xmonad-contrib/XMonad/Util/SessionStart.hs

63 lines
2.0 KiB
Haskell

-----------------------------------------------------------------------------
-- |
-- Module : XMonad.Util.SessionStart
-- Description : A module for detectiong session startup.
-- Copyright : (c) Markus Ongyerth 2017
-- License : BSD3-style (see LICENSE)
--
-- Maintainer : markus@ongy.net
-- Stability : unstable
-- Portability : not portable
--
-- A module for detectiong session startup. Useful to start
-- status bars, compositors and session initialization.
-- This is a more general approach than spawnOnce and allows spawnOn etc.
-----------------------------------------------------------------------------
module XMonad.Util.SessionStart
( doOnce
, isSessionStart
, setSessionStarted
)
where
import XMonad.Prelude (when)
import XMonad
import qualified XMonad.Util.ExtensibleState as XS
-- ---------------------------------------------------------------------
-- $usage
--
-- Add 'setSessionStarted' at the end of the 'startupHook' to set the
-- flag.
--
-- To do something only when the session is started up, use
-- 'isSessionStart' to query or wrap it in 'doOnce' to only do it when
-- the flag isn't set.
-- ---------------------------------------------------------------------
newtype SessionStart = SessionStart { unSessionStart :: Bool }
deriving (Read, Show)
instance ExtensionClass SessionStart where
initialValue = SessionStart True
extensionType = PersistentExtension
-- | Use this to only do a part of your hook on session start
doOnce :: X () -> X ()
doOnce act = do
startup <- isSessionStart
when startup act
-- | Query if the current startup is the session start
isSessionStart :: X Bool
isSessionStart = unSessionStart <$> XS.get
-- This should become a noop/be deprecated when merged into master, and
-- the flag should be set when the state file is loaded.
-- | This currently has to be added to the end of the startup hook to
-- set the flag.
setSessionStarted :: X ()
setSessionStarted = XS.put $ SessionStart False