Multi-workspace projects/scopes

[ivanbrennan]

Problem Description

A project defined by X.A.DynamicProjects or X.A.TopicSpace is limited to a single workspace. I often want to treat a group of workspaces as a scope, constraining workspace cycling and status-bar display to a particular scope.

For example, if I have workspaces A B C D E, I can define a "personal" scope spanning A B and a "work" scope spanning C D. When the "personal" scope is active, my statusbar shows A B and workspace cycling is limited to those workspaces. Switching to the "work" scope behaves similarly, for C D. Switching to unscoped makes all workspaces accessible.

Tmux has a concept of "sessions" that works like this. Each session has an independent set of workspaces (or rather, "windows", in tmux terminology), and you can easily switch between sessions. This provides a nice way to group related workspaces into independent units and choose which unit you want to work with.

I looked into X.A.DynamicWorkspaceGroups, but its group represents a set of simultaneously visible workspaces on a multi-screen setup, as opposed to a set of workspaces that a given screen can cycle through.

Solution

I'm interested in implementing this, but I'm not sure how best to do it. I'd be interested to hear anyone's thoughts/suggestions.

After reading through X.A.DynamicWorkspaceGroups, X.A.DynamicProjects, and X.L.IndependentScreens, I started sketching something out, using ExtensibleState to keep track of which scopes have been defined, activated, etc.

newtype WorkScope = WorkScope { unWorkScope :: !(Set WorkspaceId) }

type WorkScopeName = String

newtype ScopeSets = ScopeSets
  { workScopes   :: !(Map WorkScopeName WorkScope),
    activeScopes :: !(Map ScreenId WorkScopeName) -- TODO: track which workspace is displayed?
  }
  deriving (Typeable, Read, Show)

instance ExtensionClass WorkScopes where
  initialValue = WorkScopes mempty
  extensionType = PersistentExtension

It looks like there's a fair amount of state to keep track of and several edge-cases to consider (e.g. workspaces being renamed/removed, selecting a scope that's active on another screen, ...), so I haven't really settled on how to model it or keep state in sync (maybe using a layout modifier?).

Another approach I'm considering would attach a Maybe WorkScopeName to a workspace, and scoping would involve filtering workspaces based on the relevant scope. I suspect this would be more reliable than my initial Map-based idea, since it wouldn't need to update state any time a workspace is removed or renamed. And X.L.WorkspaceDir provides an example of how to use a layout modifier to attach metadata to a workspace. If we wanted to allow a workspace to be a member of multiple scopes, the Maybe WorkScopeName could instead be a Set WorkScopeName.

Checklist

• [x] I've read CONTRIBUTING.md

• [ ] I tested my configuration with xmonad-testing

[jeyj0]

If we wanted to allow a workspace to be a member of multiple scopes

That's definitely a feature I would want :)

[liskin]

And X.L.WorkspaceDir provides an example of how to use a layout modifier to attach metadata to a workspace.

Unfortunately it doesn't provide a way to read that metadata. But I'm working on that, specifically to provide a way to read the dir out of WorkspaceDir, see https://github.com/xmonad/xmonad-contrib/pull/398#issuecomment-723937287. The Typeable changes required are merged to xmonad/xmonad-contrib, ale the latest prototype of InspectLayoutModifier is here: https://github.com/liskin/xmonad-contrib/commit/77c1821ed6e70668f02e0f5f28e11262209d0ded. I think I'll just need to add a few (overlapping 🙁) instanes and some documentation and we might be good to go.

And I feel like I could use this feature as well! I now have 11 workspaces, 6 of which are related to a project that is currently on hold while I'm hacking on xmonad. Would be awesome to be able to hide those somehow. I'm a bit afraid that this will need to be wired into quite a lot of various places, but we can figure something out!

[mislavzanic]

Hi, I've been working on something similar to this for my personal use. Here's the module if anyone is still interested. I'm somewhat of a haskell newbie and the module is a work in progress, so keep that in mind when looking at the code. I've been using this for 2 weeks now and it's good enough for me.

Feel free to message me if you have any suggestions 🙂.

[ivanbrennan]

Thanks @mislavzanic, I for one am still very interested in this feature. Regretfully, I haven't looked into it for a while, but this is a good reason to revisit it.

[ivanbrennan]

@liskin Is there anything I could help with to get InspectLayout ready for a PR?

Experimenting in my config, I was able to make use of your Inspect module, defining a simple layout modifier that attaches metadata to a workspace and using inspectWorkspace to read that data.

[liskin]

@ivanbrennan If you help me with the docs (TODOs) in https://github.com/liskin/xmonad-contrib/commits/layout-inspect, specifically https://github.com/liskin/xmonad-contrib/commit/07dd2194196603a7465ae4f51fc6ef57645add15, then a PR can definitely be opened. I've been burned out lately so my initiative is limited, but you're right that this one doesn't need much additional work to be generally usable.

[mislavzanic]

@ivanbrennan I would love to help out, so don't hesitate to contact me.

[ivanbrennan]

@liskin @mislavzanic Thanks! I'll take a look at those TODOs.

I'm just starting to play around with possible implementations of workspace scopes. At the moment, I'm grouping workspaces into layers, so rather than 1, 2, ..., 9 I have (1_1, 1_2, ..., 1_9), (2_1, 2_2, ..., 2_9), ..., and tracking which layer is considered currently active.

I just came across XMonad.Actions.WorkspaceCursors, which looks very powerful (and cleanly implemented) and could be used to implement such layers.

I haven't yet explored dynamic layer manipulation or naming layers, but plan to do so -- thanks @mislavzanic for sharing the Profiles idea.

[mislavzanic]

Anybody still interested in this? I've been using my extension for about a year.. There may be some details that need to be discussed, but it's working pretty nicely.

If anybody is interested in using it feel free to ping me.

[geekosaur]

There's been some interest expressed on the IRC channel recently. In any case, contrib is always open to new submissions. 😀

[mislavzanic]

Ok, I'll start working on a PR then. Will need a couple of days to tidy up and write the documentation.
Hope to be done by end of the week.