{-# LANGUAGE OverloadedStrings #-} module Main where import Control.Lens import Control.Monad (void) import Data.Monoid import Graphics.Vty import Brick.Main import Brick.Core import Brick.Widgets.Core import Brick.Widgets.Border import Brick.Widgets.List import Brick.Widgets.Center import Brick.AttrMap import Brick.Util drawUI :: List Int -> [Widget] drawUI l = [ui] where label = "Item " <+> cur <+> " of " <+> total cur = case l^.listSelectedL of Nothing -> "-" Just i -> str (show (i + 1)) total = str $ show $ length $ l^.listElementsL box = borderWithLabel label $ hLimit 25 $ vLimit 15 $ renderList l ui = vCenter $ vBox [ hCenter box , " " , hCenter "Press +/- to add/remove list elements." , hCenter "Press Esc to exit." ] appEvent :: List Int -> Event -> EventM (Next (List Int)) appEvent l e = case e of EvKey (KChar '+') [] -> let el = length $ l^.listElementsL in continue $ listInsert el el l EvKey (KChar '-') [] -> case l^.listSelectedL of Nothing -> continue l Just i -> continue $ listRemove i l EvKey KEsc [] -> halt l ev -> continue $ handleEvent ev l listDrawElement :: Bool -> Int -> Widget listDrawElement sel i = let selStr s = if sel then withAttr customAttr (str $ "<" <> s <> ">") else str s in hCenter $ "Item " <+> (selStr $ show i) initialState :: List Int initialState = list (Name "list") listDrawElement [0, 1, 2] customAttr :: AttrName customAttr = listSelectedAttr <> "custom" theMap :: AttrMap theMap = attrMap defAttr [ (listAttr, white `on` blue) , (listSelectedAttr, blue `on` white) , (customAttr, fg cyan) ] theApp :: App (List Int) Event theApp = App { appDraw = drawUI , appChooseCursor = showFirstCursor , appHandleEvent = appEvent , appStartEvent = return , appAttrMap = const theMap , appMakeVtyEvent = id } main :: IO () main = void $ defaultMain theApp initialState