adds binding to textfield

adds validation for text in message
formatting text and time

Author: addee1

src/main/java/com/example/HelloController.java

@@ -1,8 +1,9 @@
 package com.example;
 import javafx.event.ActionEvent;
 import javafx.fxml.FXML;
-import javafx.scene.control.Label;
-import javafx.scene.control.ListView;
+import javafx.geometry.Insets;
+import javafx.scene.control.*;
+import javafx.scene.layout.HBox;
 
 /**
  * Controller layer: mediates between the view (FXML) and the model.
@@ -14,6 +15,8 @@ public class HelloController {
 
     @FXML
     private Label messageLabel;
+    @FXML
+    private TextField messageField;
 
     @FXML
     private void initialize() {
@@ -22,9 +25,61 @@ private void initialize() {
         }
         messageView.setItems(model.getMessages());
 
+        messageView.setCellFactory(list -> new ListCell<>() {
+            private final Label messageLabel = new Label();
+            private final HBox bubble = new HBox(messageLabel);
+            {
+                bubble.setPadding(new Insets(5, 10, 5, 10));
+                bubble.setMaxWidth(200);
+                messageLabel.setWrapText(true);
+                bubble.getStyleClass().add("chat-bubble");
+            }
+
+            @Override
+            protected void updateItem(NtfyMessageDto item, boolean empty) {
+                super.updateItem(item, empty);
+                if (empty || item == null) {
+                    setGraphic(null);
+                } else {
+                    // Format tid + text
+                    java.time.LocalTime time = java.time.Instant.ofEpochSecond(item.time())
+                            .atZone(java.time.ZoneId.systemDefault())
+                            .toLocalTime();
+                    String formattedTime = time.format(java.time.format.DateTimeFormatter.ofPattern("HH:mm"));
+
+                    messageLabel.setText(formattedTime + "\n" + item.message());
+                    setGraphic(bubble);
+                }
+            }
+        });
+
+        model.messageToSendProperty().bind(messageField.textProperty());
+
     }
 
     public void sendMessage(ActionEvent actionEvent) {
+        String message = messageField.getText();
+        if(message == null || message.isBlank()){
+            showTemporaryAlert("You must write something before sending!");
+            return;
+        }
+
         model.sendMessage();
+        messageField.clear();
+    }
+
+    private void showTemporaryAlert(String alertMessage) {
+        Alert alert = new Alert(Alert.AlertType.WARNING);
+        alert.setHeaderText(null);
+        alert.setContentText(alertMessage);
+        alert.initOwner(messageField.getScene().getWindow());
+
+        alert.show();
+
+        new Thread(() -> {
+            try {
+                Thread.sleep(2000);
+            } catch (InterruptedException e) {}
+        }).start();
     }
 }