src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/chat/ChatController.java

@@ -63,13 +63,17 @@ public class ChatController {
         localUserList = new ArrayList<>();
         this.chatBoxController = new ChatBoxController(username, this);
         this.logger = LogManager.getLogger(ChatController.class);
-        this.timer = new Timer();
+        this.timer = new Timer(true);
         timer.schedule(
                 new TimerTask() {
                     @Override
                     public void run() {
-                        receiveMessage();
+                        try {
-                        checkWhisperUsers();
+                            receiveMessage();
+                            checkWhisperUsers();
+                        } catch (RuntimeException e) {
+                            logger.warn("Chat refresh failed: {}", e.getMessage());
+                        }
                     }
                 },
                 0,
@@ -84,8 +88,12 @@ public class ChatController {
      */
     public void setLobbyChat(int lobbyId) {
         this.lobbyId = lobbyId;
+        ChatKey key = new ChatKey(ChatType.LOBBY);
+        if (chatModelMap.containsKey(key)) {
+            return;
+        }
         ChatModel lobbyChatModel = new ChatModel(ChatType.LOBBY, username, lobbyId, null);
-        chatModelMap.put(new ChatKey(ChatType.LOBBY), lobbyChatModel);
+        chatModelMap.put(key, lobbyChatModel);
         this.chatBoxController.addChatTab("Lobby", lobbyChatModel);
     }
 
@@ -162,15 +170,32 @@ public class ChatController {
             for (String user : users) {
                 String value = user.split("\\=")[1];
                 logger.info(value);
-                if (!(localUserList.contains(value) || value.equals(username))) {
+                addWhisperUser(value);
-                    localUserList.add(value);
-                    logger.info("adding new whisper user");
-                    chatBoxController.addWhisperUser(value);
-                }
             }
         }
     }
 
+    /**
+     * Registers a whisper target locally and updates the UI if it is a new user.
+     *
+     * @param user target username
+     */
+    public synchronized void addWhisperUser(String user) {
+        if (user == null || user.isBlank()) {
+            return;
+        }
+        if (!(localUserList.contains(user) || user.equals(username))) {
+            localUserList.add(user);
+            logger.info("adding new whisper user");
+            chatBoxController.addWhisperUser(user);
+        }
+    }
+
+    /** Stops polling background tasks for this chat controller instance. */
+    public void shutdown() {
+        timer.cancel();
+    }
+
     /**
      * method to send a message to the server
      *

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/ui/gameui/CasinoGameController.java

@@ -1,19 +1,27 @@
 package ch.unibas.dmi.dbis.cs108.casono.client.ui.gameui;
 
+import ch.unibas.dmi.dbis.cs108.casono.client.chat.ChatController;
 import ch.unibas.dmi.dbis.cs108.casono.client.game.Card;
 import ch.unibas.dmi.dbis.cs108.casono.client.game.GameService;
 import ch.unibas.dmi.dbis.cs108.casono.client.game.GameState;
 import ch.unibas.dmi.dbis.cs108.casono.client.game.Player;
 import ch.unibas.dmi.dbis.cs108.casono.client.game.PlayerId;
+import ch.unibas.dmi.dbis.cs108.casono.client.network.ClientService;
 import ch.unibas.dmi.dbis.cs108.casono.client.ui.gameui.gameuicomponents.PlayerStatusController;
 import ch.unibas.dmi.dbis.cs108.casono.client.ui.gameui.gameuicomponents.TaskbarController;
+import java.io.IOException;
+import java.net.URL;
+import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
 import java.util.concurrent.CompletableFuture;
 import java.util.logging.Logger;
 import javafx.fxml.FXML;
+import javafx.fxml.FXMLLoader;
 import javafx.scene.control.Label;
 import javafx.scene.image.Image;
 import javafx.scene.image.ImageView;
+import javafx.scene.layout.AnchorPane;
 import javafx.scene.layout.HBox;
 import javafx.scene.layout.VBox;
 
@@ -44,6 +52,7 @@ public class CasinoGameController {
     @FXML private VBox player2;
     @FXML private VBox player3;
     @FXML private ImageView myDealerIcon;
+    @FXML private AnchorPane chatContainer;
 
     private GameService gameService;
     private PlayerId myPlayerId;
@@ -125,6 +134,12 @@ public class CasinoGameController {
     private static final long CHIP_DROP_DURATION_MS = 250;
     private static final long CHIP_STAGGER_DELAY_MULTIPLIER = 35L;
 
+    private ChatController chatController;
+    private String chatUsername;
+    private ClientService chatClientService;
+    private int chatLobbyId = -1;
+    private boolean chatInitialized;
+
     /** Standard constructor. Used by FXML. */
     public CasinoGameController() {
         // default constructor for FXML
@@ -203,6 +218,38 @@ public class CasinoGameController {
         // empty display only (optional)
         renderCommunityCards(List.of());
         renderPlayerCards(List.of());
+        initializeChatIfPossible();
+    }
+
+    public void setChatContext(String username, ClientService clientService, int lobbyId) {
+        this.chatUsername = username;
+        this.chatClientService = clientService;
+        this.chatLobbyId = lobbyId;
+        initializeChatIfPossible();
+    }
+
+    private void initializeChatIfPossible() {
+        if (chatInitialized || chatContainer == null || chatClientService == null || chatUsername == null) {
+            return;
+        }
+        try {
+            chatController = new ChatController(chatUsername, chatClientService);
+            URL resource = getClass().getResource("/ui-structure/components/chatui/chatbox.fxml");
+            FXMLLoader loader = new FXMLLoader(resource);
+            loader.setController(chatController.getChatBoxController());
+            javafx.scene.Node chatNode = loader.load();
+            chatContainer.getChildren().setAll(chatNode);
+            AnchorPane.setTopAnchor(chatNode, 0.0);
+            AnchorPane.setBottomAnchor(chatNode, 0.0);
+            AnchorPane.setLeftAnchor(chatNode, 0.0);
+            AnchorPane.setRightAnchor(chatNode, 0.0);
+            if (chatLobbyId >= 0) {
+                chatController.setLobbyChat(chatLobbyId);
+            }
+            chatInitialized = true;
+        } catch (IOException e) {
+            LOGGER.warning("Could not initialize game chat UI: " + e.getMessage());
+        }
     }
 
     // Test method to demonstrate the UI functionality with sample data.
@@ -329,6 +376,9 @@ public class CasinoGameController {
         if (timeline != null) {
             timeline.stop();
         }
+        if (chatController != null) {
+            chatController.shutdown();
+        }
     }
 
     /**
@@ -405,6 +455,7 @@ public class CasinoGameController {
         }
 
         updatePlayers(players);
+        syncWhisperTargetsFromPlayers(players);
         updateGameInfo(s);
         highlightDealer(s);
         updateTaskbar(s);
@@ -419,6 +470,22 @@ public class CasinoGameController {
         }
     }
 
+    private void syncWhisperTargetsFromPlayers(List<Player> players) {
+        if (chatController == null || players == null || players.isEmpty()) {
+            return;
+        }
+        Set<String> seen = new HashSet<>();
+        for (Player player : players) {
+            if (player == null) {
+                continue;
+            }
+            String name = player.getName();
+            if (name != null && !name.isBlank() && seen.add(name)) {
+                chatController.addWhisperUser(name);
+            }
+        }
+    }
+
     private List<Card> getMyCards(List<Player> players) {
 
         if (myPlayerId == null || players == null) {

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/ui/gameui/CasinoGameUI.java

@@ -26,6 +26,7 @@ public class CasinoGameUI extends Application {
     private static ClientService clientService;
 
     private static String username;
+    private static int lobbyId = -1;
 
     private static final int DEFAULT_WIDTH = 1200;
     private static final int DEFAULT_HEIGHT = 800;
@@ -42,6 +43,10 @@ public class CasinoGameUI extends Application {
         CasinoGameUI.username = username;
     }
 
+    public static void setLobbyId(int lobbyId) {
+        CasinoGameUI.lobbyId = lobbyId;
+    }
+
     @Override
     public void start(Stage stage) throws IOException {
 
@@ -81,6 +86,7 @@ public class CasinoGameUI extends Application {
         controller.setGameService(gameService);
 
         controller.setMyPlayerId(PlayerId.of(effectiveUsername));
+        controller.setChatContext(effectiveUsername, clientService, lobbyId);
 
         Scene scene = new Scene(root, DEFAULT_WIDTH, DEFAULT_HEIGHT);
         stage.setTitle("Casono");
@@ -90,6 +96,7 @@ public class CasinoGameUI extends Application {
 
         stage.setScene(scene);
         stage.setFullScreen(true);
+        stage.setOnHidden(e -> controller.stop());
         stage.show();
 
         controller.start();

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/ui/lobbyui/CasinomainuiController.java

@@ -1,10 +1,14 @@
 package ch.unibas.dmi.dbis.cs108.casono.client.ui.lobbyui;
 
 import ch.unibas.dmi.dbis.cs108.casono.client.ClientApp;
+import ch.unibas.dmi.dbis.cs108.casono.client.chat.ChatController;
 import ch.unibas.dmi.dbis.cs108.casono.client.network.ClientService;
 import ch.unibas.dmi.dbis.cs108.casono.client.network.LobbyClient;
+import java.io.IOException;
+import java.net.URL;
 import javafx.application.Platform;
 import javafx.fxml.FXML;
+import javafx.fxml.FXMLLoader;
 import javafx.scene.control.Alert;
 import javafx.scene.control.Alert.AlertType;
 import javafx.scene.control.Button;
@@ -13,6 +17,7 @@ import javafx.scene.control.TextField;
 import javafx.scene.image.Image;
 import javafx.scene.image.ImageView;
 import javafx.scene.layout.AnchorPane;
+import javafx.scene.Node;
 import javafx.scene.layout.VBox;
 import javafx.scene.shape.Rectangle;
 import org.apache.logging.log4j.LogManager;
@@ -31,11 +36,13 @@ public class CasinomainuiController {
     @FXML private VBox casinoTable;
     @FXML private TextField usernameField;
     @FXML private Button loginButton;
+    @FXML private AnchorPane chatContainer;
 
     private LobbyButtonTranslationManager translationManager;
     private LobbyButtonGridManager gridManager;
     private int nextButtonId = 1;
     private LobbyClient lobbyClient;
+    private ChatController chatController;
 
     /** Default constructor used by FXMLLoader. */
     public CasinomainuiController() {
@@ -96,6 +103,40 @@ public class CasinomainuiController {
         casinoTable.getChildren().clear();
         casinoTable.getChildren().add(gridManager.getGridPane());
         gridManager.renderLobbyButtons();
+
+        initializeChat(clientService);
+    }
+
+    private void initializeChat(ClientService clientService) {
+        if (clientService == null || clientService.isOffline() || chatContainer == null) {
+            return;
+        }
+        try {
+            String username = resolveChatUsername();
+            chatController = new ChatController(username, clientService);
+            URL resource = getClass().getResource("/ui-structure/components/chatui/chatbox.fxml");
+            FXMLLoader loader = new FXMLLoader(resource);
+            loader.setController(chatController.getChatBoxController());
+            Node chatNode = loader.load();
+            chatContainer.getChildren().setAll(chatNode);
+            AnchorPane.setTopAnchor(chatNode, 0.0);
+            AnchorPane.setBottomAnchor(chatNode, 0.0);
+            AnchorPane.setLeftAnchor(chatNode, 0.0);
+            AnchorPane.setRightAnchor(chatNode, 0.0);
+        } catch (IOException e) {
+            LOGGER.warn("Could not initialize lobby chat UI: {}", e.getMessage());
+        }
+    }
+
+    private String resolveChatUsername() {
+        String shared = ClientApp.getSharedUsername();
+        if (shared != null && !shared.isBlank()) {
+            return shared.trim();
+        }
+        if (usernameField != null && usernameField.getText() != null && !usernameField.getText().isBlank()) {
+            return usernameField.getText().trim();
+        }
+        return "Guest";
     }
 
     /** Handles the login button action. Validates input and calls LobbyClient.login(). */
@@ -139,6 +180,9 @@ public class CasinomainuiController {
     /** Handles the exit button action to close the application. */
     @FXML
     public void handleexitbutton() {
+        if (chatController != null) {
+            chatController.shutdown();
+        }
         Platform.exit();
     }
 

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/ui/lobbyui/LobbyButtonGridManager.java

@@ -554,6 +554,7 @@ public class LobbyButtonGridManager {
                         var cs = lobbyClient.getClientService();
 
                         ch.unibas.dmi.dbis.cs108.casono.client.ui.gameui.CasinoGameUI.setClientService(cs);
+                        ch.unibas.dmi.dbis.cs108.casono.client.ui.gameui.CasinoGameUI.setLobbyId(lobbyId);
 
                         String username = ch.unibas.dmi.dbis.cs108.casono.client.ClientApp.getSharedUsername();
                         if (username == null || username.isBlank()) {