brick/tests/Render.hs

{-# LANGUAGE TypeApplications #-}
module Render
  ( main
  )
where

import Brick
import qualified Graphics.Vty as V
import Brick.Widgets.Border (hBorder)
import Control.Exception (try)

region :: V.DisplayRegion
region = (30, 10)

renderDisplay :: Ord n => [Widget n] -> IO ()
renderDisplay ws = do
    outp <- V.outputForConfig V.defaultConfig
    ctx <- V.displayContext outp region
    V.outputPicture ctx (renderWidget Nothing ws region)

myWidget :: Widget ()
myWidget = str "Why" <=> hBorder <=> str "not?"

-- Since you can't Read a Picture, we have to compare the result with
-- the Shown one
renderedMyWidget :: String
renderedMyWidget = "Picture ?? [VertJoin {partTop = VertJoin {partTop = HorizText {attr = Attr {attrStyle = Default, attrForeColor = Default, attrBackColor = Default, attrURL = Default}, displayText = \"Why                           \", outputWidth = 30, charWidth = 30}, partBottom = VertJoin {partTop = HorizText {attr = Attr {attrStyle = Default, attrForeColor = Default, attrBackColor = Default, attrURL = Default}, displayText = \"\\9472\\9472\\9472\\9472\\9472\\9472\\9472\\9472\\9472\\9472\\9472\\9472\\9472\\9472\\9472\\9472\\9472\\9472\\9472\\9472\\9472\\9472\\9472\\9472\\9472\\9472\\9472\\9472\\9472\\9472\", outputWidth = 30, charWidth = 30}, partBottom = HorizText {attr = Attr {attrStyle = Default, attrForeColor = Default, attrBackColor = Default, attrURL = Default}, displayText = \"not?                          \", outputWidth = 30, charWidth = 30}, outputWidth = 30, outputHeight = 2}, outputWidth = 30, outputHeight = 3}, partBottom = BGFill {outputWidth = 30, outputHeight = 7}, outputWidth = 30, outputHeight = 10}] ??"

main :: IO Bool
main = do
    result <- try (renderDisplay [myWidget]) :: IO (Either V.VtyConfigurationError ())
    case result of
      Left _ -> putStrLn "Terminal is not available"
      Right () -> return ()

    print $ show $ renderWidget Nothing [myWidget] region

    return $
      show (renderWidget Nothing [myWidget] region) == renderedMyWidget