Why is the getPane() method protected in Listing 1? Why is the data field text protected?L...

Why is the getPane() method protected in Listing 1? Why is the data field text protected?

LISTING 1 ButtonDemo.java

1 import javafx.application.Application;
2 import javafx.stage.Stage;
3 import javafx.geometry.Pos;
4 import javafx.scene.Scene;
5 import javafx.scene.control.Button;
6 import javafx.scene.image.ImageView;
7 import javafx.scene.layout.BorderPane;
8 import javafx.scene.layout.HBox;
9 import javafx.scene.layout.Pane;
10 import javafx.scene.text.Text;
11
12 public class ButtonDemo extends Application {
13 protected Text text = new Text(50, 50, "JavaFX Programming");
14
15 protected BorderPane getPane() {
16 HBox paneForButtons = new HBox(20);
17 Button btLeft = new Button("Left",
18 new ImageView("image/left.gif"));
19 Button btRight = new Button("Right",
20 new ImageView("image/right.gif"));
21 paneForButtons.getChildren().addAll(btLeft, btRight);
22 paneForButtons.setAlignment(Pos.CENTER);
23 paneForButtons.setStyle("-fx-border-color: green");
24
25 BorderPane pane = new BorderPane();
26 pane.setBottom(paneForButtons);
27
28 Pane paneForText = new Pane();
29 paneForText.getChildren().add(text);
30 pane.setCenter(paneForText);
31
32 btLeft.setOnAction(e -> text.setX(text.getX() - 10));
33 btRight.setOnAction(e -> text.setX(text.getX() + 10));
34
35 return pane;
36 }
37
38 @Override // Override the start method in the Application class
39 public void start(Stage primaryStage) {
40 // Create a scene and place it in the stage
41 Scene scene = new Scene(getPane(), 450, 200);
42 primaryStage.setTitle("ButtonDemo"); // Set the stage title
43 primaryStage.setScene(scene); // Place the scene in the stage
44 primaryStage.show(); // Display the stage
45 }
46 }