elm/libraries/Keyboard.elm
2013-07-26 16:38:11 +02:00

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1.8 KiB
Elm

module Keyboard where
import Native.Keyboard as Native
-- Type alias to make it clearer what integers are supposed to represent
-- in this library. Use [`Char.toCode`](docs/Char.elm#toCode) and
-- [`Char.fromCode`](/docs/Char.elm#fromCode) to convert key codes to characters.
type KeyCode = Int
-- A signal of records indicating which arrow keys are pressed.
--
-- `{ x = 0, y = 0 }` when pressing no arrows.<br>
-- `{ x =-1, y = 0 }` when pressing the left arrow.<br>
-- `{ x = 1, y = 1 }` when pressing the up and right arrows.<br>
-- `{ x = 0, y =-1 }` when pressing the down, left, and right arrows.
arrows : Signal { x:Int, y:Int }
arrows = Native.directions 38 40 37 39
-- Just like the arrows signal, but this uses keys w, a, s, and d,
-- which are common controls for many computer games.
wasd : Signal { x:Int, y:Int }
wasd = Native.directions 87 83 65 68
-- Custom key directions so that you can support different locales.
-- The plan is to have a locale independent version of this function
-- that uses the physical location of keys, but I don't know how to do it.
directions : KeyCode -> KeyCode -> KeyCode -> KeyCode -> Signal { x:Int, y:Int }
directions = Native.directions
-- Whether an arbitrary key is pressed.
isDown : KeyCode -> Signal Bool
isDown = Native.isDown
-- Whether the shift key is pressed.
shift : Signal Bool
shift = Native.isDown 16
-- Whether the control key is pressed.
ctrl : Signal Bool
ctrl = Native.isDown 17
-- Whether the space key is pressed.
space : Signal Bool
space = Native.isDown 32
-- Whether the enter key is pressed.
enter : Signal Bool
enter = Native.isDown 13
-- List of keys that are currently down.
keysDown : Signal [KeyCode]
keysDown = Native.keysDown
-- The latest key that has been pressed.
lastPressed : Signal KeyCode
lastPressed = Native.lastPressed