HBox.setMargin(Node child, Insets value) has the following syntax.
public static void setMargin(Node child, Insets value)
In the following code shows how to use HBox.setMargin(Node child, Insets value) method.
/* w w w . j av a 2s . com*/ import javafx.application.Application; import javafx.geometry.Insets; import javafx.scene.Group; import javafx.scene.Scene; import javafx.scene.control.Button; import javafx.scene.layout.HBox; import javafx.scene.layout.Priority; import javafx.scene.paint.Color; import javafx.stage.Stage; public class Main extends Application { public static void main(String[] args) { Application.launch(args); } @Override public void start(Stage primaryStage) { Group root = new Group(); Scene scene = new Scene(root, 300, 250, Color.WHITE); HBox hbox = new HBox(); Button button1 = new Button("Add"); Button button2 = new Button("Remove"); HBox.setHgrow(button1, Priority.ALWAYS); HBox.setHgrow(button2, Priority.ALWAYS); button1.setMaxWidth(Double.MAX_VALUE); button2.setMaxWidth(Double.MAX_VALUE); hbox.getChildren().addAll(button1, button2); hbox.setPrefWidth(400); HBox.setMargin(button1,new Insets(1,1,1,1)); root.getChildren().add(hbox); primaryStage.setScene(scene); primaryStage.show(); } }