add draft XMonad.Actions.WindowNavigation

This is an experiment with replacing the WindowNavigation LayoutModifier with
one that simply adds keybindings and stores state in an IORef. Credit to
droundy for the original code -- hopefully I'm not butchering it. The end
intent is to add Xinerama support, but it'll be a little while before I get
there.

XMonad/Actions/WindowNavigation.hs

@@ -0,0 +1,135 @@
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  XMonad.Layout.WindowNavigation
+-- Copyright   :  (c) 2007  David Roundy <droundy@darcs.net>,
+--                          Devin Mullins <me@twifkak.com>
+-- Maintainer  :  Devin Mullins <me@twifkak.com>
+-- License     :  BSD3-style (see LICENSE)
+--
+-- This is a rewrite of "XMonad.Layout.WindowNavigation", for the purposes of
+-- code cleanup and Xinerama support. It's not complete, so you'll want to
+-- use that one for now.
+--
+-- WindowNavigation lets you assign keys to move up/down/left/right, based on
+-- actual window geometry, rather than just going j/k on the stack.
+--
+-----------------------------------------------------------------------------
+
+module XMonad.Actions.WindowNavigation (
+                                       -- * Usage
+                                       -- $usage
+                                       go, swap,
+                                       Direction(..)
+                                       ) where
+
+import XMonad
+import XMonad.Hooks.ManageDocks (Direction(..))
+import qualified XMonad.StackSet as W
+
+import Control.Applicative ((<$>))
+import Data.IORef
+import Data.List (sortBy)
+import Data.Maybe (catMaybes, fromMaybe, listToMaybe)
+import Graphics.X11.Xlib
+
+-- $usage
+--
+-- Don't use it! What, are you crazy?
+
+-- TODO: IORef should be a map from WorkspaceId to Point
+-- TODO: solve the 2+3, middle right to bottom left problem
+--       logHook to update currentPosition?
+
+-- go:
+-- 1. get current position, verifying it matches the current window
+-- 2. get target windowrect
+-- 3. focus window
+-- 4. set new position
+
+-- key bindings to do the important stuff
+
+-- 1. Get current position, window
+-- 2. Determine list of windows in dir from pos, except window
+-- 3. Grab closest one
+
+go :: IORef (Maybe Point) -> Direction -> X ()
+go posRef dir = fromCurrentPoint $ \win pos -> do
+    targets <- filter ((/= win) . fst) <$> navigableTargets pos dir
+    io $ putStrLn $ "pos: " ++ show pos ++ "; tgts: " ++ show targets
+    whenJust (listToMaybe targets) $ \(tw, tr) -> do
+      windows (W.focusWindow tw)
+      setPosition posRef pos tr
+  where fromCurrentPoint f = withFocused $ \win -> do
+                                 currentPosition posRef >>= f win
+
+swap :: IORef (Maybe Point) -> Direction -> X ()
+swap _ _ = return ()
+
+-- Gets the current position from the IORef passed in, or if nothing (say, from
+-- a restart), derives the current position from the current window. Also,
+-- verifies that the position is congruent with the current window (say, if you
+-- used mod-j/k or mouse or something).
+-- TODO: replace 0 0 0 0 with 'middle of current window'
+-- TODO: correct if not in window, or add logHook
+currentPosition :: IORef (Maybe Point) -> X Point
+currentPosition posRef = do
+    mp <- io $ readIORef posRef
+    return $ fromMaybe (Point 0 0) mp
+
+navigableTargets :: Point -> Direction -> X [(Window, Rectangle)]
+navigableTargets point dir = navigable dir point <$> windowRects
+
+setPosition :: IORef (Maybe Point) -> Point -> Rectangle -> X ()
+setPosition posRef _ (Rectangle x y w h) =
+    let position = Point (x + (fromIntegral w `div` 2)) (y + (fromIntegral h `div` 2)) in
+    io $ writeIORef posRef (Just position)
+
+-- Filters and sorts the windows in terms of what is closest from the Point in
+-- the Direction.
+navigable :: Direction -> Point -> [(Window, Rectangle)] -> [(Window, Rectangle)]
+navigable d pt = sortby d . filter (inr d (fromPoint pt) . snd)
+
+-- Produces a list of normal-state windows, on any screen. Rectangles are
+-- adjusted based on screen position relative to the current screen, because I'm
+-- bad like that.
+-- TODO: only the visible windows
+-- TODO: adjust rectangles based on screen position :P
+windowRects :: X [(Window, Rectangle)]
+windowRects = do
+    dpy <- asks display
+    wins <- gets (visibleWindows . windowset)
+    catMaybes <$> mapM (windowRect dpy) wins
+  where visibleWindows wset = concatMap (W.integrate' . W.stack . W.workspace)
+                                        (W.current wset : W.visible wset)
+
+windowRect :: Display -> Window -> X (Maybe (Window, Rectangle))
+windowRect dpy win = do
+    (_, x, y, w, h, _, _) <- io $ getGeometry dpy win
+    return $ Just $ (win, Rectangle x y w h)
+    `catchX` return Nothing
+
+-- manageHook to draw window decos?
+
+fromPoint :: Point -> FPoint
+fromPoint p = P (fromIntegral $ pt_x p) (fromIntegral $ pt_y p)
+
+-- Stolen from droundy's implementation of WindowNavigation. I should probably take the time
+-- to understand the black magic below at some point.
+
+data FPoint = P Double Double
+
+inr :: Direction -> FPoint -> Rectangle -> Bool
+inr D (P x y) (Rectangle l yr w h) = x >= fromIntegral l && x < fromIntegral l + fromIntegral w &&
+                                     y <  fromIntegral yr + fromIntegral h
+inr U (P x y) (Rectangle l yr w _) = x >= fromIntegral l && x < fromIntegral l + fromIntegral w &&
+                                     y >  fromIntegral yr
+inr R (P a x) (Rectangle b l _ w)  = x >= fromIntegral l && x < fromIntegral l + fromIntegral w &&
+                                     a <  fromIntegral b
+inr L (P a x) (Rectangle b l c w)  = x >= fromIntegral l && x < fromIntegral l + fromIntegral w &&
+                                     a >  fromIntegral b + fromIntegral c
+
+sortby :: Direction -> [(a,Rectangle)] -> [(a,Rectangle)]
+sortby U = sortBy (\(_,Rectangle _ y _ _) (_,Rectangle _ y' _ _) -> compare y' y)
+sortby D = sortBy (\(_,Rectangle _ y _ _) (_,Rectangle _ y' _ _) -> compare y y')
+sortby R = sortBy (\(_,Rectangle x _ _ _) (_,Rectangle x' _ _ _) -> compare x x')
+sortby L = sortBy (\(_,Rectangle x _ _ _) (_,Rectangle x' _ _ _) -> compare x' x)

xmonad-contrib.cabal

@@ -96,6 +96,7 @@ library
                         XMonad.Actions.TagWindows
                         XMonad.Actions.UpdatePointer
                         XMonad.Actions.Warp
+                        XMonad.Actions.WindowNavigation
                         XMonad.Actions.WindowGo
                         XMonad.Actions.WindowBringer
                         XMonad.Config.Arossato