brick/programs/VisibilityDemo.hs
Jonathan Daugherty 6f1b62ae53 AttrName: remove IsString instance
This change is motivated by the API wart that results from the
overloading of both "<>" and string literals that resulted in code like
this:

  a :: AttrName
  a = "blah" <> "things"

While this worked to create an AttrName with two segments, it is far too
easy to read this as two strings concatenated. The overloading hides
what is really going on with the segments of the attribute name. The way
to write the above example after this change is:

  a :: AttrName
  a = attrName "blah" <> attrName "things"
2022-08-04 18:44:57 -07:00

136 lines
4.1 KiB
Haskell

{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE CPP #-}
module Main where
import Control.Monad (void)
import Lens.Micro
import Lens.Micro.TH
import Lens.Micro.Mtl
#if !(MIN_VERSION_base(4,11,0))
import Data.Monoid
#endif
import qualified Graphics.Vty as V
import qualified Brick.Types as T
import qualified Brick.Main as M
import qualified Brick.Widgets.Center as C
import qualified Brick.Widgets.Border as B
import Brick.AttrMap (AttrMap, AttrName, attrMap, attrName)
import Brick.Util (on)
import Brick.Types
( Widget
, ViewportType(Horizontal, Vertical, Both)
)
import Brick.Widgets.Core
( withAttr
, hLimit
, vLimit
, hBox
, vBox
, viewport
, str
, visible
)
data St =
St { _vp1Index :: Int
, _vp2Index :: Int
, _vp3Index :: (Int, Int)
}
makeLenses ''St
data Name = VP1
| VP2
| VP3
deriving (Show, Ord, Eq)
vp1Size :: Int
vp1Size = 15
vp2Size :: Int
vp2Size = 15
vp3Size :: (Int, Int)
vp3Size = (25, 25)
selectedAttr :: AttrName
selectedAttr = attrName "selected"
drawUi :: St -> [Widget Name]
drawUi st = [ui]
where
ui = C.center $ hLimit 60 $ vLimit 30 $
vBox [ B.border $ vBox [ pair, B.hBorder, singleton ]
, str $ "- Up/down arrow keys scroll the top-left viewport\n" <>
"- Left/right arrow keys scroll the top-right viewport\n" <>
"- Ctrl-arrow keys move the bottom viewport"
]
singleton = viewport VP3 Both $
vBox $ do
i <- [1..vp3Size^._1]
let row = do
j <- [1..vp3Size^._2]
let mkItem = if (i, j) == st^.vp3Index
then withAttr selectedAttr . visible
else id
return $ mkItem $ str $ "Item " <> show (i, j) <> " "
return $ hBox row
pair = hBox [ vp1, B.vBorder, vp2 ]
vp1 = viewport VP1 Vertical $
vBox $ do
i <- [1..vp1Size]
let mkItem = if i == st^.vp1Index
then withAttr selectedAttr . visible
else id
return $ mkItem $ str $ "Item " <> show i
vp2 = viewport VP2 Horizontal $
hBox $ do
i <- [1..vp2Size]
let mkItem = if i == st^.vp2Index
then withAttr selectedAttr . visible
else id
return $ mkItem $ str $ "Item " <> show i <> " "
vp1Scroll :: M.ViewportScroll Name
vp1Scroll = M.viewportScroll VP1
vp2Scroll :: M.ViewportScroll Name
vp2Scroll = M.viewportScroll VP2
vp3Scroll :: M.ViewportScroll Name
vp3Scroll = M.viewportScroll VP3
appEvent :: T.BrickEvent Name e -> T.EventM Name St ()
appEvent (T.VtyEvent (V.EvKey V.KDown [V.MCtrl])) = vp3Index._1 %= min (vp3Size^._1) . (+ 1)
appEvent (T.VtyEvent (V.EvKey V.KUp [V.MCtrl])) = vp3Index._1 %= max 1 . subtract 1
appEvent (T.VtyEvent (V.EvKey V.KRight [V.MCtrl])) = vp3Index._2 %= min (vp3Size^._1) . (+ 1)
appEvent (T.VtyEvent (V.EvKey V.KLeft [V.MCtrl])) = vp3Index._2 %= max 1 . subtract 1
appEvent (T.VtyEvent (V.EvKey V.KDown [])) = vp1Index %= min vp1Size . (+ 1)
appEvent (T.VtyEvent (V.EvKey V.KUp [])) = vp1Index %= max 1 . subtract 1
appEvent (T.VtyEvent (V.EvKey V.KRight [])) = vp2Index %= min vp2Size . (+ 1)
appEvent (T.VtyEvent (V.EvKey V.KLeft [])) = vp2Index %= max 1 . subtract 1
appEvent (T.VtyEvent (V.EvKey V.KEsc [])) = M.halt
appEvent _ = return ()
theMap :: AttrMap
theMap = attrMap V.defAttr
[ (selectedAttr, V.black `on` V.yellow)
]
app :: M.App St e Name
app =
M.App { M.appDraw = drawUi
, M.appStartEvent = return ()
, M.appHandleEvent = appEvent
, M.appAttrMap = const theMap
, M.appChooseCursor = M.neverShowCursor
}
initialState :: St
initialState = St 1 1 (1, 1)
main :: IO ()
main = void $ M.defaultMain app initialState