packages feed

yi-0.4: Yi/UI/Vty.hs

-- Copyright (C) 2007-8 JP Bernardy
-- Copyright (C) 2004-5 Don Stewart - http://www.cse.unsw.edu.au/~dons
-- Originally derived from: riot/UI.hs Copyright (c) Tuomo Valkonen 2004.


-- | This module defines a user interface implemented using vty.

module Yi.UI.Vty (start) where

import Yi.Prelude hiding ((<|>))
import Prelude (map, take, zip, repeat, length, break, splitAt)
import Control.Concurrent
import Control.Exception
import Control.Monad (forever)
import Control.Monad.State (runState, State, gets, modify, get, put)
import Control.Monad.Trans (liftIO, MonadIO)
import Data.Char (ord,chr)
import Data.Foldable
import Data.IORef
import Data.List (partition, sort)
import qualified Data.Map as M
import Data.Maybe
import Data.Traversable
import System.Exit
import System.Posix.Signals         ( raiseSignal, sigTSTP )
import Yi.Buffer
import Yi.Buffer.Implementation
import Yi.Buffer.Region
import Yi.Buffer.HighLevel
import Yi.Debug
import Yi.Editor
import Yi.Event
import Yi.Monad
import Yi.Regex (SearchExp)
import Yi.Style
import Yi.WindowSet as WS
import qualified Data.ByteString.Char8 as B
import qualified Yi.UI.Common as Common
import Yi.Config
import Yi.Window
import Yi.Style as Style
import Graphics.Vty as Vty

import Yi.UI.Utils
import Yi.Syntax (Stroke)
import Yi.Indent (indentSettingsB, IndentSettings(..))

------------------------------------------------------------------------

data Rendered = 
    Rendered {
              picture :: !Image           -- ^ the picture currently displayed.
             ,cursor  :: !(Maybe (Int,Int)) -- ^ cursor point on the above
             }




data UI = UI { 
              vty       :: Vty              -- ^ Vty
             ,scrsize   :: IORef (Int,Int)  -- ^ screen size
             ,uiThread  :: ThreadId
             ,uiRefresh :: MVar ()
             ,uiEditor  :: IORef Editor
             ,config  :: Config
             }
mkUI :: UI -> Common.UI
mkUI ui = Common.UI 
  {
   Common.main           = main ui,
   Common.end            = end ui,
   Common.suspend        = raiseSignal sigTSTP,
   Common.refresh        = scheduleRefresh ui,
   Common.prepareAction  = prepareAction ui,
   Common.reloadProject  = \_ -> return ()
  }

-- | Initialise the ui
start :: UIBoot
start cfg ch _outCh editor = do
  liftIO $ do 
          v <- mkVty
          (x0,y0) <- Vty.getSize v
          sz <- newIORef (y0,x0)
          -- fork input-reading thread. important to block *thread* on getKey
          -- otherwise all threads will block waiting for input
          t <- myThreadId
          tuiRefresh <- newEmptyMVar
          editorRef <- newIORef editor
          let result = UI v sz t tuiRefresh editorRef cfg
              -- | Action to read characters into a channel
              getcLoop = forever $ getKey >>= ch

              -- | Read a key. UIs need to define a method for getting events.
              getKey = do 
                event <- getEvent v
                case event of 
                  (EvResize x y) -> do logPutStrLn $ "UI: EvResize: " ++ show (x,y)
                                       writeIORef sz (y,x) >> readRef (uiEditor result) >>= refresh result >> getKey
                  _ -> return (fromVtyEvent event)
          forkIO $ getcLoop
          return (mkUI result)
        

main :: UI -> IO ()
main ui = do
  let
      -- | When the editor state isn't being modified, refresh, then wait for
      -- it to be modified again. 
      refreshLoop :: IO ()
      refreshLoop = forever $ do 
                      logPutStrLn "waiting for refresh"
                      takeMVar (uiRefresh ui)
                      handleJust ioErrors (\except -> do 
                                             logPutStrLn "refresh crashed with IO Error"
                                             logError $ show $ except)
                                     (readRef (uiEditor ui) >>= refresh ui >> return ())
  readRef (uiEditor ui) >>= scheduleRefresh ui
  logPutStrLn "refreshLoop started"
  refreshLoop
  

-- | Clean up and go home
end :: UI -> IO ()
end i = do  
  Vty.shutdown (vty i)
  throwTo (uiThread i) (ExitException ExitSuccess)

fromVtyEvent :: Vty.Event -> Yi.Event.Event
fromVtyEvent (EvKey k mods) = Event (fromVtyKey k) (sort $ map fromVtyMod mods)
fromVtyEvent _ = error "fromVtyEvent: unsupported event encountered."


fromVtyKey :: Vty.Key -> Yi.Event.Key
fromVtyKey (Vty.KEsc     ) = Yi.Event.KEsc      
fromVtyKey (Vty.KFun x   ) = Yi.Event.KFun x    
fromVtyKey (Vty.KPrtScr  ) = Yi.Event.KPrtScr   
fromVtyKey (Vty.KPause   ) = Yi.Event.KPause    
fromVtyKey (Vty.KASCII '\t') = Yi.Event.KTab
fromVtyKey (Vty.KASCII c ) = Yi.Event.KASCII c  
fromVtyKey (Vty.KBS      ) = Yi.Event.KBS       
fromVtyKey (Vty.KIns     ) = Yi.Event.KIns      
fromVtyKey (Vty.KHome    ) = Yi.Event.KHome     
fromVtyKey (Vty.KPageUp  ) = Yi.Event.KPageUp   
fromVtyKey (Vty.KDel     ) = Yi.Event.KDel      
fromVtyKey (Vty.KEnd     ) = Yi.Event.KEnd      
fromVtyKey (Vty.KPageDown) = Yi.Event.KPageDown 
fromVtyKey (Vty.KNP5     ) = Yi.Event.KNP5      
fromVtyKey (Vty.KUp      ) = Yi.Event.KUp       
fromVtyKey (Vty.KMenu    ) = Yi.Event.KMenu     
fromVtyKey (Vty.KLeft    ) = Yi.Event.KLeft     
fromVtyKey (Vty.KDown    ) = Yi.Event.KDown     
fromVtyKey (Vty.KRight   ) = Yi.Event.KRight    
fromVtyKey (Vty.KEnter   ) = Yi.Event.KEnter    

fromVtyMod :: Vty.Modifier -> Yi.Event.Modifier
fromVtyMod Vty.MShift = Yi.Event.MShift
fromVtyMod Vty.MCtrl  = Yi.Event.MCtrl
fromVtyMod Vty.MMeta  = Yi.Event.MMeta
fromVtyMod Vty.MAlt   = Yi.Event.MMeta

prepareAction :: UI -> IO (EditorM ())
prepareAction ui = do
  (yss,xss) <- readRef (scrsize ui)
  return $ do
    modifyWindows (computeHeights yss)
    e <- get
    let ws = windows e
        renderSeq = fmap (scrollAndRenderWindow (configUI $ config ui) (configStyle $ configUI $ config $ ui) xss) (WS.withFocus ws)
    sequence_ renderSeq


-- | Redraw the entire terminal from the UI.
-- Among others, this re-computes the heights and widths of all the windows.

-- Two points remain: horizontal scrolling, and tab handling.
refresh :: UI -> Editor -> IO Editor
refresh ui e = do
  let ws = windows e
  logPutStrLn "refreshing screen."
  (yss,xss) <- readRef (scrsize ui)
  let ws' = computeHeights yss ws
      cmd = statusLine e
      renderSeq = fmap (scrollAndRenderWindow (configUI $ config ui) (configStyle $ configUI $ config $ ui) xss) (WS.withFocus ws')
      (e', renders) = runEditor (config ui) (sequence renderSeq) e

  let startXs = scanrT (+) 0 (fmap height ws')
      wImages = fmap picture renders
     
  WS.debug "Drawing: " ws'
  logPutStrLn $ "startXs: " ++ show startXs
  Vty.update (vty $ ui) 
      pic {pImage = vertcat (toList wImages) <-> withStyle (window $ configStyle $ configUI $ config $ ui) (take xss $ cmd ++ repeat ' '),
           pCursor = case cursor (WS.current renders) of
                       Just (y,x) -> Cursor x (y + WS.current startXs) 
                       -- Add the position of the window to the position of the cursor
                       Nothing -> NoCursor
                       -- This can happen if the user resizes the window. 
                       -- Not really nice, but upon the next refresh the cursor will show.
                       }

  return e'

scanrT :: (Int -> Int -> Int) -> Int -> WindowSet Int -> WindowSet Int
scanrT (+*+) k t = fst $ runState (mapM f t) k
    where f x = do s <- get
                   let s' = s +*+ x
                   put s'
                   return s
           

-- | Scrolls the window to show the point if needed
scrollAndRenderWindow :: UIConfig -> UIStyle -> Int -> (Window, Bool) -> EditorM Rendered
scrollAndRenderWindow cfg sty width (win,hasFocus) = do 
    e <- get
    let b = findBufferWith (bufkey win) e
        (point, _) = runBuffer win b pointB
        (inWindow, _) = runBuffer win b $ pointInWindowB point
        b' = if inWindow then b else showPoint b win
        (rendered, b'') = drawWindow cfg (regex e) b' sty hasFocus width win
    put e { buffers = M.insert (bufkey win) b'' (buffers e) }
    return rendered


-- | Draw a window
-- TODO: horizontal scrolling.
drawWindow :: UIConfig -> Maybe SearchExp -> FBuffer -> UIStyle -> Bool -> Int -> Window -> (Rendered, FBuffer)
drawWindow cfg mre b sty focused w win = (Rendered { picture = pict,cursor = cur}, b')
    where
        notMini = not (isMini win)
        -- off reserves space for the mode line. The mini window does not have a mode line.
        off = if notMini then 1 else 0
        h' = height win - off
        wsty = styleToAttr (window sty) attr
        selsty = styleToAttr (selected sty) attr
        eofsty = eof sty
        (selreg, _) = runBuffer win b getSelectRegionB
        (point, _) = runBuffer win b pointB
        (eofPoint, _) = runBuffer win b sizeB
        sz = Size (w*h')
        -- Work around a problem with the mini window never displaying it's contents due to a
        -- fromMark that is always equal to the end of the buffer contents.
        (Just (WinMarks fromM _ toM), _) = runBuffer win b (getMarks win)
        fromMarkPoint = if notMini
                            then fst $ runBuffer win b (getMarkPointB fromM)
                            else Point 0
        (text, _)    = runBuffer win b (streamB Forward fromMarkPoint) -- read enough chars from the buffer.
        (strokes, _) = runBuffer win b (strokesRangesB  mre fromMarkPoint (fromMarkPoint +~ sz)) -- corresponding strokes
        colors = paintPicture attr (map (map toVtyStroke) strokes)
        bufData = -- trace (unlines (map show text) ++ unlines (map show $ concat strokes)) $ 
                  paintChars attr colors $ toIndexedString fromMarkPoint text
        (showSel, _) = runBuffer win b (gets highlightSelection)
        -- TODO: This resolves issue #123 but not very cleanly IMO - coconnor
        tabWidth = tabSize . fst $ runBuffer win b indentSettingsB
        prompt = if isMini win then name b else ""

        (rendered,toMarkPoint',cur) = drawText h' w
                                fromMarkPoint
                                point 
                                tabWidth
                                (if showSel then selreg else emptyRegion)
                                selsty wsty 
                                ([(c,(wsty, 0)) | c <- prompt] ++ bufData ++ [(' ',(attr, eofPoint))])
                             -- we always add one character which can be used to position the cursor at the end of file
        (_, b') = runBuffer win b (setMarkPointB toM toMarkPoint')
        (modeLine0, _) = runBuffer win b getModeLine
        modeLine = if notMini then Just modeLine0 else Nothing
        modeLines = map (withStyle (modeStyle sty) . take w . (++ repeat ' ')) $ maybeToList $ modeLine
        modeStyle = if focused then modeline_focused else modeline        
        filler = take w (configWindowFill cfg : repeat ' ')
    
        pict = vertcat (take h' (rendered ++ repeat (withStyle eofsty filler)) ++ modeLines)
  
-- | Renders text in a rectangle.
-- This also returns 
-- * the index of the last character fitting in the rectangle
-- * the position of the Point in (x,y) coordinates, if in the window.
drawText :: Int    -- ^ The height of the part of the window we are in
         -> Int    -- ^ The width of the part of the window we are in
         -> Point  -- ^ The position of the first character to draw
         -> Point  -- ^ The position of the cursor
         -> Int    -- ^ The number of spaces to represent a tab character with.
         -> Region -- ^ The selected region
         -> Vty.Attr   -- ^ The attribute with which to draw selected text
         -> Vty.Attr   -- ^ The attribute with which to draw the background
                   -- this is not used for drawing but only to compare
                   -- it against the selection attribute to avoid making
                   -- the selection invisible.
         -> [(Char,(Vty.Attr,Point))]  -- ^ The data to draw.
         -> ([Image], Point, Maybe (Int,Int))
drawText h w topPoint point tabWidth selreg selsty wsty bufData
    | h == 0 || w == 0 = ([], topPoint, Nothing)
    | otherwise        = (rendered_lines, bottomPoint, pntpos)
  where 

  lns0 = take h $ concatMap (wrapLine w) $ map (concatMap expandGraphic) $ take h $ lines' $ bufData

  bottomPoint = case lns0 of 
                 [] -> topPoint 
                 _ -> snd $ snd $ last $ last $ lns0

  pntpos = listToMaybe [(y,x) | (y,l) <- zip [0..] lns0, (x,(_char,(_attr,p))) <- zip [0..] l, p == point]

  -- fill lines with blanks, so the selection looks ok.
  rendered_lines = map fillColorLine lns0
  colorChar (c, (a, x)) = renderChar (pointStyle x a) c

  pointStyle :: Point -> Vty.Attr -> Vty.Attr
  pointStyle x a 
    | x == point          = a
    | x `inRegion` selreg 
      && selsty /= wsty   = selsty
    | otherwise           = a

  fillColorLine :: [(Char, (Vty.Attr, Point))] -> Image
  fillColorLine [] = renderHFill attr ' ' w
  fillColorLine l = horzcat (map colorChar l) 
                    <|>
                    renderHFill (pointStyle x a) ' ' (w - length l)
                    where (_,(a,x)) = last l

  -- | Cut a string in lines separated by a '\n' char. Note
  -- that we add a blank character where the \n was, so the
  -- cursor can be positioned there.

  lines' :: [(Char,a)] -> [[(Char,a)]]
  lines' [] =  []
  lines' s  = case s' of
                []          -> [l]
                ((_,x):s'') -> (l++[(' ',x)]) : lines' s''
              where
              (l, s') = break ((== '\n') . fst) s

  wrapLine :: Int -> [x] -> [[x]]
  wrapLine _ [] = []
  wrapLine n l = let (x,rest) = splitAt n l in x : wrapLine n rest
                                      
  expandGraphic ('\t', p) = replicate tabWidth (' ', p)
  expandGraphic (c,p) 
    | ord c < 32 = [('^',p),(chr (ord c + 64),p)]
    | otherwise = [(c,p)]

withStyle :: Style -> String -> Image
withStyle sty str = renderBS (styleToAttr sty attr) (B.pack str)


------------------------------------------------------------------------


-- | Schedule a refresh of the UI.
scheduleRefresh :: UI -> Editor -> IO ()
scheduleRefresh ui e = do
  writeRef (uiEditor ui) e
  logPutStrLn "scheduleRefresh"
  tryPutMVar (uiRefresh ui) ()
  return ()
-- The non-blocking behviour was set up with this in mind: if the display
-- thread is not able to catch up with the editor updates (possible since
-- display is much more time consuming than simple editor operations),
-- then there will be fewer display refreshes. 

-- | Calculate window heights, given all the windows and current height.
-- (No specific code for modelines)
computeHeights :: Int -> WindowSet Window  -> WindowSet Window
computeHeights totalHeight ws = result
  where (mwls, wls) = partition isMini (toList ws)
        (y,r) = getY (totalHeight - length mwls) (length wls) 
        (result, _) = runState (Data.Traversable.mapM distribute ws) ((y+r-1) : repeat y)

distribute :: Window -> State [Int] Window
distribute win = case isMini win of
                 True -> return win {height = 1}
                 False -> do h <- gets head
                             modify tail
                             return win {height = h}

getY :: Int -> Int -> (Int,Int)
getY screenHeight 0               = (screenHeight, 0)
getY screenHeight numberOfWindows = screenHeight `quotRem` numberOfWindows

------------------------------
-- Low-level stuff

------------------------------------------------------------------------

--
-- Combine attribute with another attribute
--
boldA, reverseA, nullA :: Vty.Attr -> Vty.Attr
boldA       = setBold
reverseA    = setRV
nullA       = id

------------------------------------------------------------------------

-- | Convert a Yi Attr into a Vty attribute change.
attrToAttr :: Style.Attr -> (Vty.Attr -> Vty.Attr)
attrToAttr (Foreground c) = 
  case c of 
    RGB 0 0 0         -> nullA    . setFG Vty.black
    RGB 128 128 128   -> boldA    . setFG Vty.black
    RGB 139 0 0       -> nullA    . setFG Vty.red
    RGB 255 0 0       -> boldA    . setFG Vty.red
    RGB 0 100 0       -> nullA    . setFG Vty.green
    RGB 0 128 0       -> boldA    . setFG Vty.green
    RGB 165 42 42     -> nullA    . setFG Vty.yellow
    RGB 255 255 0     -> boldA    . setFG Vty.yellow
    RGB 0 0 139       -> nullA    . setFG Vty.blue
    RGB 0 0 255       -> boldA    . setFG Vty.blue
    RGB 128 0 128     -> nullA    . setFG Vty.magenta
    RGB 255 0 255     -> boldA    . setFG Vty.magenta
    RGB 0 139 139     -> nullA    . setFG Vty.cyan
    RGB 0 255 255     -> boldA    . setFG Vty.cyan
    RGB 165 165 165   -> nullA    . setFG Vty.white
    RGB 255 255 255   -> boldA    . setFG Vty.white
    Default           -> nullA    . setFG Vty.def
    Reverse           -> reverseA . setFG Vty.def
    _                 -> nullA    . setFG Vty.black -- NB
attrToAttr (Background c) = 
  case c of 
    RGB 0 0 0         -> nullA    . setBG Vty.black
    RGB 128 128 128   -> nullA    . setBG Vty.black
    RGB 139 0 0       -> nullA    . setBG Vty.red
    RGB 255 0 0       -> nullA    . setBG Vty.red
    RGB 0 100 0       -> nullA    . setBG Vty.green
    RGB 0 128 0       -> nullA    . setBG Vty.green
    RGB 165 42 42     -> nullA    . setBG Vty.yellow
    RGB 255 255 0     -> nullA    . setBG Vty.yellow
    RGB 0 0 139       -> nullA    . setBG Vty.blue
    RGB 0 0 255       -> nullA    . setBG Vty.blue
    RGB 128 0 128     -> nullA    . setBG Vty.magenta
    RGB 255 0 255     -> nullA    . setBG Vty.magenta
    RGB 0 139 139     -> nullA    . setBG Vty.cyan
    RGB 0 255 255     -> nullA    . setBG Vty.cyan
    RGB 165 165 165   -> nullA    . setBG Vty.white
    RGB 255 255 255   -> nullA    . setBG Vty.white
    Default           -> nullA    . setBG Vty.def
    Reverse           -> reverseA . setBG Vty.def
    _                 -> nullA    . setBG Vty.white    -- NB

styleToAttr :: Style -> (Vty.Attr -> Vty.Attr)
styleToAttr = foldr (.) id . map attrToAttr



---------------------------------


-- | Return @n@ elems starting at @i@ of the buffer as a list.
-- This routine also does syntax highlighting and applies overlays.
paintChars :: a -> [(Point,a)] -> [(Point,Char)] -> [(Char, (a,Point))]
paintChars sty [] cs = setSty sty cs
paintChars sty ((endPos,sty'):xs) cs = setSty sty left ++ paintChars sty' xs right
        where (left, right) = break ((endPos <=) . fst) cs

setSty :: a -> [(Point,Char)] -> [(Char, (a,Point))]
setSty sty cs = [(c,(sty,p)) | (p,c) <- cs]


-- | @paintStrokes colorToTheRight strokes picture@: paint the strokes over a given picture.
-- Precondition: input list is sorted and strokes do not overlap.
paintStrokes :: a -> [(Point,(a -> a),Point)] -> [(Point,a)] -> [(Point,a)]
paintStrokes _  []     rest = rest
paintStrokes s0 ss     [] = concat [[(l,s s0),(r,s0)] | (l,s,r) <- ss]
paintStrokes s0 ls@((l,s,r):ts) lp@((p,s'):tp) 
             | p < l  = (p,s') : paintStrokes s' ls tp
             | p <= r =          paintStrokes s' ls tp
             | r == p = (l,s s0) : (p,s') : paintStrokes s' ts tp 
             | otherwise {-r < p-}  = (l,s s0) : (r,s0) : paintStrokes s' ts lp

paintPicture :: a -> [[(Point,(a -> a),Point)]] -> [(Point,a)]
paintPicture a = foldr (paintStrokes a) []

toVtyStroke :: Stroke -> (Point, Vty.Attr -> Vty.Attr, Point)
toVtyStroke (l,s,r) = (l,styleToAttr s,r)