JAVAFX BASICS - Introduction to Java Programming: Comprehensive Version - page 538

Stage
Scene

Button

(a) (b)

F IGURE 14.2

(a) Stage is a window for displaying a scene that contains nodes. (b) Multiple
stages can be displayed in a JavaFX program.

L ISTING 14.2

MultipleStageDemo.java
1 import javafx.application.Application;
2 import javafx.scene.Scene;
3 import javafx.scene.control.Button;
4 import javafx.stage.Stage;
5
6 public class MultipleStageDemo extends Application {
7 @Override // Override the start method in the Application class
8 public void start(Stage primaryStage) {
9 // Create a scene and place a button in the scene
10 Scene scene = new Scene( new Button( " OK " ), 200 , 250 );
11 primaryStage.setTitle( " MyJavaFX " ); // Set the stage title
12 primaryStage.setScene(scene); // Place the scene in the stage
13

primary stage in start

primaryStage.show(); // Display the stage display primary stage

14
15 Stage stage = new Stage(); // Create a new stage
16 stage.setTitle( " Second Stage " ); // Set the stage title
17 // Set a scene with a button in the stage
18 stage.setScene( new Scene( new Button( " New Stage " ), 100 , 100 ));
19

create second stage

display second stage

stage.show(); // Display the stage

20 }
21 }

main method omitted

Note that the main method is omitted in the listing since it is identical for every JavaFX
application. From now on, we will not list the main method in our JavaFX source code for
brevity.
By default, the user can resize the stage. To prevent the user from resizing the stage, invoke
stage.setResizable(false) .

main method omitted

prevent stage resizing

14.3

✓ ✓

How do you define a JavaFX main class? What is the signature of the start method?
What is a stage? What is a primary stage? Is a primary stage automatically created?
How do you display a stage? Can you prevent the user from resizing the stage? Can you
replace Application.launch(args) by launch(args) in line 22 in Listing 14.1?

Check

Point

14.4

Show the output of the following JavaFX program.

import javafx.application.Application;
import javafx.stage.Stage;

public class Test extends Application {
public Test() {
System.out.println( " Test constructor is invoked " );
}