setFullscreen in a ComboBox - javafx

Question

Hello I am programming a UI for a game. In this UI I want a Scene with settings. In the settings I have a ComboBox where I want setFullscreen in true or false. Actually I get the Error "Cannot make a static reference to the non-static method setFullScreen(boolean) from the type " how can I solve my Problem. I want that the BorderlessWindow setFullscreen true the println are working.
CONTROLLER CLASS;
package Menue;
public class SettingEinstellungen {
#FXML
private ComboBox<String> Combobox;
ObservableList <String> Auswahl =
FXCollections.observableArrayList("Fullscree","Windowmode","Borderless Window");
#FXML
Button exit;
#FXML
public void initialize() {
Combobox.setValue("Fullscree");
Combobox.setItems(Auswahl);
Combobox.getSelectionModel().select("Fullscreen");
Combobox.getSelectionModel().selectedItemProperty().addListener(new ChangeListener<String>(){
public void changed(ObservableValue<? extends String> observable, String alt, String new) {
if(new != null) {
switch(new) {
case "Fullscreen": System.out.println("Vollbildgeklickt" +alt +neu);
break;
case "Window-mode": System.out.println("Fenster\t" +alt);
break;
case "Borderless Window": Stage.setFullScreen(true);
break;
default: ;
break;
}
}
}
});}
//public void changeCombo(ActionEvent event) {
//Stage.setFullscreen(true)(comboBox.getValue(Vollbild));
//}
#FXML
public void exit_press (ActionEvent event) throws IOException {
Stage window = (Stage)((Node)event.getSource()).getScene().getWindow();
//window.setFullScreen(true);
//window.setScene(new Scene(FXMLLoader.load(new File("menue_UI_1.fxml").toURI().toURL())));
Parent root_3 = FXMLLoader.load(getClass().getResource("menue_UI_2.fxml"));
Scene scene_3 = new Scene(root_3);
window.setScene(scene_3);
window.setTitle("Hauptmenü");
window.show();
}
}

Answer 1

The problem is that you are not referencing the actual stage which is why you are getting that error you need to reference the actual stage that is shown you can do this by getting the window during execution like so or you can initialize it at the top when you start the program
comboBox.getSelectionModel()
.selectedItemProperty()
.addListener((obs, oldVal, newVal) -> {
if(newVal != null) {
System.out.println(newVal);
switch(newVal) {
case "Fullscreen":
System.out.println("Vollbildgeklickt" +oldVal + newVal);
break;
case "Window-mode":
System.out.println("Fenster\t" +newVal);
break;
case "Borderless Window":
Stage window = (Stage) comboBox.getScene().getWindow();
window.setFullScreen(true);
break;
default:
break;
}
}
});