Extended PP with sorting algorithm specification and added xinerama sorting

  algorithm
  - idea is to specify sorting algorithm from user's xmonad.hs
  - xinerama sorting algorithm produces same ordering as
    pprWindowSetXinerama
  - default ppSort is set to getSortByTag, so the default functionality
    is the same as it was before

darcs-hash:20080109154923-69f16-2b9674eab322c2cac47698a66402cecae6abe253.gz

1 files changed, 34 insertions, 6 deletions

diff --git a/XMonad/Util/WorkspaceCompare.hs b/XMonad/Util/WorkspaceCompare.hs
index bba9ebe..3517100 100644
--- a/XMonad/Util/WorkspaceCompare.hs
+++ b/XMonad/Util/WorkspaceCompare.hs
@@ -9,12 +9,17 @@
 -- Portability :  unportable
 --
 
-module XMonad.Util.WorkspaceCompare ( getWsIndex, getWsCompare, getSortByTag ) where
+module XMonad.Util.WorkspaceCompare ( getWsIndex
+                                    , getWsCompare
+                                    , getSortByTag
+                                    , getSortByXineramaRule ) where
 
 import XMonad
 import qualified XMonad.StackSet as S
 import Data.List
 import Data.Monoid
+import Data.Ord
+import Data.Maybe
 
 -- | Lookup the index of a workspace id in the user's config, return Nothing
 -- if that workspace does not exist in the config.
@@ -28,14 +33,37 @@ getWsCompare :: X (WorkspaceId -> WorkspaceId -> Ordering)
 getWsCompare = do
     wsIndex <- getWsIndex
     return $ \a b -> f (wsIndex a) (wsIndex b) `mappend` compare a b
- where
-   f Nothing Nothing   = EQ
-   f (Just _) Nothing  = LT
-   f Nothing (Just _)  = GT
-   f (Just x) (Just y) = compare x y
+  where
+    f Nothing Nothing   = EQ
+    f (Just _) Nothing  = LT
+    f Nothing (Just _)  = GT
+    f (Just x) (Just y) = compare x y
+
+-- | A comparison function for Xinerama based on visibility, workspace and
+-- screen id. It produces same ordering as pprWindowSetXinerama does.
+getXineramaWsCompare :: X(WorkspaceId -> WorkspaceId -> Ordering)
+getXineramaWsCompare = do
+    w <- gets windowset
+    return $ \ a b -> case (isOnScreen a w, isOnScreen b w) of
+        (True, True)   -> comparing (tagToSid (onScreen w)) a b
+        (False, False) -> compare a b
+        (True, False)  -> LT
+        (False, True)  -> GT
+  where
+    onScreen w =  S.current w : S.visible w
+    isOnScreen a w  = a `elem` map (S.tag . S.workspace) (onScreen w)
+    tagToSid s x = S.screen $ fromJust $ find ((== x) . S.tag . S.workspace) s
+                 --S.screen $ head $ filter ((== x) . S.tag . S.workspace) s
 
 -- | Sort several workspaces according to the order in getWsCompare
 getSortByTag :: X ([WindowSpace] -> [WindowSpace])
 getSortByTag = do
     cmp <- getWsCompare
     return $ sortBy (\a b -> cmp (S.tag a) (S.tag b))
+
+-- | Sort serveral workspaces for xinerama displays
+getSortByXineramaRule :: X ([WindowSpace] -> [WindowSpace])
+getSortByXineramaRule = do
+    cmp <- getXineramaWsCompare
+    return $ sortBy (\a b -> cmp (S.tag a) (S.tag b))
+