-----------------------------------------------------------------------------
-- |
-- Module      :  XMonad.Actions.CycleWorkspaceByScreen
-- Description :  Cycle workspaces in a screen-aware fashion.
-- Copyright   :  (c) 2017 Ivan Malison
-- License     :  BSD3-style (see LICENSE)
--
-- Maintainer  :  IvanMalison@gmail.com
-- Stability   :  unstable
-- Portability :  unportable
--
-- Cycle through previously viewed workspaces in the order they were viewed most
-- recently on the screen where cycling is taking place.
--
-----------------------------------------------------------------------------

module XMonad.Actions.CycleWorkspaceByScreen (
    -- * Usage
    -- $usage
    cycleWorkspaceOnScreen
  , cycleWorkspaceOnCurrentScreen
  , handleKeyEvent
  , repeatableAction
  ) where

import           Data.IORef

import           Graphics.X11.Xlib.Extras

import           XMonad
import           XMonad.Prelude
import           XMonad.Hooks.WorkspaceHistory
import qualified XMonad.StackSet as W

-- $usage
--
-- To use this module, first import it as well as
-- "XMonad.Hooks.WorkspaceHistory":
--
-- > import XMonad.Hooks.WorkspaceHistory (workspaceHistoryHook)
-- > import XMonad.Actions.CycleWorkspaceByScreen
--
-- Then add 'workspaceHistoryHook' to your @logHook@ like this:
--
-- > main :: IO ()
-- > main = xmonad $ def
-- >    { ...
-- >    , logHook = workspaceHistoryHook >> ...
-- >    }
--
-- Finally, define a new keybinding for cycling (seen) workspaces per
-- screen:
--
-- > , ((mod4Mask, xK_slash), cycleWorkspaceOnCurrentScreen [xK_Super_L] xK_slash xK_p)

repeatableAction :: [KeySym] -> (EventType -> KeySym -> X ()) -> X ()
repeatableAction :: [KeySym] -> (EventType -> KeySym -> X ()) -> X ()
repeatableAction [KeySym]
mods EventType -> KeySym -> X ()
pressHandler = do
  XConf {theRoot :: XConf -> KeySym
theRoot = KeySym
root, display :: XConf -> Display
display = Display
d} <- forall r (m :: * -> *). MonadReader r m => m r
ask
  let getNextEvent :: X (EventType, KeySym)
getNextEvent = forall (m :: * -> *) a. MonadIO m => IO a -> m a
io forall a b. (a -> b) -> a -> b
$ forall a. (XEventPtr -> IO a) -> IO a
allocaXEvent forall a b. (a -> b) -> a -> b
$ \XEventPtr
p ->
                 do
                   Display -> KeySym -> XEventPtr -> IO ()
maskEvent Display
d (KeySym
keyPressMask forall a. Bits a => a -> a -> a
.|. KeySym
keyReleaseMask) XEventPtr
p
                   KeyEvent {ev_event_type :: Event -> EventType
ev_event_type = EventType
t, ev_keycode :: Event -> KeyCode
ev_keycode = KeyCode
c} <- XEventPtr -> IO Event
getEvent XEventPtr
p
                   KeySym
s <- forall (m :: * -> *) a. MonadIO m => IO a -> m a
io forall a b. (a -> b) -> a -> b
$ Display -> KeyCode -> CInt -> IO KeySym
keycodeToKeysym Display
d KeyCode
c CInt
0
                   forall (m :: * -> *) a. Monad m => a -> m a
return (EventType
t, KeySym
s)
      handleEvent :: (EventType, KeySym) -> X ()
handleEvent (EventType
t, KeySym
s)
        | EventType
t forall a. Eq a => a -> a -> Bool
== EventType
keyRelease Bool -> Bool -> Bool
&& KeySym
s forall (t :: * -> *) a. (Foldable t, Eq a) => a -> t a -> Bool
`elem` [KeySym]
mods = forall (m :: * -> *) a. Monad m => a -> m a
return ()
        | Bool
otherwise = EventType -> KeySym -> X ()
pressHandler EventType
t KeySym
s forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>> X (EventType, KeySym)
getNextEvent forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= (EventType, KeySym) -> X ()
handleEvent

  forall (m :: * -> *) a. MonadIO m => IO a -> m a
io forall a b. (a -> b) -> a -> b
$ Display -> KeySym -> Bool -> CInt -> CInt -> KeySym -> IO CInt
grabKeyboard Display
d KeySym
root Bool
False CInt
grabModeAsync CInt
grabModeAsync KeySym
currentTime
  X (EventType, KeySym)
getNextEvent forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= (EventType, KeySym) -> X ()
handleEvent
  forall (m :: * -> *) a. MonadIO m => IO a -> m a
io forall a b. (a -> b) -> a -> b
$ Display -> KeySym -> IO ()
ungrabKeyboard Display
d KeySym
currentTime

handleKeyEvent :: EventType
               -> KeySym
               -> X ()
               -> EventType
               -> KeySym
               -> Maybe (X ())
handleKeyEvent :: EventType -> KeySym -> X () -> EventType -> KeySym -> Maybe (X ())
handleKeyEvent EventType
eventType KeySym
key X ()
action = EventType -> KeySym -> Maybe (X ())
helper
  where
  helper :: EventType -> KeySym -> Maybe (X ())
helper EventType
et KeySym
k
    | EventType
et forall a. Eq a => a -> a -> Bool
== EventType
eventType Bool -> Bool -> Bool
&& KeySym
k forall a. Eq a => a -> a -> Bool
== KeySym
key = forall a. a -> Maybe a
Just X ()
action
    | Bool
otherwise = forall a. Maybe a
Nothing


runFirst :: [EventType -> KeySym -> Maybe (X ())] -> EventType -> KeySym -> X ()
runFirst :: [EventType -> KeySym -> Maybe (X ())]
-> EventType -> KeySym -> X ()
runFirst [EventType -> KeySym -> Maybe (X ())]
matchers EventType
eventType KeySym
key =
  forall a. a -> Maybe a -> a
fromMaybe (forall (m :: * -> *) a. Monad m => a -> m a
return ()) forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a. Monad m => m (m a) -> m a
join forall a b. (a -> b) -> a -> b
$ forall (t :: * -> *) a. Foldable t => (a -> Bool) -> t a -> Maybe a
find forall a. Maybe a -> Bool
isJust forall a b. (a -> b) -> a -> b
$ forall a b. (a -> b) -> [a] -> [b]
map (\EventType -> KeySym -> Maybe (X ())
fn -> EventType -> KeySym -> Maybe (X ())
fn EventType
eventType KeySym
key) [EventType -> KeySym -> Maybe (X ())]
matchers

-- | Like 'XMonad.Actions.CycleRecentWS.cycleRecentWS', but only cycle
-- through the most recent workspaces on the given screen.
cycleWorkspaceOnScreen
  :: ScreenId -- ^ The screen to cycle on.
  -> [KeySym] -- ^ A list of modifier keys used when invoking this
              --   action; as soon as one of them is released, the final
              --   switch is made.
  -> KeySym   -- ^ Key used to switch to next workspace.
  -> KeySym   -- ^ Key used to switch to previous workspace.
  -> X ()
cycleWorkspaceOnScreen :: ScreenId -> [KeySym] -> KeySym -> KeySym -> X ()
cycleWorkspaceOnScreen ScreenId
screenId [KeySym]
mods KeySym
nextKey KeySym
prevKey = X () -> X ()
workspaceHistoryTransaction forall a b. (a -> b) -> a -> b
$ do
  [(ScreenId, [WorkspaceId])]
startingHistory <- X [(ScreenId, [WorkspaceId])]
workspaceHistoryByScreen
  IORef Int
currentWSIndex <- forall (m :: * -> *) a. MonadIO m => IO a -> m a
io forall a b. (a -> b) -> a -> b
$ forall a. a -> IO (IORef a)
newIORef Int
1
  let cycleWorkspaces :: [WorkspaceId]
cycleWorkspaces = forall a. a -> Maybe a -> a
fromMaybe [] forall a b. (a -> b) -> a -> b
$ forall a b. Eq a => a -> [(a, b)] -> Maybe b
lookup ScreenId
screenId [(ScreenId, [WorkspaceId])]
startingHistory
      getAndIncrementWS :: Int -> IO WorkspaceId
getAndIncrementWS Int
increment = do
        Int
current <- forall a. IORef a -> IO a
readIORef IORef Int
currentWSIndex
        forall a. IORef a -> (a -> a) -> IO ()
modifyIORef
          IORef Int
currentWSIndex
          ((forall a. Integral a => a -> a -> a
`mod` forall (t :: * -> *) a. Foldable t => t a -> Int
length [WorkspaceId]
cycleWorkspaces) forall b c a. (b -> c) -> (a -> b) -> a -> c
. (forall a. Num a => a -> a -> a
+ Int
increment))
        forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$ [WorkspaceId]
cycleWorkspaces forall a. [a] -> Int -> a
!! Int
current
      focusIncrement :: Int -> X ()
focusIncrement Int
i = forall (m :: * -> *) a. MonadIO m => IO a -> m a
io (Int -> IO WorkspaceId
getAndIncrementWS Int
i) forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= ((WindowSet -> WindowSet) -> X ()
windows forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall s i l a sd.
(Eq s, Eq i) =>
i -> StackSet i l a s sd -> StackSet i l a s sd
W.greedyView)

  Int -> X ()
focusIncrement Int
1 -- Do the first workspace cycle
  [KeySym] -> (EventType -> KeySym -> X ()) -> X ()
repeatableAction [KeySym]
mods forall a b. (a -> b) -> a -> b
$
    [EventType -> KeySym -> Maybe (X ())]
-> EventType -> KeySym -> X ()
runFirst
      [ EventType -> KeySym -> X () -> EventType -> KeySym -> Maybe (X ())
handleKeyEvent EventType
keyPress KeySym
nextKey forall a b. (a -> b) -> a -> b
$ Int -> X ()
focusIncrement Int
1
      , EventType -> KeySym -> X () -> EventType -> KeySym -> Maybe (X ())
handleKeyEvent EventType
keyPress KeySym
prevKey forall a b. (a -> b) -> a -> b
$ Int -> X ()
focusIncrement (-Int
1)
      ]
  forall (m :: * -> *) a. Monad m => a -> m a
return ()

-- | Like 'cycleWorkspaceOnScreen', but supply the currently focused
-- screen as the @screenId@.
cycleWorkspaceOnCurrentScreen
  :: [KeySym] -> KeySym -> KeySym -> X ()
cycleWorkspaceOnCurrentScreen :: [KeySym] -> KeySym -> KeySym -> X ()
cycleWorkspaceOnCurrentScreen [KeySym]
mods KeySym
n KeySym
p =
  forall a. (WindowSet -> X a) -> X a
withWindowSet forall a b. (a -> b) -> a -> b
$ \WindowSet
ws ->
    ScreenId -> [KeySym] -> KeySym -> KeySym -> X ()
cycleWorkspaceOnScreen (forall i l a sid sd. Screen i l a sid sd -> sid
W.screen forall a b. (a -> b) -> a -> b
$ forall i l a sid sd. StackSet i l a sid sd -> Screen i l a sid sd
W.current WindowSet
ws) [KeySym]
mods KeySym
n KeySym
p