1 files changed, 77 insertions, 0 deletions
diff --git a/src/Internal/Marking.hs b/src/Internal/Marking.hs
new file mode 100644
index 0000000..352131b
--- /dev/null
+++ b/src/Internal/Marking.hs
@@ -0,0 +1,77 @@
+{-# LANGUAGE ScopedTypeVariables #-}
+module Internal.Marking where
+
+import XMonad
+import Data.IORef
+import Data.Map (Map)
+
+import System.FilePath
+import System.IO
+import Control.Exception
+
+import qualified Data.Map as Map
+
+{- Submodule that handles marking windows so they can be jumped back to. -}
+
+type Mark = Char
+
+data MarkState =
+  MarkState {
+    markStateMap :: Map Mark Window 
+  , markLast :: Maybe Window
+  } deriving (Read, Show)
+
+data MarkContext = MarkContext (IORef MarkState)
+
+readMarkState :: IO MarkState
+readMarkState = do
+  dir <- getXMonadDir
+  let markstate = dir </> "markstate"
+  catch
+    (read <$> (hGetContents =<< openFile markstate ReadMode))
+    (\(e :: IOError) -> return (MarkState mempty Nothing))
+
+saveMarkState :: MarkState -> X ()
+saveMarkState ms = do
+  dir <- getXMonadDir
+  let markstate = dir </> "markstate"
+  liftIO $ writeFile markstate (show ms)
+
+
+withNewMarkContext :: (MarkContext -> IO a) -> IO a
+withNewMarkContext fn = do
+  ioref <- newIORef =<< readMarkState
+  fn (MarkContext ioref)
+
+markCurrentWindow :: MarkContext -> Mark -> X ()
+markCurrentWindow (MarkContext ioref) mark = do
+  withFocused $ \win ->
+    liftIO $
+      modifyIORef ioref $ \state@(MarkState {markStateMap = ms}) ->
+        state {
+          markStateMap = Map.insert mark win ms
+        }
+
+  saveMarkState =<< liftIO (readIORef ioref)
+
+jumpToLast :: MarkContext -> X ()
+jumpToLast (MarkContext ioref) = do
+  withFocused $ \win -> do
+    m <- markLast <$> (liftIO $ readIORef ioref)
+    liftIO $ modifyIORef ioref (\state -> state { markLast = Just win })
+    mapM_ focus m
+
+  saveMarkState =<< liftIO (readIORef ioref)
+
+jumpToMark :: MarkContext -> Mark -> X ()
+jumpToMark (MarkContext ioref) mark = do
+  withFocused $ \win -> do
+    MarkState {markStateMap = m} <- liftIO $ readIORef ioref
+    case Map.lookup mark m of
+      Nothing -> return ()
+      Just w -> do
+        liftIO $ modifyIORef ioref $ \state ->
+          state { markLast = Just win }
+        focus w
+
+  saveMarkState =<< liftIO (readIORef ioref)