Initialised the LIstener in the Initilisation method instead of an onclick function

src/main/java/seng202/group9/GUI/HelpController.java

@@ -69,12 +69,7 @@ public class HelpController extends Controller {
 
         text = new Text("Please select an option on the left side menu to display its contents.");
         textArea.getChildren().add(text);
-    }
 
-    /**
-     * Changes the text in the TextFlow depending on which option has been selected in the TreeView.
-     */
-    public void changeView() {
         treeView.getSelectionModel().selectedItemProperty().addListener(new ChangeListener() {
 
             public void changed(ObservableValue observable, Object oldValue,
@@ -170,5 +165,4 @@ public class HelpController extends Controller {
             }
         });
     }
-
 }

src/main/resources/help.fxml

@@ -34,7 +34,7 @@
             <TextFlow fx:id="textArea" maxHeight="-Infinity" maxWidth="-Infinity" prefHeight="289.0" prefWidth="364.0" textAlignment="JUSTIFY" />
          </content>
       </ScrollPane>
-      <TreeView fx:id="treeView" onMouseClicked="#changeView" prefHeight="200.0" prefWidth="200.0" GridPane.rowIndex="1">
+      <TreeView fx:id="treeView" prefHeight="200.0" prefWidth="200.0" GridPane.rowIndex="1">
          <GridPane.margin>
             <Insets bottom="10.0" left="10.0" right="10.0" />
          </GridPane.margin>