EVENT-DRIVEN PROGRAMMING AND ANIMATIONS - Introduction to Java Programming: Comprehensive Version - page 596

6 import javafx.scene.control.Button;
7 import javafx.scene.layout.HBox;
8 import javafx.stage.Stage;
9
10 public class AnonymousHandlerDemo extends Application {
11 @Override // Override the start method in the Application class
12 public void start(Stage primaryStage) {
13 // Hold two buttons in an HBox
14 HBox hBox = new HBox();
15 hBox.setSpacing( 10 );
16 hBox.setAlignment(Pos.CENTER);
17 Button btNew = new Button( "New" );
18 Button btOpen = new Button( "Open" );
19 Button btSave = new Button( "Save" );
20 Button btPrint = new Button( "Print" );
21 hBox.getChildren().addAll(btNew, btOpen, btSave, btPrint);
22
23 // Create and register the handler
24 btNew.setOnAction( new EventHandler<ActionEvent>() {
25 @Override // Override the handle method
26

anonymous handler

public void handle(ActionEvent e) { handle event

27 System.out.println( "Process New" );

28 }

29 });

30
31 btOpen.setOnAction( new EventHandler<ActionEvent>() {
32 @Override // Override the handle method
33 public void handle(ActionEvent e) {
34 System.out.println( "Process Open" );
35 }
36 });
37
38 btSave.setOnAction( new EventHandler<ActionEvent>() {
39 @Override // Override the handle method
40 public void handle(ActionEvent e) {
41 System.out.println( "Process Save" );
42 }
43 });
44
45 btPrint.setOnAction( new EventHandler<ActionEvent>() {
46 @Override // Override the handle method
47 public void handle(ActionEvent e) {
48 System.out.println( "Process Print" );
49 }
50 });
51
52 // Create a scene and place it in the stage
53 Scene scene = new Scene(hBox, 300 , 50 );
54 primaryStage.setTitle( "AnonymousHandlerDemo" ); // Set title
55 primaryStage.setScene(scene); // Place the scene in the stage
56 primaryStage.show(); // Display the stage
57 }
58 }

The program creates four handlers using anonymous inner classes (lines 24-50). Without
using anonymous inner classes, you would have to create four separate classes. An anony-
mous handler works the same way as that of an inner class handler. The program is condensed
using an anonymous inner class.