[xmonad] MultiToggle with WorkspaceCursors

ivan ivan.brennan at gmail.com
Sun Mar 26 12:59:53 UTC 2023 

That makes sense, thanks again.

I've revisited my initial approach, but might also take a stab at storing a
cursors-like tree in extensibleState.
In case it's of interest, this is a somewhat minimal config demonstrating
the approach I'm revisiting:
https://github.com/ivanbrennan/xmonad-testing/commit/8ff9e594d55885b0b2915fee71b1cd5f61598aa0#diff-74b618a2356f7943b297a5769de732a94848295a4bd563c68f998eafb843dd36

On Sun, Mar 26, 2023 at 12:21 AM Platon Pronko <platon7pronko at gmail.com>
wrote:

> Yes, you are right, my original analysis was incorrect. WorkspaceCursors
> does indeed store a tree of cursors, and that is not derivable from the
> current workspace id.
>
> However I still think that storing cursors state in LayoutModifier is
> incorrect - layout information is local for every workspace, while cursors
> state should be global, not duplicated per every workspace (I can't prove
> it, but I definitely feel that there are bugs lurking in WorkspaceCursors
> because of that duplication).
>
> I think you can achieve what you need without using WorkspaceCursors as a
> layout modifier. You can store cursors state in a global variable and work
> with it yourself. Something like:
>
> cursors = unsafePerformIO $ newIORef $ makeCursors [nominalIds, groupIds]
>
> (if you don't like unsafePerformIO, you also store cursors inside XMonad's
> XState.extensibleState)
>
> Unfortunately you won't be able to reuse most of WorkspaceCursors stack
> management functions, because they are either private or call modifyCursors
> directly or indirectly. You'll have to copy them and adapt them to work on
> your cursors state.
>
> --
> Best regards,
> Platon Pronko
> PGP 2A62D77A7A2CB94E
>
> On 2023-03-26 09:49, ivan wrote:
> > Following up on this:
> >
> >> In my opinion WorkspaceCursors doesn't need to be a LayoutModifier at
> all
> > - current state can be derived from the list of cursors and currently
> > focused workspace, no need to store it somewhere.
> >
> > I've been using WorkspaceCursors to switch between (simulated) groups of
> > workspaces, relying on the Cursors state to remember which workspace has
> > focus within each group. So switching to group G will focus whichever
> > workspace was focused last time I visited that group. (Or, if it's the
> > first time I've visited that group, its first workspace gets focus).
> >
> > The Cursors state feels like a natural way to implement that, but it's
> not
> > the only way. My initial implementation treated StackSet.workspaces as a
> > recency list, and switching to group G meant finding the first workspace
> in
> > that list that was a member of G. When I started using Cursors state
> > instead, I ran into the problem you explained.
> >
> > For now, I'll revisit my initial approach.
> >
> > Thanks again!
> >
> > On Sat, Mar 25, 2023 at 8:15 AM ivan <ivan.brennan at gmail.com> wrote:
> >
> >> Amazing! Thank you so much for the clear explanation.
> >>
> >> On Sat, Mar 25, 2023 at 4:26 AM Platon Pronko <platon7pronko at gmail.com>
> >> wrote:
> >>
> >>> Hi!
> >>>
> >>> WorkspaceCursors doesn't introduce any groups, it's just a glorified
> >>> workspace switcher - underneath all the chrome it uses the standard
> flat
> >>> workspaces list. In essense it just defines some helper functions that
> >>> allow user to imagine that workspaces are arranged as a
> multidimensional
> >>> cube and navigate along axes of said cube. But it still does it using
> the
> >>> usual StackSet.greedyView function.
> >>>
> >>> MultiToggle is irrelevant in this case, the same effect can be seen
> with
> >>> the boring Choose layout combinator (i.e. `Tall ||| Full`) - the layout
> >>> state is "spilling" over to other workspaces.
> >>>
> >>> It seems that the problem arises because WorspaceCursors calls
> `windows $
> >>> greedyView` inside LayoutClass.handleMessage function - current
> workspace
> >>> is switched at the same time as layout is updated, and Xmonad assigns
> the
> >>> updated layout to the new workspace.
> >>>
> >>> Here's a reproducer (should work on all configs that have a workspace
> >>> with id "4"):
> >>>
> >>> ```
> >>> -- necessary language pragmas
> >>> {-# LANGUAGE FlexibleInstances, MultiParamTypeClasses #-}
> >>>
> >>> -- imports
> >>> import qualified XMonad.StackSet as W
> >>> import XMonad.Layout.LayoutModifier(ModifiedLayout(..),
> >>> LayoutModifier(handleMess))
> >>> import XMonad(Message, X, windows, sendMessage, fromMessage)
> >>>
> >>> -- Example LayoutModifier that showcases the issue.
> >>> -- It does nothing except calling `greedyView "4"` upon reciept of
> >>> SwitchWorkspace message
> >>> data BadLayoutModifier a = BadLayoutModifier deriving (Read, Show)
> >>>
> >>> data SwitchWorkspace = SwitchWorkspace
> >>> instance Message SwitchWorkspace
> >>>
> >>> instance LayoutModifier BadLayoutModifier a where
> >>>     handleMess BadLayoutModifier m = do
> >>>       case fromMessage m of
> >>>         Just SwitchWorkspace -> do
> >>>           windows $ W.greedyView "4"
> >>>           return $ Just BadLayoutModifier
> >>>         Nothing -> return Nothing
> >>>
> >>> -- add to keys (tweak the keybinding to your taste)
> >>>     , ((modm, xK_v), sendMessage SwitchWorkspace)
> >>>
> >>> -- prepend BadLayoutModifier to layoutHook
> >>> layoutHook =
> >>>     ModifiedLayout BadLayoutModifier $
> >>>     (Tall 1 (3/100) (1/2) ||| Full)
> >>> ```
> >>>
> >>> Steps to reproduce:
> >>>
> >>> 1. Recompile and restart Xmonad.
> >>> 2. Toggle workspace "2" to "Tall" layout, toggle workspace "4" to
> "Full"
> >>> layout.
> >>> 3. Switch to workspace "2".
> >>> 4. Press keybinding to send the SwitchWorkspace message (Super-v in my
> >>> case).
> >>> 5. Observe that Xmonad switches to workspace "4", and layout on that
> >>> workspace is now "Tall" instead of "Full" as set up originally.
> >>>
> >>> In my opinion WorkspaceCursors doesn't need to be a LayoutModifier at
> all
> >>> - current state can be derived from the list of cursors and currently
> >>> focused workspace, no need to store it somewhere. This will sidestep
> the
> >>> problem of calling `greedyView` during layout update.
> >>>
> >>> --
> >>> Best regards,
> >>> Platon Pronko
> >>> PGP 2A62D77A7A2CB94E
> >>>
> >>> On 2023-03-24 23:27, Brandon Allbery wrote:
> >>>> My guess is that MultiToggle doesn't and can't know about
> >>>> WorkspaceCursors, and WorkspaceCursors doesn't and can't know that it
> >>>> needs to duplicate the layout state for each group it introduces, so
> >>>> any layout state change applies to all groups.
> >>>>
> >>>> On Fri, Mar 24, 2023 at 11:22 AM ivan <ivan.brennan at gmail.com> wrote:
> >>>>>
> >>>>> Hi, I'm trying to get MultiToggle and WorkspaceCursors to play nicely
> >>> with each other.
> >>>>>
> >>>>> Ordinarily, MultiToggle lets you apply a layout transformation to the
> >>> current workspace without affecting the layouts of other workspaces.
> E.g.
> >>> if I toggle workspace 1 to Full layout, it won't impact the layouts
> being
> >>> used on workspaces 2, 3, etc.
> >>>>>
> >>>>> I've started using WorkspaceCursors (XMonad.Actions.WorkspaceCursors)
> >>> to manage independent groups of workspaces, and noticed that if I use
> it's
> >>> functions (e.g. modifyLayer) to navigate between workspaces, layout
> toggle
> >>> states seem to bleed across workspaces rather than remaining
> independent
> >>> per workspace.
> >>>>>
> >>>>> For example, starting on workspace 1 with my regular Tall layout, I
> >>> navigate to workspace 2 and toggle it to Full layout. Then I go back to
> >>> workspace 1 and see that it, too, has been toggled to Full layout.
> >>>>>
> >>>>> I can't figure out exactly what's causing this, or how to fix it so
> >>> that workspace layouts toggle independently. I'm hoping someone here
> sees
> >>> what I'm missing.
> >>>>>
> >>>>> I put together a minimal config to reproduce the problem:
> >>>>>
> >>>
> https://github.com/ivanbrennan/xmonad-testing/commit/2e9541b0937eee31ae7f300e130dc55a9c5933af#diff-61bfccbc988708bd118b33f9299c64aa8b3e532e25cc8eaa3b716f53215fb196
> >>>>>
> >>>>> The config provides two groups (A and B) of nine workspaces.
> >>>>>
> >>>>>       group A: 1A 2A 3A 4A 5A 6A 7A 8A 9A
> >>>>>       group B: 1B 2B 3B 4B 5B 6B 7B 8B 9B
> >>>>>
> >>>>> Its layoutHook consists of:
> >>>>>
> >>>>>       myLayoutHook =
> >>>>>         workspaceCursors cursors
> >>>>>           . avoidStruts
> >>>>>           . mkToggle1 FULL
> >>>>>           $ Tall 1 (3/100) (1/2)
> >>>>>
> >>>>> Keys super+1 .. super+9 use WorkspaceCursors functions to switch
> >>> between workspaces within the currently active group.
> >>>>>
> >>>>> Keys super+ctrl+1 .. super+ctrl+2 use WorkspaceCursors functions to
> >>> switch between groups A and B.
> >>>>>
> >>>>> Additionally, keys super+meta+1 .. super+meta+9 use traditional
> >>> StackSet functions to switch between workspaces 1A .. 9A. I added
> these for
> >>> comparison, showing that MultiToggle state is recognized per-workspace
> when
> >>> using this form of navigation.
> >>>>>
> >>>>> I can't figure out the root cause. I suspect the most relevant pieces
> >>> of code from WorkspaceCursors and MultiToggle are the following:
> >>>>>
> >>>>>
> >>>
> https://github.com/xmonad/xmonad-contrib/blob/e60805bd45ca2feb9ef3335d023daae5d02dbf4f/XMonad/Actions/WorkspaceCursors.hs#L204-L215
> >>>>>
> >>>>>
> >>>
> https://github.com/xmonad/xmonad-contrib/blob/e60805bd45ca2feb9ef3335d023daae5d02dbf4f/XMonad/Layout/MultiToggle.hs#L193-L218
> >>>>>
> >>>>> Does anyone know what I might be missing, or how I could debug
> further
> >>> to get to the root of the problem?
> >>>>>
> >>>>> Thanks!
> >>>>> Ivan
> >>>>> _______________________________________________
> >>>>> xmonad mailing list
> >>>>> xmonad at haskell.org
> >>>>> http://mail.haskell.org/cgi-bin/mailman/listinfo/xmonad
> >>>>
> >>>>
> >>>>
> >>>
> >>
> >
>
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