X.A.FloatKeys: Add direction{Move,Resize}Window

These are simpler, more easily understood, alternatives to the existing
functions.

Fixes: https://github.com/xmonad/xmonad-contrib/issues/712

CHANGES.md

@@ -74,6 +74,11 @@
     and `manyTill` functions, in order to achieve feature parity with
     `Text.ParserCombinators.ReadP`.
 
+* `XMonad.Actions.FloatKeys`
+
+  - Added `directionMoveWindow` and `directionMoveWindow` as more
+    alternatives to the existing functions.
+
 ### Other changes
 
 ## 0.17.1 (September 3, 2022)

XMonad/Actions/FloatKeys.hs

@@ -19,11 +19,15 @@ module XMonad.Actions.FloatKeys (
                 keysMoveWindowTo,
                 keysResizeWindow,
                 keysAbsResizeWindow,
+                directionMoveWindow,
+                directionResizeWindow,
+                Direction2D(..),
                 P, G, ChangeDim
                 ) where
 
 import XMonad
 import XMonad.Prelude (fi)
+import XMonad.Util.Types
 
 -- $usage
 -- You can use this module with the following in your @~\/.xmonad\/xmonad.hs@:
@@ -38,9 +42,37 @@ import XMonad.Prelude (fi)
 -- >  , ((modm .|. shiftMask, xK_s     ), withFocused (keysAbsResizeWindow (10,10) (1024,752)))
 -- >  , ((modm,               xK_a     ), withFocused (keysMoveWindowTo (512,384) (1%2,1%2)))
 --
+-- Using "XMonad.Util.EZConfig" syntax, we can easily build keybindings
+-- where @M-<arrow-keys>@ moves the currently focused window and
+-- @M-S-<arrow-keys>@ resizes it using 'directionMoveWindow' and
+-- 'directionResizeWindow':
+--
+-- > [ ("M-" <> m <> k, withFocused $ f i)
+-- > | (i, k) <- zip [U, D, R, L] ["<Up>", "<Down>", "<Right>", "<Left>"]
+-- > , (f, m) <- [(directionMoveWindow 10, ""), (directionResizeWindow 10, "S-")]
+-- > ]
+--
 -- For detailed instructions on editing your key bindings, see
 -- <https://xmonad.org/TUTORIAL.html#customizing-xmonad the tutorial>.
 
+-- | @directionMoveWindow delta dir win@ moves the window @win@ by
+--   @delta@ pixels in direction @dir@.
+directionMoveWindow :: Int -> Direction2D -> Window -> X ()
+directionMoveWindow delta dir win = case dir of
+  U -> keysMoveWindow (0, -delta) win
+  D -> keysMoveWindow (0, delta)  win
+  R -> keysMoveWindow (delta, 0)  win
+  L -> keysMoveWindow (-delta, 0) win
+
+-- | @directionResizeWindow delta dir win@ resizes the window @win@ by
+--   @delta@ pixels in direction @dir@.
+directionResizeWindow :: Int -> Direction2D -> Window -> X ()
+directionResizeWindow delta dir win = case dir of
+  U -> keysResizeWindow (0, -delta) (0, 0) win
+  D -> keysResizeWindow (0, delta)  (0, 0) win
+  R -> keysResizeWindow (delta, 0)  (0, 0) win
+  L -> keysResizeWindow (-delta, 0) (0, 0) win
+
 -- | @keysMoveWindow (dx, dy)@ moves the window by @dx@ pixels to the
 --   right and @dy@ pixels down.
 keysMoveWindow :: ChangeDim -> Window -> X ()