Added a way to do per-window bindings in XMonad.

This is particularly great for Chrome where one cannot remap
the built-in bindings and some built-in bindings are really dumb
(looking at you Ctrl+w!!).

1 files changed, 157 insertions, 0 deletions

diff --git a/src/Internal/Intercept.hs b/src/Internal/Intercept.hs
new file mode 100644
index 0000000..987733b
--- /dev/null
+++ b/src/Internal/Intercept.hs
@@ -0,0 +1,157 @@
+module Internal.Intercept where
+
+import XMonad
+
+import Text.Printf
+import Data.Monoid (Endo(..))
+import Control.Monad.Trans.Class (lift)
+import Control.Monad (forM, forM_)
+import Data.Default (Default, def)
+import Data.Map (Map)
+import qualified Data.Map as Map
+import qualified XMonad.Util.ExtensibleState as XS
+import Data.Monoid (All(..))
+
+import Internal.Logger
+
+type WindowHook = Query ()
+
+newtype NoPersist a = NoPersist a
+  deriving (Typeable)
+
+instance Show (NoPersist a) where
+  show (NoPersist _) = show ()
+
+instance (Default a) => Read (NoPersist a) where
+  readsPrec i s = map (\(_, s) -> (NoPersist def, s)) (readsPrec i s :: [((), String)])
+
+instance (Default a) => Default (NoPersist a) where
+  def = NoPersist def
+
+instance (Default a, Typeable a) => ExtensionClass (NoPersist a) where
+  initialValue = NoPersist def
+
+
+data InterceptState = InterceptState (NoPersist (Map (KeyMask, KeySym) (X ())))
+
+data RemapState = RemapState (NoPersist (Map (Window, (KeyMask, KeySym)) (X ())))
+
+instance ExtensionClass InterceptState where
+  initialValue = InterceptState def
+
+instance ExtensionClass RemapState where
+  initialValue = RemapState def
+
+remapHook :: Event -> X All
+remapHook event = do
+  RemapState (NoPersist map) <- XS.get
+
+  case event of
+    KeyEvent { ev_window = win, ev_event_type = typ, ev_keycode = code, ev_state = m }
+        | typ == keyPress-> do
+      XConf {display = dpy, theRoot = rootw} <- ask
+      keysym <- io $ keycodeToKeysym dpy code 0
+
+      case Map.lookup (win, (m, keysym)) map of
+
+        Just xdo -> do
+          xdo
+          return (All False)
+
+        Nothing -> return (All True)
+
+    _ -> return (All True)
+
+interceptHook :: Event -> X All
+interceptHook event = do
+  InterceptState (NoPersist map) <- XS.get
+  case event of
+    KeyEvent { ev_event_type = typ, ev_keycode = code, ev_state = m }
+        | typ == keyPress-> do
+      XConf {display = dpy, theRoot = rootw} <- ask
+      keysym <- io $ keycodeToKeysym dpy code 0
+
+      case Map.lookup (m, keysym) map of
+
+        Just xdo -> do
+          xdo
+          mapM_ (\m' -> io $ ungrabKey dpy code (m .|. m') rootw)
+              =<< extraModifiers
+          return (All False)
+
+        Nothing -> return (All True)
+
+    _ -> return (All True)
+
+setIntercept :: (KeyMask, KeySym) -> X () -> X ()
+setIntercept (keyMask, keysym) action = do
+  XS.modify $ \(InterceptState (NoPersist m)) -> InterceptState $ NoPersist $
+    Map.insert (keyMask, keysym) action m
+  XConf { display = dpy, theRoot = rootw } <- ask
+
+  doGrab dpy rootw (keyMask, keysym)
+
+
+getKeyCodesForKeysym :: Display -> KeySym -> IO [KeyCode]
+getKeyCodesForKeysym dpy keysym = do
+  let (minCode, maxCode) = displayKeycodes dpy
+      allCodes = [fromIntegral minCode .. fromIntegral maxCode]
+
+  syms <- forM allCodes $ \code -> keycodeToKeysym dpy code 0
+  let keysymMap' = Map.fromListWith (++) (zip syms [[code] | code <- allCodes])
+
+  -- keycodeToKeysym returns noSymbol for all unbound keycodes, and we don't
+  -- want to grab those whenever someone accidentally uses def :: KeySym
+  let keysymMap = Map.delete noSymbol keysymMap'
+  let keysymToKeycodes sym = Map.findWithDefault [] keysym keysymMap
+
+  return $ keysymToKeycodes keysym
+
+
+doGrab :: Display -> Window -> (KeyMask, KeySym) -> X ()
+doGrab dpy win (keyMask, keysym) = do
+  let grab kc m = io $ grabKey dpy kc m win True grabModeAsync grabModeAsync
+      (minCode, maxCode) = displayKeycodes dpy
+      allCodes = [fromIntegral minCode .. fromIntegral maxCode]
+
+  -- build a map from keysyms to lists of keysyms (doing what
+  -- XGetKeyboardMapping would do if the X11 package bound it)
+  syms <- forM allCodes $ \code -> io (keycodeToKeysym dpy code 0)
+  let keysymMap' = Map.fromListWith (++) (zip syms [[code] | code <- allCodes])
+  -- keycodeToKeysym returns noSymbol for all unbound keycodes, and we don't
+  -- want to grab those whenever someone accidentally uses def :: KeySym
+  let keysymMap = Map.delete noSymbol keysymMap'
+  let keysymToKeycodes sym = Map.findWithDefault [] keysym keysymMap
+
+  forM_ (keysymToKeycodes keysym) $ \kc ->
+    mapM_ (grab kc . (keyMask .|.)) =<< extraModifiers
+
+disableKey :: (KeyMask, KeySym) -> WindowHook
+disableKey key = remapKey key (return ())
+
+remapKey :: (KeyMask, KeySym) -> X () -> WindowHook
+remapKey keyFrom action = do
+  window <- ask
+  Query $ lift $ do
+    XConf { display = disp, theRoot = rootw } <- ask
+    doGrab disp window keyFrom
+
+    XS.modify $ \(RemapState (NoPersist keyMap)) -> RemapState $ NoPersist $
+      Map.insert (window, keyFrom) action keyMap
+
+rebindKey :: (KeyMask, KeySym) -> (KeyMask, KeySym) -> WindowHook
+rebindKey keyFrom keyTo = do
+  window <- ask
+  remapKey keyFrom $ do
+    XConf { display = disp, theRoot = rootw } <- ask
+    codes <- io $ getKeyCodesForKeysym disp (snd keyTo)
+    case codes of
+      (keyCode:_) -> do
+        io $ allocaXEvent $ \xEv -> do
+          setEventType xEv keyPress
+          setKeyEvent xEv window rootw none (fst keyTo) keyCode True
+          sendEvent disp window True keyPressMask xEv
+          setEventType xEv keyRelease
+          sendEvent disp window True keyPressMask xEv
+
+      _ -> return ()