simplified algorithm which doesn't take setups with multiple monitors into account, but I think an additional check against WORKSPACES reply will do the trick.

Of course you'll have to send SIGCONT to windows on current workspace analogously.