Move "measuring tape" concern into Tabletop

Formalize Distance as a Float

src/Main.elm

@@ -1,6 +1,5 @@
 module Main exposing (..)
 
-import Dict
 import Gang
 import Html exposing (Html)
 import Html.App as App
@@ -15,7 +14,7 @@ import Player exposing (Player)
 import String exposing (join)
 import Svg exposing (..)
 import Svg.Attributes exposing (..)
-import Tabletop exposing (posX, posY, Tabletop, positionFromMouseCoords)
+import Tabletop exposing (Tabletop, positionFromMouseCoords)
 import Task
 import Window
 
@@ -169,9 +168,9 @@ onClickWithCoords message =
 view : GameState -> Html Msg
 view game =
     let
-        movementArea =
+        measuringTape =
             Player.getSelectedGangMember game.player
-                |> Maybe.map (\fighter -> Model.movementView fighter game.player.movementIntention :: [])
+                |> Maybe.map (\fighter -> Tabletop.viewMeasuringTape fighter.position game.player.movementIntention fighter.remainingMove :: [])
                 |> Maybe.withDefault []
     in
         svg
@@ -181,7 +180,7 @@ view game =
                 (game.windowWidth |> toString)
             , onClickWithCoords Click
             ]
-            (Tabletop.view game.tabletop []
-                :: movementArea
+            (Tabletop.view game.tabletop
+                :: measuringTape
                 ++ Gang.view game.player.gang Select
             )

src/Model.elm

@@ -141,8 +141,11 @@ attemptMove model pos =
 
         allowableDistance =
             model.remainingMove - distance
+
+        maxPosition =
+            Tabletop.positionFromDirection model.position pos model.remainingMove
     in
-        if allowableDistance >= 0 then
+        if allowableDistance > 0 then
             Ok
                 { model
                     | position = pos
@@ -152,22 +155,12 @@ attemptMove model pos =
             Err
                 ( "Can't move there"
                 , { model
-                    | position = maxAllowedMovement model pos
+                    | position = maxPosition
                     , remainingMove = 0
                   }
                 )
 
 
-maxAllowedMovement : Model -> Position -> Position
-maxAllowedMovement model intent =
-    Tabletop.positionFromDirection model.position intent model.remainingMove
-
-
-type Injury
-    = FleshWound
-    | Down
-    | OutOfAction
-
 
 view : Model -> msg -> Svg msg
 view model msg =

src/Tabletop.elm

@@ -1,8 +1,9 @@
 module Tabletop exposing (..)
 
-import Svg exposing (rect, Svg)
+import Svg exposing (Svg, rect, g, line)
 import Svg.Attributes exposing (..)
 
+
 {-| The Tabletop module exposes types and functions related to the
 structure of the game board as well as positioning and movement on the
 board.
@@ -13,13 +14,19 @@ type alias Tabletop =
     , height : Inch
     }
 
+
 type alias Inch =
     Int
 
+
 type alias Position =
     ( Float, Float )
 
 
+type alias Distance =
+    Float
+
+
 posX : Position -> Float
 posX ( x', _ ) =
     x'
@@ -48,10 +55,10 @@ positionFromMouseCoords ( x, y ) scale =
 
 center : Tabletop -> Position
 center table =
-    ( toFloat table.width / 2 , toFloat table.height / 2 )
+    ( toFloat table.width / 2, toFloat table.height / 2 )
 
 
-distance : Position -> Position -> Float
+distance : Position -> Position -> Distance
 distance ( x1, y1 ) ( x2, y2 ) =
     let
         y' =
@@ -60,10 +67,10 @@ distance ( x1, y1 ) ( x2, y2 ) =
         x' =
             (x1 - x2) ^ 2
     in
-        (x' + y') |> sqrt
+        sqrt (x' + y')
 
 
-positionFromDirection : Position -> Position -> Float -> Position
+positionFromDirection : Position -> Position -> Distance -> Position
 positionFromDirection start end len =
     let
         h =
@@ -76,7 +83,7 @@ positionFromDirection start end len =
             (posY end) - (posY start)
 
         angle =
-            acos <| y' / h
+            acos (y' / h)
 
         co =
             if x' > 0 then
@@ -89,11 +96,45 @@ positionFromDirection start end len =
         )
 
 
-view : Tabletop -> List (Svg msg) -> Svg msg
-view tabletop children =
+view : Tabletop -> Svg msg
+view tabletop =
     rect
         [ width (tabletop.width |> toString)
         , height (tabletop.height |> toString)
         , fill "silver"
         ]
-        children
+        []
+
+
+viewMeasuringTape : Position -> Position -> Distance -> Svg msg
+viewMeasuringTape start end range =
+    let
+        length =
+            distance start end
+
+        ( rangeX, rangeY ) =
+            if length > range then
+                positionFromDirection start end range
+            else
+                end
+    in
+        g []
+            [ line
+                [ x1 (start |> posX |> toString)
+                , y1 (start |> posY |> toString)
+                , x2 (rangeX |> toString)
+                , y2 (rangeY |> toString)
+                , stroke "yellow"
+                , strokeWidth "0.63"
+                ]
+                []
+            , line
+                [ x1 (rangeX |> toString)
+                , y1 (rangeY |> toString)
+                , x2 (end |> posX |> toString)
+                , y2 (end |> posY |> toString)
+                , stroke "grey"
+                , strokeWidth "0.63"
+                ]
+                []
+            ]