Elm hardware demo

Main.elm

module Main exposing (..)

import Time
import Launchpad exposing (Node, button, group, Color, green, red)


type alias Model =
    { color : Color }


model : Model
model =
    { color = green }


type Msg
    = ChangeColor


update : Msg -> Model -> Model
update msg model =
    let
        nextColor =
            if model.color == green then
                red
            else
                green
    in
        case msg of
            ChangeColor ->
                { model | color = nextColor }


viewButton : Model -> Int -> Node Msg
viewButton model row =
    button model.color True row 0 []


view : Model -> Node Msg
view model =
    group <| List.map (viewButton model) [0..7]


subscriptions : Model -> Sub Msg
subscriptions model =
    Time.every 1000 <| always ChangeColor


main : Program Never
main =
    Launchpad.program
        { view = view
        , update = \msg model -> ( update msg model, Cmd.none )
        , init = ( model, Cmd.none )
        , subscriptions = subscriptions
        }