prevent sending empty messages

src/main/java/fr/insa/clavardator/ui/chat/ChatFooterController.java

@@ -1,5 +1,6 @@
 package fr.insa.clavardator.ui.chat;
 
+import com.jfoenix.controls.JFXButton;
 import com.jfoenix.controls.JFXTextField;
 import fr.insa.clavardator.ui.ButtonPressEvent;
 import fr.insa.clavardator.users.PeerUser;
@@ -23,6 +24,8 @@ public class ChatFooterController implements Initializable {
 	private HBox container;
 	@FXML
 	private JFXTextField textField;
+	@FXML
+	private JFXButton sendButton;
 
 	private List<ButtonPressEvent> attachmentListeners;
 	private List<ErrorCallback> sendErrorListeners;
@@ -42,12 +45,14 @@ public class ChatFooterController implements Initializable {
 		attachmentListeners.forEach(ButtonPressEvent::onPress);
 	}
 	public void onSend() {
-		if (remoteUser != null) {
-			remoteUser.sendTextMessage(textField.getText(), this::onSendError);
-		} else {
-			Log.e(this.getClass().getSimpleName(), "Error: remote user not set");
+		if(!textField.getText().isEmpty()) {
+			if (remoteUser != null) {
+				remoteUser.sendTextMessage(textField.getText(), this::onSendError);
+			} else {
+				Log.e(this.getClass().getSimpleName(), "Error: remote user not set");
+			}
+			textField.setText("");
 		}
-		textField.setText("");
 	}
 
 	public void onSendError(Exception e) {
@@ -75,6 +80,7 @@ public class ChatFooterController implements Initializable {
 
 	public void onTextChange(ObservableValue<? extends String> observable, String oldText, String newText) {
 		saveText(newText);
+		sendButton.setDisable(isTextFieldEmpty());
 	}
 
 	@Override
@@ -86,19 +92,18 @@ public class ChatFooterController implements Initializable {
 		textField.setOnKeyPressed(event -> {
 			if (event.getCode() == KeyCode.ENTER) {
 				event.consume();
-				if(!textField.getText().isEmpty()){
-					onSend();
-				}
+				onSend();
 			}
 		});
 	}
 
+	private boolean isTextFieldEmpty() {
+		return textField.getText().equals("");
+	}
+
 	public void setRemoteUser(PeerUser remoteUser) {
 		this.remoteUser = remoteUser;
 		textField.setText(findSavedText());
-	}
-
-	public interface SendMessageEvent {
-		void onSend(String text);
+		sendButton.setDisable(isTextFieldEmpty());
 	}
 }

src/main/resources/fr/insa/clavardator/ui/chat/chatFooter.fxml

@@ -18,7 +18,7 @@
       <FontIcon iconLiteral="fas-paperclip" iconSize="24"/>
     </graphic>
   </JFXButton>
-  <JFXButton mnemonicParsing="false" text="Envoyer" onMouseClicked="#onSend">
+  <JFXButton mnemonicParsing="false" text="Envoyer" onMouseClicked="#onSend" fx:id="sendButton">
     <graphic>
       <FontIcon iconLiteral="fas-paper-plane" iconSize="24"/>
     </graphic>