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{- |
Module : XMonad.Util.XSelection
Copyright : (C) 2007 Andrea Rossato, Matthew Sackman
License : BSD3
Maintainer : Andrea Rossato <andrea.rossato@unibz.it>,
Matthew Sackman <matthew@wellquite.org>
Stability : unstable
Portability : unportable
A module for accessing and manipulating X Window's mouse selection (the buffer used in copy and pasting).
'getSelection' and 'putSelection' are adaptations of Hxsel.hs and Hxput.hs from the XMonad-utils, available:
> $ darcs get <http://gorgias.mine.nu/repos/xmonad-utils>
-}
module XMonad.Util.XSelection ( -- * Usage
-- $usage
getSelection,
promptSelection,
safePromptSelection,
putSelection) where
import Control.Concurrent (forkIO)
import Control.Exception as E (catch)
import Control.Monad(Monad (return, (>>)), Functor(..), liftM, join)
import Data.Bits (shiftL, (.&.), (.|.))
import Data.Char (chr, ord)
import Data.Maybe (fromMaybe)
import Data.Word (Word8)
import XMonad
import XMonad.Util.Run (safeSpawn, unsafeSpawn)
{- $usage
Add @import XMonad.Util.XSelection@ to the top of Config.hs
Then make use of getSelection or promptSelection as needed; if
one wanted to run Firefox with the selection as an argument (perhaps
the selection string is an URL you just highlighted), then one could add
to the xmonad.hs a line like thus:
> , ((modMask .|. shiftMask, xK_b), promptSelection "firefox")
There are a number of known problems with XSelection:
* Unicode handling is busted. But it's still better than calling
'chr' to translate to ASCII, at least.
As near as I can tell, the mangling happens when the String is
outputted somewhere, such as via promptSelection's passing through
the shell, or GHCi printing to the terminal. utf-string has IO functions
which can fix this, though I do not know have to use them here. It's
a complex issue; see
<http://www.haskell.org/pipermail/xmonad/2007-September/001967.html>
and <http://www.haskell.org/pipermail/xmonad/2007-September/001966.html>.
* Needs more elaborate functionality: Emacs' registers are nice; if you
don't know what they are, see <http://www.gnu.org/software/emacs/manual/html_node/emacs/Registers.html#Registers> -}
-- | Returns a String corresponding to the current mouse selection in X; if there is none, an empty string is returned. Note that this is
-- really only reliable for ASCII text and currently escapes or otherwise mangles more complex UTF-8 characters.
getSelection :: MonadIO m => m String
getSelection = io $ do
dpy <- openDisplay ""
let dflt = defaultScreen dpy
rootw <- rootWindow dpy dflt
win <- createSimpleWindow dpy rootw 0 0 1 1 0 0 0
p <- internAtom dpy "PRIMARY" True
ty <- E.catch
(E.catch
(internAtom dpy "UTF8_STRING" False)
(\_ -> internAtom dpy "COMPOUND_TEXT" False))
(\_ -> internAtom dpy "sTring" False)
clp <- internAtom dpy "BLITZ_SEL_STRING" False
xConvertSelection dpy p ty clp win currentTime
allocaXEvent $ \e -> do
nextEvent dpy e
ev <- getEvent e
if ev_event_type ev == selectionNotify
then do res <- getWindowProperty8 dpy clp win
return $ decode . map fromIntegral . fromMaybe [] $ res
else destroyWindow dpy win >> return ""
-- | Set the current X Selection to a specified string.
putSelection :: MonadIO m => String -> m ()
putSelection text = io $ do
dpy <- openDisplay ""
let dflt = defaultScreen dpy
rootw <- rootWindow dpy dflt
win <- createSimpleWindow dpy rootw 0 0 1 1 0 0 0
p <- internAtom dpy "PRIMARY" True
ty <- internAtom dpy "UTF8_STRING" False
xSetSelectionOwner dpy p win currentTime
winOwn <- xGetSelectionOwner dpy p
if winOwn == win
then do forkIO ((allocaXEvent $ processEvent dpy ty text) >> destroyWindow dpy win) >> return ()
else do putStrLn "Unable to obtain ownership of the selection" >> destroyWindow dpy win
return ()
where
processEvent :: Display -> Atom -> [Char] -> XEventPtr -> IO ()
processEvent dpy ty txt e = do
nextEvent dpy e
ev <- getEvent e
if ev_event_type ev == selectionRequest
then do print ev
allocaXEvent $ \replyPtr -> do
changeProperty8 (ev_event_display ev)
(ev_requestor ev)
(ev_property ev)
ty
propModeReplace
(map (fromIntegral . ord) txt)
setSelectionNotify replyPtr (ev_requestor ev) (ev_selection ev)
(ev_target ev) (ev_property ev) (ev_time ev)
sendEvent dpy (ev_requestor ev) False noEventMask replyPtr
sync dpy False
else do putStrLn "Unexpected Message Received"
print ev
processEvent dpy ty text e
{- | A wrapper around 'getSelection'. Makes it convenient to run a program with the current selection as an argument.
This is convenient for handling URLs, in particular. For example, in your Config.hs you could bind a key to
@promptSelection \"firefox\"@;
this would allow you to highlight a URL string and then immediately open it up in Firefox.
'promptSelection' passes strings through the system shell, \/bin\/sh; if you do not wish your selected text
to be interpreted or mangled by the shell, use 'safePromptSelection'. safePromptSelection will bypass the
shell using 'safeSpawn' from "XMonad.Util.Run"; see its documentation for more
details on the advantages and disadvantages of using safeSpawn. -}
promptSelection, safePromptSelection, unsafePromptSelection :: String -> X ()
promptSelection = unsafePromptSelection
safePromptSelection app = join $ io $ liftM (safeSpawn app) (getSelection)
unsafePromptSelection app = join $ io $ liftM unsafeSpawn $ fmap (\x -> app ++ " " ++ x) getSelection
{- | Decode a UTF8 string packed into a list of Word8 values, directly to
String; does not deal with CChar, hence you will want the counter-intuitive @map fromIntegral@
UTF-8 decoding for internal use in getSelection.
This code is copied from Eric Mertens's "utf-string" library <http://code.haskell.org/utf8-string/>
(as of version 0.1),\which is BSD-3 licensed like this module.
It'd be better to just @import Codec.Binary.UTF8.String (decode)@, but then users of this would need to install it; XMonad has enough
dependencies already. -}
decode :: [Word8] -> String
decode [ ] = ""
decode (c:cs)
| c < 0x80 = chr (fromEnum c) : decode cs
| c < 0xc0 = replacement_character : decode cs
| c < 0xe0 = multi_byte 1 0x1f 0x80
| c < 0xf0 = multi_byte 2 0xf 0x800
| c < 0xf8 = multi_byte 3 0x7 0x10000
| c < 0xfc = multi_byte 4 0x3 0x200000
| c < 0xfe = multi_byte 5 0x1 0x4000000
| otherwise = replacement_character : decode cs
where
replacement_character :: Char
replacement_character = '\xfffd'
multi_byte :: Int -> Word8 -> Int -> [Char]
multi_byte i mask overlong = aux i cs (fromEnum (c .&. mask))
where
aux 0 rs acc
| overlong <= acc && acc <= 0x10ffff &&
(acc < 0xd800 || 0xdfff < acc) &&
(acc < 0xfffe || 0xffff < acc) = chr acc : decode rs
| otherwise = replacement_character : decode rs
aux n (r:rs) acc
| r .&. 0xc0 == 0x80 = aux (n-1) rs
$ shiftL acc 6 .|. fromEnum (r .&. 0x3f)
aux _ rs _ = replacement_character : decode rs
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