{-# LANGUAGE ScopedTypeVariables #-}
-----------------------------------------------------------------------------
-- |
-- Module      :  XMonadContrib.UpdatePointer
-- Description :  Causes the pointer to follow whichever window focus changes to.
-- Copyright   :  (c) Robert Marlow <robreim@bobturf.org>, 2015 Evgeny Kurnevsky
-- License     :  BSD3-style (see LICENSE)
--
-- Maintainer  :  Robert Marlow <robreim@bobturf.org>
-- Stability   :  stable
-- Portability :  portable
--
-- Causes the pointer to follow whichever window focus changes to. Compliments
-- the idea of switching focus as the mouse crosses window boundaries to
-- keep the mouse near the currently focused window
--
-----------------------------------------------------------------------------

module XMonad.Actions.UpdatePointer
    (
     -- * Usage
     -- $usage
     updatePointer
    )
    where

import XMonad
import XMonad.Prelude
import XMonad.StackSet (member, peek, screenDetail, current)

import Control.Arrow ((&&&), (***))

-- $usage
-- You can use this module with the following in your @xmonad.hs@:
--
-- > import XMonad
-- > import XMonad.Actions.UpdatePointer
--
-- Enable it by including it in your logHook definition, e.g.:
--
-- > logHook = updatePointer (0.5, 0.5) (1, 1)
--
-- 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 (0.5, 0.5) (0, 0) -- exact centre of window
-- > logHook = updatePointer (0.25, 0.25) (0.25, 0.25) -- near the top-left
-- > logHook = updatePointer (0.5, 0.5) (1.1, 1.1) -- within 110% of the edge
--
-- To use this with an existing logHook, use >> :
--
-- > logHook = dynamicLog
-- >           >> updatePointer (1, 1) (0, 0)
--
-- which moves the pointer to the bottom-right corner of the focused window.

-- | 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
--
-- See also 'XMonad.Actions.UpdateFocus.focusUnderPointer' for an inverse
-- operation that updates the focus instead. The two can be combined in a
-- single config if neither goes into 'logHook' but are invoked explicitly in
-- individual key bindings.
updatePointer :: (Rational, Rational) -> (Rational, Rational) -> X ()
updatePointer :: (Rational, Rational) -> (Rational, Rational) -> X ()
updatePointer (Rational, Rational)
refPos (Rational, Rational)
ratio = do
  ws <- (XState -> WindowSet) -> X WindowSet
forall s (m :: * -> *) a. MonadState s m => (s -> a) -> m a
gets XState -> WindowSet
windowset
  dpy <- asks display
  let defaultRect = ScreenDetail -> Rectangle
screenRect (ScreenDetail -> Rectangle) -> ScreenDetail -> Rectangle
forall a b. (a -> b) -> a -> b
$ Screen WorkspaceId (Layout Window) Window ScreenId ScreenDetail
-> ScreenDetail
forall i l a sid sd. Screen i l a sid sd -> sd
screenDetail (Screen WorkspaceId (Layout Window) Window ScreenId ScreenDetail
 -> ScreenDetail)
-> Screen WorkspaceId (Layout Window) Window ScreenId ScreenDetail
-> ScreenDetail
forall a b. (a -> b) -> a -> b
$ WindowSet
-> Screen WorkspaceId (Layout Window) Window ScreenId ScreenDetail
forall i l a sid sd. StackSet i l a sid sd -> Screen i l a sid sd
current WindowSet
ws
  rect <- case peek ws of
        Maybe Window
Nothing -> Rectangle -> X Rectangle
forall a. a -> X a
forall (m :: * -> *) a. Monad m => a -> m a
return Rectangle
defaultRect
        Just Window
w  -> Rectangle
-> (WindowAttributes -> Rectangle)
-> Maybe WindowAttributes
-> Rectangle
forall b a. b -> (a -> b) -> Maybe a -> b
maybe Rectangle
defaultRect WindowAttributes -> Rectangle
windowAttributesToRectangle
               (Maybe WindowAttributes -> Rectangle)
-> X (Maybe WindowAttributes) -> X Rectangle
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> Window -> X (Maybe WindowAttributes)
safeGetWindowAttributes Window
w

  root <- asks theRoot
  mouseIsMoving <- asks mouseFocused
  (_sameRoot,_,currentWindow,rootX,rootY,_,_,_) <- io $ queryPointer dpy root
  drag <- gets dragging
  unless (pointWithin (fi rootX) (fi rootY) rect
          || mouseIsMoving
          || isJust drag
          || not (currentWindow `member` ws || currentWindow == none)) $ let
    -- focused rectangle
    (rectX, rectY) = (rect_x &&& rect_y) rect
    (rectW, rectH) = (fi . rect_width &&& fi . rect_height) rect
    -- reference position, with (0,0) and (1,1) being top-left and bottom-right
    refX = Rational -> Position -> Position -> Rational
forall r a b. (RealFrac r, Real a, Real b) => r -> a -> b -> r
lerp ((Rational, Rational) -> Rational
forall a b. (a, b) -> a
fst (Rational, Rational)
refPos) Position
rectX (Position
rectX Position -> Position -> Position
forall a. Num a => a -> a -> a
+ Position
rectW)
    refY = Rational -> Position -> Position -> Rational
forall r a b. (RealFrac r, Real a, Real b) => r -> a -> b -> r
lerp ((Rational, Rational) -> Rational
forall a b. (a, b) -> b
snd (Rational, Rational)
refPos) Position
rectY (Position
rectY Position -> Position -> Position
forall a. Num a => a -> a -> a
+ Position
rectH)
    -- final pointer bounds, lerped *outwards* from reference position
    boundsX = ((Position -> Rational)
 -> (Position -> Rational)
 -> (Position, Position)
 -> (Rational, Rational))
-> (Position -> Rational)
-> (Position, Position)
-> (Rational, Rational)
forall (m :: * -> *) a. Monad m => m (m a) -> m a
join (Position -> Rational)
-> (Position -> Rational)
-> (Position, Position)
-> (Rational, Rational)
forall b c b' c'. (b -> c) -> (b' -> c') -> (b, b') -> (c, c')
forall (a :: * -> * -> *) b c b' c'.
Arrow a =>
a b c -> a b' c' -> a (b, b') (c, c')
(***) (Rational -> Rational -> Position -> Rational
forall r a b. (RealFrac r, Real a, Real b) => r -> a -> b -> r
lerp ((Rational, Rational) -> Rational
forall a b. (a, b) -> a
fst (Rational, Rational)
ratio) Rational
refX) (Position
rectX, Position
rectX Position -> Position -> Position
forall a. Num a => a -> a -> a
+ Position
rectW)
    boundsY = ((Position -> Rational)
 -> (Position -> Rational)
 -> (Position, Position)
 -> (Rational, Rational))
-> (Position -> Rational)
-> (Position, Position)
-> (Rational, Rational)
forall (m :: * -> *) a. Monad m => m (m a) -> m a
join (Position -> Rational)
-> (Position -> Rational)
-> (Position, Position)
-> (Rational, Rational)
forall b c b' c'. (b -> c) -> (b' -> c') -> (b, b') -> (c, c')
forall (a :: * -> * -> *) b c b' c'.
Arrow a =>
a b c -> a b' c' -> a (b, b') (c, c')
(***) (Rational -> Rational -> Position -> Rational
forall r a b. (RealFrac r, Real a, Real b) => r -> a -> b -> r
lerp ((Rational, Rational) -> Rational
forall a b. (a, b) -> b
snd (Rational, Rational)
ratio) Rational
refY) (Position
rectY, Position
rectY Position -> Position -> Position
forall a. Num a => a -> a -> a
+ Position
rectH)
    -- ideally we ought to move the pointer in a straight line towards the
    -- reference point until it is within the above bounds, but…
    in io $ warpPointer dpy none root 0 0 0 0
        (round . clip boundsX $ fi rootX)
        (round . clip boundsY $ fi rootY)

windowAttributesToRectangle :: WindowAttributes -> Rectangle
windowAttributesToRectangle :: WindowAttributes -> Rectangle
windowAttributesToRectangle WindowAttributes
wa = Position -> Position -> Dimension -> Dimension -> Rectangle
Rectangle (CInt -> Position
forall a b. (Integral a, Num b) => a -> b
fi (WindowAttributes -> CInt
wa_x WindowAttributes
wa))
                                           (CInt -> Position
forall a b. (Integral a, Num b) => a -> b
fi (WindowAttributes -> CInt
wa_y WindowAttributes
wa))
                                           (CInt -> Dimension
forall a b. (Integral a, Num b) => a -> b
fi (WindowAttributes -> CInt
wa_width WindowAttributes
wa CInt -> CInt -> CInt
forall a. Num a => a -> a -> a
+ CInt
2 CInt -> CInt -> CInt
forall a. Num a => a -> a -> a
* WindowAttributes -> CInt
wa_border_width WindowAttributes
wa))
                                           (CInt -> Dimension
forall a b. (Integral a, Num b) => a -> b
fi (WindowAttributes -> CInt
wa_height WindowAttributes
wa CInt -> CInt -> CInt
forall a. Num a => a -> a -> a
+ CInt
2 CInt -> CInt -> CInt
forall a. Num a => a -> a -> a
* WindowAttributes -> CInt
wa_border_width WindowAttributes
wa))

lerp :: (RealFrac r, Real a, Real b) => r -> a -> b -> r
lerp :: forall r a b. (RealFrac r, Real a, Real b) => r -> a -> b -> r
lerp r
r a
a b
b = (r
1 r -> r -> r
forall a. Num a => a -> a -> a
- r
r) r -> r -> r
forall a. Num a => a -> a -> a
* a -> r
forall a b. (Real a, Fractional b) => a -> b
realToFrac a
a r -> r -> r
forall a. Num a => a -> a -> a
+ r
r r -> r -> r
forall a. Num a => a -> a -> a
* b -> r
forall a b. (Real a, Fractional b) => a -> b
realToFrac b
b

clip :: Ord a => (a, a) -> a -> a
clip :: forall a. Ord a => (a, a) -> a -> a
clip (a
lower, a
upper) a
x
  | a
x a -> a -> Bool
forall a. Ord a => a -> a -> Bool
< a
lower = a
lower
  | a
x a -> a -> Bool
forall a. Ord a => a -> a -> Bool
> a
upper = a
upper
  | Bool
otherwise = a
x