Safe Haskell	Safe-Inferred
Language	Haskell2010

Termbox.Banana

Contents

Main
Terminal contents
Event handling
Miscellaneous types

Description

This module provides a reactive-banana FRP interface to termbox, a simple C library for writing text-based user interfaces: https://github.com/termbox/termbox

👉 Quick start example

Expand

This termbox program displays the number of keys pressed.

{-# LANGUAGE BlockArguments #-}
{-# LANGUAGE DuplicateRecordFields #-}
{-# LANGUAGE ImportQualifiedPost #-}
{-# LANGUAGE LambdaCase #-}
{-# LANGUAGE OverloadedRecordDot #-}

module Main (main) where

import Data.Foldable (fold)
import Data.Function ((&))
import Reactive.Banana ((<@>))
import Reactive.Banana qualified as Banana
import Termbox.Banana qualified as Termbox

main :: IO ()
main = do
  result <- Termbox.run network
  putStrLn case result of
    Left err -> "Termbox program failed to initialize: " ++ show err
    Right state -> "Final state: " ++ show state

network :: (Banana.MonadMoment m) => Termbox.Inputs -> m (Termbox.Outputs Int)
network inputs = do
  keysPressed <- Banana.accumB 0 ((+ 1) <$ inputs.keys)
  pure
    Termbox.Outputs
      { scene = render <$> keysPressed,
        done = Banana.filterJust (isDone <$> keysPressed <@> inputs.keys)
      }
  where
    isDone :: Int -> Termbox.Key -> Maybe Int
    isDone n = \case
      Termbox.KeyEsc -> Just n
      _ -> Nothing

render :: Int -> Termbox.Scene
render keysPressed =
  fold
    [ string ("Number of keys pressed: " ++ show keysPressed),
      fold
        [ string "Press",
          string "Esc" & Termbox.bold & Termbox.atCol 6,
          string "to quit." & Termbox.atCol 10
        ]
        & Termbox.atRow 2
    ]
    & Termbox.at Termbox.Pos {row = 2, col = 4}
    & Termbox.image

string :: [Char] -> Termbox.Image
string chars =
  zip [0 ..] chars & foldMap \(i, char) ->
    Termbox.char char & Termbox.atCol i

Synopsis

data Inputs = Inputs {
- initialSize :: !Size
- keys :: !(Event Key)
- resizes :: !(Event Size)
- mouses :: !(Event Mouse)
}
data Outputs a = Outputs {
- scene :: !(Behavior Scene)
- done :: !(Event a)
}
run :: (Inputs -> MomentIO (Outputs a)) -> IO (Either InitError a)
data InitError
- = FailedToOpenTTY
- | PipeTrapError
- | UnsupportedTerminal
data Scene
image :: Image -> Scene
fill :: Color -> Scene -> Scene
cursor :: Pos -> Scene -> Scene
data Image
char :: Char -> Image
fg :: Color -> Image -> Image
bg :: Color -> Image -> Image
bold :: Image -> Image
underline :: Image -> Image
blink :: Image -> Image
at :: Pos -> Image -> Image
atRow :: Int -> Image -> Image
atCol :: Int -> Image -> Image
data Color
defaultColor :: Color
red :: Color
green :: Color
yellow :: Color
blue :: Color
magenta :: Color
cyan :: Color
white :: Color
bright :: Color -> Color
color :: Int -> Color
gray :: Int -> Color
data Key where
- KeyChar !Char
- KeyArrowDown
- KeyArrowLeft
- KeyArrowRight
- KeyArrowUp
- KeyBackspace
- KeyCtrlBackspace
- KeyCtrl6
- KeyCtrl8
- KeyCtrlA
- KeyCtrlB
- KeyCtrlBackslash
- KeyCtrlC
- KeyCtrlD
- KeyCtrlE
- KeyCtrlF
- KeyCtrlG
- KeyCtrlJ
- KeyCtrlK
- KeyCtrlL
- KeyCtrlN
- KeyCtrlO
- KeyCtrlP
- KeyCtrlQ
- KeyCtrlR
- KeyCtrlRsqBracket
- KeyCtrlS
- KeyCtrlSlash
- KeyCtrlTilde
- KeyCtrlT
- KeyCtrlU
- KeyCtrlV
- KeyCtrlW
- KeyCtrlX
- KeyCtrlY
- KeyCtrlZ
- KeyDelete
- KeyEnd
- KeyEnter
- KeyEsc
- KeyF1
- KeyF10
- KeyF11
- KeyF12
- KeyF2
- KeyF3
- KeyF4
- KeyF5
- KeyF6
- KeyF7
- KeyF8
- KeyF9
- KeyHome
- KeyInsert
- KeyPageDn
- KeyPageUp
- KeySpace
- KeyTab
- pattern KeyCtrlUnderscore :: Key
- pattern KeyCtrlI :: Key
- pattern KeyCtrlM :: Key
- pattern KeyCtrl7 :: Key
- pattern KeyCtrl5 :: Key
- pattern KeyCtrl4 :: Key
- pattern KeyCtrl3 :: Key
- pattern KeyCtrl2 :: Key
- pattern KeyCtrlLsqBracket :: Key
- pattern KeyCtrlH :: Key
data Mouse = Mouse {
- button :: !MouseButton
- pos :: !Pos
}
data MouseButton where
- pattern WheelUp :: MouseButton
- pattern WheelDown :: MouseButton
- pattern ReleaseClick :: MouseButton
- pattern RightClick :: MouseButton
- pattern MiddleClick :: MouseButton
- pattern LeftClick :: MouseButton
data Pos = Pos {
- row :: !Int
- col :: !Int
}
posUp :: Int -> Pos -> Pos
posDown :: Int -> Pos -> Pos
posLeft :: Int -> Pos -> Pos
posRight :: Int -> Pos -> Pos
data Size = Size {
- width :: !Int
- height :: !Int
}

Main

data Inputs Source #

The inputs to a termbox FRP network.

Constructors

Inputs
Fields initialSize :: !Size The initial terminal size. keys :: !(Event Key) Key events. resizes :: !(Event Size) Resize events. mouses :: !(Event Mouse) Mouse events.

data Outputs a Source #

The outputs from a termbox FRP network.

Constructors

Outputs
Fields scene :: !(Behavior Scene) The scene to render. done :: !(Event a) The events of arbitrary values, on the first of which is relevant, which causes `run` to return. Note: Wrapping this event in `once` is not necessary, as this library does so internally.

run Source #

Arguments

:: (Inputs -> MomentIO (Outputs a))	The FRP network.
-> IO (Either InitError a)	The result of the FRP network.

Run a termbox FRP network.

run either:

Returns immediately with an InitError.
Returns the first value emitted by done.

data InitError #

termbox initialization errors.

Constructors

FailedToOpenTTY
PipeTrapError
UnsupportedTerminal

Instances

Instances details

Exception InitError
Instance details Defined in Termbox.Internal.Main Methods toException :: InitError -> SomeException # fromException :: SomeException -> Maybe InitError # displayException :: InitError -> String #
Show InitError
Instance details Defined in Termbox.Internal.Main Methods showsPrec :: Int -> InitError -> ShowS # show :: InitError -> String # showList :: [InitError] -> ShowS #

Terminal contents

Scene

data Scene #

A scene, which contains an image, an optional background fill color, and an optional cursor.

Create a scene with image.
Set a scene's background fill color with fill.
Set a scene's cursor position with cursor.

image :: Image -> Scene #

Create a scene from an image.

fill :: Color -> Scene -> Scene #

Set a scene's background fill color.

cursor :: Pos -> Scene -> Scene #

Set a scene's cursor position.

Image

data Image #

An image.

Create an image with char.
Set an image's color with fg / bg.
Style an image with bold / underline / blink.
Translate an image with at / atRow / atCol.
Overlay an image atop another with (<>).

Instances

Instances details

Monoid Image
Instance details Defined in Termbox.Internal.Image Methods mempty :: Image # mappend :: Image -> Image -> Image # mconcat :: [Image] -> Image #
Semigroup Image
Instance details Defined in Termbox.Internal.Image Methods (<>) :: Image -> Image -> Image # sconcat :: NonEmpty Image -> Image # stimes :: Integral b => b -> Image -> Image #

char :: Char -> Image #

Create an image from a character.

If the character is not 1 character wide, it will not be displayed.

Color

fg :: Color -> Image -> Image #

Set the foreground color of an image.

bg :: Color -> Image -> Image #

Set the background color of an image.

Style

bold :: Image -> Image #

Make an image bold.

underline :: Image -> Image #

Make an image underlined.

blink :: Image -> Image #

Make an image blink.

Translation

at :: Pos -> Image -> Image #

Translate an image.

atRow :: Int -> Image -> Image #

Translate an image by a number of rows.

atCol :: Int -> Image -> Image #

Translate an image by a number of columns.

Colors

data Color #

A color.

There are three classes of colors:

Basic named colors and their bright variants, such as red and bright blue.
Miscellaneous colors, such as color 33.
Monochrome colors that range from black (gray 0) to white (gray 23).

Instances

Instances details

Eq Color
Instance details Defined in Termbox.Internal.Color Methods (==) :: Color -> Color -> Bool # (/=) :: Color -> Color -> Bool #

Basic colors

defaultColor :: Color #

red :: Color #

green :: Color #

yellow :: Color #

blue :: Color #

magenta :: Color #

cyan :: Color #

white :: Color #

bright :: Color -> Color #

Make a basic color bright.

216 miscellaneous colors

color :: Int -> Color #

A miscellaneous color.

Valid values are in the range [0, 215]; values outside of this range are clamped.

24 monochrome colors

gray :: Int -> Color #

A monochrome color; black is 0 and white is 23.

Valid values are in the range [0, 23]; values outside of this range are clamped.

Event handling

data Key #

A key event.

Some distinct key sequences map to the same key event. For example, to a termbox program, Enter is indistinguishable from Ctrl+M. Pattern synonyms below are provided for an alternate syntax in these cases, if desired.

Bundled Patterns

pattern KeyCtrlUnderscore :: Key
pattern KeyCtrlI :: Key
pattern KeyCtrlM :: Key
pattern KeyCtrl7 :: Key
pattern KeyCtrl5 :: Key
pattern KeyCtrl4 :: Key
pattern KeyCtrl3 :: Key
pattern KeyCtrl2 :: Key
pattern KeyCtrlLsqBracket :: Key
pattern KeyCtrlH :: Key

Instances

Instances details

Show Key
Instance details Defined in Termbox.Internal.Key Methods showsPrec :: Int -> Key -> ShowS # show :: Key -> String # showList :: [Key] -> ShowS #
Eq Key
Instance details Defined in Termbox.Internal.Key Methods (==) :: Key -> Key -> Bool # (/=) :: Key -> Key -> Bool #
Ord Key
Instance details Defined in Termbox.Internal.Key Methods compare :: Key -> Key -> Ordering # (<) :: Key -> Key -> Bool # (<=) :: Key -> Key -> Bool # (>) :: Key -> Key -> Bool # (>=) :: Key -> Key -> Bool # max :: Key -> Key -> Key # min :: Key -> Key -> Key #

data Mouse #

A mouse event.

Constructors

Mouse
Fields button :: !MouseButton pos :: !Pos

Instances

Instances details

Generic Mouse
Instance details Defined in Termbox.Internal.Mouse Associated Types type Rep Mouse :: Type -> Type # Methods from :: Mouse -> Rep Mouse x # to :: Rep Mouse x -> Mouse #
Show Mouse
Instance details Defined in Termbox.Internal.Mouse Methods showsPrec :: Int -> Mouse -> ShowS # show :: Mouse -> String # showList :: [Mouse] -> ShowS #
Eq Mouse
Instance details Defined in Termbox.Internal.Mouse Methods (==) :: Mouse -> Mouse -> Bool # (/=) :: Mouse -> Mouse -> Bool #
Ord Mouse
Instance details Defined in Termbox.Internal.Mouse Methods compare :: Mouse -> Mouse -> Ordering # (<) :: Mouse -> Mouse -> Bool # (<=) :: Mouse -> Mouse -> Bool # (>) :: Mouse -> Mouse -> Bool # (>=) :: Mouse -> Mouse -> Bool # max :: Mouse -> Mouse -> Mouse # min :: Mouse -> Mouse -> Mouse #
type Rep Mouse
Instance details Defined in Termbox.Internal.Mouse type Rep Mouse = D1 ('MetaData "Mouse" "Termbox.Internal.Mouse" "termbox-2.0.0-inplace" 'False) (C1 ('MetaCons "Mouse" 'PrefixI 'True) (S1 ('MetaSel ('Just "button") 'NoSourceUnpackedness 'SourceStrict 'DecidedUnpack) (Rec0 MouseButton) :*: S1 ('MetaSel ('Just "pos") 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 Pos)))

data MouseButton where #

A mouse button.

Bundled Patterns

pattern WheelUp :: MouseButton
pattern WheelDown :: MouseButton
pattern ReleaseClick :: MouseButton
pattern RightClick :: MouseButton
pattern MiddleClick :: MouseButton
pattern LeftClick :: MouseButton

Instances

Instances details

Show MouseButton
Instance details Defined in Termbox.Internal.Mouse Methods showsPrec :: Int -> MouseButton -> ShowS # show :: MouseButton -> String # showList :: [MouseButton] -> ShowS #
Eq MouseButton
Instance details Defined in Termbox.Internal.Mouse Methods (==) :: MouseButton -> MouseButton -> Bool # (/=) :: MouseButton -> MouseButton -> Bool #
Ord MouseButton
Instance details Defined in Termbox.Internal.Mouse Methods compare :: MouseButton -> MouseButton -> Ordering # (<) :: MouseButton -> MouseButton -> Bool # (<=) :: MouseButton -> MouseButton -> Bool # (>) :: MouseButton -> MouseButton -> Bool # (>=) :: MouseButton -> MouseButton -> Bool # max :: MouseButton -> MouseButton -> MouseButton # min :: MouseButton -> MouseButton -> MouseButton #

Miscellaneous types

data Pos #

A relative terminal position.

Constructors

Pos
Fields row :: !Int col :: !Int

Instances

Instances details

Monoid Pos
Instance details Defined in Termbox.Internal.Pos Methods mempty :: Pos # mappend :: Pos -> Pos -> Pos # mconcat :: [Pos] -> Pos #
Semigroup Pos
Instance details Defined in Termbox.Internal.Pos Methods (<>) :: Pos -> Pos -> Pos # sconcat :: NonEmpty Pos -> Pos # stimes :: Integral b => b -> Pos -> Pos #
Generic Pos
Instance details Defined in Termbox.Internal.Pos Associated Types type Rep Pos :: Type -> Type # Methods from :: Pos -> Rep Pos x # to :: Rep Pos x -> Pos #
Show Pos
Instance details Defined in Termbox.Internal.Pos Methods showsPrec :: Int -> Pos -> ShowS # show :: Pos -> String # showList :: [Pos] -> ShowS #
Eq Pos
Instance details Defined in Termbox.Internal.Pos Methods (==) :: Pos -> Pos -> Bool # (/=) :: Pos -> Pos -> Bool #
Ord Pos
Instance details Defined in Termbox.Internal.Pos Methods compare :: Pos -> Pos -> Ordering # (<) :: Pos -> Pos -> Bool # (<=) :: Pos -> Pos -> Bool # (>) :: Pos -> Pos -> Bool # (>=) :: Pos -> Pos -> Bool # max :: Pos -> Pos -> Pos # min :: Pos -> Pos -> Pos #
type Rep Pos
Instance details Defined in Termbox.Internal.Pos type Rep Pos = D1 ('MetaData "Pos" "Termbox.Internal.Pos" "termbox-2.0.0-inplace" 'False) (C1 ('MetaCons "Pos" 'PrefixI 'True) (S1 ('MetaSel ('Just "row") 'SourceUnpack 'SourceStrict 'DecidedUnpack) (Rec0 Int) :*: S1 ('MetaSel ('Just "col") 'SourceUnpack 'SourceStrict 'DecidedUnpack) (Rec0 Int)))

posUp :: Int -> Pos -> Pos #

Move a position up.

posDown :: Int -> Pos -> Pos #

Move a position down.

posLeft :: Int -> Pos -> Pos #

Move a position left.

posRight :: Int -> Pos -> Pos #

Move a position right.

data Size #

A terminal size.

Constructors

Size
Fields width :: !Int height :: !Int

Instances

Instances details

Generic Size
Instance details Defined in Termbox.Internal.Size Associated Types type Rep Size :: Type -> Type # Methods from :: Size -> Rep Size x # to :: Rep Size x -> Size #
Show Size
Instance details Defined in Termbox.Internal.Size Methods showsPrec :: Int -> Size -> ShowS # show :: Size -> String # showList :: [Size] -> ShowS #
Eq Size
Instance details Defined in Termbox.Internal.Size Methods (==) :: Size -> Size -> Bool # (/=) :: Size -> Size -> Bool #
Ord Size
Instance details Defined in Termbox.Internal.Size Methods compare :: Size -> Size -> Ordering # (<) :: Size -> Size -> Bool # (<=) :: Size -> Size -> Bool # (>) :: Size -> Size -> Bool # (>=) :: Size -> Size -> Bool # max :: Size -> Size -> Size # min :: Size -> Size -> Size #
type Rep Size
Instance details Defined in Termbox.Internal.Size type Rep Size = D1 ('MetaData "Size" "Termbox.Internal.Size" "termbox-2.0.0-inplace" 'False) (C1 ('MetaCons "Size" 'PrefixI 'True) (S1 ('MetaSel ('Just "width") 'SourceUnpack 'SourceStrict 'DecidedUnpack) (Rec0 Int) :*: S1 ('MetaSel ('Just "height") 'SourceUnpack 'SourceStrict 'DecidedUnpack) (Rec0 Int)))

KeyChar !Char
KeyArrowDown
KeyArrowLeft
KeyArrowRight
KeyArrowUp
KeyBackspace
KeyCtrlBackspace	Also `KeyCtrlH`
KeyCtrl6
KeyCtrl8
KeyCtrlA
KeyCtrlB
KeyCtrlBackslash	Also `KeyCtrl4`
KeyCtrlC
KeyCtrlD
KeyCtrlE
KeyCtrlF
KeyCtrlG
KeyCtrlJ
KeyCtrlK
KeyCtrlL
KeyCtrlN
KeyCtrlO
KeyCtrlP
KeyCtrlQ
KeyCtrlR
KeyCtrlRsqBracket	Also `KeyCtrl5`
KeyCtrlS
KeyCtrlSlash	Also `KeyCtrl7`, `KeyCtrlUnderscore`
KeyCtrlTilde	Also `KeyCtrl2`
KeyCtrlT
KeyCtrlU
KeyCtrlV
KeyCtrlW
KeyCtrlX
KeyCtrlY
KeyCtrlZ
KeyDelete
KeyEnd
KeyEnter	Also `KeyCtrlM`
KeyEsc	Also `KeyCtrlLsqBracket`, `KeyCtrl3`
KeyF1
KeyF10
KeyF11
KeyF12
KeyF2
KeyF3
KeyF4
KeyF5
KeyF6
KeyF7
KeyF8
KeyF9
KeyHome
KeyInsert
KeyPageDn
KeyPageUp
KeySpace
KeyTab	Also `KeyCtrlI`