Re: [xmonad] run a program when switching to a workspace

On Thu, May 28, 2009 at 10:50:34AM +0300, Roman Cheplyaka wrote:

* Brent Yorgey [2009-05-27 22:52:04-0400]

...

On Mon, May 25, 2009 at 08:47:42AM -0600, Sergey Manucharian wrote:

...

Hi folks,

How can I configure xmonad to run a program when switching to a particular workspace? Example: I want to run a script changing the keyboard layout to "us" unconditionally when I'm on particular workspaces (with ssh, rdesktop etc.).

The easiest way to do this is to add an action to your logHook that checks the current workspace, and sets the keyboard layout if it is the desired workspace:

... logHook = ...other stuff... >> checkKBLayout

...

checkKBLayout :: X () checkKBLayout = do curTag <- gets (W.currentTag . windowset) when (curTag == "foo") $ spawn "set keyboard layout"

Of course, "foo" should be replaced with whatever workspace you want, and "set keyboard layout" should be replaced with a suitable command for setting the keyboard layout.

Just to make it clear: the command will be spawned each time when windowset changes -- e.g. when you change the focus. It's harmless with setting kb layout, but if you use it for e.g. launching an application you'll get a new instance each time you change focus.

Another possibility is to create IORef and store previous workspace there, so you can know whether you really _switched_ to current workspace.

Maybe create a layer on top of logHook which would provide incremental information?

That's a nice idea! I've always thought that the logHook could be generalized in a number of interesting ways. There are lots of things that might want to be notified of status changes which have nothing to do with logging. -Brent