stack-overflow.elm

import Html exposing (p, text, div, canvas, Html)
import Html.Attributes exposing (id, style)
import Html.Events exposing (..)
import List exposing (repeat, concat)
import Array exposing (Array, fromList)
import Color exposing (rgb, Color)
import Debug exposing (log)


main = 
  Html.program
  { init  = (model, Cmd.none) 
  , view   = view 
  , update = update
  , subscriptions = always Sub.none
  }


-- MODEL


type alias Canvas =
  { id        : String
  , imageData : ImageData
  }

type alias ImageData =
  { width  : Int
  , height : Int
  , data   : Array Int
  }


type alias Model = Canvas


type Msg
  = Draw 


model : Canvas
model =
  let
    width  = 500
    height = 400
  in
  { id = "the-canvas"
  , imageData =
    { width  = width
    , height = height
    , data   = 
        black
        |>repeat (width * height)
        |>concat
        |>fromList
    }
  }


black : List Int
black =
  [ 0, 0, 0, 255 ]


prettyBlue : Color
prettyBlue =
  rgb 23 92 254


-- UPDATE


update :  Msg -> Model -> (Model, Cmd Msg)
update message canvas =
  case message of 


    Draw ->
      let _ = log "draw" "draw" in
      (canvas, Cmd.none)



-- VIEW



view : Model -> Html Msg
view canvas =
  div 
  [] 
  [ p [] [ text "v--- stack overflow if you click there :^(" ]
  , Html.canvas [ onMouseDown Draw ] []
  ]