highlight selection on map

frontend/src/Main.elm

@@ -461,6 +461,17 @@ trackView leftedge topedge zoom selection points =
             in (String.fromInt x_) ++ ", " ++
                 (String.fromInt y_) ++ ", "
         line = String.concat (List.map plot points)
+        selectedPoints =
+            Maybe.map
+                (\(s, e) ->
+                     List.filter (\p -> p.time >= s && p.time <= e) points)
+                selection
+        selectionLine =
+            case selectedPoints of
+                Just spoints ->
+                    polyline [ S.points (String.concat (List.map plot spoints)) ] []
+                Nothing -> g [] []
+
     in
     svg
     [ H.style "width" "100%"
@@ -470,13 +481,15 @@ trackView leftedge topedge zoom selection points =
     [ g
       [ fill "none"
       , stroke "blue"
-      , strokeWidth "7"
+      , strokeWidth "5"
       , strokeOpacity "0.5"]
       [
        polyline
        [ fill "none"
-       , S.points  line
+       , S.points line
        ] []
+      , g [ stroke "red", strokeWidth "7",  strokeOpacity "0.9" ]
+          [ selectionLine ]
       ]
     ]