{-# LANGUAGE DeriveDataTypeable, MultiParamTypeClasses, PatternGuards, RankNTypes, TypeSynonymInstances #-} ----------------------------------------------------------------------------- -- | -- Module : XMonad.Layout.Navigation2D -- Copyright : (c) 2011 Norbert Zeh <nzeh@cs.dal.ca> -- License : BSD3-style (see LICENSE) -- -- Maintainer : Norbert Zeh <nzeh@cs.dal.ca> -- Stability : unstable -- Portability : unportable -- -- Navigation2D is an xmonad extension that allows easy directional -- navigation of windows and screens (in a multi-monitor setup). ----------------------------------------------------------------------------- module XMonad.Actions.Navigation2D ( -- * Usage -- $usage -- * Finer points -- $finer_points -- * Alternative directional navigation modules -- $alternatives -- * Incompatibilities -- $incompatibilities -- * Detailed technical discussion -- $technical -- * Exported functions and types -- #Exports# withNavigation2DConfig , Navigation2DConfig(..) , defaultNavigation2DConfig , Navigation2D , lineNavigation , centerNavigation , fullScreenRect , singleWindowRect , switchLayer , windowGo , windowSwap , windowToScreen , screenGo , screenSwap , Direction2D(..) ) where import Control.Applicative import qualified Data.List as L import qualified Data.Map as M import Data.Maybe import XMonad hiding (Screen) import qualified XMonad.StackSet as W import qualified XMonad.Util.ExtensibleState as XS import XMonad.Util.Types -- $usage -- #Usage# -- Navigation2D provides directional navigation (go left, right, up, down) for -- windows and screens. It treats floating and tiled windows as two separate -- layers and provides mechanisms to navigate within each layer and to switch -- between layers. Navigation2D provides two different navigation strategies -- (see <#Technical_Discussion> for details): /Line navigation/ feels rather -- natural but may make it impossible to navigate to a given window from the -- current window, particularly in the floating layer. /Center navigation/ -- feels less natural in certain situations but ensures that all windows can be -- reached without the need to involve the mouse. Navigation2D allows different -- navigation strategies to be used in the two layers and allows customization -- of the navigation strategy for the tiled layer based on the layout currently -- in effect. -- -- You can use this module with (a subset of) the following in your @~\/.xmonad\/xmonad.hs@: -- -- > import XMonad.Actions.Navigation2D -- -- Then edit your keybindings: -- -- > -- Switch between layers -- > , ((modm, xK_space), switchLayers) -- > -- > -- Directional navigation of windows -- > , ((modm, xK_Right), windowGo R False) -- > , ((modm, xK_Left ), windowGo L False) -- > , ((modm, xK_Up ), windowGo U False) -- > , ((modm, xK_Down ), windowGo D False) -- > -- > -- Swap adjacent windows -- > , ((modm .|. controlMask, xK_Right), windowSwap R False) -- > , ((modm .|. controlMask, xK_Left ), windowSwap L False) -- > , ((modm .|. controlMask, xK_Up ), windowSwap U False) -- > , ((modm .|. controlMask, xK_Down ), windowSwap D False) -- > -- > -- Directional navigation of screens -- > , ((modm, xK_r ), screenGo R False) -- > , ((modm, xK_l ), screenGo L False) -- > , ((modm, xK_u ), screenGo U False) -- > , ((modm, xK_d ), screenGo D False) -- > -- > -- Swap workspaces on adjacent screens -- > , ((modm .|. controlMask, xK_r ), screenSwap R False) -- > , ((modm .|. controlMask, xK_l ), screenSwap L False) -- > , ((modm .|. controlMask, xK_u ), screenSwap U False) -- > , ((modm .|. controlMask, xK_d ), screenSwap D False) -- > -- > -- Send window to adjacent screen -- > , ((modm .|. mod1Mask, xK_r ), windowToScreen R False) -- > , ((modm .|. mod1Mask, xK_l ), windowToScreen L False) -- > , ((modm .|. mod1Mask, xK_u ), windowToScreen U False) -- > , ((modm .|. mod1Mask, xK_d ), windowToScreen D False) -- -- and add the configuration of the module to your main function: -- -- > main = xmonad $ withNavigation2DConfig defaultNavigation2DConfig -- > $ defaultConfig -- -- For detailed instruction on editing the key binding see: -- -- "XMonad.Doc.Extending#Editing_key_bindings". -- $finer_points -- #Finer_Points# -- The above should get you started. Here are some finer points: -- -- Navigation2D has the ability to wrap around at screen edges. For example, if -- you navigated to the rightmost window on the rightmost screen and you -- continued to go right, this would get you to the leftmost window on the -- leftmost screen. This feature may be useful for switching between screens -- that are far apart but may be confusing at least to novice users. Therefore, -- it is disabled in the above example (e.g., navigation beyond the rightmost -- window on the rightmost screen is not possible and trying to do so will -- simply not do anything.) If you want this feature, change all the 'False' -- values in the above example to 'True'. You could also decide you want -- wrapping only for a subset of the operations and no wrapping for others. -- -- By default, all layouts use the 'defaultTiledNavigation' strategy specified -- in the 'Navigation2DConfig' (by default, line navigation is used). To -- override this behaviour for some layouts, add a pair (\"layout name\", -- navigation strategy) to the 'layoutNavigation' list in the -- 'Navigation2DConfig', where \"layout name\" is the string reported by the -- layout's description method (normally what is shown as the layout name in -- your status bar). For example, all navigation strategies normally allow only -- navigation between mapped windows. The first step to overcome this, for -- example, for the Full layout, is to switch to center navigation for the Full -- layout: -- -- > myNavigation2DConfig = defaultNavigation2DConfig { layoutNavigation = [("Full", centerNavigation)] } -- > -- > main = xmonad $ withNavigation2DConfig myNavigation2DConfig -- > $ defaultConfig -- -- The navigation between windows is based on their screen rectangles, which are -- available /and meaningful/ only for mapped windows. Thus, as already said, -- the default is to allow navigation only between mapped windows. However, -- there are layouts that do not keep all windows mapped. One example is the -- Full layout, which unmaps all windows except the one that has the focus, -- thereby preventing navigation to any other window in the layout. To make -- navigation to unmapped windows possible, unmapped windows need to be assigned -- rectangles to pretend they are mapped, and a natural way to do this for the -- Full layout is to pretend all windows occupy the full screen and are stacked -- on top of each other so that only the frontmost one is visible. This can be -- done as follows: -- -- > myNavigation2DConfig = defaultNavigation2DConfig { layoutNavigation = [("Full", centerNavigation)] -- > , unmappedWindowRect = [("Full", singleWindowRect)] -- > } -- > -- > main = xmonad $ withNavigation2DConfig myNavigation2DConfig -- > $ defaultConfig -- -- With this setup, Left/Up navigation behaves like standard -- 'XMonad.StackSet.focusUp' and Right/Down navigation behaves like -- 'XMonad.StackSet.focusDown', thus allowing navigation between windows in the -- layout. -- -- In general, each entry in the 'unmappedWindowRect' association list is a pair -- (\"layout description\", function), where the function computes a rectangle -- for each unmapped window from the screen it is on and the window ID. -- Currently, Navigation2D provides only two functions of this type: -- 'singleWindowRect' and 'fullScreenRect'. -- -- With per-layout navigation strategies, if different layouts are in effect on -- different screens in a multi-monitor setup, and different navigation -- strategies are defined for these active layouts, the most general of these -- navigation strategies is used across all screens (because Navigation2D does -- not distinguish between windows on different workspaces), where center -- navigation is more general than line navigation, as discussed formally under -- <#Technical_Discussion>. -- $alternatives -- #Alternatives# -- -- There exist two alternatives to Navigation2D: -- "XMonad.Actions.WindowNavigation" and "XMonad.Layout.WindowNavigation". -- X.L.WindowNavigation has the advantage of colouring windows to indicate the -- window that would receive the focus in each navigation direction, but it does -- not support navigation across multiple monitors, does not support directional -- navigation of floating windows, and has a very unintuitive definition of -- which window receives the focus next in each direction. X.A.WindowNavigation -- does support navigation across multiple monitors but does not provide window -- colouring while retaining the unintuitive navigational semantics of -- X.L.WindowNavigation. This makes it very difficult to predict which window -- receives the focus next. Neither X.A.WindowNavigation nor -- X.L.WindowNavigation supports directional navigation of screens. -- $technical -- #Technical_Discussion# -- An in-depth discussion of the navigational strategies implemented in -- Navigation2D, including formal proofs of their properties, can be found -- at <http://www.cs.dal.ca/~nzeh/xmonad/Navigation2D.pdf>. -- $incompatibilities -- #Incompatibilities# -- Currently Navigation2D is known not to play nicely with tabbed layouts, but -- it should work well with any other tiled layout. My hope is to address the -- incompatibility with tabbed layouts in a future version. The navigation to -- unmapped windows, for example in a Full layout, by assigning rectangles to -- unmapped windows is more a workaround than a clean solution. Figuring out -- how to deal with tabbed layouts may also lead to a more general and cleaner -- solution to query the layout for a window's rectangle that may make this -- workaround unnecessary. At that point, the 'unmappedWindowRect' field of the -- 'Navigation2DConfig' will disappear. -- | A rectangle paired with an object type Rect a = (a, Rectangle) -- | A shorthand for window-rectangle pairs. Reduces typing. type WinRect = Rect Window -- | A shorthand for workspace-rectangle pairs. Reduces typing. type WSRect = Rect WorkspaceId ---------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- -- -- -- PUBLIC INTERFACE -- -- -- ---------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- -- | Encapsulates the navigation strategy data Navigation2D = N Generality (forall a . Eq a => Direction2D -> Rect a -> [Rect a] -> Maybe a) runNav :: forall a . Eq a => Navigation2D -> (Direction2D -> Rect a -> [Rect a] -> Maybe a) runNav (N _ nav) = nav -- | Score that indicates how general a navigation strategy is type Generality = Int instance Eq Navigation2D where (N x _) == (N y _) = x == y instance Ord Navigation2D where (N x _) <= (N y _) = x <= y -- | Line navigation. To illustrate this navigation strategy, consider -- navigating to the left from the current window. In this case, we draw a -- horizontal line through the center of the current window and consider all -- windows that intersect this horizontal line and whose right boundaries are to -- the left of the left boundary of the current window. From among these -- windows, we choose the one with the rightmost right boundary. lineNavigation :: Navigation2D lineNavigation = N 1 doLineNavigation -- | Center navigation. Again, consider navigating to the left. Then we -- consider the cone bounded by the two rays shot at 45-degree angles in -- north-west and south-west direction from the center of the current window. A -- window is a candidate to receive the focus if its center lies in this cone. -- We choose the window whose center has minimum L1-distance from the current -- window center. The tie breaking strategy for windows with the same distance -- is a bit complicated (see <#Technical_Discussion>) but ensures that all -- windows can be reached and that windows with the same center are traversed in -- their order in the window stack, that is, in the order -- 'XMonad.StackSet.focusUp' and 'XMonad.StackSet.focusDown' would traverse -- them. centerNavigation :: Navigation2D centerNavigation = N 2 doCenterNavigation -- | Stores the configuration of directional navigation data Navigation2DConfig = Navigation2DConfig { defaultTiledNavigation :: Navigation2D -- ^ default navigation strategy for the tiled layer , floatNavigation :: Navigation2D -- ^ navigation strategy for the float layer , screenNavigation :: Navigation2D -- ^ strategy for navigation between screens , layoutNavigation :: [(String, Navigation2D)] -- ^ association list of customized navigation strategies -- for different layouts in the tiled layer. Each pair -- is of the form (\"layout description\", navigation -- strategy). If there is no pair in this list whose first -- component is the name of the current layout, the -- 'defaultTiledNavigation' strategy is used. , unmappedWindowRect :: [(String, Screen -> Window -> X (Maybe Rectangle))] -- ^ list associating functions to calculate rectangles -- for unmapped windows with layouts to which they are -- to be applied. Each pair in this list is of -- the form (\"layout description\", function), where the -- function calculates a rectangle for a given unmapped -- window from the screen it is on and its window ID. -- See <#Finer_Points> for how to use this. } deriving Typeable -- | Shorthand for the tedious screen type type Screen = W.Screen WorkspaceId (Layout Window) Window ScreenId ScreenDetail -- So we can store the configuration in extensible state instance ExtensionClass Navigation2DConfig where initialValue = defaultNavigation2DConfig -- | Modifies the xmonad configuration to store the Navigation2D configuration withNavigation2DConfig :: Navigation2DConfig -> XConfig a -> XConfig a withNavigation2DConfig conf2d xconf = xconf { startupHook = startupHook xconf >> XS.put conf2d } -- | Default navigation configuration. It uses line navigation for the tiled -- layer and for navigation between screens, and center navigation for the float -- layer. No custom navigation strategies or rectangles for unmapped windows are -- defined for individual layouts. defaultNavigation2DConfig :: Navigation2DConfig defaultNavigation2DConfig = Navigation2DConfig { defaultTiledNavigation = lineNavigation , floatNavigation = centerNavigation , screenNavigation = lineNavigation , layoutNavigation = [] , unmappedWindowRect = [] } -- | Switches focus to the closest window in the other layer (floating if the -- current window is tiled, tiled if the current window is floating). Closest -- means that the L1-distance between the centers of the windows is minimized. switchLayer :: X () switchLayer = actOnLayer otherLayer ( \ _ cur wins -> windows $ doFocusClosestWindow cur wins ) ( \ _ cur wins -> windows $ doFocusClosestWindow cur wins ) ( \ _ _ _ -> return () ) False -- | Moves the focus to the next window in the given direction and in the same -- layer as the current window. The second argument indicates whether -- navigation should wrap around (e.g., from the left edge of the leftmost -- screen to the right edge of the rightmost screen). windowGo :: Direction2D -> Bool -> X () windowGo dir wrap = actOnLayer thisLayer ( \ conf cur wins -> windows $ doTiledNavigation conf dir W.focusWindow cur wins ) ( \ conf cur wins -> windows $ doFloatNavigation conf dir W.focusWindow cur wins ) ( \ conf cur wspcs -> windows $ doScreenNavigation conf dir W.view cur wspcs ) wrap -- | Swaps the current window with the next window in the given direction and in -- the same layer as the current window. (In the floating layer, all that -- changes for the two windows is their stacking order if they're on the same -- screen. If they're on different screens, each window is moved to the other -- window's screen but retains its position and size relative to the screen.) -- The second argument indicates wrapping (see 'windowGo'). windowSwap :: Direction2D -> Bool -> X () windowSwap dir wrap = actOnLayer thisLayer ( \ conf cur wins -> windows $ doTiledNavigation conf dir swap cur wins ) ( \ conf cur wins -> windows $ doFloatNavigation conf dir swap cur wins ) ( \ _ _ _ -> return () ) wrap -- | Moves the current window to the next screen in the given direction. The -- second argument indicates wrapping (see 'windowGo'). windowToScreen :: Direction2D -> Bool -> X () windowToScreen dir wrap = actOnScreens ( \ conf cur wspcs -> windows $ doScreenNavigation conf dir W.shift cur wspcs ) wrap -- | Moves the focus to the next screen in the given direction. The second -- argument indicates wrapping (see 'windowGo'). screenGo :: Direction2D -> Bool -> X () screenGo dir wrap = actOnScreens ( \ conf cur wspcs -> windows $ doScreenNavigation conf dir W.view cur wspcs ) wrap -- | Swaps the workspace on the current screen with the workspace on the screen -- in the given direction. The second argument indicates wrapping (see -- 'windowGo'). screenSwap :: Direction2D -> Bool -> X () screenSwap dir wrap = actOnScreens ( \ conf cur wspcs -> windows $ doScreenNavigation conf dir W.greedyView cur wspcs ) wrap -- | Maps each window to a fullscreen rect. This may not be the same rectangle the -- window maps to under the Full layout or a similar layout if the layout -- respects statusbar struts. In such cases, it may be better to use -- 'singleWindowRect'. fullScreenRect :: Screen -> Window -> X (Maybe Rectangle) fullScreenRect scr _ = return (Just . screenRect . W.screenDetail $ scr) -- | Maps each window to the rectangle it would receive if it was the only -- window in the layout. Useful, for example, for determining the default -- rectangle for unmapped windows in a Full layout that respects statusbar -- struts. singleWindowRect :: Screen -> Window -> X (Maybe Rectangle) singleWindowRect scr win = listToMaybe . map snd . fst <$> runLayout ((W.workspace scr) { W.stack = W.differentiate [win] }) (screenRect . W.screenDetail $ scr) ---------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- -- -- -- PRIVATE X ACTIONS -- -- -- ---------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- -- | Acts on the appropriate layer using the given action functions actOnLayer :: ([WinRect] -> [WinRect] -> [WinRect]) -- ^ Chooses which layer to operate on, relative -- to the current window (same or other layer) -> (Navigation2DConfig -> WinRect -> [WinRect] -> X ()) -- ^ The action for the tiled layer -> (Navigation2DConfig -> WinRect -> [WinRect] -> X ()) -- ^ The action for the float layer -> (Navigation2DConfig -> WSRect -> [WSRect] -> X ()) -- ^ The action if the current workspace is empty -> Bool -- ^ Should navigation wrap around screen edges? -> X () actOnLayer choice tiledact floatact wsact wrap = withWindowSet $ \winset -> do conf <- XS.get (floating, tiled) <- navigableWindows conf wrap winset let cur = W.peek winset case cur of Nothing -> actOnScreens wsact wrap Just w | Just rect <- L.lookup w tiled -> tiledact conf (w, rect) (choice tiled floating) | Just rect <- L.lookup w floating -> floatact conf (w, rect) (choice floating tiled) | otherwise -> return () -- | Returns the list of windows on the currently visible workspaces navigableWindows :: Navigation2DConfig -> Bool -> WindowSet -> X ([WinRect], [WinRect]) navigableWindows conf wrap winset = L.partition (\(win, _) -> M.member win (W.floating winset)) . addWrapping winset wrap . catMaybes . concat <$> ( mapM ( \scr -> mapM (maybeWinRect scr) $ W.integrate' $ W.stack $ W.workspace scr ) . sortedScreens ) winset where maybeWinRect scr win = do winrect <- windowRect win rect <- case winrect of Just _ -> return winrect Nothing -> maybe (return Nothing) (\f -> f scr win) (L.lookup (description . W.layout . W.workspace $ scr) (unmappedWindowRect conf)) return ((,) win <$> rect) -- | Returns the current rectangle of the given window, Nothing if the window isn't mapped windowRect :: Window -> X (Maybe Rectangle) windowRect win = withDisplay $ \dpy -> do mp <- isMapped win if mp then do (_, x, y, w, h, bw, _) <- io $ getGeometry dpy win return $ Just $ Rectangle x y (w + 2 * bw) (h + 2 * bw) `catchX` return Nothing else return Nothing -- | Acts on the screens using the given action function actOnScreens :: (Navigation2DConfig -> WSRect -> [WSRect] -> X ()) -> Bool -- ^ Should wrapping be used? -> X () actOnScreens act wrap = withWindowSet $ \winset -> do conf <- XS.get let wsrects = visibleWorkspaces winset wrap cur = W.tag . W.workspace . W.current $ winset rect = fromJust $ L.lookup cur wsrects act conf (cur, rect) wsrects -- | Determines whether a given window is mapped isMapped :: Window -> X Bool isMapped win = withDisplay $ \dpy -> io $ (waIsUnmapped /=) . wa_map_state <$> getWindowAttributes dpy win ---------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- -- -- -- PRIVATE PURE FUNCTIONS -- -- -- ---------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------- -- | Finds the window closest to the given window and focuses it. Ties are -- broken by choosing the first window in the window stack among the tied -- windows. (The stack order is the one produced by integrate'ing each visible -- workspace's window stack and concatenating these lists for all visible -- workspaces.) doFocusClosestWindow :: WinRect -> [WinRect] -> (WindowSet -> WindowSet) doFocusClosestWindow (cur, rect) winrects | null winctrs = id | otherwise = W.focusWindow . fst $ L.foldl1' closer winctrs where ctr = centerOf rect winctrs = filter ((cur /=) . fst) $ map (\(w, r) -> (w, centerOf r)) winrects closer wc1@(_, c1) wc2@(_, c2) | lDist ctr c1 > lDist ctr c2 = wc2 | otherwise = wc1 -- | Implements navigation for the tiled layer doTiledNavigation :: Navigation2DConfig -> Direction2D -> (Window -> WindowSet -> WindowSet) -> WinRect -> [WinRect] -> (WindowSet -> WindowSet) doTiledNavigation conf dir act cur winrects winset | Just win <- runNav nav dir cur winrects = act win winset | otherwise = winset where layouts = map (description . W.layout . W.workspace) $ W.screens winset nav = maximum $ map ( fromMaybe (defaultTiledNavigation conf) . flip L.lookup (layoutNavigation conf) ) $ layouts -- | Implements navigation for the float layer doFloatNavigation :: Navigation2DConfig -> Direction2D -> (Window -> WindowSet -> WindowSet) -> WinRect -> [WinRect] -> (WindowSet -> WindowSet) doFloatNavigation conf dir act cur winrects | Just win <- runNav nav dir cur winrects = act win | otherwise = id where nav = floatNavigation conf -- | Implements navigation between screens doScreenNavigation :: Navigation2DConfig -> Direction2D -> (WorkspaceId -> WindowSet -> WindowSet) -> WSRect -> [WSRect] -> (WindowSet -> WindowSet) doScreenNavigation conf dir act cur wsrects | Just ws <- runNav nav dir cur wsrects = act ws | otherwise = id where nav = screenNavigation conf -- | Implements line navigation. For layouts without overlapping windows, there -- is no need to break ties between equidistant windows. When windows do -- overlap, even the best tie breaking rule cannot make line navigation feel -- natural. Thus, we fairly arbtitrarily break ties by preferring the window -- that comes first in the window stack. (The stack order is the one produced -- by integrate'ing each visible workspace's window stack and concatenating -- these lists for all visible workspaces.) doLineNavigation :: Eq a => Direction2D -> Rect a -> [Rect a] -> Maybe a doLineNavigation dir (cur, rect) winrects | null winrects' = Nothing | otherwise = Just . fst $ L.foldl1' closer winrects' where -- The current window's center ctr@(xc, yc) = centerOf rect -- The list of windows that are candidates to receive focus. winrects' = filter dirFilter $ filter ((cur /=) . fst) $ winrects -- Decides whether a given window matches the criteria to be a candidate to -- receive the focus. dirFilter (_, r) = (dir == L && leftOf r rect && intersectsY yc r) || (dir == R && leftOf rect r && intersectsY yc r) || (dir == U && above r rect && intersectsX xc r) || (dir == D && above rect r && intersectsX xc r) -- Decide whether r1 is left of/above r2. leftOf r1 r2 = rect_x r1 + fi (rect_width r1) <= rect_x r2 above r1 r2 = rect_y r1 + fi (rect_height r1) <= rect_y r2 -- Check whether r's x-/y-range contains the given x-/y-coordinate. intersectsX x r = rect_x r <= x && rect_x r + fi (rect_width r) >= x intersectsY y r = rect_y r <= y && rect_y r + fi (rect_height r) >= y -- Decides whether r1 is closer to the current window's center than r2 closer wr1@(_, r1) wr2@(_, r2) | dist ctr r1 > dist ctr r2 = wr2 | otherwise = wr1 -- Returns the distance of r from the point (x, y) dist (x, y) r | dir == L = x - rect_x r - fi (rect_width r) | dir == R = rect_x r - x | dir == U = y - rect_y r - fi (rect_height r) | otherwise = rect_y r - y -- | Implements center navigation doCenterNavigation :: Eq a => Direction2D -> Rect a -> [Rect a] -> Maybe a doCenterNavigation dir (cur, rect) winrects | ((w, _):_) <- onCtr' = Just w | otherwise = closestOffCtr where -- The center of the current window (xc, yc) = centerOf rect -- All the windows with their center points relative to the current -- center rotated so the right cone becomes the relevant cone. -- The windows are ordered in the order they should be preferred -- when they are otherwise tied. winctrs = map (\(w, r) -> (w, dirTransform . centerOf $ r)) $ stackTransform $ winrects -- Give preference to windows later in the stack for going left or up and to -- windows earlier in the stack for going right or down. (The stack order -- is the one produced by integrate'ing each visible workspace's window -- stack and concatenating these lists for all visible workspaces.) stackTransform | dir == L || dir == U = reverse | otherwise = id -- Transform a point into a difference to the current window center and -- rotate it so that the relevant cone becomes the right cone. dirTransform (x, y) | dir == R = ( x - xc , y - yc ) | dir == L = (-(x - xc), -(y - yc)) | dir == D = ( y - yc , x - xc ) | otherwise = (-(y - yc), -(x - xc)) -- Partition the points into points that coincide with the center -- and points that do not. (onCtr, offCtr) = L.partition (\(_, (x, y)) -> x == 0 && y == 0) winctrs -- All the points that coincide with the current center and succeed it -- in the (appropriately ordered) window stack. onCtr' = L.tail $ L.dropWhile ((cur /=) . fst) onCtr -- tail should be safe here because cur should be in onCtr -- All the points that do not coincide with the current center and which -- lie in the (rotated) right cone. offCtr' = L.filter (\(_, (x, y)) -> x > 0 && y < x && y >= -x) offCtr -- The off-center point closest to the center and -- closest to the bottom ray of the cone. Nothing if no off-center -- point is in the cone closestOffCtr = if null offCtr' then Nothing else Just $ fst $ L.foldl1' closest offCtr' closest wp@(_, p@(_, yp)) wq@(_, q@(_, yq)) | lDist (0, 0) q < lDist (0, 0) p = wq -- q is closer than p | lDist (0, 0) p < lDist (0, 0) q = wp -- q is farther away than p | yq < yp = wq -- q is closer to the bottom ray than p | otherwise = wp -- q is farther away from the bottom ray than p -- or it has the same distance but comes later -- in the window stack -- | Swaps the current window with the window given as argument swap :: Window -> WindowSet -> WindowSet swap win winset = W.focusWindow cur $ L.foldl' (flip W.focusWindow) newwinset newfocused where -- The current window cur = fromJust $ W.peek winset -- All screens scrs = W.screens winset -- All visible workspaces visws = map W.workspace scrs -- The focused windows of the visible workspaces focused = mapMaybe (\ws -> W.focus <$> W.stack ws) visws -- The window lists of the visible workspaces wins = map (W.integrate' . W.stack) visws -- Update focused windows and window lists to reflect swap of windows. newfocused = map swapWins focused newwins = map (map swapWins) wins -- Replaces the current window with the argument window and vice versa. swapWins x | x == cur = win | x == win = cur | otherwise = x -- Reconstruct the workspaces' window stacks to reflect the swap. newvisws = zipWith (\ws wns -> ws { W.stack = W.differentiate wns }) visws newwins newscrs = zipWith (\scr ws -> scr { W.workspace = ws }) scrs newvisws newwinset = winset { W.current = head newscrs , W.visible = tail newscrs } -- | Calculates the center of a rectangle centerOf :: Rectangle -> (Position, Position) centerOf r = (rect_x r + fi (rect_width r) `div` 2, rect_y r + fi (rect_height r) `div` 2) -- | Shorthand for integer conversions fi :: (Integral a, Num b) => a -> b fi = fromIntegral -- | Functions to choose the subset of windows to operate on thisLayer, otherLayer :: a -> a -> a thisLayer = curry fst otherLayer = curry snd -- | Returns the list of visible workspaces and their screen rects visibleWorkspaces :: WindowSet -> Bool -> [WSRect] visibleWorkspaces winset wrap = addWrapping winset wrap $ map ( \scr -> ( W.tag . W.workspace $ scr , screenRect . W.screenDetail $ scr ) ) $ sortedScreens winset -- | Creates five copies of each (window/workspace, rect) pair in the input: the -- original and four offset one desktop size (desktop = collection of all -- screens) to the left, to the right, up, and down. Wrap-around at desktop -- edges is implemented by navigating into these displaced copies. addWrapping :: WindowSet -- ^ The window set, used to get the desktop size -> Bool -- ^ Should wrapping be used? Do nothing if not. -> [Rect a] -- ^ Input set of (window/workspace, rect) pairs -> [Rect a] addWrapping _ False wrects = wrects addWrapping winset True wrects = [ (w, r { rect_x = rect_x r + fi x , rect_y = rect_y r + fi y } ) | (w, r) <- wrects , (x, y) <- [(0, 0), (-xoff, 0), (xoff, 0), (0, -yoff), (0, yoff)] ] where (xoff, yoff) = wrapOffsets winset -- | Calculates the offsets for window/screen coordinates for the duplication -- of windows/workspaces that implements wrap-around. wrapOffsets :: WindowSet -> (Integer, Integer) wrapOffsets winset = (max_x - min_x, max_y - min_y) where min_x = fi $ minimum $ map rect_x rects min_y = fi $ minimum $ map rect_y rects max_x = fi $ maximum $ map (\r -> rect_x r + (fi $ rect_width r)) rects max_y = fi $ maximum $ map (\r -> rect_y r + (fi $ rect_height r)) rects rects = map snd $ visibleWorkspaces winset False -- | Returns the list of screens sorted primarily by their centers' -- x-coordinates and secondarily by their y-coordinates. sortedScreens :: WindowSet -> [Screen] sortedScreens winset = L.sortBy cmp $ W.screens winset where cmp s1 s2 | x1 < x2 = LT | x1 > x2 = GT | y1 < x2 = LT | y1 > y2 = GT | otherwise = EQ where (x1, y1) = centerOf (screenRect . W.screenDetail $ s1) (x2, y2) = centerOf (screenRect . W.screenDetail $ s2) -- | Calculates the L1-distance between two points. lDist :: (Position, Position) -> (Position, Position) -> Int lDist (x1, y1) (x2, y2) = abs (fi $ x1 - x2) + abs (fi $ y1 - y2)