[feat] properly color the borders when swapping windows.

1 files changed, 19 insertions, 2 deletions

diff --git a/src/Rahm/Desktop/Keys/KeyFeed.hs b/src/Rahm/Desktop/Keys/KeyFeed.hs
index 46a2520..5b00af9 100644
--- a/src/Rahm/Desktop/Keys/KeyFeed.hs
+++ b/src/Rahm/Desktop/Keys/KeyFeed.hs
@@ -4,7 +4,7 @@
 module Rahm.Desktop.Keys.KeyFeed where
 
 import Control.Monad (void, when)
-import Control.Monad.State (MonadTrans (lift), StateT, evalStateT, modify')
+import Control.Monad.State (MonadTrans (lift), StateT (..), evalStateT, modify')
 import Control.Monad.Trans.Maybe (MaybeT (MaybeT, runMaybeT))
 import Data.List.Safe (head, last)
 import Linear.V (reifyDim)
@@ -28,7 +28,24 @@ newtype KeyFeed a = KeyFeed (StateT KeyStream (MaybeT X) a)
   deriving (Functor, Applicative, Monad)
 
 instance Xish KeyFeed where
-  liftFromX = liftXToFeed
+  liftFromX = KeyFeed . lift . lift
+
+  finallyX (KeyFeed mt) (KeyFeed err) =
+    KeyFeed $ do
+      r <- recover mt
+      case r of
+        Nothing -> do
+          err
+          let (KeyFeed r) = feedFail in r
+        Just a -> err >> pure a
+    where
+      recover fn = StateT $ \s -> MaybeT $ do
+        r <- runMaybeT (runStateT fn s)
+        pure $
+          Just $
+            case r of
+              Nothing -> (Nothing, s)
+              Just (a, s') -> (Just a, s')
 
 -- Executes a KeyFeed, returning a MaybeT of the result
 runKeyFeed :: KeyFeed a -> MaybeT X a