Javafx: Change scene in setOnAction

Question

I\'m building a JavaFX application with multiple Scenes. I have a problem with scope of variable when changing scenes within setOnAction event. This is my code:

Answer 1

This question has already been solved, but I think it's worth clarifying that your line fails because the this keyword refers to the anonymous EventHandler you are implementing. In Java, you reference the outer class instance with OuterClass.this. So OuterClass.this.getStage().allScene(createAccountPane1); will work.

If you are looking for a prettier solution, some coders like to define a local variable that points to the outer class instance:

final OuterClass self = this;
createAccountButton.setOnAction(new EventHandler<ActionEvent>(){
        public void handle(ActionEvent t){
              self.getStage().allScene(createAccountPane1);
        }
}

Answer 2

Your code works as long as you keep consistency:

import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.layout.AnchorPane;
import javafx.scene.layout.Pane;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

public class Test extends Application{
    private Stage stage;
    @Override
    public void start(Stage primaryStage) throws Exception {
        stage = primaryStage;
        Scene scene = logInScene();
        primaryStage.setScene(scene);
        primaryStage.show();
    }
    public Scene logInScene(){
        Pane root = new Pane();
        Button createAccountButton = new Button("create account");
        createAccountButton.setOnAction(new EventHandler<ActionEvent>(){
            public void handle(ActionEvent t){
                  stage.setScene(CreateAccountScene());
            }
       });
        root.getChildren().add(createAccountButton);
        return new Scene(root);
    }
    protected Scene CreateAccountScene() {
        VBox root = new VBox();
        Label userLabel = new Label("Insert the username:");
        final TextField userField = new TextField();
        Button createAccountButton = new Button("create account");
        createAccountButton.setOnAction(new EventHandler<ActionEvent>(){
            public void handle(ActionEvent t){
                  System.out.println("Account for user " + userField.getText() + " was created succesfully");
            }
       });
        root.getChildren().addAll(userLabel,userField,createAccountButton);
        return new Scene(root);
    }
    public static void main(String[] args) {
        launch(args);
    }

}