diff --git a/app/Main.hs b/app/Main.hs
index 94d6ee9..8978d99 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -7,6 +7,8 @@ import Data.Functor ( (<&>) )
 import Control.Monad ( filterM )
 import System.Directory.Extra ( listContents )
 import Brick
+import Graphics.Vty
+import Data.List.Extra
 
 listNonSymFiles :: FilePath -> IO [FilePath]
 listNonSymFiles dir = filterM (fmap not . pathIsSymbolicLink) =<< filterM doesFileExist =<< listContents dir
@@ -19,9 +21,61 @@ getSizeSubpaths x = do
   sub   <- listNonSymDirectories x
   subby <- mapM (\y -> (y,) . sum . map snd <$> getSizeSubpaths y) sub
   local <- listNonSymFiles x >>= (\y -> mapM getFileSize y <&> zip y)
-  return $ local ++ subby
+  pure $ local ++ subby
+
+data AppS = AppS
+  {
+    _appCWD :: FilePath
+  , _appCursor :: Int
+  , _appFocus :: Maybe FilePath
+  , _appSubFiles :: [(FilePath, Integer)]
+  }
+
+data ScrollDirection where
+  SUp   :: ScrollDirection
+  SDown :: ScrollDirection
+
+ui :: Widget ()
+ui = viewport () Vertical $ str "Svamp är gott"
+
+app :: App () e ()
+app =
+    App { appDraw = const [ui]
+        , appHandleEvent = resizeOrQuit
+        , appStartEvent = pure ()
+        , appAttrMap = const $ attrMap (white `on` blue) []
+        , appChooseCursor = neverShowCursor
+        }
+
+sizeDir :: AppS -> IO AppS
+sizeDir s = do
+  subFiles <- getSizeSubpaths $ _appCWD s
+  pure $ s {_appSubFiles = subFiles}
+
+changeDir :: AppS -> FilePath -> IO AppS
+changeDir so f =
+  let s = so {
+          _appCWD = f
+        , _appSubFiles = []
+        } in
+   sizeDir s
+
+scroll :: ScrollDirection -> AppS -> AppS
+scroll d s = s {
+                 _appCursor = newCursor
+               , _appFocus  = maybeNewPath
+               }
+  where cursor =
+          _appCursor s +
+          case d of
+            SUp   -> (-1)
+            SDown -> 1
+        newCursor = max 0 (min ((-) 1 . length $ _appSubFiles s) cursor)
+        maybeNewPath = fst <$> _appSubFiles s !? newCursor
+
 
 main :: IO ()
 main = do
   a <- getWorkingDirectory
   print =<< getSizeSubpaths a
+  defaultMain app ()
diff --git a/hcdu.cabal b/hcdu.cabal
index f9ba179..c1755bf 100644
--- a/hcdu.cabal
+++ b/hcdu.cabal
@@ -74,9 +74,13 @@ executable hcdu
                     , unix
                     , extra
                     , directory
+                    , vty
 
     -- Directories containing source files.
     hs-source-dirs:   app
 
     -- Base language which the package is written in.
     default-language: GHC2021
+
+    ghc-options:
+        -threaded