SpawnOn modification for issue 523

Ignore-this: 703f7dc0f800366b752f0ec1cecb52e5

This moves the function to help clean up the `Spawner' to the ManageHook
rather than in functions like spawnOn. Probably it makes no difference, the
reason is because there's one manageSpawn function but many different so this
way there are less functions to write.

darcs-hash:20130114014642-1499c-5d00aa9a169d200f22b278b541ae0f9efe2d0358.gz

1 files changed, 11 insertions, 6 deletions

diff --git a/XMonad/Actions/SpawnOn.hs b/XMonad/Actions/SpawnOn.hs
index d7500b2..1154ce5 100644
--- a/XMonad/Actions/SpawnOn.hs
+++ b/XMonad/Actions/SpawnOn.hs
@@ -20,6 +20,7 @@ module XMonad.Actions.SpawnOn (
     -- $usage
     Spawner,
     manageSpawn,
+    manageSpawnWithGC,
     spawnHere,
     spawnOn,
     spawnAndDo,
@@ -66,8 +67,6 @@ newtype Spawner = Spawner {pidsRef :: [(ProcessID, ManageHook)]} deriving Typeab
 instance ExtensionClass Spawner where
     initialValue = Spawner []
 
-maxPids :: Int
-maxPids = 5
 
 -- | Get the current Spawner or create one if it doesn't exist.
 modifySpawner :: ([(ProcessID, ManageHook)] -> [(ProcessID, ManageHook)]) -> X ()
@@ -76,14 +75,20 @@ modifySpawner f = XS.modify (Spawner . f . pidsRef)
 -- | Provides a manage hook to react on process spawned with
 -- 'spawnOn', 'spawnHere' etc.
 manageSpawn :: ManageHook
-manageSpawn = do
+manageSpawn = manageSpawnWithGC (return . take 20)
+
+manageSpawnWithGC :: ([(ProcessID, ManageHook)] -> X [(ProcessID, ManageHook)])
+        -- ^ function to stop accumulation of entries for windows that never set @_NET_WM_PID@
+       -> ManageHook
+manageSpawnWithGC garbageCollect = do
     Spawner pids <- liftX XS.get
     mp <- pid
     case flip lookup pids =<< mp of
         Nothing -> idHook
         Just mh  -> do
-            whenJust mp $ \p ->
-                liftX . modifySpawner $ filter ((/= p) . fst)
+            whenJust mp $ \p -> liftX $ do
+                ps <- XS.gets pidsRef
+                XS.put . Spawner =<< garbageCollect (filter ((/= p) . fst) ps)
             mh
 
 mkPrompt :: (String -> X ()) -> XPConfig -> X ()
@@ -115,7 +120,7 @@ spawnOn ws cmd = spawnAndDo (doShift ws) cmd
 spawnAndDo :: ManageHook -> String -> X ()
 spawnAndDo mh cmd = do
     p <- spawnPID $ mangle cmd
-    modifySpawner $ (take maxPids . ((p,mh) :))
+    modifySpawner $ ((p,mh) :)
  where
     -- TODO this is silly, search for a better solution
     mangle xs | any (`elem` metaChars) xs || "exec" `isInfixOf` xs = xs