brick/programs/SuspendAndResumeDemo.hs
Jonathan Daugherty fc8cfe3b4a Remove appLiftVtyEvent in favor of library event type BrickEvent
This change makes it possible for brick to extent the event space using
its own event notions in addition those provided by Vty and the
application itself. This means we no longer need the user to provide the
type and appLiftVtyEvent went away. This makes pattern-matching in event
handlers a little noisier with the benefit that we can now add events
like mouse clicks or drags to the event type.
2016-10-25 20:19:31 -07:00

68 lines
1.5 KiB
Haskell

{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE TemplateHaskell #-}
module Main where
import Lens.Micro ((.~), (^.), (&))
import Lens.Micro.TH (makeLenses)
import Control.Monad (void)
import Data.Monoid
import Data.Default
import qualified Graphics.Vty as V
import Brick.Main
( App(..), neverShowCursor, defaultMain
, suspendAndResume, halt, continue
)
import Brick.Types
( Widget
, EventM
, Next
, BrickEvent(..)
)
import Brick.Widgets.Core
( vBox
, str
)
data St =
St { _stExternalInput :: String
}
makeLenses ''St
drawUI :: St -> [Widget ()]
drawUI st = [ui]
where
ui = vBox [ str $ "External input: \"" <> st^.stExternalInput <> "\""
, str "(Press Esc to quit or Space to ask for input)"
]
appEvent :: St -> BrickEvent () e -> EventM () (Next St)
appEvent st (VtyEvent e) =
case e of
V.EvKey V.KEsc [] -> halt st
V.EvKey (V.KChar ' ') [] -> suspendAndResume $ do
putStrLn "Suspended. Please enter something and press enter to resume:"
s <- getLine
return $ st & stExternalInput .~ s
_ -> continue st
appEvent st _ = continue st
initialState :: St
initialState =
St { _stExternalInput = ""
}
theApp :: App St e ()
theApp =
App { appDraw = drawUI
, appChooseCursor = neverShowCursor
, appHandleEvent = appEvent
, appStartEvent = return
, appAttrMap = const def
}
main :: IO ()
main =
void $ defaultMain theApp initialState