swaywm/hsroots

A Haskell wrapper/binding to wlroots

hsroots, the Haskell bindings to wlroots

If you haven't seen it, wlroots is the compositor library created by the same people who built sway to implement a few things that weren't possible with wlc.

What is this:

• Basic (low! level) bindings to wlroots functionality
• (Re)implementation of basic examples. This is mostly to test
• cabal project to track updated dependencies (I had to expose a bit of functionality, this isn't upstreamed yet).

What this is (mostly) not [help wanted]:

• Complete
• well documented
• Abstracting

This one is semi-intentional. This library is intended to expose pointers as they are, so it can be used with other middlewares etc.

• In a good functional style

Why does this exist?

I mainly created this to support my own endavours. This implies that I will somewhat selectivly add to this as I need it in any project based on this.

Should you be interested in using this and feel like there's a feature missing, I will always appreciate PRs, and will aim to implemented feature requests in a timely manner.

Build instructions

• Install wlroots with the instructions provided in their Readme
• git clone --recursive https://github.com/swaywm/hsroots
• cd hsroots
• cabal new-build

This should download all dependencies needed for hsroots and build it together with the examples provided in this repository.

hsroots's Issues

Is this dead

This has not been updated in 3 years.

Listener finalizer gets called early

addListener finalizers (or more specifically: finalizers associated with their wl_listeners) get called early in hsroots, causing compositors to freeze. Here is a minimum reproducible example:

outputFrameNotify :: WlListener WlrOutput
outputFrameNotify = WlListener $ \ptrWlrOutput ->
  do now <- getTime Realtime
     putStrLn (show now)  --- <-- This pauses after a few seconds due to an early finalizer call

newOutputNotify :: WlListener WlrOutput
newOutputNotify = WlListener $ \ptrWlrOutput ->
  do let outputSignals = getOutputSignals ptrWlrOutput
     let frameSignal  = outSignalFrame outputSignals
     addListener outputFrameNotify frameSignal
     return ()

main :: IO ()
main = do displayServer <- displayCreate
          eventLoop     <- displayGetEventLoop displayServer
          ptrBackend    <- backendAutocreate displayServer

          let newOutputSignal = (backendEvtOutput $ backendGetSignals ptrBackend) :: Ptr (WlSignal WlrOutput)
          addListener newOutputNotify newOutputSignal

          backendStart ptrBackend
          displayRun displayServer
          displayDestroy displayServer

Unable to get hsroots to build with stack

I'm trying to get hsroots to build with stack. To get around

$ stack init
# ...
Selected resolver: lts-13.3
Resolver 'lts-13.3' does not have all the packages to match your requirements.
    data-flags not found
        - hayland requires <0.1
        - xkbcommon requires -any

This may be resolved by:
    - Using '--solver' to ask cabal-install to generate extra-deps, atop the chosen snapshot.
    - Using '--omit-packages' to exclude mismatching package(s).
    - Using '--resolver' to specify a matching snapshot/resolver

I tried

  stack install cabal-install
  stack init --solver --force

but this just yields

# …
CallStack (from HasCallStack):
  error, called at src/Stack/Solver.hs:164:16 in stack-1.10.0-EBfIplDZnWH5c6Nkfwa7eL:Stack.Solver

wlr_output lx,ly removed

Now that swaywm/wlroots#1611 has been merged I'm getting a compilation error here.

What is the input dependency listed as an Extra-Lib

I can't figure out what this dependency is supposed to be.

Consider moving to swaywm GitHub org

I've established the swaywm GitHub org and moved wlroots there. We have discussed maintaining wlroots API wrappers within the swaywm organization - if you'd like, I can add you and we can host it there. Of course, the project would remain yours and you'd still have complete autonomy over it.