#7 Add randomization of upcoming tetroid on startup.

src/Main.elm

@@ -1,16 +1,17 @@
 module Tetris exposing (main)
 
 import Browser
+import Messages exposing (Msg)
 import Model exposing (Model, initialModel)
-import Update exposing (Msg, update)
+import Update exposing (update)
 import View exposing (view)
 
 
 main : Program () Model Msg
 main =
     Browser.element
-        { init = \_ -> ( initialModel, Cmd.none )
+        { init = \_ -> initialModel
         , subscriptions = \_ -> Sub.none
         , view = View.view
-        , update = \msg model -> ( Update.update msg model, Cmd.none )
+        , update = \msg model -> update msg model
         }

src/Messages.elm

@@ -2,11 +2,12 @@ module Messages exposing (Msg(..))
 
 import Movement exposing (Direction)
 import Rotation exposing (Axis)
+import Tetroids exposing (Tetroid)
 
 
 type Msg
     = NoOp
-    | Start
+    | Start Tetroid
     | Stop
     | Tick Float
     | FastFallDown Bool

src/Model.elm

@@ -2,6 +2,8 @@ module Model exposing (Model, initialModel)
 
 import Dimensions exposing (WorldDimensions)
 import Grid exposing (Cell, Color, Grid, Position)
+import Messages exposing (Msg(..))
+import Random exposing (..)
 import Tetroids exposing (..)
 
 
@@ -16,8 +18,8 @@ type GameState
 
 type alias Model =
     { dimensions : WorldDimensions
-    , activeTetroid : Tetroid
-    , upcomingTetroid : Tetroid
+    , activeTetroid : Maybe Tetroid
+    , upcomingTetroid : Maybe Tetroid
     , grid : Grid
     , gameState : GameState
     , fastFallDown : Bool
@@ -32,12 +34,14 @@ initialWorldDimensions =
     }
 
 
-initialModel : Model
+initialModel : ( Model, Cmd Msg )
 initialModel =
-    { dimensions = initialWorldDimensions
-    , activeTetroid = createBlueTetroid
-    , upcomingTetroid = createGreenTetroid
-    , grid = []
-    , gameState = Running
-    , fastFallDown = False
-    }
+    ( { dimensions = initialWorldDimensions
+      , activeTetroid = Nothing
+      , upcomingTetroid = Nothing
+      , grid = []
+      , gameState = Running
+      , fastFallDown = False
+      }
+    , Random.generate Start tetroidGenerator
+    )

src/Tetroids.elm

@@ -1,6 +1,7 @@
-module Tetroids exposing (Tetroid, createBlueTetroid, createGreenTetroid, createOrangeTetroid, createPinkTetroid, createYellowTetroid, tetroids)
+module Tetroids exposing (Tetroid, createBlueTetroid, createGreenTetroid, createOrangeTetroid, createPinkTetroid, createYellowTetroid, tetroidGenerator, tetroids)
 
 import Grid exposing (Color, Grid, Position)
+import Random exposing (..)
 
 
 
@@ -46,6 +47,16 @@ pink =
 -- Tetroid creation
 
 
+tetroidGenerator : Generator Tetroid
+tetroidGenerator =
+    case tetroids of
+        x :: xs ->
+            Random.uniform x xs
+
+        [] ->
+            Random.uniform createBlueTetroid []
+
+
 createTetroid : Color -> Position -> List Position -> Tetroid
 createTetroid color center positions =
     { grid = List.map (\position -> { color = color, position = position }) positions

src/Update.elm

@@ -1,16 +1,14 @@
-module Update exposing (Msg(..), update)
+module Update exposing (update)
 
+import Messages exposing (Msg(..))
 import Model exposing (Model)
 
 
-
--- Just placeholder. Will be placed in Messages.elm asap.
-
-
-type Msg
-    = NoOp
-
-
-update : Msg -> Model -> Model
+update : Msg -> Model -> ( Model, Cmd Msg )
 update msg model =
-    model
+    case msg of
+        Start tetroid ->
+            ( { model | upcomingTetroid = Just tetroid }, Cmd.none )
+
+        _ ->
+            ( model, Cmd.none )

src/View.elm

@@ -3,8 +3,8 @@ module View exposing (view)
 import Html exposing (Html, br, button, div, p, span, text)
 import Html.Attributes exposing (class, disabled, style)
 import Html.Events exposing (onClick)
+import Messages exposing (Msg)
 import Model exposing (Model)
-import Update exposing (Msg)
 
 
 
@@ -15,5 +15,5 @@ import Update exposing (Msg)
 view : Model -> Html Msg
 view model =
     div [ Html.Attributes.style "display" "flex", Html.Attributes.style "justify-content" "center" ]
-        [ Html.text "Hallo Welt!"
+        [ Html.text (Debug.toString model)
         ]