Experimental ability to pin a window using Mod+p

A pinned window will always try to stay on the same screen in the sname
position if it can.

1 files changed, 32 insertions, 33 deletions

diff --git a/src/Rahm/Desktop/History.hs b/src/Rahm/Desktop/History.hs
index ffcb10e..d1a4bb9 100644
--- a/src/Rahm/Desktop/History.hs
+++ b/src/Rahm/Desktop/History.hs
@@ -58,7 +58,7 @@ zipperDbgPrint _ = "<empty>"
 pushZipper :: a -> BoundedSeqZipper a -> BoundedSeqZipper a
 pushZipper e (BoundedSeqZipper maxSize _ (tail :|> _))
   | maxSize <= Seq.length tail =
-    BoundedSeqZipper maxSize mempty (e :<| tail)
+      BoundedSeqZipper maxSize mempty (e :<| tail)
 pushZipper e (BoundedSeqZipper maxSize _ tail) =
   BoundedSeqZipper maxSize mempty (e :<| tail)
 
@@ -133,44 +133,44 @@ data ScreenDiff = ScreenDiff
     newLocation :: Location
   }
 
-historyHook :: WindowStack -> WindowStack -> X ()
+historyHook :: StackChangeHook
 -- History hook where the 'from' location workspace does not match the 'to'
 -- location workspace.
-historyHook lastWindowSet currentWindowSet = do
+historyHook = StackChangeHook $ \lastWindowSet currentWindowSet -> do
   (History hist) <- XS.get
   forM_ (getScreenDiffs lastWindowSet currentWindowSet) $
     -- Read as "the screen <sid> went from <oloc> to <nloc>"
     \(ScreenDiff sid oloc nloc) ->
       let (ows, nws) = (locationWorkspace oloc, locationWorkspace nloc)
-
-       -- The goal here is to preserve history in as intuitive a way as possible
-       -- When the stackset changes, for each screen that changed in the last
-       -- windowchange, one of 2 situations are possibel:
-       --
-       --   1. The workspace on the screen was swapped with an already visible
-       --      screen
-       --
-       --   2. The workspace on the screen was swapped with a hidden workspace.
-       --
-       --   In the case of 1, we want to treat it as if the screen was
-       --   "reseated" to a different monitor, preserving the history for that
-       --   screen on its new screen.
-       --
-       --   In case of 2, we want to add the old workspace to the history of the
-       --   screen that changed.
-       in case () of
-            () | nws `visibleIn` lastWindowSet,
-                 (Just oscr) <- screenOf nws lastWindowSet ->
-              -- The last workspace was on a different screen. Swap the current
-              -- screen's history with the history from the last screen the
-              -- workspace was on.
-              XS.modify $ \(History byScreen) ->
-                History
-                  ( Map.alter
-                      (const $ Map.lookup oscr hist)
-                      sid
-                      byScreen
-                  )
+       in -- The goal here is to preserve history in as intuitive a way as possible
+          -- When the stackset changes, for each screen that changed in the last
+          -- windowchange, one of 2 situations are possibel:
+          --
+          --   1. The workspace on the screen was swapped with an already visible
+          --      screen
+          --
+          --   2. The workspace on the screen was swapped with a hidden workspace.
+          --
+          --   In the case of 1, we want to treat it as if the screen was
+          --   "reseated" to a different monitor, preserving the history for that
+          --   screen on its new screen.
+          --
+          --   In case of 2, we want to add the old workspace to the history of the
+          --   screen that changed.
+          case () of
+            ()
+              | nws `visibleIn` lastWindowSet,
+                (Just oscr) <- screenOf nws lastWindowSet ->
+                  -- The last workspace was on a different screen. Swap the current
+                  -- screen's history with the history from the last screen the
+                  -- workspace was on.
+                  XS.modify $ \(History byScreen) ->
+                    History
+                      ( Map.alter
+                          (const $ Map.lookup oscr hist)
+                          sid
+                          byScreen
+                      )
             -- The new workspace was not originally visible, add to history
             () | not (nws `visibleIn` lastWindowSet) ->
               XS.modify $ \(History byScreen) ->
@@ -180,7 +180,6 @@ historyHook lastWindowSet currentWindowSet = do
                       sid
                       byScreen
                   )
-
             -- This is typically not a possible case. It's only possible when a
             -- screen is unplugged. If that's the case, do nothing.
             _ -> return ()