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diff --git a/XMonad/StackSet.hs b/XMonad/StackSet.hs deleted file mode 100644 index 958b94b..0000000 --- a/XMonad/StackSet.hs +++ /dev/null @@ -1,549 +0,0 @@ -{-# LANGUAGE PatternGuards #-} - ------------------------------------------------------------------------------ --- | --- Module : XMonad.StackSet --- Copyright : (c) Don Stewart 2007 --- License : BSD3-style (see LICENSE) --- --- Maintainer : dons@galois.com --- Stability : experimental --- Portability : portable, Haskell 98 --- - -module XMonad.StackSet ( - -- * Introduction - -- $intro - - -- ** The Zipper - -- $zipper - - -- ** Xinerama support - -- $xinerama - - -- ** Master and Focus - -- $focus - - StackSet(..), Workspace(..), Screen(..), Stack(..), RationalRect(..), - -- * Construction - -- $construction - new, view, greedyView, - -- * Xinerama operations - -- $xinerama - lookupWorkspace, - screens, screenWorkspaces, workspaces, hidden, allWindows, currentTag, - -- * Operations on the current stack - -- $stackOperations - peek, index, integrate, integrate', differentiate, - focusUp, focusDown, focusUp', focusDown', focusMaster, focusWindow, - tagMember, renameTag, member, findTag, mapWorkspace, mapLayout, - -- * Modifying the stackset - -- $modifyStackset - insertUp, delete, filter, - -- * Setting the master window - -- $settingMW - swapUp, swapDown, swapMaster, shiftMaster, modify, modify', -- needed by users - -- * Composite operations - -- $composite - shift, shiftWin, - - -- for testing - abort - ) where - -import Prelude hiding (filter) -import Data.Function (on) -import Data.Maybe (listToMaybe,isJust,fromMaybe) -import qualified Data.List as L (deleteBy,find,splitAt,filter,nub) - --- $intro --- --- The 'StackSet' data type encodes a window manager abstraction. The --- window manager is a set of virtual workspaces. On each workspace is a --- stack of windows. A given workspace is always current, and a given --- window on each workspace has focus. The focused window on the current --- workspace is the one which will take user input. It can be visualised --- as follows: --- --- > Workspace { 0*} { 1 } { 2 } { 3 } { 4 } --- > --- > Windows [1 [] [3* [6*] [] --- > ,2*] ,4 --- > ,5] --- --- Note that workspaces are indexed from 0, windows are numbered --- uniquely. A '*' indicates the window on each workspace that has --- focus, and which workspace is current. - --- $zipper --- --- We encode all the focus tracking directly in the data structure, with a 'zipper': --- --- A Zipper is essentially an `updateable' and yet pure functional --- cursor into a data structure. Zipper is also a delimited --- continuation reified as a data structure. --- --- The Zipper lets us replace an item deep in a complex data --- structure, e.g., a tree or a term, without an mutation. The --- resulting data structure will share as much of its components with --- the old structure as possible. --- --- Oleg Kiselyov, 27 Apr 2005, haskell\@, "Zipper as a delimited continuation" --- --- We use the zipper to keep track of the focused workspace and the --- focused window on each workspace, allowing us to have correct focus --- by construction. We closely follow Huet's original implementation: --- --- G. Huet, /Functional Pearl: The Zipper/, --- 1997, J. Functional Programming 75(5):549-554. --- and: --- R. Hinze and J. Jeuring, /Functional Pearl: The Web/. --- --- and Conor McBride's zipper differentiation paper. --- Another good reference is: --- --- The Zipper, Haskell wikibook - --- $xinerama --- Xinerama in X11 lets us view multiple virtual workspaces --- simultaneously. While only one will ever be in focus (i.e. will --- receive keyboard events), other workspaces may be passively --- viewable. We thus need to track which virtual workspaces are --- associated (viewed) on which physical screens. To keep track of --- this, 'StackSet' keeps separate lists of visible but non-focused --- workspaces, and non-visible workspaces. - --- $focus --- --- Each stack tracks a focused item, and for tiling purposes also tracks --- a 'master' position. The connection between 'master' and 'focus' --- needs to be well defined, particularly in relation to 'insert' and --- 'delete'. --- - ------------------------------------------------------------------------- --- | --- A cursor into a non-empty list of workspaces. --- --- We puncture the workspace list, producing a hole in the structure --- used to track the currently focused workspace. The two other lists --- that are produced are used to track those workspaces visible as --- Xinerama screens, and those workspaces not visible anywhere. - -data StackSet i l a sid sd = - StackSet { current :: !(Screen i l a sid sd) -- ^ currently focused workspace - , visible :: [Screen i l a sid sd] -- ^ non-focused workspaces, visible in xinerama - } deriving (Show, Read, Eq) - --- | Visible workspaces, and their Xinerama screens. -data Screen i l a sid sd = Screen { screenWorkspace :: !(Workspace i l a) - , screenHidden :: [Workspace i l a] - , screen :: !sid - , screenDetail :: !sd } - deriving (Show, Read, Eq) - --- | --- A workspace is just a tag, a layout, and a stack. --- -data Workspace i l a = Workspace { tag :: !i, layout :: l, stack :: Maybe (Stack a) } - deriving (Show, Read, Eq) - --- | A structure for window geometries -data RationalRect = RationalRect Rational Rational Rational Rational - deriving (Show, Read, Eq) - --- | --- A stack is a cursor onto a window list. --- The data structure tracks focus by construction, and --- the master window is by convention the top-most item. --- Focus operations will not reorder the list that results from --- flattening the cursor. The structure can be envisaged as: --- --- > +-- master: < '7' > --- > up | [ '2' ] --- > +--------- [ '3' ] --- > focus: < '4' > --- > dn +----------- [ '8' ] --- --- A 'Stack' can be viewed as a list with a hole punched in it to make --- the focused position. Under the zipper\/calculus view of such --- structures, it is the differentiation of a [a], and integrating it --- back has a natural implementation used in 'index'. --- -data Stack a = Stack { focus :: !a -- focused thing in this set - , up :: [a] -- clowns to the left - , down :: [a] } -- jokers to the right - deriving (Show, Read, Eq) - - --- | this function indicates to catch that an error is expected -abort :: String -> a -abort x = error $ "xmonad: StackSet: " ++ x - --- --------------------------------------------------------------------- --- $construction - --- | /O(n)/. Create a new stackset, of empty stacks, with given tags, --- with physical screens whose descriptions are given by 'm'. The --- number of physical screens (@length 'm'@) should be less than or --- equal to the number of workspace tags. The first workspace in the --- list will be current. --- --- Xinerama: Virtual workspaces are assigned to physical screens, starting at 0. --- -new :: (Integral s) => l -> [i] -> [sd] -> StackSet i l a s sd -new l wids m | not (null wids) && length m <= length wids && not (null m) - = StackSet cur visi - where (seen,unseen) = L.splitAt (length m) $ map (\i -> Workspace i l Nothing) wids - cur = Screen (head seen) unseen 0 (head m) - visi = [ Screen i [] s sd | (i, s, sd) <- zip3 (tail seen) [1..] (tail m) ] - -- now zip up visibles with their screen id -new _ _ _ = abort "non-positive argument to StackSet.new" - --- | --- /O(w)/. Set focus to the workspace with index \'i\'. --- If the index is out of range, return the original 'StackSet'. --- --- Xinerama: If the workspace is not visible on any Xinerama screen, it --- becomes the current screen. If it is in the visible list, it becomes --- current. - -view :: (Eq s, Eq i) => i -> StackSet i l a s sd -> StackSet i l a s sd -view i s = s { current = head s', visible = tail s' } - where - s' = map makeVisible (current s : visible s) - - makeVisible scr - | Just x <- L.find ((i==) . tag) (screenHidden scr) = scr { screenWorkspace = x, screenHidden = (screenWorkspace scr) : L.deleteBy ((==) `on` tag) x (screenHidden scr)} - | otherwise = scr - - -- 'Catch'ing this might be hard. Relies on monotonically increasing - -- workspace tags defined in 'new' - -- - -- and now tags are not monotonic, what happens here? - --- | --- Set focus to the given workspace. If that workspace does not exist --- in the stackset, the original workspace is returned. If that workspace is --- 'hidden', then display that workspace on the current screen, and move the --- current workspace to 'hidden'. If that workspace is 'visible' on another --- screen, the workspaces of the current screen and the other screen are --- swapped. - -greedyView :: (Eq s, Eq i) => i -> StackSet i l a s sd -> StackSet i l a s sd -{-greedyView w ws - | any wTag (hidden ws) = view w ws - | (Just s) <- L.find (wTag . workspace) (visible ws) - = ws { current = (current ws) { workspace = workspace s } - , visible = s { workspace = workspace (current ws) } - : L.filter (not . wTag . workspace) (visible ws) } - | otherwise = ws - where wTag = (w == ) . tag-} -greedyView = view - --- --------------------------------------------------------------------- --- $xinerama - --- | Find the tag of the workspace visible on Xinerama screen 'sc'. --- 'Nothing' if screen is out of bounds. -lookupWorkspace :: Eq s => s -> StackSet i l a s sd -> Maybe i -lookupWorkspace sc w = listToMaybe [ tag i | Screen i _ s _ <- current w : visible w, s == sc ] - --- --------------------------------------------------------------------- --- $stackOperations - --- | --- The 'with' function takes a default value, a function, and a --- StackSet. If the current stack is Nothing, 'with' returns the --- default value. Otherwise, it applies the function to the stack, --- returning the result. It is like 'maybe' for the focused workspace. --- -with :: b -> (Stack a -> b) -> StackSet i l a s sd -> b -with dflt f = maybe dflt f . stack . screenWorkspace . current - --- | --- Apply a function, and a default value for 'Nothing', to modify the current stack. --- -modify :: Maybe (Stack a) -> (Stack a -> Maybe (Stack a)) -> StackSet i l a s sd -> StackSet i l a s sd -modify d f s = s { current = (current s) - { screenWorkspace = (screenWorkspace (current s)) { stack = with d f s }}} - --- | --- Apply a function to modify the current stack if it isn't empty, and we don't --- want to empty it. --- -modify' :: (Stack a -> Stack a) -> StackSet i l a s sd -> StackSet i l a s sd -modify' f = modify Nothing (Just . f) - --- | --- /O(1)/. Extract the focused element of the current stack. --- Return 'Just' that element, or 'Nothing' for an empty stack. --- -peek :: StackSet i l a s sd -> Maybe a -peek = with Nothing (return . focus) - --- | --- /O(n)/. Flatten a 'Stack' into a list. --- -integrate :: Stack a -> [a] -integrate (Stack x l r) = reverse l ++ x : r - --- | --- /O(n)/ Flatten a possibly empty stack into a list. -integrate' :: Maybe (Stack a) -> [a] -integrate' = maybe [] integrate - --- | --- /O(n)/. Turn a list into a possibly empty stack (i.e., a zipper): --- the first element of the list is current, and the rest of the list --- is down. -differentiate :: [a] -> Maybe (Stack a) -differentiate [] = Nothing -differentiate (x:xs) = Just $ Stack x [] xs - --- | --- /O(n)/. 'filter p s' returns the elements of 's' such that 'p' evaluates to --- 'True'. Order is preserved, and focus moves as described for 'delete'. --- -filter :: (a -> Bool) -> Stack a -> Maybe (Stack a) -filter p (Stack f ls rs) = case L.filter p (f:rs) of - f':rs' -> Just $ Stack f' (L.filter p ls) rs' -- maybe move focus down - [] -> case L.filter p ls of -- filter back up - f':ls' -> Just $ Stack f' ls' [] -- else up - [] -> Nothing - --- | --- /O(s)/. Extract the stack on the current workspace, as a list. --- The order of the stack is determined by the master window -- it will be --- the head of the list. The implementation is given by the natural --- integration of a one-hole list cursor, back to a list. --- -index :: StackSet i l a s sd -> [a] -index = with [] integrate - --- | --- /O(1), O(w) on the wrapping case/. --- --- focusUp, focusDown. Move the window focus up or down the stack, --- wrapping if we reach the end. The wrapping should model a 'cycle' --- on the current stack. The 'master' window, and window order, --- are unaffected by movement of focus. --- --- swapUp, swapDown, swap the neighbour in the stack ordering, wrapping --- if we reach the end. Again the wrapping model should 'cycle' on --- the current stack. --- -focusUp, focusDown, swapUp, swapDown :: StackSet i l a s sd -> StackSet i l a s sd -focusUp = modify' focusUp' -focusDown = modify' focusDown' - -swapUp = modify' swapUp' -swapDown = modify' (reverseStack . swapUp' . reverseStack) - --- | Variants of 'focusUp' and 'focusDown' that work on a --- 'Stack' rather than an entire 'StackSet'. -focusUp', focusDown' :: Stack a -> Stack a -focusUp' (Stack t (l:ls) rs) = Stack l ls (t:rs) -focusUp' (Stack t [] rs) = Stack x xs [] where (x:xs) = reverse (t:rs) -focusDown' = reverseStack . focusUp' . reverseStack - -swapUp' :: Stack a -> Stack a -swapUp' (Stack t (l:ls) rs) = Stack t ls (l:rs) -swapUp' (Stack t [] rs) = Stack t (reverse rs) [] - --- | reverse a stack: up becomes down and down becomes up. -reverseStack :: Stack a -> Stack a -reverseStack (Stack t ls rs) = Stack t rs ls - --- --- | /O(1) on current window, O(n) in general/. Focus the window 'w', --- and set its workspace as current. --- -focusWindow :: (Eq s, Eq a, Eq i) => a -> StackSet i l a s sd -> StackSet i l a s sd -focusWindow w s | Just w == peek s = s - | otherwise = fromMaybe s $ do - n <- findTag w s - return $ until ((Just w ==) . peek) focusUp (view n s) - --- | Get a list of all screens in the 'StackSet'. -screens :: StackSet i l a s sd -> [Screen i l a s sd] -screens s = current s : visible s - --- | Get a list of all workspaces in the 'StackSet'. -workspaces :: StackSet i l a s sd -> [Workspace i l a] -workspaces s = concatMap screenWorkspaces $ (current s) : (visible s) - -screenWorkspaces :: Screen i l a sid sd -> [Workspace i l a] -screenWorkspaces scr = screenWorkspace scr : screenHidden scr - -hidden :: StackSet i l a s sd -> [Workspace i l a] -hidden = concatMap screenHidden . screens - --- | Get a list of all windows in the 'StackSet' in no particular order -allWindows :: Eq a => StackSet i l a s sd -> [a] -allWindows = L.nub . concatMap (integrate' . stack) . workspaces - --- | Get the tag of the currently focused workspace. -currentTag :: StackSet i l a s sd -> i -currentTag = tag . screenWorkspace . current - --- | Is the given tag present in the 'StackSet'? -tagMember :: Eq i => i -> StackSet i l a s sd -> Bool -tagMember t = elem t . map tag . workspaces - --- | Rename a given tag if present in the 'StackSet'. -renameTag :: Eq i => i -> i -> StackSet i l a s sd -> StackSet i l a s sd -renameTag o n = mapWorkspace rename - where rename w = if tag w == o then w { tag = n } else w - --- | Ensure that a given set of workspace tags is present by renaming --- existing workspaces and\/or creating new hidden workspaces as --- necessary. -{-ensureTags :: Eq i => l -> [i] -> StackSet i l a s sd -> StackSet i l a s sd -ensureTags l allt st = et allt (map tag (workspaces st) \\ allt) st - where et [] _ s = s - et (i:is) rn s | i `tagMember` s = et is rn s - et (i:is) [] s = et is [] (s { hidden = Workspace i l Nothing : hidden s }) - et (i:is) (r:rs) s = et is rs $ renameTag r i s-} - --- | Map a function on all the workspaces in the 'StackSet'. -mapWorkspace :: (Workspace i l a -> Workspace i l a) -> StackSet i l a s sd -> StackSet i l a s sd -mapWorkspace f s = s { current = updScr (current s) - , visible = map updScr (visible s) } - where updScr scr = scr { screenWorkspace = f (screenWorkspace scr), screenHidden = map f (screenHidden scr) } - --- | Map a function on all the layouts in the 'StackSet'. -mapLayout :: (l -> l') -> StackSet i l a s sd -> StackSet i l' a s sd -mapLayout f (StackSet v vs) = StackSet (fScreen v) (map fScreen vs) - where - fScreen (Screen ws hd s sd) = Screen (fWorkspace ws) (map fWorkspace hd) s sd - fWorkspace (Workspace t l s) = Workspace t (f l) s - --- | /O(n)/. Is a window in the 'StackSet'? -member :: Eq a => a -> StackSet i l a s sd -> Bool -member a s = isJust (findTag a s) - --- | /O(1) on current window, O(n) in general/. --- Return 'Just' the workspace tag of the given window, or 'Nothing' --- if the window is not in the 'StackSet'. -findTag :: Eq a => a -> StackSet i l a s sd -> Maybe i -findTag a s = listToMaybe - [ tag w | w <- workspaces s, has a (stack w) ] - where has _ Nothing = False - has x (Just (Stack t l r)) = x `elem` (t : l ++ r) - --- --------------------------------------------------------------------- --- $modifyStackset - --- | --- /O(n)/. (Complexity due to duplicate check). Insert a new element --- into the stack, above the currently focused element. The new --- element is given focus; the previously focused element is moved --- down. --- --- If the element is already in the stackset, the original stackset is --- returned unmodified. --- --- Semantics in Huet's paper is that insert doesn't move the cursor. --- However, we choose to insert above, and move the focus. --- -insertUp :: Eq a => a -> StackSet i l a s sd -> StackSet i l a s sd -insertUp a s = if member a s then s else insert - where insert = modify (Just $ Stack a [] []) (\(Stack t l r) -> Just $ Stack a l (t:r)) s - --- insertDown :: a -> StackSet i l a s sd -> StackSet i l a s sd --- insertDown a = modify (Stack a [] []) $ \(Stack t l r) -> Stack a (t:l) r --- Old semantics, from Huet. --- > w { down = a : down w } - --- | --- /O(1) on current window, O(n) in general/. Delete window 'w' if it exists. --- There are 4 cases to consider: --- --- * delete on an 'Nothing' workspace leaves it Nothing --- --- * otherwise, try to move focus to the down --- --- * otherwise, try to move focus to the up --- --- * otherwise, you've got an empty workspace, becomes 'Nothing' --- --- Behaviour with respect to the master: --- --- * deleting the master window resets it to the newly focused window --- --- * otherwise, delete doesn't affect the master. --- --- | Only temporarily remove the window from the stack, thereby not destroying special --- information saved in the 'Stackset' -delete :: (Eq a, Eq s) => a -> StackSet i l a s sd -> StackSet i l a s sd -delete w s = mapWorkspace removeFromWorkspace s - where removeFromWorkspace ws = ws { stack = stack ws >>= filter (/=w) } - ------------------------------------------------------------------------- - --- | Given a window, and its preferred rectangle, set it as floating --- A floating window should already be managed by the 'StackSet'. ---float :: Ord a => a -> RationalRect -> StackSet i l a s sd -> StackSet i l a s sd ---float w r s = s { floating = M.insert w r (floating s) } - --- | Clear the floating status of a window ---sink :: Ord a => a -> StackSet i l a s sd -> StackSet i l a s sd ---sink w s = s { floating = M.delete w (floating s) } - ------------------------------------------------------------------------- --- $settingMW - --- | /O(s)/. Set the master window to the focused window. --- The old master window is swapped in the tiling order with the focused window. --- Focus stays with the item moved. -swapMaster :: StackSet i l a s sd -> StackSet i l a s sd -swapMaster = modify' $ \c -> case c of - Stack _ [] _ -> c -- already master. - Stack t ls rs -> Stack t [] (xs ++ x : rs) where (x:xs) = reverse ls - --- natural! keep focus, move current to the top, move top to current. - --- | /O(s)/. Set the master window to the focused window. --- The other windows are kept in order and shifted down on the stack, as if you --- just hit mod-shift-k a bunch of times. --- Focus stays with the item moved. -shiftMaster :: StackSet i l a s sd -> StackSet i l a s sd -shiftMaster = modify' $ \c -> case c of - Stack _ [] _ -> c -- already master. - Stack t ls rs -> Stack t [] (reverse ls ++ rs) - --- | /O(s)/. Set focus to the master window. -focusMaster :: StackSet i l a s sd -> StackSet i l a s sd -focusMaster = modify' $ \c -> case c of - Stack _ [] _ -> c - Stack t ls rs -> Stack x [] (xs ++ t : rs) where (x:xs) = reverse ls - --- --- --------------------------------------------------------------------- --- $composite - --- | /O(w)/. shift. Move the focused element of the current stack to stack --- 'n', leaving it as the focused element on that stack. The item is --- inserted above the currently focused element on that workspace. --- The actual focused workspace doesn't change. If there is no --- element on the current stack, the original stackSet is returned. --- -shift :: (Ord a, Eq s, Eq i) => i -> StackSet i l a s sd -> StackSet i l a s sd -shift n s = maybe s (\w -> shiftWin n w s) (peek s) - --- | /O(n)/. shiftWin. Searches for the specified window 'w' on all workspaces --- of the stackSet and moves it to stack 'n', leaving it as the focused --- element on that stack. The item is inserted above the currently --- focused element on that workspace. --- The actual focused workspace doesn't change. If the window is not --- found in the stackSet, the original stackSet is returned. -shiftWin :: (Ord a, Eq a, Eq s, Eq i) => i -> a -> StackSet i l a s sd -> StackSet i l a s sd -shiftWin n w s = case findTag w s of - Just from | n `tagMember` s && n /= from -> go from s - _ -> s - where go from = onWorkspace n (insertUp w) . onWorkspace from (delete w) - -onWorkspace :: (Eq i, Eq s) => i -> (StackSet i l a s sd -> StackSet i l a s sd) - -> (StackSet i l a s sd -> StackSet i l a s sd) -onWorkspace n f s = view (currentTag s) . f . view n $ s |