brick/programs/LayerDemo.hs

79 lines
2.5 KiB
Haskell

{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE TemplateHaskell #-}
module Main where
import Lens.Micro ((^.), (&), (%~))
import Lens.Micro.TH (makeLenses)
import Control.Monad (void)
import Data.Default
import qualified Graphics.Vty as V
import qualified Brick.Types as T
import Brick.Types (locationRowL, locationColumnL, Widget)
import qualified Brick.Main as M
import qualified Brick.Widgets.Border as B
import qualified Brick.Widgets.Center as C
import Brick.Widgets.Core
( translateBy
, str
)
data St =
St { _topLayerLocation :: T.Location
, _bottomLayerLocation :: T.Location
}
makeLenses ''St
drawUi :: St -> [Widget ()]
drawUi st =
[ C.centerLayer $
B.border $ str "This layer is centered but other\nlayers are placed underneath it."
, topLayer st
, bottomLayer st
]
topLayer :: St -> Widget ()
topLayer st =
translateBy (st^.topLayerLocation) $
B.border $ str "Top layer\n(Arrow keys move)"
bottomLayer :: St -> Widget ()
bottomLayer st =
translateBy (st^.bottomLayerLocation) $
B.border $ str "Bottom layer\n(Ctrl-arrow keys move)"
appEvent :: St -> T.BrickEvent () e -> T.EventM () (T.Next St)
appEvent st (T.VtyEvent (V.EvKey V.KDown [])) =
M.continue $ st & topLayerLocation.locationRowL %~ (+ 1)
appEvent st (T.VtyEvent (V.EvKey V.KUp [])) =
M.continue $ st & topLayerLocation.locationRowL %~ (subtract 1)
appEvent st (T.VtyEvent (V.EvKey V.KRight [])) =
M.continue $ st & topLayerLocation.locationColumnL %~ (+ 1)
appEvent st (T.VtyEvent (V.EvKey V.KLeft [])) =
M.continue $ st & topLayerLocation.locationColumnL %~ (subtract 1)
appEvent st (T.VtyEvent (V.EvKey V.KDown [V.MCtrl])) =
M.continue $ st & bottomLayerLocation.locationRowL %~ (+ 1)
appEvent st (T.VtyEvent (V.EvKey V.KUp [V.MCtrl])) =
M.continue $ st & bottomLayerLocation.locationRowL %~ (subtract 1)
appEvent st (T.VtyEvent (V.EvKey V.KRight [V.MCtrl])) =
M.continue $ st & bottomLayerLocation.locationColumnL %~ (+ 1)
appEvent st (T.VtyEvent (V.EvKey V.KLeft [V.MCtrl])) =
M.continue $ st & bottomLayerLocation.locationColumnL %~ (subtract 1)
appEvent st (T.VtyEvent (V.EvKey V.KEsc [])) = M.halt st
appEvent st _ = M.continue st
app :: M.App St e ()
app =
M.App { M.appDraw = drawUi
, M.appStartEvent = return
, M.appHandleEvent = appEvent
, M.appAttrMap = const def
, M.appChooseCursor = M.neverShowCursor
}
main :: IO ()
main = void $ M.defaultMain app $ St (T.Location (0, 0)) (T.Location (0, 0))