hsedit/editor.hs

import Brick
import Brick.Markup
import Data.Maybe
import Data.Monoid
import Data.List
import Data.Text (pack, singleton)
import Data.Text.Markup ((@@))
import qualified Brick.Widgets.Edit as E
import qualified Graphics.Vty as V

data Name = Text deriving (Ord, Show, Eq)
type St = E.Editor Name

initialState :: St
initialState = E.editor Text drawContent Nothing ""

drawContent :: [String] -> Widget n
drawContent = markup . createMarkup . unlines

createMarkup :: String -> Markup V.Attr
createMarkup [] = mempty
createMarkup s@('"':ss) = case i of
                            Just n -> (pack (take (2+n) s) @@ fg V.blue) <> (createMarkup (drop (1+n) ss))
                            Nothing -> pack s @@ fg V.red
    where i = elemIndex '"' ss
createMarkup (c:ss) = (singleton c @@ fg V.white) <> (createMarkup ss)

drawUI :: St -> [Widget Name]
drawUI st = [E.renderEditor True st]

appCursor :: St -> [CursorLocation Name] -> Maybe (CursorLocation Name)
appCursor st c = Just (head c)

appEvent :: St -> V.Event -> EventM Name (Next St)
appEvent st ev =
    case ev of
        V.EvKey V.KEsc [] -> halt st
        _ -> continue =<< E.handleEditorEvent ev st

theApp :: App St V.Event Name
theApp =
    App { appDraw = drawUI
          , appChooseCursor = appCursor
          , appHandleEvent = appEvent
          , appStartEvent = return
          , appAttrMap = const (attrMap V.defAttr [ ])
          , appLiftVtyEvent = id
          }

main = do
  st <- defaultMain theApp initialState
  putStrLn $ unlines $ E.getEditContents $ st