XMonad.Actions.UpdatePointer: generalise updatePointer

XMonad/Actions/UpdatePointer.hs

@@ -19,12 +19,12 @@ module XMonad.Actions.UpdatePointer
      -- * Usage
      -- $usage
      updatePointer
-     , PointerPosition (..)
     )
     where
 
 import XMonad
 import XMonad.Util.XUtils (fi)
+import Control.Arrow
 import Control.Monad
 import XMonad.StackSet (member, peek, screenDetail, current)
 import Data.Maybe
@@ -35,36 +35,32 @@ import Data.Maybe
 -- > import XMonad
 -- > import XMonad.Actions.UpdatePointer
 --
--- Enable it by including it in your logHook definition. Eg:
+-- Enable it by including it in your logHook definition, e.g.:
 --
--- > logHook = updatePointer Nearest
+-- > logHook = updatePointer (0.5, 0.5) (1, 1)
 --
--- which will move the pointer to the nearest point of a newly focused window, or
+-- which will move the pointer to the nearest point of a newly focused
+-- window. The first argument establishes a reference point within the
+-- newly-focused window, while the second argument linearly interpolates
+-- between said reference point and the edges of the newly-focused window to
+-- obtain a bounding box for the pointer.
 --
--- > logHook = updatePointer (Relative 0.5 0.5)
+-- > logHook = updatePointer (0.5, 0.5) (0, 0) -- exact centre of window
---
+-- > logHook = updatePointer (0.25, 0.25) (0.25, 0.25) -- near the top-left
--- which will move the pointer to the center of a newly focused window, or
+-- > logHook = updatePointer (0.5, 0.5) (1.1, 1.1) -- within 110% of the edge
---
--- > logHook = updatePointer (TowardsCentre 0.75 0.75)
---
--- which will linearly interpolate the pointer between 'Nearest' and ¾ of
--- the way towards the centre of the window.
 --
 -- To use this with an existing logHook, use >> :
 --
 -- > logHook = dynamicLog
--- >           >> updatePointer (Relative 1 1)
+-- >           >> updatePointer (1, 1) (0, 0)
 --
 -- which moves the pointer to the bottom-right corner of the focused window.
 
-data PointerPosition = Nearest | Relative Rational Rational | TowardsCentre Rational Rational
-    deriving (Read,Show)
-
 -- | Update the pointer's location to the currently focused
 -- window or empty screen unless it's already there, or unless the user was changing
 -- focus with the mouse
-updatePointer :: PointerPosition -> X ()
+updatePointer :: (Rational, Rational) -> (Rational, Rational) -> X ()
-updatePointer p = do
+updatePointer refPos ratio = do
   ws <- gets windowset
   dpy <- asks display
   rect <- case peek ws of
@@ -72,39 +68,37 @@ updatePointer p = do
         Just w  -> windowAttributesToRectangle `fmap` io (getWindowAttributes dpy w)
   root <- asks theRoot
   mouseIsMoving <- asks mouseFocused
-  (_sameRoot,_,currentWindow,rootx,rooty,_,_,_) <- io $ queryPointer dpy root
+  (_sameRoot,_,currentWindow,rootX,rootY,_,_,_) <- io $ queryPointer dpy root
   drag <- gets dragging
-  unless (pointWithin (fi rootx) (fi rooty) rect
+  unless (pointWithin (fi rootX) (fi rootY) rect
           || mouseIsMoving
           || isJust drag
-          || not (currentWindow `member` ws || currentWindow == none)) $
+          || not (currentWindow `member` ws || currentWindow == none)) $ let
-    case p of
+    -- focused rectangle
-    Nearest -> do
+    (rectX, rectY) = (rect_x &&& rect_y) rect
-      let x = moveWithin (fi rootx) (rect_x rect) (fi (rect_x rect) + fi (rect_width  rect))
+    (rectW, rectH) = (fi . rect_width &&& fi . rect_height) rect
-          y = moveWithin (fi rooty) (rect_y rect) (fi (rect_y rect) + fi (rect_height rect))
+    -- reference position, with (0,0) and (1,1) being top-left and bottom-right
-      io $ warpPointer dpy none root 0 0 0 0 x y
+    refX = lerp (fst refPos) rectX (rectX + rectW)
-    TowardsCentre xfrc yfrc -> do
+    refY = lerp (snd refPos) rectY (rectY + rectH)
-      let cx = fi (rect_width rect) / 2 + fi (rect_x rect)
+    -- final pointer bounds, lerped *outwards* from reference position
-          cy = fi (rect_height rect) / 2 + fi (rect_y rect)
+    boundsX = join (***) (lerp (fst ratio) refX) (rectX, rectX + rectW)
-          x,y,cx,cy :: Rational
+    boundsY = join (***) (lerp (snd ratio) refY) (rectY, rectY + rectH)
-          x = moveWithin (fi rootx) (fi $ rect_x rect) (fi (rect_x rect) + fi (rect_width  rect))
+    -- ideally we ought to move the pointer in a straight line towards the
-          y = moveWithin (fi rooty) (fi $ rect_y rect) (fi (rect_y rect) + fi (rect_height rect))
+    -- reference point until it is within the above bounds, but…
-      io $ warpPointer dpy none root 0 0 0 0 (round $ x + xfrc*(cx-x)) (round $ y + yfrc*(cy-y))
+    in io $ warpPointer dpy none root 0 0 0 0
-    Relative h v ->
+        (round . clip boundsX $ fi rootX)
-      io $ warpPointer dpy none root 0 0 0 0
+        (round . clip boundsY $ fi rootY)
-           (rect_x rect + fraction h (rect_width rect))
-           (rect_y rect + fraction v (rect_height rect))
-        where fraction x y = floor (x * fromIntegral y)
 
 windowAttributesToRectangle :: WindowAttributes -> Rectangle
 windowAttributesToRectangle wa = Rectangle (fi (wa_x wa))
                                            (fi (wa_y wa))
                                            (fi (wa_width wa + 2 * wa_border_width wa))
                                            (fi (wa_height wa + 2 * wa_border_width wa))
-moveWithin :: Ord a => a -> a -> a -> a
+
-moveWithin now lower upper =
+lerp :: (RealFrac r, Real a, Real b) => r -> a -> b -> r
-    if now < lower
+lerp r a b = (1 - r) * realToFrac a + r * realToFrac b
-    then lower
+
-    else if now > upper
+clip :: Ord a => (a, a) -> a -> a
-         then upper
+clip (lower, upper) x = if x < lower then lower
-         else now
+    else if x > upper then upper else x
+

XMonad/Layout/MagicFocus.hs

@@ -28,7 +28,7 @@ import XMonad
 import qualified XMonad.StackSet as W
 import XMonad.Layout.LayoutModifier
 
-import XMonad.Actions.UpdatePointer(updatePointer, PointerPosition(TowardsCentre))
+import XMonad.Actions.UpdatePointer (updatePointer)
 import Data.Monoid(All(..))
 import qualified Data.Map as M
 
@@ -75,12 +75,12 @@ swap (W.Stack f u d) focused
 -- This eventHook does nothing when there are floating windows on the current
 -- workspace.
 promoteWarp :: Event -> X All
-promoteWarp = promoteWarp' (TowardsCentre 0.15 0.15)
+promoteWarp = promoteWarp' (0.5, 0.5) (0.85, 0.85)
 
--- | promoteWarp' allows you to specify an arbitrary PointerPosition to apply
+-- | promoteWarp' allows you to specify an arbitrary pair of arguments to
--- when the mouse enters another window.
+-- pass to 'updatePointer' when the mouse enters another window.
-promoteWarp' :: PointerPosition -> Event -> X All
+promoteWarp' :: (Rational, Rational) -> (Rational, Rational) -> Event -> X All
-promoteWarp' pos e@(CrossingEvent {ev_window = w, ev_event_type = t})
+promoteWarp' refPos ratio e@(CrossingEvent {ev_window = w, ev_event_type = t})
     | t == enterNotify && ev_mode   e == notifyNormal = do
         ws <- gets windowset
         let foc = W.peek ws
@@ -88,10 +88,10 @@ promoteWarp' pos e@(CrossingEvent {ev_window = w, ev_event_type = t})
             wsFloats = M.filterWithKey (\k _ -> k `elem` st) $ W.floating ws
         if Just w /= foc && M.null wsFloats then do
             windows (W.swapMaster . W.focusWindow w)
-            updatePointer pos
+            updatePointer refPos ratio
             return $ All False
           else return $ All True
-promoteWarp' _ _ = return $ All True
+promoteWarp' _ _ _ = return $ All True
 
 -- | Another event hook to override the focusFollowsMouse and make the pointer
 -- only follow if a given condition is satisfied. This could be used to disable