Add stripModMask to customize cleanMask/extraModifiers

Fixes: xmonad#172
Relates: xmonad/xmonad-contrib#290

CHANGES.md

@@ -6,6 +6,10 @@
 
   * Added custom cursor shapes for resizing and moving windows.
 
+  * Added `stripModMask` to allow customizing which modifiers are irrelevant
+    for key bindings. Useful for binding numpad keys only when Num Lock is
+    off, or to make Mod5 irrelevant in addition to the default Num/Caps Lock.
+
 ### Bug Fixes
 
   * Fixed border color of windows with alpha channel. Now all windows have the

src/XMonad/Config.hs

@@ -38,6 +38,7 @@ import XMonad.Layout
 import XMonad.Operations
 import XMonad.ManageHook
 import qualified XMonad.StackSet as W
+import Control.Monad.State (gets)
 import Data.Bits ((.|.))
 import Data.Default.Class
 import Data.Monoid
@@ -58,14 +59,22 @@ import Graphics.X11.Xlib.Extras
 workspaces :: [WorkspaceId]
 workspaces = map show [1 .. 9 :: Int]
 
--- | modMask lets you specify which modkey you want to use. The default
+-- | 'modMask' lets you specify which modkey you want to use. The default
 -- is mod1Mask ("left alt").  You may also consider using mod3Mask
 -- ("right alt"), which does not conflict with emacs keybindings. The
 -- "windows key" is usually mod4Mask.
 --
 defaultModMask :: KeyMask
 defaultModMask = mod1Mask
 
+-- | 'stripModMask' lets you specify which modifiers are irrelevant for key
+-- bindings. The default is Num Lock and Caps Lock. You will need to override
+-- this if you wish to only strip Caps Lock if you need to bind numpad keys
+-- but only when Num Lock is off (or on). Another use case is adding
+-- 'mod5Mask' to the list of stripped/irrelevant modifiers.
+defaultStripModMask :: X KeyMask
+defaultStripModMask = gets ((lockMask .|.) . numberlockMask)
+
 -- | Width of the window border in pixels.
 --
 borderWidth :: Dimension
@@ -264,6 +273,7 @@ instance (a ~ Choose Tall (Choose (Mirror Tall) Full)) => Default (XConfig a) wh
     , XMonad.normalBorderColor  = normalBorderColor
     , XMonad.focusedBorderColor = focusedBorderColor
     , XMonad.modMask            = defaultModMask
+    , XMonad.stripModMask       = defaultStripModMask
     , XMonad.keys               = keys
     , XMonad.logHook            = logHook
     , XMonad.startupHook        = startupHook

src/XMonad/Core.hs

@@ -111,6 +111,7 @@ data XConfig l = XConfig
                                                  -- event hooks in most cases.
     , workspaces         :: ![String]            -- ^ The list of workspaces' names
     , modMask            :: !KeyMask             -- ^ the mod modifier
+    , stripModMask       :: !(X KeyMask)         -- ^ The mask of modifiers to ignore in key bindings. Default: num/caps lock.
     , keys               :: !(XConfig Layout -> M.Map (ButtonMask,KeySym) (X ()))
                                                  -- ^ The key binding: a map from key presses and actions
     , mouseBindings      :: !(XConfig Layout -> M.Map (ButtonMask, Button) (Window -> X ()))

src/XMonad/Operations.hs

@@ -56,8 +56,8 @@ import qualified XMonad.StackSet as W
 
 import Data.Maybe
 import Data.Monoid          (Endo(..),Any(..))
-import Data.List            (nub, (\\), find)
-import Data.Bits            ((.|.), (.&.), complement, testBit)
+import Data.List            (nub, (\\), find, foldl', subsequences)
+import Data.Bits            ((.|.), (.&.), complement, bit, testBit, clearBit, countTrailingZeros)
 import Data.Function        (on)
 import Data.Ratio
 import qualified Data.Map as M
@@ -500,17 +500,20 @@ isClient :: Window -> X Bool
 isClient w = withWindowSet $ return . W.member w
 
 -- | Combinations of extra modifier masks we need to grab keys\/buttons for.
--- (numlock and capslock)
+-- (by default numlock and capslock, can be overridden in 'stripModMask')
 extraModifiers :: X [KeyMask]
 extraModifiers = do
-    nlm <- gets numberlockMask
-    return [0, nlm, lockMask, nlm .|. lockMask ]
+    smm <- join $ asks $ stripModMask . config
+    return $ map (foldl' (.|.) 0) (subsequences (bits smm))
+  where
+    bits 0 = []
+    bits n = let b = countTrailingZeros n in bit b : bits (n `clearBit` b)
 
--- | Strip numlock\/capslock from a mask.
+-- | Strip 'stripModMask' (by default numlock\/capslock) from a mask.
 cleanMask :: KeyMask -> X KeyMask
 cleanMask km = do
-    nlm <- gets numberlockMask
-    return (complement (nlm .|. lockMask) .&. km)
+    smm <- join $ asks $ stripModMask . config
+    return (complement smm .&. km)
 
 -- | Set the 'Pixel' alpha value to 255.
 setPixelSolid :: Pixel -> Pixel

xmonad.cabal

@@ -1,5 +1,5 @@
 name:               xmonad
-version:            0.17.0.9
+version:            0.17.0.91
 synopsis:           A tiling window manager
 description:        xmonad is a tiling window manager for X. Windows are arranged
                     automatically to tile the screen without gaps or overlap, maximising