Re: [xmonad] Strange workspace switching bug in my config

18 May 2012

      Leo Alekseyev [2012.05.18 0228 -0400]:
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On Tue, May 15, 2012 at 5:32 PM, Leo Alekseyev  wrote:
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On Tue, May 15, 2012 at 4:22 PM,   wrote:
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Quoting Norbert Zeh :
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for any starting workspace except "0" or
"0SCR", say its number is x, the above code goes to workspace x-1 or x+9.
...
What is it I don't understand here?
The workspace at index 0 in the list of workspaces is "1:blah", at index 1
is "2:blah", etc.
Well, if anyone is curious, I've isolated the breakage to the floating
scratchpad workspace.  It appears that after the first time the
scratchpad is spawned, its workspace (with the tag NSP) is inserted at
index 0 in the workspace array.  I'm assuming that it used to not be
the case with older Xmonad versions...
Ah, that explains it.  Here's a piece of code that makes the whole process
independent of the actual ordering of the workspaces (something that my previous
broken suggestion also tried to do).

jumpToMain = do
  num <- gets (head . W.tag . W.workspace . W.current . windowset)
  ws  <- asks (workspaces . config)
  let m = find (\w -> head w == num && w /= (num : "SCR")) ws
  windows (W.greedyView $ fromJust m)

jumpToScratch = do
  num <- gets (head . W.tag . W.workspace . W.current . windowset)
  windows (W.greedyView $ num : "SCR")

This should work whenever you have pairs of workspaces of the form "<x>SCR" and
"<x><something else>" and these are the only workspaces that start with <x>.  It
will do nothing for workspaces that are not paired with a corresponding
"<x>SCR".  If you modify your config so you have an "<x>SCR" and no other
workspace that starts with <x>, then the last line of jumpToMain will throw an
error.  In that situation, you should change this line to "maybe (return ())
(windows . W.greedyView) m".  jumpToMain then quietly does nothing if it cannot
find a workspace starting with <x> other than "<x>SCR".

I hope I didn't once again overlook something, as I didn't have the time to
actually set up my environment to test this.  At least it compiled once I added
it to my xmonad.hs.

Cheers,
Norbert