--------------------------------------------------------------------
-- |
-- Module : XMonad.Util.EZConfig
-- Copyright : Devin Mullins <me@twifkak.com>
-- Brent Yorgey <byorgey@gmail.com> (key parsing)
-- License : BSD3-style (see LICENSE)
--
-- Maintainer : Devin Mullins <me@twifkak.com>
--
-- Useful helper functions for amending the defaultConfig, and for
-- parsing keybindings specified in a special (emacs-like) format.
--
-- (See also "XMonad.Util.CustomKeys" in xmonad-contrib.)
--
--------------------------------------------------------------------
module XMonad.Util.EZConfig (
-- * Usage
-- $usage
-- * Adding or removing keybindings
additionalKeys, additionalKeysP,
removeKeys, removeKeysP,
additionalMouseBindings, removeMouseBindings,
-- * Emacs-style keybinding specifications
mkKeymap, checkKeymap,
) where
import XMonad
import XMonad.Actions.Submap
import qualified Data.Map as M
import Data.List (foldl', intersperse, sortBy, groupBy, nub)
import Data.Ord (comparing)
import Data.Maybe (catMaybes, isNothing, isJust, fromJust)
import Control.Arrow (first, (&&&))
import Text.ParserCombinators.ReadP
-- $usage
-- To use this module, first import it into your @~\/.xmonad\/xmonad.hs@:
--
-- > import XMonad.Util.EZConfig
--
-- Then, use one of the provided functions to modify your
-- configuration. You can use 'additionalKeys', 'removeKeys',
-- 'additionalMouseBindings', and 'removeMouseBindings' to easily add
-- and remove keybindings or mouse bindings. You can use 'mkKeymap'
-- to create a keymap using emacs-style keybinding specifications
-- like @\"M-x\"@ instead of @(modMask, xK_x)@, or 'additionalKeysP'
-- and 'removeKeysP' to easily add or remove emacs-style keybindings.
-- If you use emacs-style keybindings, the 'checkKeymap' function is
-- provided, suitable for adding to your 'startupHook', which can warn
-- you of any parse errors or duplicate bindings in your keymap.
--
-- For more information and usage eamples, see the documentation
-- provided with each exported function, and check the xmonad config
-- archive (<http://haskell.org/haskellwiki/Xmonad/Config_archive>)
-- for some real examples of use.
-- |
-- Add or override keybindings from the existing set. Example use:
--
-- > main = xmonad $ defaultConfig { terminal = "urxvt" }
-- > `additionalKeys`
-- > [ ((mod1Mask, xK_m ), spawn "echo 'Hi, mom!' | dzen2 -p 4")
-- > , ((mod1Mask, xK_BackSpace), withFocused hide) -- N.B. this is an absurd thing to do
-- > ]
--
-- This overrides the previous definition of mod-m.
--
-- Note that, unlike in xmonad 0.4 and previous, you can't use modMask to refer
-- to the modMask you configured earlier. You must specify mod1Mask (or
-- whichever), or add your own @myModMask = mod1Mask@ line.
additionalKeys :: XConfig a -> [((ButtonMask, KeySym), X ())] -> XConfig a
additionalKeys conf keyList =
conf { keys = \cnf -> M.union (M.fromList keyList) (keys conf cnf) }
-- | Like 'additionalKeys', except using short @String@ key
-- descriptors like @\"M-m\"@ instead of @(modMask, xK_m)@, as
-- described in the documentation for 'mkKeymap'. For example:
--
-- > main = xmonad $ defaultConfig { terminal = "urxvt" }
-- > `additionalKeysP`
-- > [ ("M-m", spawn "echo 'Hi, mom!' | dzen2 -p 4")
-- > , ("M-<Backspace>", withFocused hide) -- N.B. this is an absurd thing to do
-- > ]
additionalKeysP :: XConfig l -> [(String, X ())] -> XConfig l
additionalKeysP conf keyList =
conf { keys = \cnf -> M.union (mkKeymap cnf keyList) (keys conf cnf) }
-- |
-- Remove standard keybindings you're not using. Example use:
--
-- > main = xmonad $ defaultConfig { terminal = "urxvt" }
-- > `removeKeys` [(mod1Mask .|. shiftMask, n) | n <- [xK_1 .. xK_9]]
removeKeys :: XConfig a -> [(ButtonMask, KeySym)] -> XConfig a
removeKeys conf keyList =
conf { keys = \cnf -> keys conf cnf `M.difference` M.fromList (zip keyList $ return ()) }
-- | Like 'removeKeys', except using short @String@ key descriptors
-- like @\"M-m\"@ instead of @(modMask, xK_m)@, as described in the
-- documentation for 'mkKeymap'. For example:
--
-- > main = xmonad $ defaultConfig { terminal = "urxvt" }
-- > `removeKeysP` ["M-S-" ++ [n] | n <- ['1'..'9']]
removeKeysP :: XConfig l -> [String] -> XConfig l
removeKeysP conf keyList =
conf { keys = \cnf -> keys conf cnf `M.difference` mkKeymap cnf (zip keyList $ repeat (return ())) }
-- | Like 'additionalKeys', but for mouse bindings.
additionalMouseBindings :: XConfig a -> [((ButtonMask, Button), Window -> X ())] -> XConfig a
additionalMouseBindings conf mouseBindingsList =
conf { mouseBindings = \cnf -> M.union (M.fromList mouseBindingsList) (mouseBindings conf cnf) }
-- | Like 'removeKeys', but for mouse bindings.
removeMouseBindings :: XConfig a -> [(ButtonMask, Button)] -> XConfig a
removeMouseBindings conf mouseBindingList =
conf { mouseBindings = \cnf -> mouseBindings conf cnf `M.difference`
M.fromList (zip mouseBindingList $ return ()) }
--------------------------------------------------------------
-- Keybinding parsing ---------------------------------------
--------------------------------------------------------------
-- | Given a config (used to determine the proper modifier key to use)
-- and a list of @(String, X ())@ pairs, create a key map by parsing
-- the key sequence descriptions contained in the Strings. The key
-- sequence descriptions are \"emacs-style\": @M-@, @C-@, @S-@, and
-- @M\#-@ denote mod, control, shift, and mod1-mod5 (where @\#@ is
-- replaced by the appropriate number) respectively; some special
-- keys can be specified by enclosing their name in angle brackets.
--
-- For example, @\"M-C-x\"@ denotes mod+ctrl+x; @\"S-\<Escape\>\"@ denotes
-- shift-escape.
--
-- Sequences of keys can also be specified by separating the key
-- descriptions with spaces. For example, @\"M-x y \<Down\>\"@ denotes the
-- sequence of keys mod+x, y, down. Submaps (see
-- "XMonad.Actions.Submap") will be automatically generated to
-- correctly handle these cases.
--
-- So, for example, a complete key map might be specified as
--
-- > keys = \c -> mkKeymap c $
-- > [ ("M-S-<Return>", spawn $ terminal c)
-- > , ("M-x w", spawn "xmessage 'woohoo!'") -- type mod+x then w to pop up 'woohoo!'
-- > , ("M-x y", spawn "xmessage 'yay!'") -- type mod+x then y to pop up 'yay!'
-- > , ("M-S-c", kill)
-- > ]
--
-- Alternatively, you can use 'additionalKeysP' to automatically
-- create a keymap and add it to your config.
--
-- Here is a complete list of supported special keys. Note that a few
-- keys, such as the arrow keys, have synonyms:
--
-- > <Backspace>
-- > <Tab>
-- > <Return>
-- > <Pause>
-- > <Scroll_lock>
-- > <Sys_Req>
-- > <Escape>, <Esc>
-- > <Delete>
-- > <Home>
-- > <Left>, <L>
-- > <Up>, <U>
-- > <Right>, <R>
-- > <Down>, <D>
-- > <Page_Up>
-- > <Page_Down>
-- > <End>
-- > <Insert>
-- > <Break>
-- > <Space>
-- > <F1>-<F12>
mkKeymap :: XConfig l -> [(String, X ())] -> M.Map (KeyMask, KeySym) (X ())
mkKeymap c = M.fromList . mkSubmaps . readKeymap c
-- | Given a list of pairs of parsed key sequences and actions,
-- group them into submaps in the appropriate way.
mkSubmaps :: [ ([(KeyMask,KeySym)], X ()) ] -> [((KeyMask, KeySym), X ())]
mkSubmaps binds = map combine gathered
where gathered = groupBy fstKey
. sortBy (comparing fst)
$ binds
combine [([k],act)] = (k,act)
combine ks = (head . fst . head $ ks,
submap . M.fromList . mkSubmaps $ map (first tail) ks)
fstKey = (==) `on` (head . fst)
on :: (a -> a -> b) -> (c -> a) -> c -> c -> b
op `on` f = \x y -> f x `op` f y
-- | Given a configuration record and a list of (key sequence
-- description, action) pairs, parse the key sequences into lists of
-- @(KeyMask,KeySym)@ pairs. Key sequences which fail to parse will
-- be ignored.
readKeymap :: XConfig l -> [(String, X())] -> [([(KeyMask,KeySym)], X())]
readKeymap c = catMaybes . map (maybeKeys . first (readKeySequence c))
where maybeKeys (Nothing,_) = Nothing
maybeKeys (Just k, act) = Just (k, act)
-- | Parse a sequence of keys, returning Nothing if there is
-- a parse failure (no parse, or ambiguous parse).
readKeySequence :: XConfig l -> String -> Maybe [(KeyMask, KeySym)]
readKeySequence c s = case parses s of
[k] -> Just k
_ -> Nothing
where parses = map fst . filter (null.snd) . readP_to_S (parseKeySequence c)
-- | Parse a sequence of key combinations separated by spaces, e.g.
-- @\"M-c x C-S-2\"@ (mod+c, x, ctrl+shift+2).
parseKeySequence :: XConfig l -> ReadP [(KeyMask, KeySym)]
parseKeySequence c = sepBy1 (parseKeyCombo c) (many1 $ char ' ')
-- | Parse a modifier-key combination such as "M-C-s" (mod+ctrl+s).
parseKeyCombo :: XConfig l -> ReadP (KeyMask, KeySym)
parseKeyCombo c = do mods <- many (parseModifier c)
k <- parseKey
return (foldl' (.|.) 0 mods, k)
-- | Parse a modifier: either M- (user-defined mod-key),
-- C- (control), S- (shift), or M#- where # is an integer
-- from 1 to 5 (mod1Mask through mod5Mask).
parseModifier :: XConfig l -> ReadP KeyMask
parseModifier c = (string "M-" >> return (modMask c))
+++ (string "C-" >> return controlMask)
+++ (string "S-" >> return shiftMask)
+++ do char 'M'
n <- satisfy (`elem` ['1'..'5'])
char '-'
return (mod1Mask + (read [n]) - 1)
-- | Parse an unmodified basic key, like @\"x\"@, @\"<F1>\"@, etc.
parseKey :: ReadP KeySym
parseKey = parseRegular +++ parseSpecial
-- | Parse a regular key name (represented by itself).
parseRegular :: ReadP KeySym
parseRegular = choice [ char s >> return k
| (s,k) <- zip ['!'..'~'] [xK_exclam..xK_asciitilde]
]
-- | Parse a special key name (one enclosed in angle brackets).
parseSpecial :: ReadP KeySym
parseSpecial = do char '<'
key <- choice [ string name >> return k
| (name,k) <- keyNames
]
char '>'
return key
-- | A list of all special key names and their associated KeySyms.
keyNames :: [(String, KeySym)]
keyNames = functionKeys ++ specialKeys
-- | A list pairing function key descriptor strings (e.g. @\"<F2>\"@) with
-- the associated KeySyms.
functionKeys :: [(String, KeySym)]
functionKeys = [ ("F" ++ show n, k)
| (n,k) <- zip ([1..12] :: [Int]) [xK_F1..] ]
-- | A list of special key names and their corresponding KeySyms.
specialKeys :: [(String, KeySym)]
specialKeys = [ ("Backspace", xK_BackSpace)
, ("Tab" , xK_Tab )
, ("Return" , xK_Return)
, ("Pause" , xK_Pause)
, ("Scroll_lock", xK_Scroll_Lock)
, ("Sys_Req" , xK_Sys_Req)
, ("Escape" , xK_Escape)
, ("Esc" , xK_Escape)
, ("Delete" , xK_Delete)
, ("Home" , xK_Home)
, ("Left" , xK_Left)
, ("Up" , xK_Up)
, ("Right" , xK_Right)
, ("Down" , xK_Down)
, ("L" , xK_Left)
, ("U" , xK_Up)
, ("R" , xK_Right)
, ("D" , xK_Down)
, ("Page_Up" , xK_Page_Up)
, ("Page_Down", xK_Page_Down)
, ("End" , xK_End)
, ("Insert" , xK_Insert)
, ("Break" , xK_Break)
, ("Space" , xK_space)
]
-- | Given a configuration record and a list of (key sequence
-- description, action) pairs, check the key sequence descriptions
-- for validity, and warn the user (via a popup xmessage window) of
-- any unparseable or duplicate key sequences. This function is
-- appropriate for adding to your @startupHook@, and you are highly
-- encouraged to do so; otherwise, duplicate or unparseable
-- keybindings will be silently ignored.
--
-- For example, you might do something like this:
--
-- > main = xmonad $ myConfig
-- >
-- > myKeymap = [("S-M-c", kill), ...]
-- > myConfig = defaultConfig {
-- > ...
-- > keys = \c -> mkKeymap c myKeymap
-- > startupHook = return () >> checkKeymap myConfig myKeymap
-- > ...
-- > }
--
-- NOTE: the @return ()@ in the example above is very important!
-- Otherwise, you might run into problems with infinite mutual
-- recursion: the definition of myConfig depends on the definition of
-- startupHook, which depends on the definition of myConfig, ... and
-- so on. Actually, it's likely that the above example in particular
-- would be OK without the @return ()@, but making @myKeymap@ take
-- @myConfig@ as a parameter would definitely lead to
-- problems. Believe me. It, uh, happened to my friend. In... a
-- dream. Yeah. In any event, the @return () >>@ introduces enough
-- laziness to break the deadlock.
--
checkKeymap :: XConfig l -> [(String, a)] -> X ()
checkKeymap conf km = warn (doKeymapCheck conf km)
where warn ([],[]) = return ()
warn (bad,dup) = spawn $ "xmessage 'Warning:\n"
++ msg "bad" bad ++ "\n"
++ msg "duplicate" dup ++ "'"
msg _ [] = ""
msg m xs = m ++ " keybindings detected: " ++ showBindings xs
showBindings = concat . intersperse " " . map ((++"\"") . ("\""++))
-- | Given a config and a list of (key sequence description, action)
-- pairs, check the key sequence descriptions for validity,
-- returning a list of unparseable key sequences, and a list of
-- duplicate key sequences.
doKeymapCheck :: XConfig l -> [(String,a)] -> ([String], [String])
doKeymapCheck conf km = (bad,dups)
where ks = map ((readKeySequence conf &&& id) . fst) km
bad = nub . map snd . filter (isNothing . fst) $ ks
dups = map (snd . head)
. filter ((>1) . length)
. groupBy ((==) `on` fst)
. sortBy (comparing fst)
. map (first fromJust)
. filter (isJust . fst)
$ ks
