JAVAFX UI CONTROLS AND MULTIMEDIA - Introduction to Java Programming: Comprehensive Version - page 656

The code in lines 35-41 can be replaced by using binding properties as follows:

text.xProperty().bind(slHorizontal.valueProperty().
multiply(paneForText.widthProperty()).
divide(slHorizontal.maxProperty()));

text.yProperty().bind((slVertical.maxProperty().subtract(
slVertical.valueProperty()).multiply(
paneForText.heightProperty().divide(
slVertical.maxProperty()))));

Listing 15.17 gives a program that displays a bouncing ball. You can add a slider to control
the speed of the ball movement as shown in Figure 16.26. The new program is given in
Listing 16.12.

F IGURE 16.26

You can increase or decrease the speed of the ball using a slider.

L ISTING 16.12

BounceBallSlider.java
1 import javafx.application.Application;
2 import javafx.stage.Stage;
3 import javafx.scene.Scene;
4 import javafx.scene.control.Slider;
5 import javafx.scene.layout.BorderPane;
6
7 public class BounceBallSlider extends Application {
8 @Override // Override the start method in the Application class
9 public void start(Stage primaryStage) {
10 BallPane ballPane = new BallPane();
11 Slider slSpeed = new Slider();
12 slSpeed.setMax( 20 );
13

create a ball pane
create a slider
set max value for slider
bind rate with slider value ballPane.rateProperty().bind(slSpeed.valueProperty());

14
15 BorderPane pane = new BorderPane();
16 pane.setCenter(ballPane);
17 pane.setBottom(slSpeed);
18
19 // Create a scene and place it in the stage
20 Scene scene = new Scene(pane, 250 , 250 );
21 primaryStage.setTitle( "BounceBallSlider" ); // Set the stage title
22 primaryStage.setScene(scene); // Place the scene in the stage
23 primaryStage.show(); // Display the stage
24 }
25 }

create a border pane
add ball pane to center
add slider to the bottom

The BallPane class defined in Listing 15.17 animates a ball bouncing in a pane.
The rateProperty() method in BallPane returns a property value for animation rate.