Strokes of line and polyline behave different during zooming - why?

Question

Hello,
I noticed a different behaviour between the a line an a polyline during zooming. The stroke of the line will not be increased while zooming. But the stroke of the polyline will be increased while zooming. I don't understand this behaviour. Is this a feature or a bug? For a better understanding you can execute the following demo:
import javafx.application.Application;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.scene.Group;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.control.Slider;
import javafx.scene.paint.Color;
import javafx.scene.shape.Line;
import javafx.scene.shape.Polyline;
import javafx.stage.Stage;
public class ScaleDemoLinePolyline extends Application {
     public static void main(String[] args) {
          launch(args);
     @Override
     public void start(Stage stage) throws Exception {
          final Group root = new Group();
          Scene scene = new Scene(root, 800, 600, Color.WHITE);
          stage.setScene(scene);
          //create a group with line and polyline
          final Group elements = new Group();
          Line line = new Line(100, 100, 400, 100);
          Polyline polyline = new Polyline(new double[] { 100, 200, 400, 200 });
          elements.getChildren().add(line);
          elements.getChildren().add(polyline);
          root.getChildren().add(elements);
          //init the slider for zooming
          Slider scale = new Slider();
          scale.setMin(1);
          scale.setMax(50);
          scale.setValue(1);
          scale.setLayoutX(100);
          scale.setLayoutY(500);
          root.getChildren().add(scale);
          scale.valueProperty().addListener(new ChangeListener<Number>() {
               public void changed(ObservableValue<? extends Number> ov,
                         Number old_val, Number new_val) {
                    for (Node node : elements.getChildren()) {
                         node.setScaleX(new_val.doubleValue());
                         node.setScaleY(new_val.doubleValue());
          stage.show();
}Thanks for your help!
Best Regards

Answer 1

Sorry for the thread. I regonized, that this is bug, which is fixed in version 2.1. see http://javafx-jira.kenai.com/browse/RT-13328