import javafx.application.Application;
import javafx.beans.InvalidationListener;
import javafx.beans.Observable;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.Slider;
import javafx.scene.paint.Color;
import javafx.scene.shape.Rectangle;
import javafx.scene.text.Text;
import javafx.stage.Stage;

public class DashTest extends Application {
    public void start(Stage stage) {
        final Rectangle r = new Rectangle(100, 100, 100, 50);
        r.getStrokeDashArray().addAll(1.0, 1.0);
        r.setFill(null);
        r.setStroke(Color.BLACK);
        final Slider sw = new Slider(0, 4, 1);
        final Slider sd = new Slider(0, 4, 1);
        final Text tsw = new Text("stroke width = 1.0");
        final Text tsd = new Text("dash length  = 1.0");
        r.strokeWidthProperty().bind(sw.valueProperty());
        sw.valueProperty().addListener(new InvalidationListener() {
            @Override
            public void invalidated(Observable observable) {
                tsw.setText("stroke width = "+sw.getValue());
            }
        });
        sd.valueProperty().addListener(new InvalidationListener() {
            @Override
            public void invalidated(Observable observable) {
                r.getStrokeDashArray().set(0, sd.getValue());
                r.getStrokeDashArray().set(1, Float.MIN_VALUE+sd.getValue());
                tsd.setText("dash length  = "+sd.getValue());
            }
        });
        sw.setTranslateY(200);
        sd.setTranslateY(200);
        sd.setTranslateX(150);
        tsw.setTranslateY(250);
        tsd.setTranslateY(250);
        tsd.setTranslateX(150);

        Scene scene = new Scene(new Group(r, sw, tsw, sd, tsd), 300, 300);
        stage.setScene(scene);
        stage.show();
    }
}