JavaFX Using alternative FXML structure for Title (Stage is root)

Question

I read answer about putting Title in FXML (JavaFx : Set window title in fxml file), but I don't understand how to call this code.

I can't call it in the classic way:

FXMLLoader loader = new FXMLLoader(getClass().getResource("some.fxml"));
Scene scene = new Scene(loader.load());
Stage stage = new Stage();
stage.initOwner(root.getScene().getWindow());
stage.initModality(Modality.WINDOW_MODAL);
stage.setScene(scene);
stage.show();

some.fxml

<?xml version="1.0" encoding="utf-8"?>

<?import javafx.scene.layout.VBox?>
<?import javafx.stage.Stage?>
<?import javafx.scene.Scene?>
<?import javafx.scene.control.Label?>

<Stage title="Some Stage">
  <scene>
    <Scene>
      <VBox xmlns:fx="http://javafx.com/fxml">
        <children>
          <Label text="John Doe"/>
        </children>
      </VBox>
    </Scene>
  </scene>
</Stage>

Answer 1

Because the fxml is creating a stage, you don't need to create another stage in your Java code, just get a reference to the stage created by FXML and show it directly.

StageLoader.java

import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.StackPane;
import javafx.stage.*;

import java.io.IOException;

public class StageLoader extends Application {

    private void showDialog(Stage owner) {
        try {
            FXMLLoader loader = new FXMLLoader(
                    getClass().getResource("some.fxml")
            );
            Stage dialog = loader.load();
            dialog.initOwner(owner);
            dialog.initModality(Modality.WINDOW_MODAL);
            dialog.initStyle(StageStyle.UTILITY);
            dialog.show();
        } catch (IOException e) {
            System.out.println("Unable to load dialog FXML");
            e.printStackTrace();
        }
    }

    @Override
    public void start(final Stage stage) throws IOException {
        Button openDialog = new Button("Open Dialog");
        openDialog.setOnAction(event -> showDialog(stage));

        stage.setTitle("Main Window");
        stage.setScene(
                new Scene(
                        new StackPane(openDialog),
                        200, 200
                )
        );
        stage.show();
    }

    public static void main(String[] args) {
        launch(args);
    }
}

I made a couple of minor modifications to the fxml to ensure the resultant stage is large enough to actually see the dialog stage title.

some.fxml

<?xml version="1.0" encoding="utf-8"?>

<?import javafx.scene.layout.VBox?>
<?import javafx.stage.Stage?>
<?import javafx.scene.Scene?>
<?import javafx.scene.control.Label?>

<Stage title="Some Stage" resizable="false" xmlns:fx="http://javafx.com/fxml" >
  <scene>
    <Scene>
      <VBox >
        <children>
          <Label text="John Doe" prefWidth="150"/>
        </children>
      </VBox>
    </Scene>
  </scene>
</Stage>

SceneBuilder who can't open FXML after adding Stage and Scene tags.

You could write the FXML with the stage and scene definitions as an outer shell with an embedded <fx:include..> statement to include an inner FXML document which could be opened edited directly in SceneBuilder. Also, you could create a feature request against SceneBuilder (it is called the "design tool" in the issue tracker), to request direct support for FXML files with stage roots and scenes included in the FXML.