diff --git a/src/Main.hs b/src/Main.hs
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -5,30 +5,16 @@
 
 import System.Environment
 import System.IO.UTF8 as U
-import Codec.Binary.UTF8.String
 import Data.Char
+import qualified Data.List.PointedList as Zipper
+import Data.Maybe
 
 main :: IO ()
 main = getArgs >>= U.readFile . headOrUsage
-               >>= either (error . show) (runP presentation) . preprocess
-    -- vty recognizes any charactor has 1 half-width
-    -- thus for non-ascii full-width byte char,
-    -- for displaying string at center, some tuning is needed.
-    -- concretely, 1 half-width is ignored by 1 full-width char,
-    -- thus ignored width is added by adding spaces.
-    where preprocess = parseSlides . unlines . map processWideChars . lines
+               >>= either (error . show)
+                          (runP presentation . fromJust . Zipper.fromList . (++[T ["[End of Slide]"]]))
+                         . parseSlides
 
 headOrUsage :: [String] -> String
 headOrUsage ls | null ls = error "Usage: tkhs [presentation]"
                | otherwise = head ls
-
-processWideChars :: String -> String
-processWideChars str = let wideChars = length . filter (not . isHalfWidth) $ str
-                       in str ++ replicate wideChars ' '
-
--- Table of Half-width Kana
--- http://ash.jp/code/unitbl1.htm
-isHalfWidth :: Char -> Bool
-isHalfWidth c = isLatin1 c || c `elem` [h .. t]
-    where h = head . decodeString $ "\xef\xbd\xa1" -- minimum of half-kana
-          t = head . decodeString $ "\xef\xbe\x9f" -- maximum of half-kana
diff --git a/src/Parser.hs b/src/Parser.hs
--- a/src/Parser.hs
+++ b/src/Parser.hs
@@ -1,5 +1,4 @@
 {-# OPTIONS_GHC -fglasgow-exts -XNoMonomorphismRestriction #-}
-{-# OPTIONS_GHC -XPackageImports #-}
 
 module Parser (parseSlides) where
 
@@ -8,13 +7,11 @@
 import Text.Parsec hiding (newline, (<|>))
 import Control.Monad.Identity
 import Control.Applicative hiding (many)
-import Data.Maybe
-import Data.List.PointedList as Zipper
 
 import Prelude hiding (lines)
 
-parseSlides :: String -> Either ParseError SlideSet
-parseSlides str = parse (fromJust . Zipper.fromList <$> many1 slide) "" str
+parseSlides :: String -> Either ParseError [Slide]
+parseSlides str = parse (many1 slide) "" str
 
 type PC a = ParsecT String () Identity a
 
diff --git a/src/Tkhs.hs b/src/Tkhs.hs
--- a/src/Tkhs.hs
+++ b/src/Tkhs.hs
@@ -14,7 +14,7 @@
 , Zipper
 )where
 
-import Vty
+import Vty hiding (style)
 
 import qualified Data.List.PointedList as Zipper
 import Data.List.PointedList (PointedList)
@@ -37,15 +37,15 @@
     deriving (Functor, Monad, MonadState PictureSet)
 
 slideToImage :: Slide -> Image
-slideToImage (T ls) = processBy (flip centeringBy 1) ls
+slideToImage (T ls) = processBy (flip centeringBy 1 . fromIntegral) ls
 slideToImage (F ls) = processBy ljust                ls
-    where ljust maxlen img = let orig_width = imgWidth img
-                             in img <|> render (replicate (maxlen - orig_width) ' ')
+    where ljust maxlen img = let orig_width = image_width img
+                             in img <|> render (replicate (maxlen - fromIntegral orig_width) ' ')
 
 processBy :: (Int -> Image -> Image) -> [String] -> Image
 processBy f ls = let imgs = map render ls
-                     maxlen = maximum $ map imgWidth imgs
-                 in vertcat . map (f maxlen) $ imgs
+                     maxlen = fromIntegral . maximum $ map image_width imgs
+                 in vert_cat . map (f maxlen) $ imgs
 
 -- slideSetToPictureSet :: SlideSet -> V PictureSet
 -- slideSetToPictureSet = T.mapM $ fmap toPic
@@ -58,13 +58,13 @@
    let imgset = fmap slideToImage slides
    check <- F.and <$> T.mapM doesFit imgset
    when (not check) $ do
-     let maxWidth = F.maximum $ fmap imgWidth imgset
-         maxHeight = F.maximum $ fmap imgHeight imgset
+     let maxWidth = F.maximum $ fmap image_width imgset
+         maxHeight = F.maximum $ fmap image_height imgset
      mapM_ warn [ "To display this presentation, the terminal must be at least "
                       ++ show maxWidth ++ "x" ++ show maxHeight ++ "."
                 , "Please try again with a bigger terminal."
                 , "Press any key to exit." ]
-     liftIO =<< waitOnce exitFailure (return undefined)
+     liftIO =<< waitOnce exitFailure (return ())
    pictures <- T.mapM (fmap toPic . centering) imgset
    evalStateT st pictures `withVty` ourVty
 
@@ -72,7 +72,7 @@
 warn str = do
   w <- width
   liftIO . hPutStrLn stderr
-         . renderStyle style { lineLength = w, ribbonsPerLine = 1.0 }
+         . renderStyle style { lineLength = fromIntegral w, ribbonsPerLine = 1.0 }
          . fsep . map text . words $ str
 
 liftV :: V a -> P a
@@ -81,7 +81,6 @@
 presentation :: P ()
 presentation = do
   current <- Zipper.focus <$> get
-  liftV clear
   liftV . draw $ current
   control
 
diff --git a/src/Vty.hs b/src/Vty.hs
--- a/src/Vty.hs
+++ b/src/Vty.hs
@@ -37,6 +37,7 @@
 import Control.Monad.Reader
 import Control.Monad.Writer
 import Control.Exception
+import Data.Word
 -- import Codec.Binary.UTF8.String
 -- import qualified Data.ByteString.UTF8 as U
 
@@ -54,7 +55,7 @@
   return a
 
 event :: V Event
-event = ask >>= liftIO . getEvent
+event = ask >>= liftIO . next_event
 
 draw :: Picture -> V ()
 draw p = ask >>= liftIO . flip update p
@@ -62,11 +63,14 @@
 clear :: V ()
 clear = ask >>= liftIO . refresh
 
-type Width = Int
-type Height = Int
+type Width = Word
+type Height = Word
 
 size :: V (Width,Height)
-size = ask >>= liftIO . getSize
+size = do
+  term <- terminal <$> ask
+  DisplayRegion w h <- liftIO $ display_bounds term
+  return (w,h)
 
 width :: V Width
 width = fst <$> size
@@ -77,7 +81,7 @@
 centering :: Image -> V Image
 centering image = do
   (w,h) <- size
-  let imgW = imgWidth image
+  let imgW = image_width image
       newImg = if imgW > w
                then image
                else centeringBy w h image
@@ -137,27 +141,30 @@
   return . maybe r id . lookup evt $ toTable d
 
 toPic :: Image -> Picture
-toPic img = pic { pImage = img }
+toPic img = pic_for_image img
 
 render :: String -> Image
 -- render str = let bs = U.pack str
 --              in renderBS attr bs
-render = horzcat . map (renderChar attr)
+render = horiz_cat . map (char def_attr)
 
+toInt :: Word -> Int
+toInt = fromIntegral
+
 centeringBy :: Width -> Height -> Image -> Image
 centeringBy wholeWidth wholeHeight img
-    | wholeWidth < imgWidth img || wholeHeight < imgHeight img = img
-    | otherwise = let imgW = imgWidth img
-                      imgH = imgHeight img
+    | wholeWidth < image_width img || wholeHeight < image_height img = img
+    | otherwise = let imgW = image_width img
+                      imgH = image_height img
                       magW = wholeWidth - imgW
                       magH = wholeHeight - imgH
                       lpad = magW `div` 2
                       rpad = magW `div` 2 + magW `mod` 2
                       tpad = magH `div` 2
                       bpad = magH `div` 2 + magH `mod` 2
-                      spacebox w h  = vertcat
-                                    . replicate h
-                                    . render $ replicate w ' '
+                      spacebox w h  = vert_cat
+                                    . replicate (toInt h)
+                                    . render $ replicate (toInt w) ' '
                   in spacebox lpad wholeHeight
                      <|>
                         (spacebox imgW tpad
@@ -167,5 +174,5 @@
                      spacebox rpad wholeHeight
 
 doesFitBy :: Width -> Height -> Image -> Bool
-doesFitBy w h img = w >= imgWidth img && h >= imgHeight img
+doesFitBy w h img = w >= image_width img && h >= image_height img
 
diff --git a/tkhs.cabal b/tkhs.cabal
--- a/tkhs.cabal
+++ b/tkhs.cabal
@@ -1,5 +1,5 @@
 name:                tkhs
-version:             0.1.0.6
+version:             0.2.1
 synopsis:            Simple Presentation Utility
 description:         If you want to give your presentation in a terminal,
                      or if PowerPoint would be overkill, you may find tkhs useful.
@@ -26,7 +26,7 @@
   build-depends:     base == 4.*
                    , pointedlist
                    , mtl
-                   , vty == 3.*
+                   , vty == 4.*
                    , parsec == 3.*
                    , pretty
                    , utf8-string