JavaFX - Passing values between windows (stages) - javafx-8

Question

I have a JavaFX application in which I have a main window (stage) from which the user should open a second, child, window. In the second window the use should do some things which will affect the application behavior later on.
I couldn't really understand how should I access the second screen's data/values after the user closes this screen.
This is an example of a similar situation. Let's say I want to get the second stage's text box value.
package multiplestagesexample;
import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.TextField;
import javafx.scene.layout.StackPane;
import javafx.stage.Modality;
import javafx.stage.Stage;
/**
*
* #author IdoG
*/
public class MultipleStagesExample extends Application {
#Override
public void start(Stage primaryStage) {
Button btn = new Button();
btn.setText("New Stage");
btn.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
new CreateStage();
}
});
StackPane root = new StackPane();
root.getChildren().add(btn);
Scene scene = new Scene(root, 300, 250);
primaryStage.setTitle("Main Stage");
primaryStage.setScene(scene);
primaryStage.show();
// Get the TextField value from the Additional Stage ???
}
/**
* #param args the command line arguments
*/
public static void main(String[] args) {
launch(args);
}
}
class CreateStage {
public CreateStage() {
TextField textBox = new TextField();
StackPane root = new StackPane();
root.getChildren().add(textBox);
Scene scene = new Scene(root, 300, 250);
Stage stage = new Stage();
stage.setTitle("Additional Stage");
stage.setScene(scene);
stage.initModality(Modality.APPLICATION_MODAL);
stage.showAndWait();
}
}
This is a section of the relevant "real" code:
#FXML
private void handleOpenMappingToolWindowAction(ActionEvent event) throws IOException {
//mappingWindow is an instance variable
//Stage mappingWindow;
// gets a Sheet object that will be used in the "MappingToolWindow" stage
selectedSheet = (Sheet) sheetsBox.getSelectionModel().getSelectedItem();
FXMLLoader loader = new FXMLLoader(getClass().getResource("MappingToolWindow.fxml"));
Parent root = (Parent)loader.load();
MappingToolWindowController controller = loader.getController();
if (mappingWindow == null) {
Scene mappingScene = new Scene(root);
mappingWindow = new Stage();
mappingWindow.initModality(Modality.APPLICATION_MODAL);
mappingWindow.setTitle("Mapping Tool");
mappingWindow.setScene(mappingScene);
controller.setSheet(selectedSheet);
}
mappingWindow.showAndWait();
// ACCESS THE NEW STAGE ???
}

Answer 1

Make the text field an instance variable, so that you can define a method to access its text:
class CreateStage {
private TextField textBox ;
public CreateStage() {
textBox = new TextField();
StackPane root = new StackPane();
root.getChildren().add(textBox);
Scene scene = new Scene(root, 300, 250);
Stage stage = new Stage();
stage.setTitle("Additional Stage");
stage.setScene(scene);
stage.initModality(Modality.APPLICATION_MODAL);
stage.showAndWait();
}
public String getText() {
return textBox.getText();
}
}
Now of course you can just do
CreateStage dialog = new CreateStage() ;
System.out.println(dialog.getText());
in your handler.

Answer 2

public class XXXX extends Window {
private static Stage popupstage;
private Person aperson;
public XXXX (Person a) throws IOException {
Parent root = FXMLLoader.load(getClass().getResource("../UserInterface/UI_XXXXX.fxml"));
popupstage = new Stage();
popupstage.setTitle(a.getAbc());
popupstage.initModality(Modality.APPLICATION_MODAL);
popupstage.setScene(new Scene(root,400,400));
}
public Stage getPopupstage() {
return popupstage;
}
}
Have a window that takes a parameter. Your window will then read the object passed. In the above example, the person object is read and it populate the title of the stage (new window).