brick/programs/AttrDemo.hs
2015-07-10 13:53:21 -07:00

63 lines
1.8 KiB
Haskell

{-# LANGUAGE OverloadedStrings #-}
module Main where
import Data.Monoid
import Graphics.Vty
( Event, Attr, white, blue, cyan, green, red, yellow
, black
)
import Brick.Main
import Brick.Widgets.Core
( Widget
, (<=>)
, withAttr
, vBox
)
import Brick.Util (on, fg)
import Brick.AttrMap (attrMap, AttrMap)
ui :: Widget
ui =
vBox [ "This text uses the global default attribute."
, withAttr "foundFull"
"Specifying an attribute name means we look it up in the attribute tree."
, withAttr "foundFgOnly"
("When we find a value, we merge it with its parent in the attribute"
<=> "name tree all the way to the root (the global default).")
, withAttr "missing"
"A missing attribute name just resumes the search at its parent."
, withAttr ("general" <> "specific")
"In this way we build complete attribute values by using an inheritance scheme."
, withAttr "foundFull"
"You can override everything ..."
, withAttr "foundFgOnly"
"... or only you want to change and inherit the rest."
, "Attribute names are assembled with the Monoid append operation to indicate"
, "hierarchy levels, e.g. \"window\" <> \"title\"."
]
globalDefault :: Attr
globalDefault = white `on` blue
theMap :: AttrMap
theMap = attrMap globalDefault
[ ("foundFull", white `on` green)
, ("foundFgOnly", fg red)
, ("general", yellow `on` black)
, ("general" <> "specific", fg cyan)
]
app :: App () Event
app =
App { appDraw = const [ui]
, appHandleEvent = resizeOrQuit
, appStartEvent = return
, appAttrMap = const theMap
, appChooseCursor = neverShowCursor
, appLiftVtyEvent = id
}
main :: IO ()
main = defaultMain app ()