SAM with AnimationFrame

elm-package.json

{
    "version": "1.0.0",
    "summary": "helpful summary of your project, less than 80 characters",
    "repository": "https://github.com/user/project.git",
    "license": "BSD3",
    "source-directories": [
        "."
    ],
    "exposed-modules": [],
    "dependencies": {
        "elm-lang/animation-frame": "1.0.0 <= v < 2.0.0",
        "elm-lang/core": "4.0.1 <= v < 5.0.0",
        "elm-lang/html": "1.0.0 <= v < 2.0.0"
    },
    "elm-version": "0.17.0 <= v < 0.18.0"
}

Main2.elm

module Main exposing (..)

import Html exposing (..)
import Html.App as App
import Html.Events exposing (onClick)
import AnimationFrame
import Time exposing (Time, second)


-- MODEL


type Model
    = Ready
    | Countdown Time
    | Aborted
    | Launched


init : Model
init =
    Ready



-- UPDATE


type Msg
    = StartCountdown
    | UpdateTime Time
    | Abort


update : Msg -> Model -> Model
update msg model =
    case ( msg, model ) of
        ( StartCountdown, Ready ) ->
            Countdown (10 * second)

        ( UpdateTime diff, Countdown c ) ->
            if (c - diff) < 0 then
                Launched
            else
                Countdown (c - diff)

        ( Abort, Countdown _ ) ->
            Aborted

        ( _, _ ) ->
            model



-- VIEW


view : Model -> Html Msg
view model =
    case model of
        Ready ->
            div []
                [ button [ onClick StartCountdown ] [ text "Start Countdown" ] ]

        Countdown count ->
            div []
                [ p [] [ text ("Countdown: " ++ (toString (ceiling (count / 1000)))) ]
                , button [ onClick Abort ] [ text "Abort" ]
                ]

        Aborted ->
            div [] [ text "Launch Aborted!" ]

        Launched ->
            div [] [ text "Rocket Launched!" ]



-- WIRING


subscriptions : Model -> Sub Msg
subscriptions model =
    case model of
        Countdown _ ->
            AnimationFrame.diffs UpdateTime

        _ ->
            Sub.none


main : Program Never
main =
    App.program
        { init = init ! []
        , update = \msg model -> update msg model ! []
        , view = view
        , subscriptions = subscriptions
        }