Send typing notifications.

elm.json

@@ -13,12 +13,12 @@
             "elm/http": "2.0.0",
             "elm/json": "1.1.2",
             "elm/svg": "1.0.1",
+            "elm/time": "1.0.0",
             "elm/url": "1.0.0"
         },
         "indirect": {
             "elm/bytes": "1.0.7",
             "elm/file": "1.0.1",
-            "elm/time": "1.0.0",
             "elm/virtual-dom": "1.0.2"
         }
     },

src/Main.elm

@@ -7,7 +7,7 @@ import Scylla.Api exposing (..)
 import Scylla.Model exposing (..)
 import Scylla.Http exposing (..)
 import Scylla.Views exposing (viewFull)
-import Scylla.Route exposing (Route(..))
+import Scylla.Route exposing (Route(..), RoomId)
 import Scylla.UserData exposing (..)
 import Scylla.Notification exposing (..)
 import Scylla.Storage exposing (..)
@@ -16,11 +16,15 @@ import Url.Parser exposing (parse)
 import Url.Builder
 import Json.Encode
 import Json.Decode
+import Time exposing (every)
 import Html exposing (div, text)
 import Http
 import Dict
 import Task
 
+syncTimeout = 10000
+typingTimeout = 2000
+
 type alias Flags =
     { token : Maybe String
     }
@@ -73,12 +77,37 @@ update msg model = case msg of
     ReceiveFirstSyncResponse r -> updateSyncResponse model r False
     ReceiveSyncResponse r -> updateSyncResponse model r True
     ReceiveUserData s r -> updateUserData model s r
-    ChangeRoomText r t -> ({ model | roomText = Dict.insert r t model.roomText}, Cmd.none)
+    ChangeRoomText r t -> updateChangeRoomText model r t
     SendRoomText r -> updateSendRoomText model r
     SendRoomTextResponse r -> (model, Cmd.none)
     ReceiveCompletedReadMarker r -> (model, Cmd.none)
     ReceiveCompletedTypingIndicator r -> (model, Cmd.none)
     ReceiveStoreData d -> updateStoreData model d
+    TypingTick _ -> updateTypingTick model
+
+
+updateChangeRoomText : Model -> RoomId -> String -> (Model, Cmd Msg)
+updateChangeRoomText m roomId text = 
+    let
+        typingIndicator = case (text, Dict.get roomId m.roomText) of
+            ("", _) -> Just False
+            (_, Just "") -> Just True
+            _ -> Nothing
+        command = case typingIndicator of
+            Just b -> sendTypingIndicator m.apiUrl (Maybe.withDefault "" m.token) roomId m.loginUsername b typingTimeout
+            _ -> Cmd.none
+    in
+        ({ m | roomText = Dict.insert roomId text m.roomText}, command)
+
+updateTypingTick : Model -> (Model, Cmd Msg)
+updateTypingTick m = 
+    let
+        command = case currentRoomId m of
+            Just rid -> sendTypingIndicator m.apiUrl (Maybe.withDefault "" m.token) rid m.loginUsername True typingTimeout
+            Nothing -> Cmd.none
+    in
+        (m, command)
+
 
 updateStoreData : Model -> Json.Encode.Value -> (Model, Cmd Msg)
 updateStoreData m d = case (Json.Decode.decodeValue storeDataDecoder d) of
@@ -197,9 +226,16 @@ updateSyncResponse model r notify =
             _ -> (model, syncCmd)
 
 subscriptions : Model -> Sub Msg
-subscriptions m = Sub.batch
+subscriptions m =
+    let
+        typingTimer = case Maybe.withDefault "" <| Maybe.andThen (\rid -> Dict.get rid m.roomText) <| currentRoomId m of
+            "" -> Sub.none
+            _ -> every typingTimeout TypingTick
+    in
+        Sub.batch
             [ onNotificationClickPort OpenRoom
             , receiveStoreValuePort ReceiveStoreData
+            , typingTimer
             ]
 
 onUrlRequest : Browser.UrlRequest -> Msg

src/Scylla/Model.elm

@@ -9,6 +9,7 @@ import Browser.Navigation as Nav
 import Browser.Dom exposing (Viewport)
 import Url.Builder
 import Dict exposing (Dict)
+import Time exposing (Posix)
 import Json.Decode
 import Browser
 import Http
@@ -44,10 +45,11 @@ type Msg =
     | ReceiveFirstSyncResponse (Result Http.Error SyncResponse) -- HTTP, Sync has finished
     | ReceiveSyncResponse (Result Http.Error SyncResponse) -- HTTP, Sync has finished
     | ReceiveLoginResponse ApiUrl (Result Http.Error LoginResponse) -- HTTP, Login has finished
-    | ReceiveUserData Username (Result Http.Error UserData)
-    | ReceiveCompletedReadMarker (Result Http.Error ())
-    | ReceiveStoreData Json.Decode.Value
+    | ReceiveUserData Username (Result Http.Error UserData) -- HTTP, receive user data
+    | ReceiveCompletedReadMarker (Result Http.Error ()) -- HTTP, read marker request completed
     | ReceiveCompletedTypingIndicator (Result Http.Error ()) -- HTTP, typing indicator request completed
+    | ReceiveStoreData Json.Decode.Value -- We are send back a value on request from localStorage.
+    | TypingTick Posix -- Tick for updating the typing status
 
 displayName : Model -> Username -> String
 displayName m s = Maybe.withDefault (senderName s) <| Maybe.andThen .displayName <| Dict.get s m.userData