Change postion of a line to make a gauge javafx - javafx

Question

I want to make half radial gauge. I've tried to put an arc of 180° and I put a line on it, and I tried to move this line to use this as an indicator of position.
I tried to move the line to different position in Scene Builder and it appears that it could works but when I tried to move with code it doesn't.
private Scanner sc;
public void deplacement_aiguille(){
sc = new Scanner(System.in);
double angle = sc.nextDouble();
String valangle = Double.toString(angle);
valeur_gisement.setText(valangle);
float xfin = (float) ((Math.cos(angle))*200);
float yfin = (float) ((Math.sin(angle)*200));
if(angle<90){
gisement.relocate(5,10);
gisement.setEndX(xfin);
gisement.setEndY(-yfin);
}
if (angle>90){
gisement.relocate(6,10);
gisement.setEndX(xfin);
gisement.setEndY(yfin);
}
if(angle==90){
gisement.setEndX(0);
gisement.setEndY(200);
}
if(angle==180){
gisement.setEndX(200);
gisement.setEndY(0);
}
if(angle==0){
gisement.relocate(5,10);
gisement.setEndX(-200);
gisement.setEndY(0);
}
}
With this code I want to move the line in my gridpane to the column number 5 and row number 10 when my angle is smaller than 90 and to the column number 6 and row 10 when angle is bigger than 90
I'm not sure if it's the good way to do it. So if you have any better idea I'll take it. But if it's the good way to do it would you help me to make it works.
Thanks

Answer 1

I'd put the Arc and the Line in a Pane (for absolute positioning) and use a Rotate transform to move the line.
IMO More important is to bind the Rotate to the input value. In my example I use a Slider for it:
public class Gauge extends Application {
#Override
public void start(Stage primaryStage) throws Exception {
Arc arc = new Arc();
arc.setCenterX(100);
arc.setCenterY(0);
arc.setRadiusX(100);
arc.setRadiusY(100);
arc.setStartAngle(0);
arc.setLength(180);
arc.relocate(0, 0);
double lineCenterX = 100d;
double lineCenterY = 100d;
Line line = new Line(lineCenterX, lineCenterY, 0, 100);
line.setStroke(Color.YELLOW);
Rotate rotate = new Rotate();
rotate.setPivotX(lineCenterX);
rotate.setPivotY(lineCenterY);
line.getTransforms().add(rotate);
Pane pane = new Pane();
pane.getChildren().addAll(arc, line);
Slider slider = new Slider();
rotate.angleProperty().bind(slider.valueProperty().multiply(1.8));
VBox vbox = new VBox(10);
vbox.getChildren().addAll(pane, slider);
Scene scene = new Scene(vbox);
primaryStage.setScene(scene);
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}