Navigation breadcrumbs

www/src/App.elm

@@ -217,6 +217,24 @@ update msg model =
 navBar : Model -> E.Element Msg
 navBar model =
     let
+        isRoute : Route.Route -> Bool
+        isRoute route =
+            case model.route of
+                Nothing ->
+                    False
+
+                Just current ->
+                    route == current
+
+        inRoute : Route.Route -> Bool
+        inRoute route =
+            case model.route of
+                Nothing ->
+                    False
+
+                Just current ->
+                    List.member route <| Route.breadcrumbs current
+
         navLink : Route.Route -> String -> E.Element Msg
         navLink route text =
             E.link
@@ -224,9 +242,12 @@ navBar model =
                 , E.padding 10
                 , Font.center
                 , Background.color <|
-                    if Just route == model.route then
+                    if isRoute route then
                         UI.colors.primary
 
+                    else if inRoute route then
+                        UI.colors.secondary
+
                     else
                         UI.colors.background
                 , E.mouseOver [ Background.color UI.colors.primary ]

www/src/Route.elm

@@ -1,4 +1,4 @@
-module Route exposing (Route(..), fromUrl, toUrl)
+module Route exposing (Route(..), breadcrumbs, fromUrl, toUrl)
 
 import Url exposing (Url)
 import Url.Builder
@@ -37,3 +37,13 @@ toUrl route =
 fromUrl : Url.Url -> Maybe Route
 fromUrl url =
     parse parser url
+
+
+breadcrumbs : Route -> List Route
+breadcrumbs route =
+    case route of
+        Deck _ ->
+            [ DeckList, route ]
+
+        _ ->
+            [ route ]