Java tutorial
import javafx.application.Application; import javafx.beans.value.ChangeListener; import javafx.beans.value.ObservableValue; import javafx.geometry.Insets; import javafx.scene.Group; import javafx.scene.Scene; import javafx.scene.control.Label; import javafx.scene.control.Slider; import javafx.scene.layout.GridPane; import javafx.stage.Stage; public class Main extends Application { final Slider opacityLevel = new Slider(0, 1, 1); final Label opacityCaption = new Label("Opacity Level:"); final Label opacityValue = new Label(Double.toString(opacityLevel.getValue())); @Override public void start(Stage stage) { Group root = new Group(); Scene scene = new Scene(root, 600, 400); stage.setScene(scene); stage.setTitle("Slider Sample"); GridPane grid = new GridPane(); grid.setPadding(new Insets(10, 10, 10, 10)); grid.setVgap(10); grid.setHgap(70); scene.setRoot(grid); GridPane.setConstraints(opacityCaption, 0, 1); grid.getChildren().add(opacityCaption); opacityLevel.valueProperty().addListener(new ChangeListener<Number>() { public void changed(ObservableValue<? extends Number> ov, Number old_val, Number new_val) { System.out.println(new_val.doubleValue()); opacityValue.setText(String.format("%.2f", new_val)); } }); GridPane.setConstraints(opacityLevel, 1, 1); grid.getChildren().add(opacityLevel); GridPane.setConstraints(opacityValue, 2, 1); grid.getChildren().add(opacityValue); stage.show(); } public static void main(String[] args) { launch(args); } }